Objectives: This study aimed to evaluate the efficacy and toxicity of stereotactic body radiotherapy (SBRT) for spinal metastases, focusing on pain control, local tumor control, and the incidence of vertebral compression fractures (VCF). Materials and Methods: We retrospectively analyzed 179 patients with 217 spinal metastatic lesions who underwent SBRT between July 2020 and April 2022. The prescribed doses for SBRT were 18 or 20 Gy for one fraction, ≥24 Gy for three fractions, ≥20 Gy for four fractions, and ≥25 Gy for five fractions. Patient-reported treatment response was evaluated 1–3 months after SBRT completion. Local recurrence was defined as failure within the radiotherapy field. Pain response, local progression-free survival (LPFS), and the incidence of painful VCF were assessed. Prognostic factors for LPFS and VCF risk factors were evaluated. Results: The overall pain response rate was 80.8%. LPFS rates were 90.6% at 1 year and 83.0% at 2 years. Lytic/mixed lesions and involvement of multiple segments were significant prognostic factors for reduced LPFS. The cumulative incidence of painful VCF was 8.7% at 1 year and 12.8% at 2 years. A biologically effective dose (BED₃) ≥104 Gy was the only significant risk factor for painful VCF. Conclusions: SBRT demonstrated high efficacy for pain and local tumor control in spinal metastases, with an acceptable VCF risk.

Triple-negative breast cancer (TNBC) accounts for approximately 15–20% of all breast cancer types, indicating a poor survival prognosis with a more aggressive biology of metastasis to the lung and a short response duration to available therapies. Ibulocydine (IB) is a novel (cyclin-dependent kinase) CDK7/9 inhibitor prodrug displaying potent anti-cancer effects against various cancer cell types. We performed in vitro and in vivo experiments to determine whether IB inhibits metastasis and eventually overcomes the poor drug response in TNBC. The result showed that IB inhibited the growth of TNBC cells by inducing caspase-mediated apoptosis and blocking metastasis by reducing MMP-9 expression in vitro. Concurrently, in vivo experiments using the metastasis model showed that IB inhibited metastasis of MDA-MB-231-Luc cells to the lung. Collectively, these results demonstrate that IB inhibited the growth of TNBC cells and blocked metastasis by regulating MMP-9 expression, suggesting a novel therapeutic agent for metastatic TNBC.

Purpose: This study aimed to evaluate whether radiation dose escalation improves survival outcomes in early-stage extranodal natural killer/T-cell lymphoma (ENKTL) treated with intensity-modulated radiotherapy (IMRT)–based concurrent chemoradiotherapy (CCRT).Materials and Methods: We retrospectively reviewed 72 patients with Ann Arbor stage I–II ENKTL treated at our institution from 2011 to 2025 with IMRT-based CCRT followed by sequential chemotherapy with etoposide, ifosfamide, dexamethasone, and L-asparaginase. Patients were stratified at the cohort median radiation dose and inverse probability of treatment weighting (IPTW) was applied to address potential confounding by indication. The primary endpoint was overall survival (OS); secondary endpoints were local progression-free survival (LPFS), progression-free survival (PFS), and toxicity.Results: Using the cohort median (54 Gy) as the cutoff, patients were divided into <54 Gy (n = 32) and ≥54 Gy (n = 40) groups. The ≥54 Gy group had more female patients (p = 0.007), with older age and higher prognostic index for natural killer lymphoma–Epstein–Barr virus (PINK-E) scores. IPTW was applied in 62 patients with available PINK-E data. No significant difference was observed between dose groups in OS (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.22 to 2.58), LPFS (HR, 1.87; 95% CI, 0.54 to 6.51), or PFS (HR, 0.53; 95% CI, 0.23 to 1.23). No grade ≥4 toxicities occurred, and grade ≥2 toxicities did not differ between groups.Conclusion: In early-stage ENKTL treated with IMRT-based CCRT, radiation dose escalation beyond 54 Gy did not improve survival or local disease control. These findings suggest that higher radiation doses may be unnecessary in the modern IMRT era.