Para-spinal Tumors Encircling the Spinal Cord IMRT

Comparison of Several Target Definitions

SLICE 116

CTV SuperiorBrain stem and L & R eyes

Slice 104 CTV , Spinal cordL & R Parotid glands

Slice 83 Mid Volume CTV 3 – 5 mm separation between spinal cord and CTV

Slice 63Inferior CTV

13 mm Separation of spinal cord and CTV

Planning VolumesCTV 3mm Expansion 63 Gy

Spinal Cord 3mm Expansion 43 Gy

Rt & Lt Eyes 3mm Expansion 3 Gy

Brain Stem 3mm Expansion 43Gy

Parotid Glands 3mm Expansion 30 Gy

Beam Arrangement

Beam Arrangement Gantry 0Gantry 40Gantry 80Gantry 160Gantry 200Gantry 315

Basic Target Type

Dose Statistics 63 GyTarget Type Basic

DVH 63 Gy Target Type Basic

63 Gy @ ~76% Volume

Isodose Slice 104 Basic

Homogenous Target Type

Dose Statistics 63 GyTarget Type Homogenous

DVH 63 Gy

Target Type Homogenous

63Gy @ ~46 % Volume

Isodose Slice 104 Homogenous

IMRS Target Type

Dose Statistics 63 Gy Target Type IMRSEmphasizes Conformality

DVH 63 Gy

Target Type IMRS

63Gy @ ~90% Volume

Isodose Slice 104 IMRS

Esophagus IMRT Sparing Kidneys and Spinal Cord

DVH 50.4Gy

IMRT 5 Field IMRT with Intensity Maps

Intensity Levels 10 Step Increment 1cm MLC leaf 1cm

Step Increment

9991-959-08C

1cm step with 0.5cm MLC 0.5cm step with 0.5cm MLC

Intensity Level Comparison

Lung IMRT 60 Gy 5 Field 6 MV X-rays

Lung IMRT DVH

Large Field IMRT Plan with Dose Painting

Large Complex Treatment Volume

Long (~ 60 cm) volume needed 27 junctioned IMRT fields and an 16 MeV electron field

IMRT plan avoiding spinal cord and kidneys

Superior Tumor Volumes

Treatment Volumes Lower Abdomen

Treatment Volume Change in Dose Nodal Volume

Treatment Volume Pelvis Superficial Nodes

Inferior Volumes Increase in Dose Using an Electron Field

ELECTRON BEAM CHARACTERISTICS

Location of (a)Flattening Filter and (b) Electron Scattering Foils

Isodose Curves for 7 and 18 Mev Electron Beams

Small Fields with Photon Component

12 Mev Beam at 00

12 Mev beam at 400

12 Mev Beam with Density Correction

AXILA TANGENTS & ELECTRON BOOST

Breast Boost Technique

9 Mev Electron Boost Posterior Neck Nodes

Interoperative Radiation Therapy

The benefit of IORT normal tissues are removed fromthe treatment fields and the dose is delivered locally.

The enengy of the electron beams used is usually between 9-16 Mev.

The use in the country has been developed used at large medical centers.

IORT Isodose Curve 15 Mev Electron Beam

ORIGINAL HARD DOCKING COX LL STANDARD LINEAR ACCELERATOR

MGHSOFT DOCKINGLASER SYSTEM IN HEAD OF MACHINE

MOBETRON INTRA-OP ACCELERATOR

MOBETRON HARD DOCKING

Energies Available4, 6, 9 & 12 Mev