Tonetto Fabrizio, Magli Alessandro, Moretti Eugenia, Guerini Andrea Emanuele, Tullio Annarita, Reverberi Chiara, Ceschia Tino, Spiazzi Luigi, Titone Francesca, Prisco Agnese, Signor Marco Andrea, Buglione Michela, De Giorgi Gioacchino, Trovò Marco, Triggiani Luca
Department of Radiation Oncology, University General Hospital, 33100 Udine, Italy.
Department of Medical Physics, University General Hospital, 33100 Udine, Italy.
J Clin Med. 2022 Nov 23;11(23):6913. doi: 10.3390/jcm11236913.
Objective: This paper illustrates the results of a mono-institutional registry trial, aimed to test whether gastrointestinal (GI) and genitourinary (GU) toxicity rates were lower in localized prostate cancer patients treated with image-guided volumetric modulated arc therapy (IG-VMAT) compared to those treated with IG-3D conformal radiation therapy (IG-3DCRT). Materials and Methods: Histologically proven prostate cancer patients with organ-confined disease, treated between October 2008 and September 2014 with moderately hypofractionated radiotherapy, were reviewed. Fiducial markers were placed in the prostate gland by transrectal ultrasound guide. The prescribed total dose was 70 Gy in 28 fractions. The mean and median dose volume constraints for bladder and rectum as well as total volume of treatment were analyzed as potentially prognostic factors influencing toxicity. The Kaplan−Meier method was applied to calculate survival. Results: Overall, 83 consecutive patients were included. Forty-two (50.6%) patients were treated with 3D-CRT and 41 (49.4%) with the VMAT technique. The median follow-up for toxicity was 77.26 months for the whole cohort. The VMAT allowed for a dose reduction to the rectum and bladder for the large majority of the considered parameters; nonetheless, the only parameter correlated with a clinical outcome was a rectal dose limit V66 > 8.5% for late GI toxicity G ≥ 2 (p = 0.045). Rates of G ≥ 2 toxicities were low among the whole cohort of these patients treated with IGRT. The analysis for rectum dose volume histograms (DVHs) showed that a severe (grade ≥ 2) late GI toxicity was related with the rectal dose limit V66 > 8.5% (p = 0.045). Conclusions: This study shows that moderate hypofractionation is feasible and safe in patients with intermediate and high-risk prostate cancer. Daily IGRT may decrease acute and late toxicity to organs at risk and improve clinical benefit and disease control rate, cutting down the risk of PTV geographical missing. The adoption of VMAT allows for promising results in terms of OAR sparing and a reduction in toxicity that, also given the small sample, did not reach statistical significance.
本文阐述了一项单机构注册试验的结果，旨在测试与接受影像引导三维适形放射治疗（IG-3DCRT）的局限性前列腺癌患者相比，接受影像引导容积调强弧形治疗（IG-VMAT）的患者胃肠道（GI）和泌尿生殖系统（GU）毒性发生率是否更低。材料与方法：回顾了2008年10月至2014年9月期间接受中度低分割放疗的组织学确诊的器官局限性前列腺癌患者。通过经直肠超声引导在前列腺内放置基准标记物。处方总剂量为70 Gy，分28次照射。分析膀胱和直肠的平均及中位剂量体积限制以及治疗总体积，将其作为影响毒性的潜在预后因素。采用Kaplan-Meier法计算生存率。结果：总体而言，共纳入83例连续患者。42例（50.6%）患者接受3D-CRT治疗，41例（49.4%）患者接受VMAT技术治疗。整个队列毒性的中位随访时间为77.26个月。对于大多数考虑的参数，VMAT可降低直肠和膀胱的剂量；尽管如此，与临床结果相关的唯一参数是晚期GI毒性G≥2时直肠剂量限制V66＞8.5%（p = 0.045）。在这些接受IGRT治疗的患者整个队列中，G≥2毒性的发生率较低。直肠剂量体积直方图（DVH）分析表明，严重（≥2级）晚期GI毒性与直肠剂量限制V66＞8.5%相关（p = 0.045）。结论：本研究表明，中度低分割放疗在中高危前列腺癌患者中是可行且安全的。每日IGRT可降低对危及器官的急性和晚期毒性，提高临床获益和疾病控制率，降低计划靶体积（PTV）几何遗漏的风险。VMAT的应用在危及器官（OAR）保护和毒性降低方面取得了有前景的结果，不过鉴于样本量小，未达到统计学意义。
