Acute and Late Toxicity After Dose Escalation to 82 GyE Using Conformal Proton Radiation for Localized Prostate Cancer: Initial Report of American College of Radiology Phase II Study 03-12

• Published in: International journal of radiation oncology, biology, physics Vol. 81; no. 4; pp. 1005 - 1009
• Main Authors: Coen, John J., M.D, Bae, Kyounghwa, Ph.D, Zietman, Anthony L., M.D, Patel, Baldev, Ph.D, Shipley, William U., M.D, Slater, Jerry D., M.D, Rossi, Carl J., M.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15-11-2011; Elsevier
• Subjects: Acute toxicity; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Clinical trial; CLINICAL TRIALS; Data processing; DISEASE INCIDENCE; Dose escalation; Dose–volume histogram; Follow-Up Studies; Gastrointestinal Tract - radiation effects; Gynecology. Andrology. Obstetrics; Hematology, Oncology and Palliative Medicine; Humans; Male; Male genital diseases; Maximum Tolerated Dose; Medical sciences; MEN; Middle Aged; Morbidity; NEOPLASMS; Nephrology. Urinary tract diseases; PROSTATE; Prostate cancer; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Proton radiation; PROTONS; Protons - adverse effects; Protons - therapeutic use; Radiation; RADIATION DOSES; Radiation Injuries - pathology; Radiation Oncology; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; RADIOTHERAPY; Radiotherapy Dosage; Radiotherapy, Conformal - adverse effects; Radiotherapy, Conformal - methods; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); TOXICITY; Tumors; Tumors of the urinary system; United States; Urinary tract. Prostate gland; Urogenital System - radiation effects; United States; Clinical trial; Dose escalation; Proton radiation; Prostate cancer; Dose–volume histogram; Human; Urinary system disease; Prostate disease; Male; Malignant tumor; Proton therapy; Radiotherapy; Increasing dose; Conformal radiotherapy; Cancerology; Complication; Male genital diseases; Dose-volume histogram; Cancer
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2010.06.047

Purpose Several randomized trials have shown a benefit of dose escalation to 78 to 79 Gy for men treated with external radiation for localized prostate cancer. Single-institution data suggest a benefit with even higher doses. American College of Radiology 03-12 is a Phase II trial testing the safety and efficacy of 82 GyE (Gray equivalent) delivered with conformal proton radiation. Methods and Materials From 2003–2006, 85 men with localized prostate cancer were accrued to American College of Radiology 03-12. Eighty-four were eligible for analysis. They were treated with conformal proton radiation alone to a total dose of 82 GyE. The study was designed to test whether the rate of 18-month Grade 3+ late toxicity was greater than 10%. Results The median follow-up was 31.6 months. Regarding treatment-related acute toxicity, there were 39 Grade 1 cases (46%), 19 Grade 2 cases (23%) and 2 Grade 3 cases (2%). Regarding genitourinary/gastrointestinal toxicity, there were 42 Grade 1 cases (50%), 12 Grade 2 cases (14%) and 1 Grade 3 case (1%). Regarding late toxicity, there were 28 Grade 1 cases (33%), 22 Grade 2 cases (26%), 6 Grade 3 cases (7%), and 1 Grade 4 case (1%). The late genitourinary/gastrointestinal rates were the same. The estimated rate of Grade 3+ late toxicity at 18 months was 6.08%. Conclusions Although not free of late toxicity, 82 GyE at 2 GyE per fraction delivered with conformal proton radiation did not exceed the late morbidity target tested in this trial. There was sufficient morbidity, however, that this may be the maximal dose that can be delivered safely with this technique and fractionation.