Abstract:Purpose/Objective: Purpose: This study was designed to determine the incidence of chronic toxicity, disease free and overall survival among patients with locally advanced prostate cancer who received mixed photon and neutron irradiation on a phase II study. Materials/Methods: Methods and Materials: Between October 1992 and February 1995, 52 patients with locally advanced prostate cancer (stage 〉 T2c or Gleason Score 〉 8) were treated on a phase II dose finding study of mixed neutron and photon irradiation. Protocol treatment consisted of 15 neutron Gy in 15 fractions alternating with 18 photon Gy in 10 fractions to the prostate and seminal vesicles. The pelvic lymph nodes received 9 neutron Gy and 18 Gy of photons. Results: Results: The median follow-up was 88 months (range: 5-116 months). Ninety-two percent of patients had stage T2c or greater. Eighty-five percent had a Gleason Score 〉7. The median pre-treatment PSA level was 22.5 ng/ml (range 5-400). At 5 years, the actuarial rates of Grade 2 and Grade 3 GU morbidity were 33% and 14% respectively. There was no Grade 4 GU toxicity recorded. At 5 years, the actuarial rates of Grade 2 and Grade 3 GI morbidity were 31% and 9% respectively. At 5 years, the actuarial rate of overall survival was 82%. Forty-two percent of patients were disease-free at five years. There was no significant difference in overall or disease free survival in patients who did or did not receive neo-adjuvant hormones. At the time of analysis, one patient had Grade 4 rectal complications resulting in colostomy. Conclusions: Conclusion: The use of conformal mixed neutron and photon irradiation at the 15 N Gy + 18 Ph Gy dose level resulted in an 82% 5 year survival. This compares favorably with other studies of locally advanced prostate cancer. However, as a result of the significant rates of long term urinary and bowel morbidity seen in this study, this dose level is no longer used. Subsequent trials with a reduced neutron dose (10-11Gy) appear to have a more favorable therapeutic ratio.
Forman MD, J,
Results of a Phase II Dose-Finding Study of Mixed Neutron and Photon Irradiation in Locally Advanced Prostate Cancer. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3241532.html
