Dataset Information

Long-term results of a phase II study of hypofractionated proton therapy for prostate cancer: moderate versus extreme hypofractionation.

ABSTRACT: BACKGROUND:We performed a prospective phase II study to compare acute toxicity among five different hypofractionated schedules using proton therapy. This study was an exploratory analysis to investigate the secondary end-point of biochemical failure-free survival (BCFFS) of patients with long-term follow-up. METHODS:Eighty-two patients with T1-3bN0M0 prostate cancer who had not received androgen-deprivation therapy were randomized to one of five arms: Arm 1, 60 cobalt gray equivalent (CGE)/20 fractions/5?weeks; Arm 2, 54 CGE/15 fractions/5?weeks; Arm 3, 47 CGE/10 fractions/5?weeks; Arm 4, 35 CGE/5 fractions/2.5?weeks; and Arm 5, 35 CGE/5 fractions/4?weeks. In the current exploratory analysis, these ardms were categorized into the moderate hypofractionated (MHF) group (52 patients in Arms 1-3) and the extreme hypofractionated (EHF) group (30 patients in Arms 4-5). RESULTS:At a median follow-up of 7.5?years (range, 1.3-9.6?years), 7-year BCFFS was 76.2% for the MHF group and 46.2% for the EHF group (p?=?0.005). The 7-year BCFFS of the MHF and EHF groups were 90.5 and 57.1% in the low-risk group (p?=?0.154); 83.5 and 42.9% in the intermediate risk group (p?=?0.018); and 41.7 and 40.0% in the high risk group (p?=?0.786), respectively. Biochemical failure tended to be a late event with a median time to occurrence of 5?years. Acute GU toxicities were more common in the MHF than the EHF group (85 vs. 57%, p?=?0.009), but late GI and GU toxicities did not differ between groups. CONCLUSIONS:Our results suggest that the efficacy of EHF is potentially inferior to that of MHF and that further studies are warranted, therefore, to confirm these findings. TRIAL REGISTRATION:This study is registered at ClinicalTrials.gov, no. NCT01709253 ; registered October 18, 2012; retrospectively registered).

SUBMITTER: Ha B

PROVIDER: S-EPMC6327508 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:PurposeTo explore whether the rectal distension-mediated technique, harnessing human physiology to achieve intrafractional prostate motion mitigation, enables urethra sparing by inverse dose painting, thus promoting dose escalation with extreme hypofractionated stereotactic ablative radiotherapy (SABR) in prostate cancer.Materials and methodsBetween June 2013 and December 2018, 444 patients received 5 × 9 Gy SABR over 5 consecutive days. Rectal distension-mediated SABR was employed via insertion of a 150-cm3 air-inflated endorectal balloon. A Foley catheter loaded with 3 beacon transponders was used for urethra visualization and online tracking. MRI-based planning using Volumetric Modulated Arc Therapy - Image Guided Radiotherapy (VMAT-IGRT) with inverse dose painting was employed in delivering the planning target volume (PTV) dose and in sculpting exposure of organs at risk (OARs). A 2-mm margin was used for PTV expansion, reduced to 0 mm at the interface with critical OARs. All plans fulfilled Dmean ≥45 Gy. Target motion ≥2 mm/5 s motions mandated treatment interruption and target realignment prior to completion of the planned dose delivery.ResultsPatient compliance to the rectal distension-mediated immobilization protocol was excellent, achieving reproducible daily prostate localization at a patient-specific retropubic niche. Online tracking recorded ≤1-mm intrafractional target deviations in 95% of treatment sessions, while target realignment in ≥2-mm deviations enabled treatment completion as scheduled in all cases. The cumulative incidence rates of late grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxicities were 5.3% and 1.1%, respectively. The favorable toxicity profile was corroborated by patient-reported quality of life (QOL) outcomes. Median prostate-specific antigen (PSA) nadir by 5 years was 0.19 ng/ml. The cumulative incidence rate of biochemical failure using the Phoenix definition was 2%, 16.6%, and 27.2% for the combined low/favorable-intermediate, unfavorable intermediate, and high-risk categories, respectively. Patients with a PSA failure underwent a 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA) scan showing a 20.2% cumulative incidence of intraprostatic relapses in biopsy International Society of Urological Pathology (ISUP) grade ≥3.ConclusionThe rectal distension-mediated technique is feasible and well tolerated. Dose escalation to 45 Gy with urethra-sparing results in excellent toxicity profiles and PSA relapse rates similar to those reported by other dose-escalated regimens. The existence of intraprostatic recurrences in patients with high-risk features confirms the notion of a high α/β ratio in these phenotypes resulting in diminished effectiveness with hypofractionated dose escalation.

Project description:IntroductionThere has been an interest in studying the efficacy of extreme hypofractionation in low and intermediate risk prostate cancer utilising the low alpha/beta ratio of prostate. Its role in high-risk and node-positive prostate cancer, however, is unknown. We hypothesise that a five-fraction schedule of extreme hypofractionation will be non-inferior to a moderately hypofractionated regimen over 5 weeks in efficacy and will have acceptable toxicity and quality of life while reducing the cost implications during treatment.Methods and analysisThis is an ongoing, non-inferiority, multicentre, randomised trial (NCT03561961) of two schedules for National Cancer Control Network high-risk and/or node-positive non-metastatic carcinoma of the prostate. The standard arm will be a schedule of 68 Gy/25# over 5 weeks while the test arm will be extremely hypofractionated radiotherapy with stereotactic body radiation therapy to 36.25 Gy/5# (7 to 10 days). The block randomisation will be stratified by nodal status (N0/N+), hormonal therapy (luteinizing hormone-releasing hormone therapy/orchiectomy) and centre. All patients will receive daily image-guided radiotherapy.The primary end point is 4-year biochemical failure free survival (BFFS). The power calculations assume 4-year BFFS of 80% in the moderate hypofractionation arm. With a 5% one-sided significance and 80% power, a total of 434 patients will be randomised to both arms equally (217 in each arm). The secondary end points include overall survival, prostate cancer specific survival, acute and late toxicities, quality of life and out-of-pocket expenditure.DiscussionThe trial aims to establish a therapeutically efficacious and cost-efficient modality for high-risk and node-positive prostate cancer with an acceptable toxicity profile. Presently, this is the only trial evaluating and answering such a question in this cohort.Ethics and disseminationThe trial has been approved by IEC-III of Tata Memorial Centre, Mumbai.Trial registration numberRegistered with CTRI/2018/05/014054 (http://ctri.nic.in) on 24 May 2018.

Dataset Information

Long-term results of a phase II study of hypofractionated proton therapy for prostate cancer: moderate versus extreme hypofractionation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets