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A STUDY OFRUTHENIUM 106 AS A BETA SOURCE IN

RADIATION THERAPY

Russell B. Buchanan, Jr.Captain, U. S. ArmyRadiological Defense Engineering Prog

1951

a stmt or smmm 106 as a bra

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Hid Ohio 3t**t Univ«rtit*

Approved fejr»

William a. kyar#, Advisor

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Biological Iffartt i . i

Fraparatio* of a TharapautJLc Applicator

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k STUM 'UiliM 106 AS A B«TA SOT

XX sADXATXOS THEfcAPT

irogagcnQg

It is the purpose of this paper to present a study of

the properties of the radiation* emitted by Ruthenium 106 and

its daughters as applied to the therapy of the external lesions

of cancer, various varta and moles* and such ether surface dis-

turbances of the body as nay be responsive to irradiation.

The generally accepted current medical practice is to

treat these abnormal conditions by surgery (excision or cauterisa-

tion) , by the use of various shemotherapeutie agents (very limited

in caster and scope ) t or by irradiation of the affected area when

other methods are not considered practicable. Surgery and, to n

lesser degree # chemotherapy are frequently considered impractica-

ble* ' for a number of reasons!

1* The position of the growth r*adi9TB surgical

approach difficult without high mortality or crippling

Nats

2. The growth may be too extensive*

3* Metastases may be present.

4* The poor irsneral health of the patient due

to cardlo-vaaeulnr or renal disease , obesity, or

debility from old age.

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5* The patient asy, for his ana reasons, refuse

surgical treatment*

According to statistic* compiled by the Swedish Cancer

Association, only one-third of ell cancerous eendltieae cowing

under medieal supervision arc suitable for surgery f and, of those

who undergo surgery, only one-third (1/9 of the total) show other

than temporary, short-lived relief* One must also consider all

of the noncancerous conditions, many of which are not suitable

for surgery. It is, therefore* frequently neoessery to employ one

or Bore of the various methods for radiation therapy* Currently*

the most commonly employed radiation sources are X-ray machines

and radium for gamma and/or beta-ray treatments* Any of these

methods involve essentially the same hacards an are found in the

deep Irradiation therapy of malignant growths which cannot be

reached by the short-range beta particles. This is true even of

the radiun beta ray applicators since the beta-emitting daughters

of rediun are oaintained in equilibrium with those emitting gamma

rays, and thus produce a dean irradiation field whleh is unnecessary

la the treatment of surface lesions, and is undesirably detrimental

to the normal tissues of the patient and to the health of the attend-

ing physician. The euoeei* fa treatment of any malignant or disfig-

uring erowth by Irradiation depends upon the administration of s

quantity of radiation suffielent to produce nermannnt arrest of the

growth without causing extensive damage to the underlying normal

tissue which is essential to proper repair* Where usable, surface

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Irradiation baa the distinct added advantage la that no surgical

or anaesthetic risks mao be taken*

Fortunately* daring the treatment of a surface lesion, the

X-ray or gamma ray dose received by both the patient and the radiol-

ogist is not normally sufficient to induce either the acute or the

chronic tyre of radiation sickness* the patient, having received

his treatment, leavts the radiation field and, therefore, discontin-

ues his exposure. This is not true of the attending physlolem*

however, for he must also expose himself during the preliminary

preparations for a treatment and again afterward in returning the

source used to its place of safe storage (when sources other than

X-ray machines are need). In addition, it most fee considered that

a busy radiologist will expose himself In this *«me manner many

times during a single day, and that this daily exposure Is continued

throughout the year. The proof that many of these doctors do receive

an Injurious dose leading to chronic radiation injuries may he soon

in the lares numhor of radiologist* And dentists who have been com-

pelled to underfo amputation of finders, and even of hands, in the

malformed fingernail structure of others* and in the frequently

observed pigjmmtation changes, loukemias, aplastic anemias, and

high incidence of carcinoma observed in pioneer radiologists(4)

,

Zt has definitely heen shown that chronic exposure to nuclear

radiations, even at low dose levels, is carcinogenic'*'.

It is, therefore, essential to develop some new source

or sources of mildly penetrating radiation for treatment of these

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surface lesione, vbiob vill not Include tfa© serious gamma-ray

haaard incidental to the use of radium sources for beta particles*

Another advantage of employing beta ray sources other than radium

derivatives la the elimination of the gas-leek hasard, union ia ao

dangeroua ia radius work* For this purpose, many inveetlgatore nave

been examining the table of isotopes, particularTyr those fiaaion

products available in relatively large quantities fro* nuclear

reactors, In an effort to find beta-emitting materiale with a

suitable penetrating power and half-life, with a ainimue of elec-

tromagnetic radiation, Of the various isotopes investigated to

date, the current favorite ia the strontium 9®-yttriu» 90 family,

of which the effective beta particle has a amxiuBuw energy of B*l

Mev. However, with appropriate filtering to eliminate the low

energy 0*63 Mev particle emitted by Br 90, the intensity of the

radiation field falls to 50$ of the surface dose in 0.3 milli-

neters of tiesmt' 3*', as shown ia Figure 7. Since the effective

penetrating depth ia aoft tissue of this bete particle la fairly

low, and, therefore, only very superficial leaions will be reached

by it, it ia desirable to find sane other bete source which pea-

ses, es a greater penetrating power, thereby requiring a lower

total surface exposure to the lesion to achieve the some thera-

peutic reeult. Thia would provide an appreciable reduction ia

tissue necrosis and the resultant ulceration and secondary Infection,

as well as a better cosmetic effect, aa the lesion heals*

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Slate high-energy *eta particles? i:*ipinflag on the

meta] lie portions of the »rrllc*tor holdom currently Id we

produce a rather high Bremsstrahlung flux, it Id oleo desirable

to develop holders whleh will minimise thin effect. In addition,

the «t r-licRtore should be designed in such a manner ss to provide

for eaey mounting on the patient without requiring the physician

to bold them in place at la the eaee with the current St 90 appli-

cators.

It la with theae faetora in mind that N is study, designed

to explore the advantageous physical properties of Ku 106 with a

view to the advantageous utill at! on of then in radiation therapy,

was initiated* Included herein are data showing the intensity

distribution of the beta field surrounding varl©us En 106 sourest

in tissue equivalent phantoms, information concerning the relative

X-ray and gamma ray output when the emitter is electroplated on

various plating bases, sons Information on the physiological effects,

at well at aethods for measuring the penetration of beta particles

la tissut phantomt.

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hu 106 waa selected as a possible radiation source

for this work due to the conveniently high energy of the beta

particle from the daughter element Rh 106, the eomperetivcly

constant output incidental to Ita ona year half-life, the

extremely low g*mme~ray output relative to a radius aouree of

the earn? beta intensity, and due to the absence of any gee-leek-

age problem. In addition, ruthenium, unlike strontium(^), does

not deposit la the skeletal structure when aocldenteily ingested;*

The decay scheme of the Ru 106 family is^3)|

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The beta particle from Ku 10© la of very low energy. That portion

which Is not eliminated by self absorption within the source

proper can be readily screened out of the effective radiation

field by a thin plastic film which will not appreciably attenuate

the dealred beta field. This nay be readily seen by comparison

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of thir ranre of the two particles* The 3*55-Mcv particle has a

rang* of 1.924 g»/eq em, while the 9*0£UM*r particle has a range

of lea* than 0*004 gn/eq em*

At part of the general aim of thia project, an effort waa

»ade to determine the relative levels of Bremsstrahlung emission

from the various plating bases* For eleotron energies In the neigh-

borhood of 100 Key, the efficiency of conversion of electron eaergy

to X»ray energy la directly proportional to the atomic number*

That thia la not directly applicable to electrons of higher energy

la substantiated by experimentel work now in pr*gr**9 at the labora-

tories of the General Hoctrio Company* However, Indications are

that the final relationship, whan developed, will ahow that the

conversion efficiency for those higher energy eleotrone will bo

eoae function of the atonic nwaber of the target material, such

that the use of a target of low atomic number will produce less

X-ray output than will targets of high atonic number* Gold, copper,

and beryllium were selected for study in this aspect.

The specific Hu 106 aources employed in this study wore

furnished from the Isotopes Division, Oak Ridge national Laboratory*

Since QH1IL does not specify the exact quantity of material provided

in any shipment of this nature, the amounts specified herein are

only within the accuracy of the information provided on the shipping

papers from 0RKL.

floaraa li 7. nC Ru 106 electroplated on a gold disc 0.01

inch thick and 1 inch in diamter. Sxperiaoatal evidence encountered

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thereon (Figure 1)» Data vat not taken from this disc due to

the unsatisfactory nature of the emitting surface*

faurme 2 . 3 uC Ru 106 electroplated on a got per disc

0.01 Inch thick and 1 inch In diameter. Again, experimental

evidence showed a lack of uniforaity in pitting the sample oa

the dlec (Figure 2), although thie aausf le was efficiently sat-

iefactory to permit the taking of data therefrom* It la believed

that both sample* were probably plated oa material which had net

received adequate preparation and, possibly, at too high a deposi-

tion rate*

Fig, !• Source 1*Autoradlograpb of source laapplicator holder* Motethe uneven plating of thefia 106.

Fig. 2. Source 2*

Autoradiograpb of source laapplicator holder* Hots thatthe Ru 106 is more evenlyplated hare*

Sourea 1 i This source has not yet been delivered from

ORKL* It has been requested that 3 mC Ru 106 be plated oa s

beryllium disc 1 aa thick and 1 inch la diameter* Although

beryllium is s difficult sad haaardous material with which to work'2*',

it was selected as the material with the lowest atonic number with

which to carry out these tssts satisfactorily* The range of the

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3*55 Mev beta particle in beryllium Is U.l mm* Sine* thia

beryllium diss should be covered with about I w of U to i

convenient handling case, essentially all the beta rays frmm

this sours* will be completely stopped within the source proper*

This will eliminate any beta hasard from back radiation to the

radiologist who nay be called upon to manipulate it, and will

also sake the applicator a convenient else and weight to bo

fastened directly to the area to be irradiated* The light-

weight feature is highly desirable in that* although surface

growths of the type to be tr»at»d with this applicator are *:ot

normally supplied with neural fibers • pressure on the lesion

transferred to the surrounding tissue can sense the patient

considerable iasomfort*

Blag Ironic Circuital

The electronic circuit employed la this study is cms

(31)designed by A* 0* Jfier ' for use in a mass spectrograph, and

modified for use as s d.c. amplifier with miniature ionization

chambers by D* T* Sggsn* who also did the initial construction

work on the instrument. Or* Eggen's modification merely con*

slsted of employing one channel of Dr, Xlsr*s circuit and modi-

fying the filament supply of the amplifier to provide the propw

current for half as many tubes in series*

Since th« equipment had been in deed storage for some

time prior to the beginning of this prelect and had been rather

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« large portion of the ayatem before it could be placed la oper-

ation* In apr lying this instrument to the work with ruthenium, it

wa« neceaaary to introduce ea additional 100,000 ohm realstor

into the feedback aad watering circuit la order to desensitise

the system to the point where it could properly handle the signal

strength obtained.

For the assistance of others who may employ this system,

operating voltagea are shown on the circuit la Figure 3* Caution

must be used to insure that the high voltages are uot applied to

the preamplifier until its cathode has had at least thirty seconds

to warm* It Is also advisable to permit the entire electronic

system to warm for several minutes to establish the stability

required for this work* Shielding is necessary on the cable from

the preamplifier to subsequent stages as there is enough cable

pickup to make the unshielded system unstable* It is also neces-

sary to establish aa electrical connection between the mercury-

water system (see discussion of phantom) and the amplifier, sines

the ohanging electric field and static eharge developed while the

mercury is flowing will otherwise drive the meter off scale,

requiring several seconds for the system to discharge • For this

purnose 9 it Is recommended that the connection be made to the

outer electrode of the chamber for the additional reasons discussed

under ion chamber windows*

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The ionization chamber und as a means of studying

the intenaity distribution ©f th«* bets ray field is shown la

Figure 4. Xt la supported from a plastic disc in the; preempllftar

housing, and la dir«etly corrected Into the preamplifier* Tha

chamber has a volume Qt 0.008 ml* Since X r/see la the equivalent

of 2M x 10 Ion paire/eec/iBl, or one atatcouloab/eec/«l, 1 r

for this chamber volume la 7*416 a lCT1* amperes. Thla would

glv« a signal Input to tha grid of tha preamplifier of 7.416

av/r/aee, and If oaa vara to uaa a aouroa of 100 r/see, tbe ^rid

awing of 0.7 volts wo ild atill be within that allowable for tha

VX-*U~A used.

Various window materials vara triad with this chamber,

and tha ohaabar was also triad as an open-ended ohaabar* This

latter proved to be unsatisfactory since water vapor from the

surface of the phantom aborted tha chamber* The moat satisfactory

window material used waa 0*002 inch Zepoa* Plaatloa each as

Zapoa are so close to the stopping power of water and are so

thla that they need not be taken into account in computing the

reduction in bean intensity by passage through the water phantom*

aluminum windows were tried and found to be unsatisfactory.

Electrolytic ectlon In the phantom teak rapidly produced pin-

bolea in tha window, which resulted In the short-circuiting of

the chamber* Thla affect waa partially eliminated by placing

the entire bath at the aame potential aa tha window , but-15-

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aluesinuw continued to enter Into solution, although

slowly, to produce punctures In the foil.

sr; Heater Md«»

The applicator holder used la these test* (Figure 5)

van designed to take advantage of the low atomic number of elusd-

nun in the production of -radiation* The actual structural

design was as shown to pormit easy and rapid changes from one

source to another, as well as to permit the taking of data on

one type of beam collimator (the scarce may be placed in position

at either end of the retaining cylinder)*

The beryllium* «se source may also be used in this

holder for comparison purposes • although such a massive construe*

tion would not be used in therapy*

7o determine the penetration pattern of the hh 106 bets

particles in tissue, It vws necessary to devise some met. od of

simulating tbe stopping power of soft tissue, since the use of

tissue itself is not practicable* Water is commonly used for

that purpose^,16,30,36), mn(j ^%a m9& b#re*

In ti is system, thero also had to be included provisions

for accurately varying the position relationship between the

emitting surface and the measuring device (ion chamber), provision

for measuring these variations, and safety measures for protecting

~17-

m» Of frfv;

.»:.. Mr1

-

*•! tow tU*<*-;^jt «,,*!*

.-**> 1 1NT BTIftttlC *Jw I

APPLICATOR MOLDCR

All pa.rts a^rt AlummwrA except

i **&

O.OOZ. Ration

O.I2^" \

O. /^J"

J| kvi m rod

i" r^

O .0\ Source Pi$c

Coaled uJitb Ku

due ^

/="/? 5"

-£-

the operator fro* the high bote flux involved*

The aye tea ee stowa la Figure 6 was finelly evolved

after trial of several variations thereof. Sinee mechanical

systems are vulnerable to the corrosive effects of water and

electrolytes, frequently develop leaks, and contain inherent

backlash and other neeheudeal difficulties, it wee decided to

employ a hydraulic system to drive the .oving parte of tv ie

acehanisr.. The t«ck need was e rises cylinder, 9. 56 on Inside

dle&etrvr, and ID em long* this was mounted on a half-inch

Plaglglas sheet drilled as shown, and fitted vith glass nipples

for attachment of the mercury reservoir and a bottoa drain for

removing mercury without reaoving water or otherwise disturbing

the system. A F^exlglas stage was used upon which the applicator

was aountod This whole assembly plus the phantoai water • vat then

floated on the mercury surface* The seal* on the side of the tank

is divided Into millimeters, and can, therefore, be read to the

nearest 0*1 mm with the aid of a suitable Magnifying lens. Thus,

by adding or substreeting oercury from the system and reading the

position of the Flexiglas stage* it Is possible to da terai* • the

position of the scarce relative to the lea chamber* Xf greater

accuracy or acre finely spaaed readinga are desirable, it is mere-

ly necessary to eonputs froa the physical dimensions of the teal

the voltasa of aeroury which Bust be added or taken away to provide

the desired variation in source-chamber spaaing* When employing

the volumetrio addition of mercury* constant temperature must

•19»

' «av 4 * mm x**is>\,* mdX

?*«..*».*. j. *wm V> I hit:- i-iU

4 MK

o* -*. * .. *.-•* .•* , i• *.* *: *•;: Himrn iu4IM &.* fttl >**

• rto

Ml * M fcv

I O04V INMKF MIT /:;• if» fCltTT f^ 1 .nfcts^a *H#

I ^ItfMMM f>torfv. ,' b v*8.MOC MV

*» >« aC \*.<% iwvum mdi am bmimml\

Orf* »&':&«•* I-JI . I»J _^ ;!Ai y.-U r«tt v* ;*lMft r !

"

^*** •rft 4# — art o#i«*a«» o# fin—mm yj.

<oi/>

•*1l/t

tf

rf <J->

u \(A Q_ _ T-,<r-^

„ \

\ \CO

\Jriiiiniiiiiiiiiii -

3-5\ \

o \ \iz<

-*""*

Id

r\ \a- -91 Os^Cautf

v -

uiOCO \ \D

to

\ \h g

<*>

1

\

\\

\

\

i

^j (j/ V-

/«1

<4

y»

5L6

he naintftined to prevent expaselos errors* For accuracy require*

aente within tbt lii&its of th* tank scale, acrenry la introduced

fron a separatory funnel aa a convenient reservoir. Whore greater

accuracy requirements oaoaaaltata the voluaetric addition of

aereury, a burette la substituted for the funnel. Peraca* who

nay employ this ayr.tea ara cautioned that tho burette *ast have a

long stopcock, alnea a abort l ?*ock will he 't by the

pressure of tba mercury column |a tha burette. It la »lao aug~

gaatad that all hoaa connections be clamped and la«c\arad to

prevent aplllinp ctarcury. A traversing doviec for tha ion chamber

wan alao provided to facilitate reproducible readings at all

points of the arplica tor surface. A alphon arrangement (not

ahown) waa alao provided for convenience In removing water from

the tank during operation without exposing tha operator to tha

radiation field, k light waa mounted behind the tank to improve

visibility. To add contrast between the Plexiglaa stnf© and the

water* a blue dye waa added to the water. This greatly facilitated

aeaaurenent and reduced eyeatrain.

Other equipment used for gaaemv-ray readings » autoradio-

graphs, and the adjustment of the electronic aycten ware of the

variety standard in any pkysics laboratory and nerit no special

mention or description here.

<4sV

iwasb* m» wis

oiw toot vui,^ it ttwnMb *xutt *«mi •JJsnsrf «-v tmd* bmavltomm mxn 3** •<-<(» aid* fi^t fM

, ^*?w? erf* oi —In i \wm« «s* *» •wmviq

ci fcvcorpMi lot t iiyi i l » «r iiihiI»iii—u —*d Urn tadi ft**t«§

mi. m4i

—

t

l«i *l*tmb*vm% *tatMiami mi bmbiroiq mmlm ut#•*) tmmmmwn* mrndqlm A •mmmtan *• »*tlwi md* *5© aisicq

*am a* •ttftfeMWtt* vtl trtlt^n 09JU turn (aworft

•If •# v

****** ** **** *U bm> -m mv M^ll A ,bl»n .^ilclbtt

•Af boa a»a#a ulabnis; w<# naaWarf *M*t«o9 {** oT .x#«l./10v

«a\t»a*aiM ,ionib^/i \ bM>

•*** '•' a*av a**anft • ad> 1o Jnmnfwibm wU bum % <

imlmmmm mm IJNa* ho* ., •oiartod

-a

^.ttra in, Wittr, ftantaH

The equipment for thia portion of the study vu arranged

• described* The actual measurement procedure, occasionally

modified slightly for special variations* was aa follows*

a. Preparation!

1. Balance and aero-act the awtorlog ay* tern. This was

ofaookod periodically daring all runs to insure continued satin-

factory operation*

2* Introduce auffielent mercury Into the tank to raise

the source to a convenient level for the test to be performed,

lowers* the ion chamber until contact is made with the surface

of the applicator*

b* Keasuiumanti

1* With the chamber In contact uith the applicator ,

record the meter reeding* This Initial reading is normally node

st the center of the ej plicator and is used as the "100$ of Surface

Dose" reference* Record, also, the position of the stage.

2* Move the ion chamber to other points on the surface

of the applicator end record the meter reeding and ^ceition date

et each point. These lateral potato et wv Ich readings are node

ere selected to provide date which will permit accurate determin-

ation of the penetration pattern.

•22-

"-. ,..--. .

MM

,a»fMft lidtottB *&.? $

|MmM^|| Hi* :'•' lft#M " n"

' ttttMft ^gy gfift „

;

i tAlMnec «! awfi—« f»t#J*t •**? »*!*• n i*?«kt ***

I * *0Q£" •** fii t>«ftv ai to* it&tati *««• «**# tn

•ftftflfft •*'? 1» ".':f'i «oq ftft> jtftUt^HMdl •ftftftyxoferi "ftafttf

fctt tffttftMV *ftftft «€M Jw«rr

oftM in ftfftMftftt rt» *ft«4f »*ifte« 4ftft* .r*

3. drain nercury fr<r* ih*- tank until th* deeired

aouroe-ehajRber apselug is obtained. Record the new stage portion

and the «eter reading* at each of the lateral positions selected

In Step 2*

4* Repeat Step 3 at aa a*ny positions aa nay ^* neceeeary

to obtain sufficient data to plot a curve of intensity versus dis-

tance for e«ah point on tha applicator arorfsea, The s^urco-chamber

spacing" la dsteraiwad aa tha difference betveen tha oontaet position

of tha atago and tha pooitloft at any given reeding. Dietsnee

intervals of 0*2 or 9 J an vara need up to ranges where tha intenaity

becaae less than 70% of tha surfacq intensity and where pattarn

fringe* were baing examined* Thi» was dona It locate tha femes of

tha curve accurately (Figure 7)* Greater intervals ara permiaaibls

thereafter*

5* For each readlnf obtained in Stops 3-4» compute tha

percentage of tha contact reading , using aa reference tha reading

obtained In Step 1. From tbaee data, plot isodose pattern* for

each source cfsploy^d (i.e., Figure 0)*

Autoradiographf! ware introduced into thic study to

provide the reader with visual conformation of some of tha informa-

tion determined during tha penetration »*a*ure»eote in tha tleaue

phantom*

-23-

Mt> *i•

• liftt' **

Ml

As was mentioned previously, the nonuniform!ty of source

plating la demonstrate 1 by Figures 1 and 2. Additional autoradio-

graphy vara prepared to eubstantlat* the iaodoaa patterns ©twined

by electronic messurement. Theee are included In the data auction,

along with photodensitoaeter readings obtained therefrom. These

vara prepared by stacking film to a depth equivalent to tha maximum

range of the beta partielaa and allying tha aourea to tha top of

that atack for tha Indicated period, or by mounting the* film

vertically between paraffin blooka and applying the aourea to tha

edge of the film. Each film layer with emulaton was measured to

have an average thiekneae of 0.223 n» and a density of 1.41 g»/ce.

Thua, each 0*71 mm of film has an equivalent stopping pewey of 1

an of tissue or water. Figure 7 demonstrates tha correlation be-

tween the deasitometric data and th* electronic data along tha axis

of tha ar plicator. Sines film enuliions undergo a saturation

affect st high intensitiesU0) f proper correlation at close ranges

is difficult to accomplish.

Exposures are indicated with each autoradlograph. Enfant

Type 508 It-ray film was used, sad was developed according to the

manufacturer's specifications U minute* in Du Font X-ray Developer}

10 minutes in Kodak X-ray Fixer) 69 degress F.).

Ths information obtained in the brief biological test

dons in conjunction vitb this study osnnet be considered adequate.

«snV

4*m*Mb« fmhi Iff>j| * bu i • *s-M - ifmtmtfm il v-^'-K

attvs'SJ HP "V- I.*/.*»'-' ; f - f ' *J «

a«tf e# fMm *f# *

•»•%) X mdb * hem tm

t» w**q »/il<pr.t» tjtt*/av!- r-.» an •* lr 'ami ? a*rf7

aer^WM'f a#GM> #j> b*» fa #•>

fa*** J br

wit OS aolb^»OM tiaocrwftf' «M» te ,k« «*v oil 1

* X»*«I IP? a^I

<*»C -/at-5. #«o* tA «1 ••ftml* >) a >aqa a'lvwtotffcKaai

!•*•*• WW an.' Mi na*la#ifo ooi^aenricJ' ttff

Tbt test was aerely perfonaed to obtain an Indication of the nature

of the biological reaction to a Ru 106 eource.

Source 2 was taped to the shaved back of a ronle rabbit

for a period of 15 hours and -CO nlnutes* for a total surface dose

of 23,930 rep* The rabbit was then observed periodically to deter-

in* any biological effects*

Stoli sad Sfflrartatfana

tAfftt of i

To prepare a therapeutic an Ileator vhieb will proviso

s dose rate suitable for clinical use* the physician's require-

seats Bust be considered* JBaob tuntor typo possesses its own

Minimum lctVT dose which must be applied to nsure

growth (6*17*2. \

eor*dition of the w^,.m

periods of treatment* In addition* evidence has been presented

whioh purports to show a relstlonsblp between the effectiveness of

the total doss and the rate at which it is applied*6 ). It is the

function of the physician to correlate thase factors and select

the optiausj total dose and optima* doss rats for a particular

pathological condition* This paper does not attempt to do this

for hla*

Included herein are the calculations to be used to

dotontine the activity for a specific treatment based upon

-25-

tint j *m^.-

.:« 0|J

Yofl'CiJxP-j II tod - .;.-1 tttaUlf» *&*

the desired total dose and the rate at which it is to he

administered.

Rh 106 has two decay paths for each of which separate

calculation must he nade to determine the actual energy trans-

ferred to an Irradiated area*

Assuming no Breasstrahlung to be present (introduced

later)* the rate at which energy is emitted from any beta source

1st

energy/sec • (number of beta particles emitted/sec)(average energy per particle).

gg 1 ergs/sec • W&M where K * number of mC present

1 number of particles emittedjmr mC

- 3.7 x 10?

k * conversion factor from Hevto ergs

• 1.6 x 1CT* ergs/Mev

I average energy per particle(Mev)

To obtain the dose rate in any medium in rep/sec 9 one

must use the rep as defined t 1 rep • 95 ergs absorbed per gram

of absorbent tissue* The mass of absorbent in any material 1st

ftp 2 gms « da£ where d • density

A • area of surface irradiated

& « range of partiole of average energy

Division of Eq 1 by Eq 2 then gives the dose rate of the

source material est

«JeV»

Mf ft* si #* *#*« v-s h/tr. e

. ••'•?. Mfci

ftJsts^fta d»M» t* rfftSS (•*•& Mrf SM* 'H?£ 48

-e tartf <*f*«S -;-*.*t>r Mb *lijrs*J«B •# staff s*l ^t

iirtvl us ft* bftv

Immmmni) #mmjmi *t 9$ vmHattomm • ?> pflwmi

MW»i *#•«* V* i«7 h«#*2s» ei ^pftse rfftlrfv #• olll •*# ,(?«*•£

Ml

s?tdv m I

••* ^ '* to mum MfT • M/oaiJ Jn*4?oHc?« to

s • • «tdv Ub 9 mm £ c4

S*1S • A

• i> *>o 1 n MJi Mjfl as-.' MM : 01 I .'.'". H NfcjMI

t«S Itttf1 1MS

Sg ? rep/*ee/ga of tissue • 1eMKMq/<UA where q oonvanlon factorfroi8 org* to r9p«s defined above

• 1/95

"king the density of tIssue at unity and assuning, tenpo-

rarily, 10051 geometry, substitution of the appropriate conversion

factors into Eq 3 gives

i

rep/see » ( 3*7 x 107 )(1.6 x ICT6).^95 i

• 0.623 mJojL ab

Application of Eq A to a Sr 90 applicator produced and

calibrated by Tracerlab, Inc., gives values comparable to those

obtained by the calibration naasurenents, within a ailtable geo-

metric correction* This applicator contains ap roxlaately 25 nC

of Sr 90, maximum beta energy of 1*1 Mev, and was Measured by the

manufacturer to provide 28.1 rep/see at the surface.

The following equation*27 ' permits calculation of the

average energy per beta particle

t

la-i « - H^L- - 0.33(1 - _Z1/2

) (1 »JLJ/2

)

where a * the ratio of the average beta particle energyto the aaxiaus beta particle energy.

Tor Sr 90, the average energy Is therefore

i

I - n Bj, .(2.2)(0.33)(1 - J«l/2

)(1 - 2*^*)A3 I

• 0.853 Mev

Aaploying this average energy in £q A» the Sr 90 appli-

cator in question having a diameter of 7.7 an, the dose ratio 1st

•27-

9Dil

>*'4

'&i KWi

•

3-.1v t* Uwim IMf bstrf ,»*.• t*ww ,-^W AkhIxsk ,09 ** *•

aai *•: • #s nfm\^»i £«tfi i

aai ||

•j I PMffcl

IWC^rNdJ si tyraft

ial attar *«< a lafaa&IA k

rep/eec » O.ftgJ (p,W)(2«-)0.330 (U 7.72 )

86.5 rep/sec7.7* )

4

To obtain the calibrated value of 28.1 rep/sec, an

adjuatment factor of 32. 5,i moat be applied to account, for loaaea

due to applicator geometry and to account for conversion of beta

particle energy to Rraawatrahlung. Thla correction would aeeai

to be of the proper magnitude baaed on the limited available in-

formation on the Internal construction of thla Sr 90 applicator

,

and allowing for the approximation error in the 25 mC value.

Similar ealeulationa for kh 106 enow the average enarglea

of the two beta particles to bet

1 • 1.45 Mev for a* • 3.55 *fev

1 - OM Mev for It, « 2.30 Mev

Application of theae average energiee to 5q 4, with

proper allowance for the 824-135 relationehlp between the two

decay paths, and uaing unit area for the source, shows*

rep/aec » 2^2J Cgl) * £*&3 (*I> for 1 mCA (R )x A (R )2

where eubeerlpt 1 portaina to the 822 decay path, and

2 pertain* to the 18:4 decay path

g • fraction of transition* by the

aelected path

The range (cm of tissue) for the 1.45 Mev particle la

0.6^5 cm, and for the 0,88 Mev particle la 0.344 cm.

Substitution of the given values of g, I, and R, and

assuming unit area for convenience, gives!

mmrnVBa)

am 'S ?r- aetBV t»t

* '••'•' " Btfmm " :

.'\, p J - .*»-:- ' - '• QfHH re-.-

-•I •Id*! f^pytq .».ij 1e «,! |

na «•> jnlvoII-6 feo*

Ml*i«tt* *»;..:»•:©* wdt vol taXte

owi «dt cmw*W <ftrfar. *mmmLI» *•

& i tc^ (&) £&£*& * (la, m*\»»*

•1 «fai*i*i *

fcflfl ,« fcim * -inn I,* 0» „

0.645 0.344

- 1.429 for 1 mC Kh 106 on 1 «q cm of surface

The test applicator employed herein hat a geometry

factor of approximately 50% whan reflection froa the plating baaa

aad radiative losses arc taken into acount, Thugs, for each nC'em*

exposed in this system, 0,715 rap/see enter the area to be irradi-

ated* This is not true in the present practice, since the nonuni-

form!ty of the plated surface has already bean demonstrated, end

the inaccuracies of the ORML shipping data have bean mentioned,

ASsustt 3 mC to be plated uniformly on a Cu disc 1 inch in diameter.

Since a 1/8 inch lip covers a portion of the emitting surface, only

36,3£ of the emitter is exposed, leaving 1,69 aG effective in

creating the beta field. Applying the geometric corrections, this

applicator has 0,593 aC/oa*, and therefore, supplies (0,593) (0.715

5

• 0,424 rep/seo/cn? to the Irradiated surface,

Xa the preparation of a practical therapeutic applicator,

it la desirable that a minima of the active emitter be masked

sy the supporting structure. This can be aceoapllshed by reduction

of the width of the supporting lip and/or h> masking the ar^a, which

Is to be covered by the supporting structure, such that no active

deposit is made in this region during electroplating,

la the preceding discussion, the production of Breme-

strahlung was omitted la order not to detract from the discussion

at that time. Since this process accounts for an appreciable

-29-

(i *

4 I OC -I •

"•OBVf & **9* «i*T«! i TWITS'.* *0*<

MMf

No I BMtoX (

•

f4T« »fo «f .n+mnrtfb a«9d \b**nl» Mri •erihara hw*lq •& to f*J«rol

.ittmutl a no wmItrn « b novo. X * toalc

at *rt*99y\* dm 7&»L %nlr*9l t fri>o<pf «£ T»^.fhw «tt *> *€«<*£

taa nM»\a «»rf *ot*&McNB

ftlttVt'U' L-« !ft£I.(GKS9ii 0< 049 *>.<>n*

wr oft on » yg toi«v»» *tt •# at

<

portion of the electromagnetic radiation in a problem of this

sort, and, therefore, it a major contribution to the radiation

baiard of high energy beta ray sources, it must be taken into

consideration.

In the introductory remarks, it was noted that the

true efficiency of conversion of electron energy to X-radiation

ia probably not an exact linear function of the atonic number*

However, since such a true relationship is not yet available,

the direct proportionality approach will be employed for the pur-

poses of this discussion. The following equation' 2*" ^m ^

Jg_& n M ZA600 ac2 where

i

a • the portion of the energy convertedto Bremsetrahlung

bE m the average energy for a given betaray spectrum

me2 • the rest mass of the electron• 0.00055 »u • 0.512 Mev

Consider only the active disc without any arrlicator

holder, such that the Bremestrahlung emission is due almost en-

tirely to electrons impinging on the plating base. Over ail of

the beta energies from Rh 106, the average is 1.35 Mev§ therefor*,

this ease, n » 1.65 a 10-32. Values of n for the materials

in this project are included in the tables

•30-

floral V- **$ ftg mateticih**-,™ «sfM - R » •—**—»•* k-i nm miipiRiOT W^JM • ©I ..?•JOINTSa; ,»fl* a « tot

f i«iU b«#oii bcv *1 ( aaK«ierx

-•

istttiv *m GO*A* W • * 6 n|

*«*f»v»»» Wat* «*d to .icUioff aft » a

TABUt 1

*l*tlat &AB&IliT' UYi SB * %5?

Gold 0,130Copper 0.048AlCBRintJB 0.021Beryllium 0.006

0.31 aa 0.990.67 as 2.15?.21 m 7.133.29«i 11.10

From the ebove Talust of n, it la readily seen that

beryllium is by far the beat plating base for use in attempting

to reduce the X-radistion field around a beta applicator. It la

unfortunate that the sources did not arrive fro» ORSIL in sufficient

tine , or with sufficient accompanying informs tion, to permit verifi-

cation of this statement with adequate experimental evidence.

This syateta contains a gamma"ray source. Allowances must,

therefore, be made for this electromagnetic radiation as well as

for Bremastrshlung. As pointed out in the introductory material,

the patient undergoing treatment is exposed only for the period

of the treatment, and need not be considered in the long-term

radiation-exposure picture. Therefore, In computing the gamma-ray

intensity about one of these sources, dose rates will be figured

as pertaining to the physician, who, in general, will be in close

proximity to the patient only while actually fastening am applica-

tor to the patient 1 a person. Since he will be some distance away

(at least arm's length) for the remainder of the treatment, the

-31-

mitff'-<-

. ..

4. .-: , tlJLJBkJk

urn

am I*. ffter-.i '.

fc* ft•!

ttort ti #1 ,« *• MffJtar **e«i* •&- r

|Bl#fMJ##» sa •«! MH Mrf *£#*. ? «f# *rt x* •! a»

ImteHlM .:£ -- tm4 'I

' Ml N>r b.i:

* ?J '• '• ;•'" r •-.?• •.

-,-< -••• ;

-_,

• ' ' !' " . ' i ' *

ii.: ' " -r

. ttp.-ctf .i f& ••

%Jwr* MKtfusvo;!* tMjMJMl •te*r-«ato^ «. Ml4#«M flM>Mg| ftMl

«a H«v m «©2>*lb«i »iS«a»MK»x*»*ia -: ..t t*l m>«* «f ,orelink

t ££lT«*M f«#«rftt#il mU «i #m» fcMhtJMq ml iMrftfirrftMMiff M?t

NMMM, >H^ «H JMM MMMpt Ji* hMMtcut* r.'civ"* f n s mmIIm] ttfl

tW-mmI »-;. at tm^luN Mf Jo* 6mm mm t#ftM*Mvf* «C# fe

fcfr^&t? Mf II Iw uWm met ,aun-t:oe »MMtl ^o mm *UO0>

•Mle ci *.< 111% ,I*tM?n ei t*** Ju.iolwigrfo; #* ; *0l*t*to»q «i

\MA Mlfl ti MM • Ml M» C«T©*j J»**T*tf*| *U * *•#

Ml# ,J<IM*M«J •* M tMte **i iMwi ,.,„. i%ml ,#)

applicator may bo oooaldcrod to ftawtloa a* & point soaro*«

Oompmtaticnc may, tharcfora« be made toy tho aao of tho tmilmriat

equation'**'!

^^(tr/lon pat?) (lorn pair/*yoc)(Ulr*)

OPMPpf^HtViAaaQ^ W^P VPWfewm* e» wkww Pn OF OraOmP VHP PJP^PP) A• ^pmn- Oft M^B^^MMPl

ana moat take late aceoamt tho three dlfftreat giwi raj

lordied. Iq 7 thea tapamaPl

• 0.127 x iflrJ

where, gA • fraction of traasltl&ae by a fitem path

% • energy of the emitted phetea by the five* path

«A* »*V *rt * oaT * °*51 • 0al7 * °*73 • 0#01 * *•**

tSnffrii iiMif in ijnKMUUtiMijfi ii^iiinBri TffiBffffii nffliB*

Xba data oMaiitod by meaeoring depth doee oo o femet&aa

of ottrfaoo deem am preeeated la Figaroe 1$ 8» and o#

Figaro 7 lojloiop too axial dapth-floae date afrbaUerf

from Somree 2 (in the ai holder) by ion ahoahar meaeorweittt, a

cunra for a 3r 90 applicator'**' for pcmparlecn pureeeca , ami

photodonaitomatrio readlnge from tha avtoradicerapbe (Figaro 11).

It may bo soon that tho Sr oo applicator field falia to $0* of

ito enrfaee intenaity at 0*6 am penetration into a water phantom*

at which distance tho intenaity of tho M 106 applicator field

la excess of 100$* Theoretical eeneepte iadioato that a

ft*

'•'" ~ -

4*•* itftfl w*>*

^*#

*$4tm m • X

MK -:- .-.;,..' .,-' -';^ i

"-/:.-i.:-.,c'... :...'

* •• m* **** ^vmm f* AftoUtt* «« aft MR1

• ,ftjlMlllllli <utfft** Aeg. tf («Mte iA «ti wreyi: mft

tIWi tmmmUmM oar *t •w.t •< ttlaaUvl «tf# i—itiiti ^u» 4*

<:

(00

\

to

So

7o\

Co

SO

^

40

3o

to

—

\

10

\®

S (2/

i

Vd

r~/c y :

i 3 * S (, 7

/Penetration Death ~ mm.Depth Dose Curvms m Wa.fer Phantom

41

10

G)\£) Ph«to <len(it<"ncfnc

T~e.ff- Aw/ccater (lo« CHAMStP)0<aa-la. or> k PP I* t.o.'tc

l

PJ"

-33-

similar plateau should appear for the Sr 90 applicator, However,

1b medical practice, It is necessary to filter the 0*63 Hot

parttela emitted by the Sr 90 since It will produce an undesirable

necrotic condition at tha tissue aurfaca while the therapeutically

effective 2*2 Mev particle froa I 90 la delivering the desired

depth doea. Tbie condition doaa ot exist in the Ru-Rh system,

since the Ru 106 particle is of such lew energy* It is also

notable that at a depth of 5 mm* the Sr 90 dose rate Is leas than

2% of the surface dose while that froa Hu 106~Rh 106 sourcee is

still 261 of the surface rate* Thus, it nay be seen that the use

of Sr 90 applicators entails thirteen tinea the total surface dose

of « Hu 106»Rh 106 applicator to produce the saae dose at 5 am

depth, with a proportionately aore amff surface necrosis*

The faaily of curves in Figure 8 represents the gradation

of depth dose as aeosureaents are node laterally across the face of

the test applicator* The axial contact reading Is used as the 100$

reference* The beta ray beaa appears to be quite well colligated

by the 0,7-mm aluminum lip of the container structure, since the

Intensity beyond the limits ot the exposed emitting surface does

not exceed a small fraction of the intensity of that portion of the

field to be used in therapy* However, for long exposures, addition-

al oolliaation amy be desirable as evidenced by the autoradiegrapfae

shown in Figure 12* This requirement would, of course, be adjusted

to the typo of tumor growth or other leaion to be irradiated, since

-34*

tfrfMlMM* « mv*m

i.-» -: |M MM BMMMXM kl H 1 BWfl * ;.; foM MM '-«•

oet* «i /I ,^4'iofl* wol oMi 1» «* « »**•

m*£ si tin mm Of M • -

•2 MM»« <*U «*-*>! «K mm **** •&*** «** M«**tf» * W to tt

'4H «rf *m #1 «m*T ***** mlw «i» 1« *te UUn

mM m**w« ir.^ oAt mm# mMvM* %UU*M 9n*4>

am * 3* mm mm •*> m«mm, o.- w««l^j. *>I «M6X M • M

•MMVMB tMtWf WWW MM KltfW irww * *>** ,rf*qM

MtMftMJ • •- pJMMMJM I MMW *J HM li |BMfl Hi

* M** ««# HNM \XiM«#«i ft**u MB WIW1IIH 1« MM MM* 1*

*C0I «di «a MM M )«i'bm #B**M8 f*bc« wP ,»^aM^# *•*# Mf

|gH | M N IMM *J *J MJM - MM Ml INtf *J tMMMI

M» mbIb #MMll MBit *ft«e *«* %» «li mbJmAi m>**0 «f» *jf

MM Ms-hui Mi##lM Um« ofiar * *ti*if Mi No** **£*m#iil

ttl "l» Mi#M« #M# 10 M1m*JbJ M# %» Ml * MMM MS

•MU#Mto ,WMfil M*I Mt v«WM0l

Mj|*l*jlfctMlBB M# «tf llMMl** M BltfttlMft M" MS MMMtXiM in

M#MtM M %MMM to tllMV JMMlhIBM •!« »fiX MC^n «i M<l

MBit ,M#*i»«Ttl M M MiMX MtfM M <>Mf| ml 'to MM M* M

3rSL:lob

Isodose Curves around Ru ' /Applicator Immersed in

Water

£

l,

5f|

--

0)

o

?7o( _^

»0%

stor.

N

1 o owr*<- £-

3 l

Durante Lt i"h€. 5ot/fc e F"*» c_ C — rr* *»i

/*"/<? *? = Isodose Pattern at tbe E. al a e ol Source 2 l*nr>-> erj e dl m Wat«»C

Perce^tooes ore oi the A/iaX*"i»tQ.ct r-«aal/n<>

may require a r ther high total Job* at all the fringe*

and on into the surrounding skin. In measuring these lsodose

patterns, readings were taken along a single radius line in

order to present the conditions wMch would prevail If the source

bed been properly plated* The curves shown are for a completely

Immersed source* Tissue nay not fill tho recess in the applicator

face in actual practice* The lsodose pattern could then be applied

frost the tissue surface rather then the emitting surface, and would,

therefore, give a better collimeting effect* Due to the physical

dimensions of the ion chamber and a plicator (Figures A and 5),

It was not possible to complete a closed traverse of the 100.* and

M lsodose curves In the regie of the retaining lip Qt the a pli-

oator. Ho intensity in excess of 25£ of the surface dose rate was

noted on the surface of the applicator at a radius of 13 mm from

the center, and no beta intensity was nessureahle at the edge, back,

or side of the container. Combined gamma ray and Dremsstrahlung

readings, using a Geirer-ttueller counter, (no beta) for Source 2

•honed 14 mr/hr after penetration of A cm of tissue equivalent

plastic*

Figure 9 is an lsodose plot of data obtained using the

lorn chamber and a* roaching the edge of the unshielded Source 2

(no container) immersed in water* It is indicative of the rela-

tively small amount of eollimating material necessary to oonfine

the beta particle beam to the desired limits* Ewn as the lorn

(a

I

«l mil ZLihai *£$al« fl «**•* **«* WJ«*to»l ««fl«*#*l

tMJPPt art. U I **'H : - i-o. w MMjtlUT«Mli » *>** «« .rw- -- MTV* «tf •&* >W?«'l °*** ****

tojt&w «f «wU M««>» *«•**«r Motocl «tf 'ue#*» «1 •***

tllc«f to* ,»«**»?« yalfttm *U r.ttif X9di»t •*•*•*• mnmXi *i* **!

tolwpM **<* tt» ft » !•##* « m** %wf\m**$

i , ' M^Wi k

***** **&*» » " ** *ttfe/'>f| A*1* •«*••• ***

yvUKlMMBTtfl EMC Ca-S MtBC.

£ t*WOc i»l («#ftd >*) ,i^r*a film* a yrttff tlflfi—

t

v

«i# yiittf MMl2*#(fo "•':, *W«1 ITU 3l t? tWftftY

«*sk£ tofcltlrfaw «(# 1o **£«• *&s yiwa • tea ti<—it» «t

•*:•? mH V a #1 .a**** *1 &•* «r! (wrlfctiipp o«)

•Gi'ittu© «# yu>M»n lata*m v«1*««UI©« •*• favaat Haasa T£«vft#

eel 94* t» *«*fl ««mU tartlet* erf* o! twd ml*U%»% «>«f wtf

hanber approached so close to the edpe of the disc that appreelabia

radiation could enter directly from either face of the dice, the

intensity did not exceed 20* of the axial reading. Since the

geeaetry was so unsatisf .ctory in tfc<» measurements involved hare,

it is safe to say that the trot gradient and maximum value is

much more favorable than indicated*

iusQrttdlaimrhji

The autorediogrepbe ahovn in Figures 10, 11, and 12

were prepared in confirmstlo of the information obtained by

electronic measurement*

Figure 10 war obtained by laying the applicator holder,

with So roe 2 in place, on its side on a atrip of X-ray film.

It serves to demonstrate that no particulate enissioa is observed

from the sides of the container. The apparent curvature of the

edf© Is due to the geometry of a circular source standing on edge

on a flat plate* The apparent fringing in also due to this

itrical distortion*

Figure 10, Applicator placed en ltesside on Way film todenonet.rete sharp cutoff ofsradlation field *t appli-cator surfaoe* Exposure * 5 sen. Source 2*

-37-

•if*. Z".'"-*";. Q ', H

«f* ra

rf « •

•**»!

Xrf rfe «©

,l«rf

•Cf' rtf*-

4t r roto* «fT

raft

• <*«<lata* «rf* ^ Vftfiit #tfj _*^

-

•

>lMhN 'ccv7»r.

« This la * portion of a aarisa of autoradlopTapha ob-tained by stacking X-ray fil« in frait of tha appli-cator. It demonstrates tha variation in depth doaeiEapoeure • X sec. Sourea 2.

a* Contact b. 5 layers of fila0.15© ga/eq ca

c* 10 layers of fila0.312 ga/eq ea

d. 15 layers of fila0.468 ga/sq aa

**fl*

Ml

'

Figure U. (continued)

e. 30 layers of flla f # 25 layers ©f fii»0.624 gV«q eat 0.780 gs/aq on

ft* 30 layera of fila0.936 m/*t ob

~39_

•V*r W«tlt

m

w

.?F~

12* Edto of JHngr fil* oxpoood to beta-ny fiold ttm ftp*

plloator. Dioiwtratoa th« outline of the radiationfield, tocposuroe * $ and to tee. Sour** i*

-40-

§* ftM M

-OA-

Figure U ia • portion of the series of autoradlographs

ottalned by stacking &-ray film and remitting the beta ray bean

from Source 2 (in holder) to penetrate through the pile. Densl-

tonetrlc data are ehotm in Figure 7* The contact exposure shows

the rather slight fringing at the edge of the applicator which

can be greatly reduced by additional colligation.

Figure 12 la an edge exposure and Is, in effect, a

photographic reproduction of Figure 8* This mm greatly over*

exposed in order to denonatrate the outline of the entire beta

field,

MQlQgto«L3t)atrTjUgM»

The observations Included here are presented in diary

fom for convenience of interpretation* Elapsed tine is computed

from the tine at which the applicator* containing Source 2* was

Mounted on the test aninal*

ElapsedDate and Tine tine

1540, 25 April Applied source to the shaved nape of rab-bit1 a neck with adhesive tape* Hebreaks in the skis were observable*

0720, 26 April 15HQ No observable effect at renovel ofapplicator*

1600, 27 April 48t20 Definite erytheae existed over an area theslse and ahape of a kidney bean, correspond-ing to the aore active portion of the ap-plicator (see Fig* 2}* The coloration wasabout that of a Moderately severe sunburn.

<« *wwxpc* «&fe# nut sJt SI #sjk

-•-..•*• ^DNW Mi .'-,v ' PUpJlMJ

::.;• •.-.•:.... '...: ^-Ll

Mtrfwoo c - t ->#f<icpnilnl io imnwltwirroo to! «M&

*In« #••# *d# is©

. ...

••I f«*c»*rfo nm mMm «4* ai wU-^wf

1» Uvroaun *i #•***• AJ«n»«k) o* 0*«ei XitqA <* ,ORTO

mmm ,nt xprfi u»» wit

**.-'«> t M«) Y0#*9t£q

-J,

0815, 2S April 64135

0815, 30 April 112135

12A5, 1 Kay Uli05

1300, 3 May 189.20

1300, 5 May 213»20

0900, 12 May 37?«20

Complete erythema existed over an area27 tm in diaraeUr. The entire areawas of the ease color previously ob-served, except that the area noted 27April had become a deep marenta andport lone t>jerecf had become necrotic*There wee no discoloration observableoutside an area equivalent to the exposedemitting material of the applicator*

Severe necrosis was evident over theentire area, with some sloughing in thearea corresponding to the more denselyplated portion of the source*

the necrotic area appeared generally theseas, with the addition of two openlesions srr roxtmtely Ins la disaster,which were present in the aoat Intenselyirradiated area* A slid erythaaa hadappeared in a band about 1 But widesurrounding the necrotic area, apparent*ly due to the low intensity fringingnoted in Figure ft*

The entire ar*« appeared tfen esse as OB1 Key, with sowe additional lose ofskin ne*r the edges of the necrotic

if end in the spots previously noted*

so a rerent change*

So further sloughing of skin was observed*The necrotic area was the sane else* Theerythematous area noted on 1 May appearedto have returned to normal* The hairsurrounding the necrotic area had grown1/S tolA inch* lucre wae no apparenthair growth in the injured area, nor wasthere any observable eplllatiem*

At ell times during these observations, the animal appeared

to be otherwise completely normsl*

From the observation of this t«st animal, it is mmsjmmm)

that any radiation damage to tissue subjected to irradiation by a

•4ft,

-.

&<

mM *m: . mam *dt uv *a*o s£*«wo*a wf?

mm pt/»-

0MO ••#Mi

-

la*

•ilfrtirt off

Jtu-fth apflioator of this type ie confined to the ar«a iwaedlately

adjacent to the eaitting turface, and that any fringing affects

ara of United eererity and heal rapidly*

So histological aeetlone vera studied la a United test

of this nature* They should, v owe*er, certainly be included In

the extensive aninal etudiea which must be done before thia beta-

ray applicator any raceire any extensive clinical use*

-4>

1"? iJMhife&iftftUrf «i

CflBBTJBlQHIXmEmiiSSmSSSi

Consideration of the lsedose and panetratlon tateneity

earwes far ooft tiesns, obtained In this study, shews a in 106,

Rh 206 applicator to be wary eatlafaetory for nee Is radiation

therapy*

Properly eolUmeted, the high energy bete particles emp-

pliod by Rh 106 provide a strong radiation field to a depth at mere

thaa 5 am. Goo of thio lootopo dees not entail heavy sarfaee

nooroolo doe to a low-energy bota particle from tho paront Ha 106,

nor does It require appreciable attontaatlon of tho usable boan to

filter out lew-energy particles. Inns, for troataost of onrfaoo

laoleno to a depth of several nUliastero, an adequate flaid aan

be aatabllahad without tho introduction of othor pathological con-

ditions* For treatment of superficial snrfaoa conditions, snoh aa

fonfsa infections, tho 0.9-mm 100* dose-rate rogloa poralto high-

Intensity, snrfaoa Irradiation without causing extensive damago to

tho underlying tissue.

Proper colllaatlon of tho beta-ray boom to aula tha

thorapantla probloa aan readily ba obtalnod by variation of tho

aoohanloal etrueturv of tho applicator holder.

Although gamma radiation la inboront In tho nso of this

lootopo family, tho intensity thoroof Is below ostabUahod fan— rsy

tolaranoe values for sonroos hawing beta-ray doss rates In tho normal

therapeutic range, Tho gamma-cay Intensity iron Rh 106 Is

IttftNi H I M WiHHl

M0MIM rf Mi *•- :.'«#M(lii-f «ft '!-• Hi -

J MfMfrfltM *0i --

~^ra MMiH **«^ ^ ."Wv*?%iiJ 9&* «6Mi

%• 4MM a •# Limit imltittoi w****

JiU *« rtrw w* awft afaMiq *** till it « •# •»*

•# rated tMNv m^# 1* ifciiJiite tliialmiqi #ni#p#n

,. . -,;.,

.. v: -.-> 9-yJ ....• •• -

silt* Hi MliMi •'•*+ 3" W»4OT

•Ut lo »«j It at fnufct tl flafcftftfcfcat mmm% 4§tf«

MMICdafig mM tl Im iM yfilmam&aX

| IM MMH

lower than that fron radiua aourcsa of taa sum bata-ray intensity*

Dr. aaary*30 * baa coapilad tba ratio of th intensities of the6*

two radiations for typical r^diua plaques and also tba gradient of

doaa rata vith depth* Ha has stated!

"Th* value of tha bata-iraaawt ratio for a full-strengthapplicator with surfaaa dose-rate about 5.000 r/hr iaof tha ordar of 25"

and

"Tha moat striking feature la tha vary rapid fall-off oftha depth doaap e.g., only about 90 par oant at 1 saw"

A similar coztputetlon for &u 106 appliestore, baaad on the* raluea

obtained herein (sea Preparation of Applicator) showai

beta/gaaraa ,Ql)t7lS ,,, * bate fogf FaWaft0« 127x1(7"-' gaana dosa rete/aC

• 5.63 x 10^ for hu 136. Kb 106.

It is readily seen that, fron tha point of panatration of

bata partiolaa. Uu 106 is greatly auporior to both radium and Sr 90

applicator* as currantly prepared, and has a bsta~gaasn ratio advarv-

taga ovar radius by a factor of 210* It is belierad that tha advan-

tagas of tba fiu 106 beta-ray panatration pattarn ara so suparior to

thoaa of Sr 90 that tha low gamma-ray intensity which is introduced

nay b* tolerated, aapaclally in riaw of tha intensity currantly

tolerated ia tha usa of radian*

fta 106 is also suparior to radiua in that no gas-leakage

hasard exists. ,_-45-

3M#Si

*

•

f*\

Breneetrahluag eaa be materially reduead by aagleyaeiifc of

plating bases and eoatainers of lew atoalo aaaber eleaeatt. Of the

lower etoaio rwtot if materials* b<*.rylliue i» the aeet satluTaetatjr la

that It it * light, strong solid, and is not nearly i# ehealcaily

^B^SS eraOW^ ^W ^MOW OT•^O^e^W WO OO'^^aF OB^a'SU^H^a'aMe'r^F ^W <^Ona ^^BW^e fc*^Wfc ^&w^O^BJPW ^FaSa^PaOr^p!w ^O ^SSJF ^PaWSa^^PBW

effeete eon bo readily prevented by proper handling*

the naif life of *a 106 1* leaf enee** that on epplieeter

ooaetmeted thereof hot aa output of saffi&lent mistiaay far noraal

thorapetttie use* A simple deeey curve baaed oa lie initial eallfara-

tloa value in adequate to determine the doeo rate at the start of a

treatment* Seen a eaall portion of one half-life transpiree daring

the few hoare of a treatment period aa to permit the astusptlen of

ooaetaney of output far the period la question*

Examination of the 11aHH available blologioal data

described indicates the true tissue effeet te bo ae predicted by

the maeaureaente la the tissue pbantea and by the autoradiography

.

«^C-

•to**

TIM problo* of tbo doptb doaaf a^ntribojUoa dua to Oota

o«rtie** irradiation fron soorooa of «a 106 in oquiiibriwi with

H© 106 U atndlod la km of lonlaatlon-thaaaor naaouroaonts in

a tlaaua-nquiwalnnt, watar pbaatonw

Umi oonlanont and aothodo wm»lajfad ara doaorlbod 1a

dotal! for too aaoiotaaeo of tfeooo who nay do forthor otadloe of

tola aort.

axillary data ara provldod by aatoradloaraohla atadioo

aeing tho varioua aoaraao aoallahlo.

Caloalatioo* ara shown to ba la aooord with tbo awailabla

axpariaantal data on tbo aoaraao atadlad, fbo roonlto of tbo oal-

eolationa and axpariaantal data doaonatrata 8a 106 applioatora to

bo oraotloablo soarooa of lilgh laargy bata raya for aao 1st radia-

tion thorapy, Thm alaatfitpoMo radiation larolTOd in itt km

io aaall and amy bo fnrttior ainlalaod by ana of straataral notorial*

of low atoaio traaHtr* Tbo foil off of botanray doao rata with

tiooao danth orowidoo a ration of O.Ohbp dopth at 100£ of tbo aarfaeo

dooo rata, and a loforlthaio dooliao frno 0*0 at> to t&L at $ an*

Examination of liaitod biolofioal wldaaoa oonfirawd tbo

aatieipatod rooulto aa to araa affootod and dopth of tloatm roaotlon.

-47-

ftjfoti I•S.r- *a*«r

•

"'"

trit

tat .^I'jsr.w.'* i -vtetf. '^-.-ct -*.»•

Mil);

MMMfe

•Jab **«*> Mir TT fc**ii

9H% MM* x*** f

.«*r 2 #» Wt • « t.O wwft ate

-T,

w^mSJffWS0 A <jpHn^WPy m t» :*V_ » "a^JUpa^Bawt ? Q> ^Wwr 4k

fta 106 bota-ray mwws h**t tew a&owa to tot physlaally

aoooptablo for thorapoutie uoo9 Initial biolotioal onaoko aavo

oonfiraad tho pfeyaieal ttuaioa* Bafero tola r&dioaaix * oloaant My

bo plaeod ia gtoaral oliniaal aoo, adaitiaotl biological atadlao mast

bo parforaod and anaiyaod* beta as to tho offoottvoaoea of tola typo

of aoslieator on aonaal tiaaao mad oa iaaor tiaaao* In iriow of tho

failure of tho borylliaa-baiod aoaroo to arrivo ia tlao for ota4y#

this work anot also bo earrlod oat. Additional daaign work

bo doao wita roapoat to applicator aaapo and aatoriala*

-4*-

i(J '•*; Ml "? j STMMte l(MNf WRM MN9MWI ^MPNVIH *£

iMHMCl Wl#wmifci i ft :.'.*rv -v ;; ^. c iMtejfll MM ImrI

•*-

kllilRll I

-49-

Bibliography

1. Q* D. Adams, 0. Alagr, $• Danooff, A. Hanaoo, D. torsi, R. Koch,

I. Lanal, K. Lang* and J. Laughlinj Taohniqnaa far ApaUaatloaaf the Batatrm to Mailcal Tharapyj la. J. Boantfaa. iad. Ihar*& 15V? Ung. 19W. ^

2. M. Ulan and J. S« Saithj BaU-ray Maas*raa»nta and Dnitaj

>• 6, 6?»7* ( «fcma l$fe0; •Haoleonlca 2# »0«

Slatopatbolagy of Irradlai

roaa, 'ladrSStlll (1&2).3, W. Blood; HiatopaihoXaflr of Irradiation fro* Bxtarnal and la-

tarnal Seuraaai

a. P. Brown; /airleia Bartyra to Solanca Through fr*a/i 0* 0*Xheau Co, (1?3©J

.

5* 4» G. Burr and t. M, Garriaonf Tha gffaot »t Radiation on thaPhyataal Propartiaa of Flaatloa f aTO-WB (%•> MM),

6. 5. Cadaj Malignant Dlaaaaa and Ita Traataant byftadiuaiWiUia** anTmHaaCo.a^J, **~

7* *'• E. Oohai Toxicity of Inaalad or Ingaatad Badlaaatlva frrodaota i

WiDlaoolaa ^ lo. 1/81 (Stf).

8* A* 8. (taaptcn and 6. X. Alliaonj X-ray» in Thaary and Kaparl-ajanti Yan Soatrand (1*J*) .

9* D. T. tgfaai A Stady of ftadloactivltlaa in tha &afcnanltai Bagionjph. j>Jt£mU;

i

b. £V(i*w. — =a2=i

10. ft. D. Svana} BadioaotlTlty Unlta and Standard^ tfaolaonlea i,

Ho. 2, 3« (OetTTSWn

11. 0. Failla, M. ftoaai, ft, Clark* and II* Bailjrj tfca Maaauramaat ofTlaaaa Doaa of ionlalng Radiattenai AXCD-2U*2 iDao. 1*>7)«

12. 1. Farmit yoolaar Phyaioa t Ooapilad by J, Oraar, at al, 9ni-Taraity of Chia&go Praaa (ly50).

U. D. 0. rardi Tha Oha^iatry, of frithaniaa; IP-U0b, toivaraity of(1950).

-50-

a; MM ,d ,1) ,1

.

Xb* K. F. FrouadlloAj A Mwr Bata-ray Applicator Uaing FloalonProduct*; Satara 1&, 56WS (ilg.*!$&-.

*—*

i>» a* L. flriodoll, C. it Thorn; and J. S. firohaarj gota BayApplication tc tno gyo aiti; Saacrifrtion of an Applicator

16. H. L. F*iad«ll, C. X* Taoaaa, and 4. 3. Srohawr} Dasarlptloaof a 3r £0 Applicator and Its 0oa on tfaa afroi An. •*• iaaatfoia.

gad. ^Wepy'llrgg l?tb> iff*).^

17* 0* Glasaor, od.f Madleal ttiyalca , Vol. I| Toar Book Publisher*<l*a9).

^*

*

18. L. 2. Oloodanniaj Pataffalaation of too Snargy of 3ata Partial—and Fhotono by Aoaorpiicmt WaoIibnUo g, WoTl, IT (Jon. XfW.

!•• A. X. Hatkj iota Irradte tlon ao o Poaalblo Tharapoutlo Agant InOlanooaa, a>: J. 6pihal^W &> "J^g

1

(flot. ISW.

tO. 4m C. Hamilton* ilotaboUan of 8adlo-Strontliai audi Badlo-Otrlmi^-..j. --~„, —— IIMII I

I mill II——W—

»

I I ! —i—*———

r

KDDC-1000, U. S. A. £• G.

21. 0. W. Rolnat and M. D. Sohalsf fharapaatlc Eadlelaon Iaa andFabigor Co., (1*#».

22 • RHodgos, J. Kelt, X. Imp*, and R. laeXatyraj loarbeok ofladlolocri Toar Beak ftfbliahar* (1°50).

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A study of ruthenimum106 as a beta source inradiation therapy. tsta

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