7/23/2014

1

SAM-HDR Brachytherapy II: Integration of Real Time Imaging

US-based prostate brachytherapy:

are we there yet?

Dorin A. Todor, Ph.D.

Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA 23298,

AAPM Annual Meeting, Austin, TX 2014

No conflict of interest

Learning objective:

to learn about the current status and future developments in US-based HDR prostate

brachytherapy

7/23/2014

2

Rationale

Typical workflows. Variations

Planning. TPS choices.

Errors and Uncertainties

Quality Assurance

Future. Novel uses. Focal therapy.

Outline

7/23/2014

BJU Int, 2012, Vol. 109(Supp 1) 5

7

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Seeds

Surgery

EBRT

5

22

← Years from Treatment →

CRYO

• Prostate Cancer Results Study Group

• Numbers within symbols refer to references

1

12

24

14 8

2

HIFU

% P

SA

Pro

gre

ssio

n F

ree

11

15

Protons

4

18

9

10

EBRT &

Seeds

25

Robot RP 26

Prostate Cancer Center of Seattle

27

HDR

28 29 31

32 33

34

19 36

37

38

LOW RISK RESULTS Weighted

>40 months follow-up or less than 100 patients

Tre

atm

ent

Success 39

35

40

41

100

101

13

65

49

76

80

56

59

63

41

75

51

71 72

90

73

74

70

42

57

85 84

66

43 64

44 EBRT &

ADT

53

82 81

62

54

79

86

87

88

45

58

69

78

77

46

48

91

+ Seeds &

ADT

93

92

89

50

67

68

95 94

55 52 83

47

61

EBRT/IMRT Surgery

Hypo EBRT

96

103

102

97

98

60 6

16

104

105

106

99

107

108

Update of

20 109

110

201

202

111 112

113

114

115

7

3

17

203

LDR Brachy

HDR

Proton

7/23/2014

BJU Int, 2012, Vol. 109(Supp 1) 6

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Brachy

Surgery

EBRT

CRYO

HIFU

29

22

21

5

% P

SA

Pro

gre

ssio

n F

ree

18

12

28

3 17

10

9

8 2

1

13

Protons

HDR

← Years from Treatment

→

• Prostate Cancer Results Study Group

• Numbers within symbols refer to references

15 4

36

Prostate Cancer Center of Seattle

37

38

+

Seeds Alone

Seeds + ADT 40

Robot RP

41

42

44

43

45

46

INTERMEDIATE RISK RESULTS weighted

>40 months follow-up or less than 100 patients

7

11

14

20

35

34

39

23 24

16

6

26

82

66

88

67

70

97

63

65

102 103

101

86

87 85

58 68

71 81 50

EBRT + ADT

94

93

92

77

91 5

1

69

Hypo EBRT

99

75

90

89

56

55

54

80

57

83

60

73

72

98

53

52

79

95

64

100

84

78

59

62

74

96

76

EBRT

LDR SEEDS ALONE

Surgery

EBRT & Seeds

EBRT, Seeds +

ADT

Tre

atm

ent

Success

104

105

30

27

47

48

49

150

151

107 31

109

108

Update of

152

152

153

154

155

155

156

110

157

158

159

19

25

32

160

161

156 111

111

111 HDR

EBRT & SEEDS

F163

7/23/2014

3

7/23/2014

BJU Int, 2012, Vol. 109(Supp 1) 7

6

11

25

15

5

19

30

16 20

18

29 % P

SA

Pro

gre

ssio

n F

ree

17

21

8

22

24

26

37

41

12

Protons

← Years from Treatment

→

• Prostate Cancer Results Study Group

• Numbers within symbols refer to references

42

43

46

47

48

49

101

102

103

104

105

106

107

109

HIGH RISK RESULTS Weighted

>40 months follow-up or less than 100 patients

Tre

atm

ent

Success

10

23

35

108

4

2

39

33

34

50

51

52

53

54

55

HIFU

56

86 87

57

58

59

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

88

79

80

81

89

84

83 82

85

Surgery

EBRT + Seeds

EBRT

EBRT & ADT

EBRT & Seeds

Hypo EBRT

HDR

EBRT Seeds +

ADT

Robot RP

Prostate Cancer Center of Seattle

1

7

90

91

110

27

3

13

14

28

40

92

111

112

112

113

114

115

116

Surg & ADT

118 119

60

122

123

123

124

120

HDR + ADT

Update of

125

125

93 126

127

128

129

94

95

96 98

130

131

132

Surg & EBRT

133 9

32

32

36

36

44

31

45 45

134

135

99

136

136

EBRT, Seeds & ADT

EBRT + ADT

137

in their 2013 ACR Appropriateness Criteria® HIGH-DOSE-RATE BRACHYTHERAPY FOR PROSTATE CANCER

Expert Panel on Radiation Oncology–Prostate: I-Chow Joe Hsu, MD; Yoshiya Yamada, MD; Gregory Merrick, MD;

Dean G. Assimos, MD; Anthony V. D'Amico, MD; Brian J. Davis, MD, PhD; Steven J. Frank, MD; Alexander R.

Gottschalk, MD, PhD; Gary S. Gustafson, MD; Patrick W. McLaughlin, MD; Paul L. Nguyen, MD; Seth A. Rosenthal,

MD; Al V. Taira, MD; Neha Vapiwala, MD.

the experts state that “The transrectal ultrasound-guided implant technique is the

backbone of modern prostate brachytherapy.”

In the 2013 “GEC/ESTRO recommendations on high dose rate afterloading brachytherapy for localised

prostate cancer: An update. Peter J. Hoskin , Alessandro Colombo , Ann Henry , Peter Niehoff , Taran Paulsen

Hellebust ,Frank-Andre Siebert , Gyorgy Kovacs

“In prostate cancer real-time transrectal ultrasound (TRUS) guided transperineal template implant techniques represent the standard of care.”

Usage

Boost (together with EBRT, Androgen deprivation). Typically 1-2 Fractions

Mono-therapy. Typically 2-4 Fractions but recent results from small clinical trials point towards a single fraction future.

Salvage vs. Primary (initial) treatment

7/23/2014

4

From a “Survey of practice in Australia” we learn that:

In Australia and New Zealand, 17 of 26 brachytherapy departments performed HDR-PB in 2010 and 2011. Nucletron’s Oncentra TPS was used at 13 departments, one department used Nucletron’s Plato TPS and three used Varian’s BrachyVision TPS.

Imaging modality for treatment planning

Thirteen departments generated a treatment plan using computerised tomography data, and two departments used ultrasound (US) data. No departments reported using MRIs or fused data sets for treatment planning.

All departments, except one, verified and corrected applicator displacement prior to each fraction or, in the case of real-time US planning and more than one fraction, subsequent fractions. Applicator displacement was corrected by one of three

methods to replicate the original plan: eight departments adjusted applicator positions, four departments adjusted dwell positions and two departments created a new treatment plan.

Usage

Survey of high-dose-rate prostate brachytherapy practice in Australia and New Zealand, 2010–2011, Jane van Nieuwenhuysen, David Waterhouse,

Sean Bydder, David Joseph, Martin Ebert and Nikki Caswell. Journal of Medical Imaging and Radiation Oncology 58 (2014) 101–108

Eighty-nine percent (89%) of respondents performed LDR and 49% perform high-dose-rate brachytherapy.

HDR monotherapy - Of the respondents who perform HDR, 31% (10/32) perform HDR monotherapy for low-risk patients and 19% (6/32) for intermediate-risk

patients. The remaining 16 respondents (50%) do not perform HDR monotherapy.

Imaging - Ultrasound remains the primary imaging modality. Ultrasound was in 83% vs. 84% in 1998, CT in 9%, MRI in 0%, X-ray in 0%, and fluoroscopy in 17%.

Treatment planning - Pretreatment volume studies are performed with ultrasound in 94%, CT in 11%, and MRI in 6%. Twenty percent reported using more than one imaging modality as ‘‘primary’’ modality.

LDR and HDR treatment planning software.

The software used for planning was institutional custom developed software in 2% and commercially available in systems in 98%. The commercially available systems were: Prowess (Prowess Inc., Concord, CA, USA) in 4%, Variseed (Varian Medical Systems, Inc., Palo Alto, CA, USA) in 80%, Brachyvision (Varian Medical Systems) in 4%, and CMS (Elekta AB, Stockholm, Sweden) in 6%, Nucletron (Nucletron, Columbia, MD, USA) in 4%, Varisource (Varian Medical Systems) in 5%, Oncentra (Nucletron) in 2%, Varus (Varian Medical Systems) in 2%, and Plato (Nucletron) in 2% (percentages to not add to 100% owing to multiple systems for some respondents).

A survey of current clinical practice in permanent and temporary prostate brachytherapy: 2010 update. Mark K. Buyyounouski, Brian

J. Davis, Bradley R. Prestidge, Thomas G. Shanahan,Richard G. Stock, Peter D. Grimm, D. Jeffrey Demanes, Marco Zaider, Eric M.

Horwitz. Brachytherapy 11 (2012) 299-305

‘Real-time’ workflow

Initial imaging

Delineating structures

Define needles/applicators pattern

Needles/applicators Insertion

Update images & structures

Delineate applicators

Plan & Optimize Dose

QA for plan and applicators

Treatment delivery

7/23/2014

5

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

15 | VARIAN ONCOLOGY SYSTEMS

RAD 4145b 2013-01 RAD 4145b 2013-01

Contouring

Freehand

Draw & edit contours

using a pen or brush tool

Real Time Interpolation

Draw necessary contours & Vitesse fills in the rest

Shape Stamper

Quickly draw

urethra on transverse slices with single click

Margin

Create a symmetrical

or non symmetrical

margin structure

Review Contour Sagittal & coronal contour review

Vitesse

Image courtesy of Kevin Spetz, Varian Brachytherapy

7/23/2014

6

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

Image courtesy of Kevin Spetz, Varian Brachytherapy

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

7/23/2014

7

19 | VARIAN ONCOLOGY SYSTEMS

RAD 4145b 2013-01 RAD 4145b 2013-01

Needle Placement

o Adjust planned needle positions

o Change needle angle by aligning two nodes

o Bend needle to align with implanted needle

Vitesse

Image courtesy of Kevin Spetz, Varian Brachytherapy

20 | VARIAN ONCOLOGY SYSTEMS

RAD 4145b 2013-01 RAD 4145b 2013-01

Needle Tip Adjustment Tool

Assists in correctly

aligning needle tips

Select reference needle(s)

based on confidence of

defined tip position

Enter exposed length of the

reference needle(s) from the

template

Select needle of concern

Enter exposed length of

selected needle

Tool displays the determined

offset of selected needle and

allows adjustment

Live image of the needle and

offset applied can be viewed

before accepting the change

Vitesse

Image courtesy of Kevin Spetz, Varian Brachytherapy

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

7/23/2014

8

22 | VARIAN ONCOLOGY SYSTEMS

RAD 4145b 2013-01 RAD 4145b 2013-01

Volumetric Optimizer

o Define DVH requirements for

any structure including

priority.

o Define dwell time constraints.

o Limit hot spots by adding a

basal dose limit.

Vitesse

Image courtesy of Scott Campbell and Kim Chambers, Elekta/Nucletron

Errors and uncertainties Is an ultrasound based procedure as good as a

CT-based one?

RESULTS: A total of 574 needle tip positions have been compared between TRUS and CBCT. Of

these, 59% agreed within 1 mm, 27% within 1-2 mm, and 11% agreed within 2-3 mm. The

discrepancy between tip positions in the two modalities was greater than 3 mm for only 20 needles

(3%).

CONCLUSIONS: The US needle tip identification in vivo is at least as accurate as CT

identification, while providing all the advantages of a one-step procedure.

7/23/2014

9

Errors and uncertainties During multifractionated HDR treatment, catheter

migration could cause degradation of dosimetry. Various institutions had developed solutions to address this issue and they involve, catheters adjustments based on tip positions relative to fiducials, adjustments of dwell positions or creating a new plan.

Applicator verification/correction

Cranio-caudal displacement of the applicators during multi-fraction HDR-PB can compromise

coverage of theCTV and introduce uncertainties in normal tissue doses. Tiong et al. assessed

applicator displacements over a 12-month period (more than 270 treatment fractions), and

concluded that <= 3 mm drift was tolerable with minimal detrimental impact upon tumour control

probability. The ABS advises that if applicator drift cannot be repositioned or corrected with a

new plan, treatment should be postponed.GEC/ESTRO-EAU advise to check the applicator

geometry prior to treatment and, if necessary, to modify the dosimetry.

Quality Assurance

Future 'It's tough to make predictions, especially about the future.'

7/23/2014

10

“The advantage of TRUS-based planning is that the entire procedure of catheter insertion, planning

and treatment delivery can be carried out in a shielded brachytherapy suite without having to move

the patient. This provides added confidence that the treatment delivered is exactly as planned.

If computed tomography or MRI is used for planning, the patient usually has to be transferred from

the procedure room to the computed tomography or MRI scanner and then back again to a shielded

room for treatment. Each step risks some displacement of the catheters and requires

careful repositioning before treatment is delivered. “

“Focal therapy is gaining popularity with the ability of modern imaging (mpMRI) to identify dominant areas of the disease within the prostate and again HDRBT will have a major role to play in this area.

There is also increasing evidence for the role of HDRBT in local recurrence after external beam radiotherapy.

Future guidelines will seek to explore these areas as published evidence emerges.”

THANK YOU

7/23/2014

11

What is the most important advantage of Ultrasound-based

HDR prostate brachytherapy?

1. It is inexpensive and widely available.

2. Allows needle insertion and treatment delivery

without moving the patient, thus minimizing the

uncertainty in delivery of intended treatment

3. Allows for visual guidance during needle

placement

4. Both anatomical structures and applicators can

be visualized

5. It is now available in color.

20%

20%

20%

20%

20%

10

Answer

• The correct answer is 2.

While 1. 3. and 4. are also advantages

one can argue that 2. is really the ‘most

important’ advantage

• Ref: “Brachytherapy: Current Status and Future Strategies: Can

High Dose Rate Replace Low Dose Rate and External Beam

Radiotherapy?” G.C. Morton, P.J. Hoskin, Clinical Oncology 25

(2013) 474-482

What is the major source of uncertainty in Ultrasound-

based HDR prostate brachytherapy?

1. Contouring of anatomical structures

2. Patient breathing

3. Needles/catheters displacement

4. Visualization and delineation of

needles/catheters and specifically their tip

5. Calibration of Ultrasound scanners

20%

20%

20%

20%

20%

10

7/23/2014

12

Answer:

• The correct answer is 3.

• This is a difficult question and I think arguments can be made for

either 3. particularly if multiple fractions are to be delivered or 4. for

the case of one fraction treatments. Contouring of prostate 1. would

be a third partially correct answer, even though evidence is that

comparisons between US and CT against the MR as gold standard

are putting US relatively close to the MR.

• Ref: ”Validation study of ultrasound-based high-dose-rate prostate

brachytherapy planning compared with CT-based planning”, Deidre

Batchelar, Miren Gaztanaga, Matt Schmid, Cynthia Araujo, Francois

Bachand, Juanita Crook, Brachytherapy 13 (2014) 75-79