Dynamic conformal arc radiotherapy with rectum hollow-out technique for localized prostate cancer

Purpose: To report the feasibility of dynamic conformal arc radiotherapy with rectum hollow-out technique (DCAT-HO) for localized prostate cancer. Methods and materials: Between October 2000 and April 2007, 204 patients with clinically localized or locally advanced prostate cancer were treated with DCAT-HO. All patients were given neoadjuvant total androgen deprivation (AD) therapy (median 6 months, range 2-27 months). All patients with T3 or T4 stage received post-irradiation AD for 24 months. A total of 128 patients (63%) were treated with 70 Gy, and 76 patients (37% were treated with 74 Gy. Acute and late toxicities were scored by the Radiation therapy Oncology Group morbidity grading scales. PSA relapse was defined as three successive PSA elevations after a post-treatment nadir. The median follow-up was 37 months. Result : Both the acute Grade 2 rectal and urinary toxicities were 1.0%, and no patients experienced acute Grade 3 or higher symptoms. The 3-year rate of both >= late Grade 2 rectal and urinary toxicities were 34%. The 3-year PSA relapse-free survival for low, intermediate, and high-risk group patients treated with 70 Gy were 54%, 75%, and 87%, respectively. Conclusions: These findings demonstrate the feasibility of DCAT-HO in a large number of patients with shore follow-up. DCAT-HO reduced the volume of the rectum exposed to higher doses and this led to all overall reduction in late rectal toxicity. (C) 2008 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 90 (2009) 346-352