PURPOSE:To evaluate the efficacy and safety of salvage brachytherapy (SBT) as a curative treatment option for patients with locally recurrent prostate cancer after prior radiation therapy. MATERIALS AND METHODS:Between 2009 and 2023, we analyzed 108 prostate cancer patients with local recurrent after radiotherapy. SBT was performed as a sole treatment using either HDR (high dose rate) brachytherapy with a total dose of 30 Gy in three fractions (78.0 Gy EQD2 α/β=3 Gy) or PDR (pulse dose rate) brachytherapy with a total dose of 60 Gy in two sessions (71.5 Gy EQD2 α/β=3 Gy), with a three-week interval between sessions in both regimens. RESULTS:Median follow-up was 41 months (range 6-173). Median interval between initial radiation and salvage brachytherapy was 66 months (range 18-214). The 5-year cumulative incidence of local recurrence was 17.0%. Local relapse was observed in 15 patients (13.8%). The 2- and 5-year biochemical disease-free survival according to the Phoenix definition were 83.6% and 59.9%. The 2- and 5-year progression-free survival were 77.0% and 53.2%; overall survival rates were 96.9% and 87.4%, respectively. Grade ≥ 3 urinary toxicity was uncommon, with 2/93 (2.1%) patients requiring transurethral resection and 6/93 (6.5%) long-term catheterization. Most patients had grade 0-1 incontinence; grade 2 and grade ≥ 3 occurred in 13/79 (16.5%) and 7/79 (8.8%) at 24 months. Proctitis was rare; no grade ≥ 3. CONCLUSIONS:Salvage brachytherapy offers an effective and well-tolerated curative option for patients with locally recurrent prostate cancer after prior radiation therapy.

BACKGROUND:Intraoperative cone-beam computed tomography (CBCT) provides a valuable option for accurate three-dimensional applicator positioning in gynecologic brachytherapy, but is associated with radiation exposure and increased intervention time especially in case of repeated CBCT imaging being required for creating a sufficient implant arrangement. PURPOSE:To reduce the need for multiple CBCT scans for corresponding applicator verification, this work proposes two methods for needle path navigation, including corrections of potential bending in situ, by combining infrared tracking with planar x-ray imaging for enabling accurate intraoperative needle guidance. METHODS:An examined 200 mm brachytherapy needle was rigidly mounted on an infrared-reflective tracking tool to enable real time tracking. Two planar x-ray images, acquired from varying distinct angles, were used to determine the exact 3D position of the needle tip region via backprojection. A spline was fitted through the obtained coordinates to reconstruct the full needle path. Based on this, only a single initial CBCT scan was required to visualize the predicted needle path within this scan. Additionally, a second approach for needle prediction was presented focusing on only one planar x-ray image by incorporating prior needle bending information from the initial CBCT scan. Both methods were evaluated in preclinical studies and validated against a corresponding ground-truth obtained from CBCT. RESULTS:The proposed method considering two planar x-ray images successfully reconstructed the needle path with deviations of less than 1 mm from the CBCT reference scan, when using at least 20° offset between the x-ray image acquisitions. The single-scan approach, using prior bending information, yielded promising results with deviations at the tip of below 1.3 mm. CONCLUSIONS:Both described methods demonstrated their feasibility in preclinical studies, showing potential to improve and accelerate clinical implantation workflows by means of needle navigation in the future.

OBJECTIVE:To report clinical outcomes and toxicity of interstitial brachytherapy (IBT), with or without external beam radiotherapy, in a predominantly frail, multimorbid cohort of patients with locally advanced vulvar cancer, analyzed according to treatment intent and clinical setting. METHODS:We analyzed 47 patients with vulvar malignancies treated between 1998 and 2024 with pulse dose rate-IBT, either postoperatively or with definitive intent. Fifteen patients received pulse dose rate-IBT alone (median total dose of 57.2 Gy, range, 44.7-67.2), while 32 patients underwent combined external beam radiotherapy followed by an IBT boost (median total dose of 61.4 Gy; range, 50.7-68.1). Median age was 67 years (range, 38-90). Survival outcomes were estimated using Kaplan-Meier methods. RESULTS:Median follow-up was 2.2 years (range, 4-210). Two- and five-year overall survival rates were 58.2% and 45.7%, and disease-free survival rates were 62.5% and 53.1%, respectively. Concurrent chemotherapy was administered to 22/47 (47%) patients and was not completed in 7/22 (32%). In a predefined subgroup treated with curative intent for primary vulvar cancer, five-year overall survival, disease-free survival, and cumulative local recurrence rate were 61.7%, 66.7%, and 29.3%, respectively. Severe toxicity (≥grade 3), including ulceration, occurred in 14.2% of patients. CONCLUSION:In this real-world cohort, interstitial brachytherapy was feasible with a low rate of severe toxicity. Despite a frail, multimorbid patient population, acceptable local control was achieved. With appropriate patient selection, IBT may represent a viable option to improve local control while limiting mucosal toxicity.

PURPOSE:This prospective Phase 2 trial investigates efficacy and side effects of ultrasound-guided salvage brachytherapy with interstitial hyperthermia in locally recurrent prostate cancer following previous radiation therapy. MATERIALS AND METHODS:Altogether 109 patients with locally recurrent prostate cancer after previous external beam radiation therapy were enrolled in this Phase 2, multicentric prospective trial between 2015 and 2020. Patients received either 30 Gy in three fractions 21 days apart (78.0 Gy, EQD2, α/ β = 3 Gy) using interstitial HDR-brachytherapy alone or 60 Gy in 2 sessions 28 days apart (71.5 Gy (EQD2, α/β = 3 Gy) using interstitial PDR-brachytherapy alone. We performed the interstitial brachytherapy in all patients with plastic needles. Additionally, interstitial hyperthermia treatment was executed within one hour before or during every brachytherapy fraction/series for a therapeutic time of 60 min and a target temperature of 40-41 °C, at least. The primary endpoint of this prospective phase 2 trial was rate of late Grade ≥ 3 gastrointestinal (GI) and genitourinary (GU) side effects. Treatment-related toxicity was evaluated according to the Common Toxicity Criteria for Adverse Events version 4.03 (CTCAE). Secondary endpoints were cumulative local recurrence rate, biochemical disease-free survival (bDFS), overall survival (OS), disease-free survival (DFS) and cancer-specific survival. This trial is registered with ClinicalTrials.gov number NCT03238066. RESULTS:Median follow-up was 64 months. Median time between previous radiation therapy and salvage brachytherapy was 77 months (range 20.4 - 244 months). Serious late toxicity was generally low. Importantly we did not register any grade ≥ 2 of late rectal toxicities. We observed Grade 3 urinary incontinence in 8/109 patients (7.3%), with further seven patients scoring urinary incontinence Grade 1 or 2 toxicity (7/109, 6.4%). All other late urogenital side effects were only grade 1 or 2: urinary retention by 8/109 (7.2%), urinary frequency 5/109 (4.6%) and urinary urgency in 2/109 patients (1.8%). The cumulative 5 years local recurrence rate (cLRR) and cumulative lymph-node recurrence rate (cLndRR) for all patients was 29% and 6.8%, respectively. Five years-biochemical disease-free survival estimates according Kaplan-Meier were 58.9%. Five years metastases-free survival, cancer specific survival and overall survival estimates according Kaplan-Meier were 77.7%, 92.7% and 85.5%, respectively. CONCLUSIONS:Salvage brachytherapy with interstitial hyperthermia in local recurrent, previously irradiated, prostate cancer is effective with very low late toxicity. Since there are no meaningful randomized comparative studies available, it remains unclear whether the additional use of interstitial hyperthermia can further improve the effectiveness of salvage brachytherapy alone.

Purpose To update recommendations on patient selection criteria for accelerated partial breast irradiation (APBI) based on available clinical evidence supplemented by expert opinions. Methods and materials Between 2010 and 2024, a systematic search of the PubMed, Medline, Scopus and Cochrane database identified 618 articles using the keywords “accelerated partial breast irradiation” and “APBI”. This search was complemented by reviewing the reference lists of articles and manual reviewing of relevant conference abstracts and book chapters. Of these, ten prospective randomized clinical trials and seven retrospective comparative studies with a minimum median follow-up time of five years were identified. The authors reviewed the clinical evidence published on APBI, supplemented it with relevant clinical and pathological studies on breast-conserving therapy, and then formulated the recommendations presented in this manuscript. Results Based on published new clinical evidence, the GEC-ESTRO Breast Cancer Working Group recommends two categories as guidelines for selecting patients eligible for APBI: (1) low-risk group representing good candidates for APBI including patients ageing > 40 years with unifocal or multifocal within 2 cm, pTis,T1-2 (≤30 mm) pN0 or pN1mi, all histology types of breast cancer without the presence of an extensive intraductal component (EIC), without extensive lympho-vascular invasion (LVI) and with negative surgical margins for invasive tumors (≥2 mm for DCIS), (2) high-risk group, for whom APBI is considered contraindicated including patients with BRCA 1–2 mutations or ageing < 40 years; having positive margins for invasive tumor (<2 mm for DCIS), and/or multicentric or large (>30 mm), and/or triple negative tumours, and/or EIC positive, and/or extensive lympho-vascular invasion (LVI) or macrometastatic positive lymph nodes (≥pN1a) or unknown axillary status (pNx). Conclusions Based on emerging clinical evidence, the 2010 GEC-ESTRO APBI patient selection criteria can be significantly expanded, meaning that in the future, more patients may receive APBI as a part of routine clinical practice.

Background and purpose:Patient or treatment plan mix-ups are among the most serious patient-specific human errors in brachytherapy. However, many brachytherapy departments rely only on review by a second, independent person, which does not eliminate the risk of human failure. In this work, we developed and retrospectively evaluated an automated patient identification method based solely on the geometry of the interstitial implant in breast cancer patients. Materials and methods:The implant geometry is assessed using an electromagnetic tracking (EMT) system that provides real-time positional data of each catheter with sub-millimetre accuracy. The measured implant geometry is rigidly registered to the CT-based implant geometry associated with the clinical treatment plan. To quantitatively compare them, a similarity metric based on a distance-to-agreement (DTA) criterion (3-10 mm) and a pass rate threshold (50-95%) was used. The implants of 80 patients were included in the evaluation, resulting in 6400 patient-treatment plan combinations. Results:The classifier reliably identified patients with an area under the receiver operating characteristic (ROC) curve close to 1, highlighting an overall excellent discriminative performance. At the optimal decision threshold under the requirement of a false positive rate of 0%, it achieved a sensitivity between 94.8% and 97.5% depending on the DTA and pass rate thresholds, and an overall accuracy of 99.9%. Conclusion:Interstitial implants in breast brachytherapy are virtually unique, so determining their geometry prior to each fraction is a viable option for patient identification. The EMT-based automated technique has proven to be effective in detecting patient or treatment plan mix-ups with near-perfect accuracy.

Management of second ipsilateral breast cancer events (iBCEs) remains controversial, and there is a need to collate existing evidence and international guidance on patient selection and local treatment strategies. This project, endorsed by US and European surgical and radiation oncology societies, aimed to gather expert consensus on these issues. A questionnaire on second iBCE local treatment was developed and reviewed by a core group of eight experts, and Delphi methodology was applied over two rounds to 36 panellists, including radiation oncologists, breast surgeons, a plastic surgeon, and medical physicists. Consensus was predefined as agreement of 75% or higher. After two rounds, consensus was reached for 78 (80%) of 97 items. Panellists agreed that patient preferences are central to decision making (100%) and that a second breast-conserving therapy represents a reasonable option for selected patients (100%). Criteria associated with greater suitability for second breast-conserving therapy included an interval between surgeries of at least 60 months, low-risk accelerated partial breast irradiation classification, luminal molecular profile, and no grade 3 late toxicity related to the first breast-conserving therapy. HER2 (also known as ERBB2)-positive or triple negative subtypes were not viewed as absolute contraindications. Strong consensus was also observed regarding the importance of tumour-to-breast volume ratio, clear surgical margins, and tumour bed reirradiation. For patients undergoing mastectomy, immediate autologous reconstruction was preferred (94%) over implant-based approaches (75%). This international Delphi consensus offers structured guidance for the local management of second iBCE and supports shared decision making and individualised treatment planning.

A survey regarding utilisation of brachytherapy was distributed to European brachytherapy professionals. Eighty replies from 26 countries were received, two of which were outside Europe. The replies showed that brachytherapy is still widely used. The main indications for brachytherapy are gynaecological and prostate cancer, with >80 % of the responding countries performing brachytherapy for these indications. There is on average one brachytherapy centre per 0.8 million inhabitants, ranging from 0.4 per million to 2.3 per million inhabitants. The organisation of brachytherapy on national levels also varies from country to country, with less than half of the countries having a central brachytherapy registry. All in all, the survey shows that brachytherapy still plays a role on modern radiotherapy, but the field could benefit from a stronger collaboration both nationally and internationally.

The aim of this review is to give an overview of the results of prospective and retrospective studies using allogenic reconstruction and postmastectomy radiotherapy (PMRT) in breast cancer and to make recommendations regarding this interdisciplinary approach. A PubMed search was conducted to extract relevant articles from 2000 to 2024. The search was performed using the following terms: (breast cancer) AND (reconstruction OR implant OR expander) AND (radiotherapy OR radiation). Data from the literature on allogenic breast reconstruction and radiation are presented and discussed in relation to toxicity and cosmesis. Breast reconstruction is also feasible if PMRT is necessary. Patients need to be informed about the relevant risk of capsular fibrosis and implant failure. A planned reconstruction is no reason to forgo PMRT nor is an indication for PMRT a reason to forego implant-based breast reconstruction if desired by the patient. It is important to provide detailed information here to enable shared decision-making. There is still no clear consensus regarding implant-based reconstruction (IBR) and PMRT. However, in clinical practice, both a one-stage (immediate “implant-direct” IBR) procedure with PMRT up to the final implant and a two-stage (immediate-delayed IBR) procedure with PMRT up to the tissue expander (TE) and later exchange of the TE are used; both approaches have their specific advantages and disadvantages. Depending on patient-specific factors and the surgeon’s experience and estimates, both IBR procedures are also possible in combination with PMRT. When using a TE/implant approach, completing skin stretching by adequately filling the expander before PMRT may be favorable. This approach is particularly practical when adjuvant chemotherapy is planned but may lead to postponement of radiotherapy when primary systemic therapy is given. According to the latest data, moderate hypofractionation also appears to be safe in the context of the IBR approach. It is important to have a closely coordinated interdisciplinary approach and to fully inform patients about the increased rate of potential side effects.