Preoperative brachytherapy of early-stage cervical cancer: A multicenter study by the SFRO brachytherapy group.

OBJECTIVE: To report the results of a multicenter cohort of preoperative brachytherapy (PBT) for treatment of early-stage cervical cancer (ESCC). METHODS: A retrospective analysis was conducted among five French comprehensive cancer centers on behalf of the SFRO Brachytherapy Group to examine the outcome of patients with ESCC who received PBT between 2001 and 2019 because of adverse prognostic factors (tumor size >2 cm, presence of lymphovascular invasion, adenocarcinoma).Brachytherapy was followed 4-8 weeks later by surgery. Local relapse free, distant metastasis-free survival, disease-free, and overall survival and adverse effects were examined. Uni- and multivariate analyses were conducted looking for oncological prognostic factors. RESULTS: A total of 451 patients were identified, with a mean tumor size of 24.7 mm. Adenocarcinoma accounted for 43.5% of cases, and lympho-vascular space invasion (LVSI) was present in 15.7%. A complete histological response was observed in 69.6%. With a mean follow-up of 75.4 months, DFS, LRFS, and OS rates at five years were 88% [95% CI (84-91), 98% [95% CI (96-99), and 92% [95% CI (87-95)], respectively. At the last follow-up, 8.2% of patients had died, including 31 (6.8%) from cervical cancer. Severe side effects range from 1.1% to 2%. At multivariate analysis, adenocarcinoma histological type, tumor size ≥2 cm, and the presence of residual tumors were prognosticators for DFS and DMFS. CONCLUSION: PBT shows excellent oncological outcomes in this cohort of patients with adverse histoprognostic factors. Favorable survival rates and low complications rates were observed, supporting this strategy in the management of ESCC.

The current landscape of stereotactic body radiation therapy for metastatic castration-resistant prostate cancer.

BACKGROUND: The onset of castration-resistance is associated with dismal outcomes in patients with prostate cancer (PCa). Metastasis directed therapy has been investigated in multiple disease settings and may improve outcomes in selected patients. Our systematic review aims to summarize evidence with stereotactic body radiotherapy (SBRT) in castration-resistant prostate cancer (CRPC). METHODS: The literature search was performed on March 2024, on Pubmed, using the keywords "SBRT" AND "CRPC", and "stereotactic ablative radiotherapy (SABR)" AND "CRPC". This search retrieved a total of 108 articles, 19 were included. RESULTS: The literature is largely dominated by retrospective series. In men with metachronous oligoprogression, SBRT with androgen receptor pathway inhibitor significantly increased progression-free survival (PFS) including biochemical progression-free survival in a randomized phase II trial (hazard ratio of 0.35, p < 0.001). In patients continuing ADT, the bPFS ranged between 9.5 months to 17.9 months, and next systemic treatment-free survival (NEST-FS) reached up to 2 years. In men with induced oligoprogression, SBRT enabled NEST-FS up to 3 years. SBRT was well tolerated, with less than 5% grade 3 toxicity reported across studies. CONCLUSION: In the population of patients with oligometastatic CRPC, SBRT enables long-term biochemical response and PFS. In the oligoprogressive setting, SBRT could be integrated to prolong the duration and efficacy of systemic therapies. Nevertheless, the level of evidence remains very low and inclusion within prospective trials remain the preferred option for this population of patients.

Post- versus intra-operative implant for breast cancer interstitial brachytherapy: How to choose?

Purpose: Breast brachytherapy (BB) represents an important radiation therapy modality in modern breast cancer treatments. Currently, BB is mainly used for accelerated partial breast irradiation (APBI), local boost after whole breast radiation therapy (WBRT), and as salvage re-irradiation after second lumpectomy (APBrl). Two multi-catheter interstitial brachytherapy (MIB) techniques can be offered: intra-operative (IOB) and post-operative (POB) brachytherapy. The aim of this article was to summarize current available data on these two different brachytherapy approaches for breast cancer. Material and methods: A literature search was performed, and different experiences published by BB expert teams were analyzed and compared. These two different brachytherapy approaches for breast cancer have also been presented and discussed during meetings of the GEC-ESTRO BCWG. In addition, expert recommendations were defined. Results: A comprehensive description and practical comparison of both the techniques, i.e., IOB and POB, considering the latest available published data were presented. Different technical, logistic, and clinical aspects of both the methods were thoroughly examined and analyzed. This detailed comparison of the two breast brachytherapy techniques was supported by scientific data from extensive experience of experts, facilitating an objective analysis that, to our knowledge, has not been previously published. Conclusions: Based on the comprehensive analysis of both the brachytherapy techniques available, this article serves as a valuable resource to guide breast teams in selecting the optimal BB technique (POB or IOB), considering hospital environment, multi-disciplinary collaboration, and patient logistics.

Very accelerated partial breast irradiation in 1 or 2 days: Late toxicity and early oncological outcome of the GEC-ESTRO VAPBI cohort.

PURPOSE: To analyze late toxicity after very accelerated partial breast irradiation (VAPBI) for low-risk breast cancer. MATERIALS: Methods: In this retrospective, observational, international multicenter study (HDH F20220713143949), patients with low-risk breast cancer underwent lumpectomy + vAPBI (high-dose rate multicatheter interstitial brachytherapy-MIBT). VAPBI was performed with 4(4x6.2 Gy/2d), 3(3x7.45 Gy/2d) or 1 fraction (1x16Gy or 1x18Gy/1d). Primary endpoint was late toxicity. Secondary endpoints were cumulative incidence of breast cancer local relapse (LR) and distant metastatic relapse (DMR) and specific (SS) and overall (OS) survivals. Prognostic factors for late toxicity were analyzed. RESULTS: From 01/2012 to 06/2022, 516 pts with early breast cancer were enrolled. Median follow-up was 44 months [95 %CI 39-46]. Median age was 71 years [40-100]. Median tumor size was 12 mm [1-35]. VAPBI delivered 1, 3 and 4 fractions for 205pts (39.7 %), 167pts (32.4 %) and 144pts (28 %) respectively. 221 late toxicity events were observed in 168pts (32.6 %) (Fibrosis, dyschromia, pain and telangiectasia). Grade 2 and 3 late toxicities were observed in 7.2 and 0.6 % respectively (no G4) with no difference between 1 and ≥ 2 treatment days. CTV > 50 cc (p = 0.007) and V150 > 40 % (p = 0.027) were prognostic factors for G ≥ 2 late toxicity. Four-year cumulative incidence rates of LR and DMR were 2 % [95 %CI 0-3] and 1 % [95 %CI 0-2] respectively. CONCLUSIONS: VAPBI based on 1 or ≥ 2 days of MIBT represents an attractive de-escalation of irradiation approach for low-risk breast cancer. Late toxicity profile appears acceptable while early oncological outcome shows encouraging local control. Longer follow-up is warranted in order to confirm these preliminary results.

Salvage brachytherapy for second ipsilateral breast tumor event: Relating dosimetric analysis to late side effects.

PURPOSE: For second ipsilateral breast tumor event (2ndIBTE), conservative treatment (CT) involving wide local excision plus accelerated partial breast reirradiation (APBrI) is increasingly used as an alternative to mastectomy. This study investigates the impact of APBrI technique and multicatheter interstitial high dose-rate brachytherapy (MIB) dosimetry parameters on toxicity and survival in patients with 2ndIBTE. MATERIALS-METHODS: Data from patients with 2ndIBTE treated with CT, were analyzed. Inclusion criteria specified 2ndIBTE occurring at least one year after 1st CT for primary breast cancer. Treatment details and dosimetry parameters were recorded. Primary endpoint was late toxicity. Secondary endpoints were late toxicity prognostic factors analysis and oncological outcome. RESULTS: From 07/2005 and 07/2023, 201 patients (pts) received 2nd CT. With a median follow-up of 49.6 months (44.9-59.5), tumor size was less than 2 cm (88.1%), with estrogen receptor positive (92.7%). Patients were low (63.7%) or intermediate (29.8%) GEC-ESTRO APBI risk classification. Late toxicities were observed in 34.8% (G1 52.3%, G2 40.7%). Cutaneous fibrosis was the most common toxicity. Cosmetic outcomes were excellent in 64.1%. Dosimetry analysis revealed positive correlations between complications and absolute volumes of CTV, V100, V150, and V200. Volumes requiring higher needle number and lower DNR resulted in fewer complications. 5-year disease-free and overall survival were 88% and 95% respectively. CONCLUSION: Second CT for 2ndIBTE showed favorable oncological outcomes and survival rates. Complications were correlated with specific dosimetric parameters, emphasizing the importance of tailored treatment planning. This study provides valuable insights in risk stratification and MIB optimization for APBrI.