Drodge C S, Boychak O, Patel S, Usmani N, Amanie J, Parliament M B, Murtha A, Field C, Ghosh S, Pervez N
At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB. ; Currently: Department of Radiation Oncology, Eastern Health, Dr. H. Bliss Murphy Cancer Centre, St. John's, NL.
At the time of the study: Division of Radiation Oncology, Cross Cancer Institute, Edmonton, AB.
Curr Oncol. 2015 Apr;22(2):e76-84. doi: 10.3747/co.22.2247.
Dose-escalated hypofractionated radiotherapy (hfrt) using intensity-modulated radiotherapy (imrt), with inclusion of the pelvic lymph nodes (plns), plus androgen suppression therapy (ast) in high-risk prostate cancer patients should improve patient outcomes, but acute toxicity could limit its feasibility.
Our single-centre phase ii prospective study enrolled 40 high-risk prostate cancer patients. All patients received hfrt using imrt with daily mega-voltage computed tomography imaging guidance, with 95% of planning target volumes (ptv68 and ptv50) receiving 68 Gy and 50 Gy (respectively) in 25 daily fractions. The boost volume was targeted to the involved plns and the prostate (minus the urethra plus 3 mm and minus 3 mm from adjacent rectal wall) and totalled up to 75 Gy in 25 fractions. Acute toxicity scores were recorded weekly during and 3 months after radiotherapy (rt) administration.
For the 37 patients who completed rt and the 3-month follow-up, median age was 65.5 years (range: 50-76 years). Disease was organ-confined (T1c-T2c) in 23 patients (62.1%), and node-positive in 5 patients (13.5%). All patients received long-term ast. Maximum acute genitourinary (gu) and gastrointestinal (gi) toxicity peaked at grade 2 in 6 of 36 evaluated patients (16.6%) and in 4 of 31 evaluated patients (12.9%) respectively. Diarrhea and urinary frequency were the chief complaints. Dose-volume parameters demonstrated no correlation with toxicity. The ptv treatment objectives were met in 36 of the 37 patients.
This hfrt dose-escalation trial in high-risk prostate cancer has demonstrated the feasibility of administering 75 Gy in 25 fractions with minimal acute gi and gu toxicities. Further follow-up will report late toxicities and outcomes.
对于高危前列腺癌患者，采用调强放疗（IMRT）进行剂量递增的低分割放疗（hfrt），包括盆腔淋巴结（PLNs），再加上雄激素抑制治疗（AST），应能改善患者预后，但急性毒性可能会限制其可行性。
我们的单中心II期前瞻性研究纳入了40例高危前列腺癌患者。所有患者均接受基于IMRT的hfrt，并采用每日兆伏级计算机断层扫描成像引导，计划靶体积（PTV68和PTV50）的95%分别在25次分割中接受68 Gy和50 Gy照射。推量体积针对受累的PLNs和前列腺（尿道除外加3 mm，距相邻直肠壁减3 mm），在25次分割中总计达75 Gy。在放疗（RT）期间及放疗后3个月每周记录急性毒性评分。
对于完成RT及3个月随访的37例患者，中位年龄为65.5岁（范围：50 - 76岁）。23例患者（62.1%）疾病局限于器官（T1c - T2c），5例患者（13.5%）有淋巴结转移。所有患者均接受长期AST。在36例接受评估的患者中，6例（16.6%）的最大急性泌尿生殖系统（GU）毒性和在31例接受评估的患者中4例（12.9%）的最大急性胃肠道（GI）毒性在2级达到峰值。腹泻和尿频是主要主诉。剂量 - 体积参数与毒性无相关性。37例患者中有36例达到PTV治疗目标。
这项针对高危前列腺癌的hfrt剂量递增试验证明了在25次分割中给予75 Gy且急性GI和GU毒性最小的可行性。进一步随访将报告晚期毒性和预后情况。
