1. Modern Radiation Oncology
Jamie Cesaretti, M.D., M.S.
Radiation Oncology
Terk Oncology, Jacksonville, FL

2. The Number and Type of Ionizing Radiation Induced Lesions in DNA – per Gray/per Cell!
TYPE OF LESION NUMBER /Gy /diploid cell
double strand break
single strand break
base damage
sugar damage
DNA-DNA crosslinks
DNA-protein crosslinks 40 30
150

3. CURE RATE = DOSE 14% 81 Gy 20% 75.6 Gy 22% 70.2 Gy 58% <70.2 Gy
There is a significant difference between less than Gy (2.5D) and the higher doses.
At elevated doses there is still a significant “persistant cancer at biopsy” (risk versus benefit)‏
14% 81 Gy
20% 75.6 Gy
22% 70.2 Gy
58% <70.2 Gy
ASTRO 2004 3 3 3

4. Cure Rate = Radiation Dose

5. Cancers grow beyond their original organ in predictable ways.
BJ Davis, et al. Cancer 1999;85:

6. An Interesting Trial of Margins around the Prostate and Radiation Dose

7. MRC Dose Escalation Study
Margin
Margin

8. MRC Dose Escalation Study
BJ Davis, et al. Cancer 1999;85:

9. Toxicity = Technique
IMRT

10. Multileaf Collimator

11. IMRT with DMLC (sliding gap)
Each pair of leaves forms an individual gap
Gaps change in width as a function of beam-on time (MU)
••• a n z
a..+..n..+..z
Final intensity is sum of the individual sliding gaps

13. VMAT

14. IMRT versus VMAT

15. Toxicity = Technique
IGRT

16. Toxicity = Technique

17. Toxicity = Technique

18. Toxicity = Technique Image at proton centers kV X-rays MV X-rays
kV Cone Beam CT
Helical MV CT
MV Cone Beam CT

19. The probabilities for prostate staying
within <2 mm to its initial position are:
94.8% supine WRB
91.5% supine WORB
92.3% prone WRB
79.2% prone WORB.

21. Target Delineation MRI Treatment Planning

22. T2 axial image with
surface coil , Left SV
dark on T2 (and dark on T1…)

23. Optimal Target Identification
Fused CT/MRI showing Seminal Vesicle invasion on MRI: This justifies
including gross seminal vesicle disease to 75.6 Gy PTV
Fused CT image
Fused MRI image

24. WITHOUT RECTAL BALLOON
WITH RECTAL BALLOON
WITHOUT RECTAL BALLOON 24

25. Results (B) (A) (A) With Balloon (B) Without Balloon
Sample screen shot showing isodose lines around prostate with (A) and without (B) rectal balloon in place

26. Are all radiation particles created equal?

27. The lay implication of the
marketing material is that
photon radiation puts
radiation around the pelvis
and rectum “carelessly” and
that a higher level of precision
is more appropriate.

28. Many prostate cancers have Subclinical spread to peri-rectal and
pelvic lymph nodes at the time of initial treatment.

32. We are seeing “new” failure patterns in the local proton patients.
Photon radiation salvage plan

33. Another photon radiation salvage plan

34. Protons

36. Copyright © 2016 American Medical Association. All rights reserved.
From: Intensity-Modulated Radiation Therapy, Proton Therapy, or Conformal Radiation Therapy and Morbidity and Disease Control in Localized Prostate Cancer
JAMA. 2012;307(15): doi: /jama
Date of download: 6/1/2016
Copyright © 2016 American Medical Association. All rights reserved.

38. Comparison of Treatments

44. ASCO Prostate Cancer update March 2017

45. The End.