Background The role and impact of radiation therapy (RT) on the development of herpes zoster (HZ) has not been well studied. The objective of this study was to investigate the association between RT and HZ. Methods A propensity score‐matched, retrospective cohort study was conducted using institutional cancer registry data and medical records from 2011 to 2015. The risk of developing HZ in the RT and non‐RT groups was compared using a Cox proportional hazards model. Associations also were explored between the RT field and the anatomic location of HZ in patients who developed HZ after RT. The expected number of HZ events within the radiation field was calculated according to the RT received by each patient; then, this number was compared with the observed number of in‐field events. Results Of 17,655 patients, propensity score matching yielded 4350 pairs; of these, 3891 pairs were eligible for comparison. The cumulative incidence of HZ in the RT group (vs the non‐RT group) during the first 5 years after the index date was 2.1% (vs 0.7%) at 1 year, 3.0% (vs 1.0%) at 2 years, 3.4% (vs 1.3%) at 3 years, 4.1% vs 1.7% at 4 years, and 4.4% vs 1.8% at 5 years. The RT group showed a significantly higher risk of HZ than the non‐RT group (hazard ratio, 2.59, 95% CI, 1.84‐3.66). In the 120 patients who developed HZ after RT, HZ events were observed significantly more frequently within the RT field than expected (74 vs 43.8 events; P < .001). Conclusions Patients with cancer who received RT showed a significantly higher risk of HZ, which was commonly observed within the radiation field.

(1) Background: The superiority of stereotactic body radiotherapy (SBRT) over conventional external beam radiotherapy (cEBRT) in terms of pain palliation for bone metastases remains controversial. (2) Methods: This propensity score-matched study compared the overall pain response (OR) 3 months after radiotherapy among patients with painful (≥2 points on a 0-to-10 scale) non-spine bone metastases. Patients with lesions that were treated with SBRT or cEBRT and whose pain scores were evaluated 3 months after radiotherapy were included in this study. Pain response was evaluated according to the International Consensus Criteria. (3) Results: A total of 234 lesions (SBRT, n = 129; cEBRT, n = 105) were identified in our institutional database. To reduce the confounding effects, 162 patients were selected using a propensity score-matched analysis (n = 81 for each treatment). The OR rate at 3 months after SBRT was significantly higher than that after cEBRT (76.5% vs. 56.8%; p = 0.012). A noteworthy finding of our study is that the same trend was observed even after 6 months (75.9% vs. 50.0%; p = 0.011). The 1-year local failure rates after SBRT and cEBRT were 10.2% and 33.3% (p < 0.001), respectively. (4) Conclusions: Our findings suggest that SBRT is superior to cEBRT for pain palliation in patients with non-spine bone metastases.

Most studies of vertebral compression fractures (VCF) caused by stereotactic body radiotherapy (SBRT) do not discuss the symptoms of this complication. In this paper, we aimed to determine the rate and prognostic factors of painful VCF caused by SBRT for spinal metastases. Spinal segments with VCF in patients treated with spine SBRT between 2013 and 2021 were retrospectively reviewed. The primary endpoint was the rate of painful VCF (grades 2–3). Patient demographic and clinical characteristics were evaluated as prognosticators. In total, 779 spinal segments in 391 patients were analyzed. The median follow-up after SBRT was 18 (range: 1–107) months. Sixty iatrogenic VCFs (7.7%) were identified. The rate of painful VCF was 2.4% (19/779). Eight (1.0%) VCFs required surgery for internal fixation or spinal canal decompression. The painful VCF rate was significantly higher in patients with no posterolateral tumor involvement than in those with bilateral or unilateral involvement (50% vs. 23%; p = 0.042); it was also higher in patients with spine without fixation than in those with fixation (44% vs. 0%; p < 0.001). Painful VCFs were confirmed in only 2.4% of all the irradiated spinal segments. The absence of posterolateral tumor involvement and no fixation was significantly associated with painful VCF.

Objective Stereotactic body radiotherapy is used to treat spinal metastases; however, 10% of patients experience local failure. We aimed to clarify the outcomes of the second course of stereotactic body radiotherapy for spinal metastases with a uniform fractionation schedule at our institution. Methods Data of patients treated with a second salvage stereotactic body radiotherapy course at the same spinal level or adjacent level from July 2018 to December 2020 were retrospectively reviewed. The initial prescribed dose was 24 Gy in two fractions, and the second dose 30 or 35 Gy in five fractions. The spinal cord dose constraint at the second course was 15.5 Gy at the maximum point dose. The endpoints were local failure and adverse effects. Local failure was defined as tumor progression using imaging. Results We assessed 19 lesions in 17 patients, with radioresistant lesions in 14 (74%) cases, the second stereotactic body radiotherapy to the same/adjacent spinal level in 13/6 cases, the median interval between stereotactic body radiotherapy of 23 (range, 6–52) months, and lesions compressing the cord in 5 (26%) cases. The median follow-up period was 19 months. The 12- and 18-month local failure rates were 0% and 8%, respectively. Radiation-induced myelopathy, radiculopathy and vertebral compression fractures were observed in 0 (0%), 4 (21%) and 2 (11%) lesions, respectively. Three patients with radiculopathy experienced almost complete upper or lower limb paralysis. Conclusions The second course of salvage stereotactic body radiotherapy for spinal metastases achieved good local control with a reduced risk of myelopathy. However, a high occurrence rate of radiation-induced radiculopathy has been confirmed.

Purpose/Objective(s): Clinical trials and standardized treatment protocols have led to a marked improvement in overall survival (OS) in children diagnosed with rhabdomyosarcoma (RMS). However, OS remains poor in adults with RMS. Due to the relative rarity of adult RMS, randomized studies in adults are lacking, as are prospective comparisons between adults and children. Therefore, we retrospectively investigated outcomes after treatment for RMS in a large patient population registered to the Surveillance, Epidemiology, and End Results database. Materials/Methods: We identified 3,584 patients with RMS who were diagnosed from 1990-2014. Kaplan-Meier analyses, chi-squared, log-rank tests, and multivariate Cox proportional hazards models were used to examine the impact of prognostic factors on OS. Results: Median age at diagnosis was 16 years. Median OS for the entire cohort was 51 months. The majority of patients were children aged 19 years old (nZ2,041, 57.0%), white (nZ2,692, 75.1%) and male (nZ1,991, 55.5%). Unfavorable primary site was more common in adults (69.7%) versus children (59.4%, p<0.001). Children were more likely to present with localized (30.4% vs 27.2%) rather than metastatic (30.5% vs 34.0%, p<0.001) disease. The most common histologic subtypes in pediatric RMS were embryonal (53.7%) and alveolar (31.0%) compared to unspecified (37.1%) and pleomorphic (22.4%) in adults (p<0.001). In contrast to adults, children were more likely to receive resection and/or radiotherapy (87.9% vs 76.9%, p<0.001) or systemic therapy (95.4% vs 57.9%, p<0.001). For metastatic disease, systemic therapy was used more often in children (97.3% vs 65.5%, p<0.001). Local therapy for pediatric RMS more often included radiotherapy (65.2% vs 41.3%, p<0.001). Respective 5-, 10-, and 15-year survival estimates in children were 63.9%, 60.3%, and 59.1% compared to 28.3%, 23.3%, and 21.9% in adults (p<0.001). The prognosis for children was increased compared to adults across similar sites and stages, with the largest 5-year estimated survival differences seen in favorable site (77.5% vs 37.1%, p<0.001) and localized disease (85.4% vs 47.7%, p<0.001). With multivariate analysis accounting for primary site, race, sex, year of diagnosis, histologic subtype, stage, and type of treatment received, pediatric patients had improved OS (HRZ0.45, p<0.001) compared to adults. Conclusion: Adult RMS is associated with poor outcomes in contrast to pediatric patients; reasons for this are multi-factorial. Differences in clinical features and treatment received have been identified in our hypothesis-generating study. Limitations in these analyses include inability to account for selection biases, under-reporting receipt of therapy, and lack of molecular testing. These results may help explain the disparity in RMS between children versus adults and inform future discussions regarding their respective treatment approach.