Background: Patients with advanced breast cancer (BC) may be treated with stereotactic ablative radiotherapy (SABR) for tumor control. Variable treatment responses are a clinical challenge and there is a need to predict tumor radiosensitivity a priori. There is evidence showing that tumor infiltrating lymphocytes (TILs) are markers for chemotherapy response; however, this association has not yet been validated in breast radiation therapy. This pilot study investigates the computational analysis of TILs to predict SABR response in patients with inoperable BC. Methods: Patients with inoperable breast cancer (n = 22) were included for analysis and classified into partial response (n = 12) and stable disease (n = 10) groups. Pre-treatment tumor biopsies (n = 104) were prepared, digitally imaged, and underwent computational analysis. Whole slide images (WSIs) were pre-processed, and then a pre-trained convolutional neural network model (CNN) was employed to identify the regions of interest. The TILs were annotated, and spatial graph features were extracted. The clinical and spatial features were collected and analyzed using machine learning (ML) classifiers, including K-nearest neighbor (KNN), support vector machines (SVMs), and Gaussian Naïve Bayes (GNB), to predict the SABR response. The models were evaluated using receiver operator characteristics (ROCs) and area under the curve (AUC) analysis. Results: The KNN, SVM, and GNB models were implemented using clinical and graph features. Among the generated prediction models, the graph features showed higher predictive performances compared to the models containing clinical features alone. The highest-performing model, using computationally derived graph features, showed an AUC of 0.92, while the highest clinical model showed an AUC of 0.62 within unseen test sets. Conclusions: Spatial TIL models demonstrate strong potential for predicting SABR response in inoperable breast cancer. TILs indicate a higher independent predictive performance than clinical-level features alone.

The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire for bone metastases 22 (EORTC QLQ-BM22) is a site-specific health-related quality-of-life instrument for patients with bone metastases. However, modern treatments and extended survivorship have introduced new toxicity profiles and clinical challenges. We systematically assessed the measurement performance of QLQ-BM22 to determine if contemporary evidence supports updating the module. A search was conducted using Medline, Embase, and Cochrane Central Register of Controlled Trials from inception to November 7, 2025. Two independent reviewers screened English-language articles reporting on the development, psychometric evaluation, or clinical application of the QLQ-BM22. Data regarding reliability, validity, responsiveness, and feasibility were extracted and synthesized. Studies using the module solely as an outcome measure without psychometric data were excluded. The review protocol was registered with PROSPERO (CRD420251052602). 49 publications were included. While available in 32 language versions, clinical use was identified in at least 16. Internal consistency was generally high (Cronbach's α > 0·70), although variability was observed in the Painful Sites subscale (range α = 0·34–0·93). Test-retest reliability was excellent (intraclass correlation coefficient >0·90). Construct validity was supported by weak correlations (r < 0·40) with unrelated domains in the EORTC core questionnaire, confirming the module's divergent validity. Item-level missingness was generally low in completed questionnaires, although follow-up completion was more variable in longitudinal studies. Responsiveness was strongest in palliative radiotherapy settings, whereas evidence in surgical and systemic therapy settings remains limited. While psychometrically sound, the reliance of QLQ-BM22 on historical validation data, limited cross-cultural validation, and inconsistent reliability in the Painful Sites subscale warrant an update. A modernized module is needed to capture contemporary symptom profiles, standardize cross-cultural measurement, and reduce burden. This research was funded by the EORTC Quality of Life Group, grant number 005/2023.

PurposeTo evaluate the acute skin toxicity and treatment-related factors in patients undergoing breast re-irradiation in a tertiary cancer centre.MethodsA retrospective review was conducted of patients who received a repeat course of breast or chest wall radiation for ipsilateral breast cancer recurrence between April 20, 2011, and December 31, 2023. Patient characteristics, treatment parameters, and clinician-graded acute toxicity were recorded. Associations between toxicity and treatment factors were analyzed.ResultsSeventy patients met inclusion criteria. Acute skin toxicity was lower during retreatment than initial treatment with 22.9% of patients (n=16) developing moderate/severe reactions during re-irradiation compared with 51.4% (n=36) during the initial course. Severe toxicity at retreatment was not common, including moist desquamation in 10 patients (14.3%). Toxicity during the initial course did not predict toxicity during re-irradiation (p=0.75). Across all fractionation schedules, no significant associations were observed between dose regimen and symptoms such as pruritus, pain, erythema, discoloration, edema, burning, dry desquamation or moist desquamation.ConclusionsBreast re-irradiation was well tolerated in the acute setting, with toxicity patterns influenced primarily by radiation dose and delivery. The findings emphasize the need for ongoing prospective work to assess long-term outcomes.