Two Versus Five-Fraction Magnetic Resonance-Guided Adaptive Radiotherapy with DOminant-TArgeted Boost in Localized Prostate Cancer (DOTA-2): Interim Acute Toxicity Analysis of the Phase II Randomised Trial

IF 3 3区医学 Q2 ONCOLOGY

Clinical oncology Pub Date : 2026-03-01 Epub Date: 2025-12-27 DOI:10.1016/j.clon.2025.104029

R. Romrattaphan, P. Dankulchai, T. Prasartseree, W. Sittiwong, W. Thaweerat, S. Junlabut, S. Nitipitch

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引用次数: 0

Abstract

Aims

DOminant-TArgeted Boost in Localized Prostate Cancer (DOTA-2) is a phase II randomised controlled trial comparing two ultra-hypofractionated radiotherapy with dominant intraprostatic lesion (DIL) boost: 26 Gy/2F, 32 Gy to DIL vs 36.25 Gy/5F, 40 Gy to DIL, without androgen deprivation therapy (ADT), for prostate cancer.

Materials and methods

Patients with low- to favourable-intermediate-risk prostate cancer were randomly assigned to receive either 2 fractions or 5 fractions. Magnetic resonance-guided adaptive radiotherapy (MRgART) was delivered using the Unity® MR-Linac with the adapt-to-shape workflow for every fraction. The primary endpoint was cumulative grade ≥2 acute genitourinary (GU) and gastrointestinal (GI) toxicity. Secondary endpoints included quality of life in the urinary and sexual domains. An interim analysis of acute GU and GI toxicities was conducted on the first 22 patients from the total planned cohort of 44.

Results

Patients were randomly assigned to either the 2-fraction (N = 10) or 5-fraction stereotactic body radiotherapy (SBRT) (N = 12), stratified by risk group, prostate volume, and DIL location. The median follow-up time was 16 weeks. The cumulative worst acute grade ≥2 GU toxicity was reported in 2/10 (20%) patients in the 2-fraction group vs 4/12 (33.3%) in the 5-fraction group (P = 0.48), with no cases of grade ≥3 acute GU toxicity. No grade ≥2 acute GI toxicity was observed in either arm. The two groups had no significant difference in International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-5) scores.

Conclusion

Two-fraction SBRT with a DIL boost, delivered using MRgART without ADT, demonstrated acceptable acute GU and GI toxicity in this interim analysis, suggesting the feasibility of continuing the investigation.

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二段式与五段式磁共振引导适应放疗对局部前列腺癌（DOTA-2）的优势靶向增强：中期急性毒性分析的II期随机试验。

目的：局部前列腺癌的显性靶向增强（DOTA-2）是一项II期随机对照试验，比较两种超低分割放疗对显性前列腺内病变（DIL）的增强：26 Gy/2F， 32 Gy对DIL和36.25 Gy/5F， 40 Gy对DIL，不进行雄激素剥夺治疗（ADT），治疗前列腺癌。材料和方法：低至中危前列腺癌患者随机分为2组和5组。磁共振引导的自适应放疗（MRgART）使用Unity®MR-Linac进行，每个部分都具有自适应形状的工作流程。主要终点是累积≥2级急性泌尿生殖系统（GU）和胃肠道（GI）毒性。次要终点包括泌尿和性方面的生活质量。对44例计划队列中的前22例患者进行了急性GU和GI毒性的中期分析。结果：根据危险组、前列腺体积和DIL位置，患者被随机分配到2分位（N = 10）或5分位立体定向放射治疗（SBRT）（N = 12）。中位随访时间为16周。2分组中有2/10（20%）的患者报告了最严重的急性≥2级GU毒性，而5分组中有4/12 (33.3%)(P = 0.48)，没有病例发生≥3级急性GU毒性。两组均未观察到≥2级急性胃肠道毒性。两组在国际前列腺症状评分（IPSS）、国际勃起功能指数（IIEF-5）评分上无显著差异。结论：在这个中期分析中，使用MRgART（不含ADT）进行DIL增强的二组分SBRT显示出可接受的急性GU和GI毒性，表明继续研究的可行性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Clinical oncology 医学-肿瘤学

CiteScore

5.20

自引率

8.80%

发文量

332

审稿时长

40 days

期刊介绍： Clinical Oncology is an International cancer journal covering all aspects of the clinical management of cancer patients, reflecting a multidisciplinary approach to therapy. Papers, editorials and reviews are published on all types of malignant disease embracing, pathology, diagnosis and treatment, including radiotherapy, chemotherapy, surgery, combined modality treatment and palliative care. Research and review papers covering epidemiology, radiobiology, radiation physics, tumour biology, and immunology are also published, together with letters to the editor, case reports and book reviews.