A summary of recent innovations in radiation oncology focussing on the priniciples of different techniques and their application. An overview of clinical results has also been given

1. New Techniques in Radiation therapy Moderator: Dr S C Sharma Department of Radiotherapy PGIMER Chandigarh

2. Trends

3. Overview 3 DCRT Radiation Therapy Teletherapy Brachytherapy IMRT IGRT DART Electronic Brachytherapy Tomotherapy Image Assisted Brachytherpy Stereotactic radiotherapy Gamma Knife LINAC based Cyberknife

4. Solutions ? Develop technologies to circumvent limitations Use alternative radiation modalities Electrons Protons Neutrons π - Mesons Heavy Charged Nuclei Antiprotons

5. Development Timeline 1990 1960 Proimos develops gravity oriented blocking and conformal field shaping 1980 Brahame conceptualized inverse planning & gives prototype algorithm for (1982-88) 1 st inverse planning algorithm developed by Webb (1989) 1970 Tracking Cobalt unit invented at Royal Free Hospital 1950 Takahashi discusses conformal RT 1 st MLCs invented (1959) Boyer and Webb develop principle of static IMRT (1991) Carol demonstrates NOMOS MiMIC (1992) Tomotherapy developed in Wisconsin (1993) Stein develops optimal dMLC equations (1994) First discussion of Robotic IMRT (1999)

6. Modulation: Examples Block: Binary Modulation Wedge: Uniform Modulation Coarse spatial and Coarse intensity Fine spatial coarse intensity Fine Spatial and Fine Intensity modulation

12. Comparision

13. MLC based IMRT √

17. 3D Conformal Radiation Planning

18. How to Plan CFRT Patient positioning and Immobilization Volumetric Data acqusition Image Transfer to the TPS Target Volume Delineation 3D Model generation Forward Planning Inverse Planning Dose distribution Analysis Treatment QA Treatment Delivery

21. Cranial Immobilization TLC System Gill Thomas Cosman System Leksell Frame BrainLab System

22. Extracranial Immobilization Elekta Body Frame Body Fix system

23. Accuracy of systems With the precision of the body fix frame the target volume will be underdosed (< 90% of prescribed dose) 14% of the time!!!

30. Concept

32. Image Registration

35. Target Volumes

37. Example PTV CTV GTV

42. Planning workflow Define a dose objective Total Dose Total Time of delivery of dose Total number of fractions Choose Number of Beams Choose beam angles and couch angles Organ at risk dose levels Choose Planning Technique Forward Planning Inverse Planning

44. Planning Beams Beams Eye View Display Room's Eye View Digital Composite Radiograph

45. “Inverse” Planning 1. Dose distribution specified Forward Planning 2. Intensity map created 3. Beam Fluence modulated to recreate intensity map Inverse Planning

47. Optimization

49. Multicriteria Optimization Sliders for adjusting EUD Rectum Bladder Intestine PTV GTV DVH display

50. Plan Evaluation Colour Wash Display Differential DVH Cumulative DVH

51. Image Guided Radiotherapy and 4D planning

56. IGRT: Solution Comparision DOF = degrees of freedom – directions in which motion can be corrected – 3 translations and 3 rotations

59. On board imaging Room Mounted OBI Gantry mounted OBI KV Xray Intensifier

60. 4 D CT acqusition Axial scans are acquired with the use of a RPM camera attached to couch. The “cine” mode of the scanner is used to acquire multiple axial scans at predetermined phases of respiratory cycle for each couch position

61. RPM System Patient imaged with the RPM system to ascertain baseline motion profile A periodicity filter algorithm checks the breathing periodicity Breathing comes to a rythm Breathing cycle is recorded

62. 4D CT Data set Normal

67. Automated Contouring Movement vectors

68. Automated Contouring Day 1 Image Day 2 Image Individaul Pixels Due to the changes in shape of the object the same pixel occupies a different coordinate in the 2 nd image + = Deformable Image registration circumvents this problems

75. Results a = includes setup error

76. Adaptive Radiotherapy Planning

79. ART: Why ? Due to a change in the contours (e.g. Weight Loss) the actual dose received by the organ can vary significantly from the planned dose despite accurate setup and lack of motion.

80. ART: Problem Real time adaptive RT is not possible “today”

81. ART: Steps..

82. ART: Steps

83. Helical Tomotherapy

88. Newer Techniques in Radiation therapy Treatment Results (Clinical)

89. Prostate Cancer Late rectal toxicity (Gr 2 or more) is seen in 20 – 30%; ED occurs in 50 -60%!!!

94. Head and Neck Cancers Table showing Results of IMRT in H&N Ca

95. Head and Neck Cancers Table showing results of IMRT in H& N Ca

96. Head and Neck Cancers Table showing Salivary sparing and QOL improvement with IMRT

100. Lung Cancer Table showing results of IMRT in Lung Cancer

101. Brain Tumors Table showing results of IMRT in brain tumors

102. Cervical Cancer

103. Anal Canal

104. New Techniques in Stereotactic Radiation therapy

110. Cyberknife Floor mounted Amorphous silicon detectors 6 MV LINAC Roof mounted KV X-ray Frameless patient immobilization couch Robotic arm with 6 degrees of freedon Circular Collimator attached to head

113. Results The only randomized trial comparing stereotactic radiation therapy boost has failed to reveal a significant survival benefit for patients with malignant gliomas. (RTOG 9305). However 18% of the patients in the stereotactic radiotherapy arm had significant protocol deviations.

114. New Techniques in Brachytherapy

118. Equipment: Overview

119. Equipment: Imaging Table showing Imaging modality of choice in different anatomical areas

120. Equipment: Applicators

124. Image based brachytherapy Dose Distribution at level of ovoids and tandem 3 D view of the applicator geometry 3 D Dose distribution Rectum Bladder

125. Provisional Planning B Mode USG with stepper Template Acquired sagittal image demonstrating bladder prostate interface Saggital Image with template overlay Pubic arch Prostate Urethra Rectum

127. Image Guided Brachytherapy Radiation Oncologist acquiring sectional USG images Contouring and dose planning being done on the TPS The finalized plan with the superimposed grid on the template indicated the point of placement of each needle

128. Image Guided Brachytherapy A machine called the seed loader can receive instructions from the TPS directly “Seed afterloader” with the needle containing the in postion. Needles being inserted into the prostate under direct USG guidance

129. Image Guide Brachytherapy View of the B Mode Stepped USG device with the template for insertion of the needles. Some needles have been placed already Final Seed placement

130. Real Time dynamic IGBRT

132. Electronic Brachytherapy Customized Ballon Applicator KV Xray Tube AXXENT X ray Source Assembly