Three-Dimensional Conformal Radiotherapy
Richard Whittington, MD
Last Modified: November 1, 2001
Dear OncoLink "Ask the Experts,"
Is it wiser to begin three-dimensional conformal radiotherapy with my current PSA of 1.2 or continue to check the PSA regularly to determine if it will rise to 2.0 and then begin radiotherapy?
Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:
The situation you face is controversial. There are people who believe that all recurrences have at least a component of distant metastases. There are those who believe some patients have only local residual disease and radiation may cure them. There are 3 papers and a manuscript in preparation that bear on this.
- The Duke series waited until the average PSA was 10.0 and found that after radiation, all of the men developed metastases.
- There is also a paper from Johns Hopkins showing that when men start with PSA's between 2.0 and 7.0 that about 15% of men can still be cured with radiation.
- The third series is from the University of Washington which reports that men who regrow a nodule have a 0% salvage rate with radiation while men treated prophylactically for a high risk of recurrence have a 65% survival free of tumor. The folks from Washington argue that some tumors have spread before surgery and some may regrow locally after surgery and spread from the regrowth, not from the pre-operative tumor. In the latter situation, these patients may be curable with radiation early in the recurrence
- The final manuscript is one that we are preparing at the University of Pennsylvania. We generally treat men when the PSA is between 0.4 and 1.0. We have salvaged about 60% of the men with radiation. The workup is the same as yours. We have identified a group that has the highest salvage rate and they include men whose PSA starts to rise more than 18 months after surgery, had a Gleason Score of 7 or less, pre-operative PSA less than 20, and who had extra capsular disease with or without a positive margin, but negative seminal vesicles. There is a second group that has a low likelihood of salvage which includes men with pre-operative PSA > 20, Gleason Score 8-10, negative capsule and negative margins, although positive seminal vesicles is a bad sign, with a period of less than 12 months between surgery and the beginning of a PSA rise. We would recommend these patients take 1 to 2 years of hormones and consider radiation.
ASTRO: Fewer Side Effects With IMRT for Prostate Cancer
Oct 4, 2011 - Treatment of localized prostate cancer using intensity modulated radiation therapy is associated with a considerable reduction in late bowel and rectal side effects and significantly decreased rectal and bladder toxicity compared to three-dimensional conformal radiation therapy, according to a study presented the annual meeting of the American Society for Radiation Oncology, held from Oct. 2 to 6 in Miami Beach.
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