Purpose/Objective: This trial was initiated in 1993 to assess the risk/benefit ratio of mixed neutron/photon irradiation in patients with early stage/low grade prostate cancer. Materials/Methods: Between 1993 and 1994, fifty patients were entered on a Phase II, IRB approved protocol of mixed neutron and photon irradiation. Eligible patients had early stage (≤ T2C), low grade (Gleason score ≤ 7) prostate cancer. One patient had a Gleason score of 8. The median pre-treatment PSA level was 7.8 (range 0.7 to 72 ng/mL). The median age at the time of treatment was 67 years (46–80). Twenty patients (40%) received pre-radiation hormone therapy (median duration 3 months). Patients received 9 Gy neutrons in 10 fractions through a 4 field technique and a photon dose of 38 Gy in 19 fractions through an axial and non-axial beam arrangement. Results: The median follow-up was 9 years (range 1–12 years). At the time of last follow-up 26 patients (52%) were alive and free of recurrence, sixteen patients (32%) had died with no evidence of disease and 8 patients (16%) had evidence of recurrence according to the Houston definition (nadir + 2ng/mL). The 10 year actuarial rate of recurrence was 18.5%. Complications were graded according to the RTOG chronic toxicity scoring system. Only 1 patient had a grade 3 or higher complication, bleeding requiring cystoscopy and cauterization. Six patients had Grade ≥2 GU and 9 patients had Grade ≥ 2 GI complications. The actuarial rate of Grade ≥ 2 GI and GU toxicity was 20.0% and 14.8%, respectively, at 10 years. Conclusions: This study demonstrated that mixed neutron/photon irradiation is a safe and effective means of treatment for patients with localized, good to intermediate risk prostate cancer.
Forman, J,
Long-term Results of a Prospective Phase II Trial of Mixed Neutron/Photon Radiation in Localized Prostate Cancer. Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL.
http://archive.rsna.org/2005/4420782.html
