Department of Radiation Oncology, Tata Memorial Centre, Parel, Mumbai, India.
Department of Radiation Oncology, Tata Memorial Centre, Parel, Mumbai, India.
Int J Radiat Oncol Biol Phys. 2016 Jan 1;94(1):60-66. doi: 10.1016/j.ijrobp.2015.09.010. Epub 2015 Sep 16.
The purpose of this study was to assess feasibility, clinical outcomes, and toxicity in patients with bladder cancer treated with adaptive, image guided radiation therapy (IGRT) for bladder preservation as a part of trimodality treatment. The role of dose escalation was also studied.
Forty-four patients with localized bladder cancer were enrolled in a prospective study. They underwent maximal safe resection of bladder tumor and concurrent platinum-based chemotherapy. Patients with large tumors were offered induction chemotherapy. Radiation therapy planning was done using either 3 (n=34) or 6 (n=10) concentrically grown planning target volumes (PTV). Patients received 64 Gy in 32 fractions to the whole bladder and 55 Gy to the pelvic nodes and, if appropriate, a simultaneous integrated boost to the tumor bed to 68 Gy (equivalent dose for 2-Gy fractions assuming α/β of 10 [EQD2]10 = 68.7 Gy). Daily megavoltage (MV) imaging helped to choose the most appropriate PTV encompassing bladder for the particular day (using plan-of-the-day approach).
Most patients (88%) had T2 disease. Sixteen patients (36%) received neoadjuvant chemotherapy. A majority of the patients (73%) received prophylactic nodal irradiation, whereas 55% of the patients received escalated dose to the tumor bed. With a median follow-up of 30 months, the 3-year locoregional control (LRC), disease-free survival, and overall survival (OS) were 78%, 66%, and 67%, respectively. The bladder preservation rate was 83%. LRC (87% vs 68%, respectively, P=.748) and OS (74% vs 60%, respectively, P=.36) rates were better in patients receiving dose escalation. Instances of acute and late Radiation Therapy Oncology Group (RTOG) grade 3 genitourinary toxicity was seen in 5 (11%) and 2 (4%) patients, respectively. There was no acute or late RTOG grade 3 or higher gastrointestinal toxicity.
Adaptive IGRT using plan-of-the-day approach for bladder preservation is clinically feasible, with good oncological outcomes and low rates of acute and late toxicities. Dose escalation is safe and possibly improves outcomes in bladder preservation.
本研究旨在评估接受自适应、图像引导放疗（IGRT）治疗的膀胱癌患者的可行性、临床结果和毒性，该治疗是三联疗法的一部分，目的是保留膀胱。同时还研究了剂量递增的作用。
44 名局部膀胱癌患者入组前瞻性研究。他们接受了最大限度的安全膀胱肿瘤切除术和铂类药物化疗。对于大肿瘤患者，提供了诱导化疗。使用 3 个（n=34）或 6 个（n=10）同心生长的计划靶区（PTV）进行放疗计划。所有患者均接受 64 Gy/32 次全膀胱照射，55 Gy/32 次盆腔淋巴结照射，如果合适，同时对肿瘤床进行同步整合增敏照射至 68 Gy（2-Gy 分次数等效剂量假设 α/β 为 10 [EQD2]10 = 68.7 Gy）。每天的兆伏（MV）成像有助于为特定日选择最适合的包含膀胱的 PTV（使用每日计划方法）。
大多数患者（88%）患有 T2 期疾病。16 名患者（36%）接受了新辅助化疗。大多数患者（73%）接受了预防性淋巴结照射，而 55%的患者接受了肿瘤床的递增剂量照射。中位随访 30 个月后，3 年局部区域控制（LRC）、无疾病生存率和总生存率（OS）分别为 78%、66%和 67%。膀胱保留率为 83%。接受剂量递增的患者 LRC（87%比 68%，P=.748）和 OS（74%比 60%，P=.36）率更好。急性和晚期放射治疗肿瘤学组（RTOG）3 级泌尿生殖系统毒性分别发生在 5 名（11%）和 2 名（4%）患者中。没有急性或晚期 RTOG 3 级或更高的胃肠道毒性。
使用每日计划方法进行自适应 IGRT 用于膀胱保留是临床可行的，具有良好的肿瘤学结果和低急性和晚期毒性发生率。剂量递增是安全的，并且可能改善膀胱保留的治疗效果。
