Ablative Radiotherapy for Unfavorable Prostate Tumors (ABRUPT): Analysis of Toxicity and Quality of Life from a Prospective Study.

AIM: To assess late gastrointestinal (GI) and genitourinary (GU) side effects in patients with organ-confined unfavorable prostate cancer (PCa) treated with single dose ablative radiotherapy (SDRT). METHODS: Thirty patients enrolled in a single-arm prospective trial received 24 Gy SDRT to the whole prostate with urethra sparing and organ motion control delivered on a Linac platform with a 10MV FFF single partial arc. ADT was prescribed as per standard of care. Treatment-related acute and late GU and GI toxicities (CTCAE_v5 scale) and QoL outcomes (EORTC QLQ-PR25/C30, IPSS) were assessed at different time points. Minimal Important Difference (MID) was established as a change of >0.5 pooled SD from baseline. Statistical analysis included ANOVA test and logistic regression. RESULTS: Median follow-up was 18 months (range, 6-31), with no ≥G3 late side effects observed. G2 late GI and G2 late GU toxicities occurred in 1 and 2 patients, respectively. GI toxicity of any grade correlated with maximum rectal dose (P=0.021). Lower baseline QoL score (P=0.025), higher baseline IPSS score (P=0.049), acute GU toxicity (P=0.029), and acute urinary domain MID (P=0.045) predicted GU toxicity of any grade. In MVA, only baseline QoL score (OR, 0.95, P=0.031) and acute GU toxicity (OR, 8.4, P=0.041) remained significant. Significant QoL change was observed only in the urinary domain (P=0.005), with a median increase from 8 to 17. Late urinary MID correlated with acute urinary MID (P=0.003), acute QoL MID (P=0.029), acute GU toxicity (P=0.030), and lower baseline urinary score (P=0.033). In MVA, only acute urinary MID predicted late urinary MID (OR, 9.7, P=0.035). CONCLUSION: Our findings provide promising data on the feasibility and safety of 24 Gy whole gland SDRT with urethra sparing and organ motion control, in association with ADT and an adequate prophylactic medication, in organ confined unfavorable PCa. Long-term follow-up is needed to confirm these results.

Toxicity profile and Patient-Reported outcomes following salvage Stereotactic Ablative Radiation Therapy to the prostate Bed: The POPART multicentric prospective study.

Background: While SBRT to the prostate has become a valuable option as a radical treatment, limited data support its use in the postoperative setting. Here, we report the updated results of the multicentric Post-Prostatectomy Ablative Radiation Therapy (POPART) trial, investigating possible predictors of toxicities and patient-reported outcomes. Methods: Patients with PSA levels between 0.1-2.0 ng/mL after radical prostatectomy received Linac-based SBRT to the prostate bed in five fractions every other day for a total dose of 32.5 Gy (EQD21.5 = 74.3 Gy). Late toxicity was assessed using CTCAE v.5 scale, while EPIC-CP, ICIQ-SF, IIEF 5 questionnaires and PSA levels measured quality of life and biochemical control. Pre- and post-treatment scores were compared using a paired t-test, with MID established at > 0.5 pooled SD from the baseline. A logistic regression analysis was performed to evaluate potential associations between specific patient/tumor/treatment factors and outcome deterioration. Results: From April 2021 to April 2023 a total of 50 pts were enrolled and treated. Median follow-up was 12.2 (3-27) months. No late ≥ G2 GI or GU toxicity was registered. Late G1 urinary and rectal toxicities occurred in 46 % and 4 % of patients, respectively. Among 47 patients completing all EPIC-CP domains, four (9 %) showed worsened QoL, and eleven (26 %) developed erectile dysfunction correlating with PTV D2% (P = 0.032). At Multivariate analysis bladder wall D10cc independently correlated with late G1 GU toxicity (P = 0.034). Median post-treatment PSA nadir was 0.04 ng/mL (0.00 - 0.84). At the last follow-up, six patients presented with biochemical failure, including two nodal relapses. Conclusions: Our findings show that post-prostatectomy SBRT did not result in increased toxicity nor a significant decline in QoL measures, thus showing that it can be safely extended to the postoperative setting. Long-term follow-up and randomized comparisons with different RT schedules are needed to validate this approach.

Short-term pain control after palliative radiotherapy for uncomplicated bone metastases: a prospective cohort study.

This study aimed at evaluating the efficacy of different radiotherapy (RT) fractionation regimens in managing uncomplicated painful bone metastases (BM) and identifying predictive factors for pain control. Patients with 1 to 4 symptomatic BM from any primary solid tumors and a life expectancy exceeding 3 months were included in the study and received palliative RT, with SBRT restricted in the context of oligometastatic disease or in patients with good prognosis. Pain analysis using the Brief Pain Inventory (BPI) tool was conducted at baseline, 1 and 3 months after RT. Analgesic intake was recorded as morphine-equivalent doses (OME). Pain response was assessed using the International Consensus on Palliative Radiotherapy Endpoint (ICPRE). Multivariate logistic regression analyzed patient-related, tumor-related, and treatment-related factors predicting BM pain control at 3 months post-RT. From Feb 2022 to Feb 2023, 44 patients with 65 symptomatic BM were investigated. Breast (32%) and lung (24%) tumors were the most common primary tumors. Treatment plans included 3DCRT (60%) and VMAT (40%), with a median biological effective dose for tumors (BED) of 29 Gy [14-108]. All patients completed the 3-month follow-up. Pain response rates were 62% at 1 month and 60% at 3 months. Responders had better PS ECOG scores (67%; P = 0.008) and received active systemic therapies (67%: P = 0.036). Non-responders had lower pretreatment BPI (mean: 13.7 vs. 58.2; P = 0.032), with significantly higher values after 1 month (mean: 9.1 vs. 5.3, P = 0.033). Baseline BPI (OR: 1.17; 95% CI: 1.032-1.327; P = 0.014) and BPI at 1 month (OR: 0.83; 95% CI: 0.698-0.976; P = 0.025) were independent predictors of pain response at 3 months. Our findings show that palliative RT ensured short-term pain control in patients with BM, regardless of tumor type and dose-fractionation regimen. A larger sample size and a longer follow-up could potentially identify which patients are likely to benefit most from RT, and which fractionation might be indicated for achieving a durable pain relief. A multidisciplinary approach is paramount to provide a better care to BM patients.