Background: Cervical cancer treatment with advanced radiotherapy techniques benefits from image guidance, particularly when anatomical changes occur during therapy. This case emphasizes the need for adaptive radiotherapy when target volume shifts significantly. Methods: A 70-year-old woman with International Federation of Gynecology and Obstetrics (FIGO) IIIC2 9th edition cervical squamous cell carcinoma presented with a distended uterine cavity due to fluid accumulation. She underwent definitive chemoradiotherapy using Volumetric Modulated Arc Therapy (VMAT) and weekly cisplatin. Results: Daily Cone Beam Computed Tomography (CBCT) imaging revealed progressive uterine shrinkage as intrauterine fluid drained, significantly altering target volume and organ-at-risk (OAR) positioning. These changes necessitated two re-planning CT scans during external beam radiotherapy to maintain accurate dosing and avoid OAR toxicity. The patient completed treatment, including image-guided brachytherapy, without complications. Adaptive planning ensured adequate tumor coverage and minimized normal tissue exposure. Conclusions: This case highlights the critical role of daily CBCT in detecting anatomical changes during radiotherapy. Adaptive re-planning, though rarely required more than once, was essential here to preserve treatment accuracy. CBCT should be considered a standard verification tool in cervical cancer radiotherapy, particularly in cases involving intrauterine fluid.

Human epidermal growth factor receptor 2 (HER2)-low breast cancer is a clinically relevant subgroup defined by low but detectable HER2 protein expression, immunohistochemistry (IHC) score of 1+ or 2+ with negative in situ hybridization findings, positioned at the interface between traditional HER2-positive and HER2-negative disease. The recent introduction of antibody–drug conjugates (ADCs) has increased the clinical significance of borderline HER2 expression and exposed important diagnostic challenges, particularly in cases with very low levels of membrane staining, including the emerging HER2-ultralow category. Background and Objectives: This review summarizes the pathological and biological framework of HER2-low and HER2-ultralow breast cancer and critically appraises the magnitude, direction, and determinants of HER2 variability under systemic therapy. Particular focus is placed on treatment-associated shifts after chemotherapy, intratumoral heterogeneity, and pre-analytical and analytical factors that can influence HER2 assessment, with direct implications for therapeutic stratification and biomarker reassessment. Materials and Methods: A narrative literature review was conducted using PubMed, Scopus, and Web of Science, focusing on studies published within the last five years. Eligible publications included clinical trials, retrospective cohorts, and translational or molecular studies that reported paired HER2 assessment in breast cancer and were interpreted according to American Society of Clinical Oncology/College of American Pathologists-aligned criteria. Results: Across major cohorts, HER2-low appeared to be the most dynamic category, with variability frequently observed following systemic therapy. Beyond treatment-related effects, shifts in HER2 status may be attributable to intratumoral heterogeneity and technical variability, with the greatest impact observed at the IHC 0–1+ interface. Conclusions: Given the clinical relevance of low-level HER2 expression, standardized testing and transparent reporting are essential, and HER2 reassessment may be justified in selected clinical scenarios to optimize access to HER2-directed therapies.

Background: Brain radiation necrosis is a side effect of radiotherapy that can occur months, or even years, after the end of treatment. From an anatomical–pathological perspective, it is characterized by avascular damage, demyelination, and necrosis. Methods: We present a case of a patient with breast cancer cT2N1M0 and multiple brain metastases occurring at 2 years after diagnosis, who was treated with whole-brain radiotherapy (WBRT) and Stereotactic Radiotherapy (SRT) for tumor progression. Dynamic imaging revealed right parietal post-therapeutic changes in aggravation, requiring differential diagnosis between tumor progression (TP) and brain radionecrosis (BRN). Results: Brain radionecrosis and tumor progression are difficult to differentiate due to their similar radiological and clinical characteristics. MRI perfusion plays an important role in differentiating the two entities. Conclusions: Differentiating radiation necrosis from a recurrent tumor is crucial for appropriate treatment. Medical management includes corticosteroids as first-line treatment, after which bevacizumab is administered as secondary therapy.