Journal of radiosurgery and SBRT最新文献

Background: Though promising retrospective and prospective studies have reported on stereotactic ablative radiation therapy(SABR) for management of lung metastases from sarcoma primaries, they are limited by small patient numbers.

Methods: The primary outcomes of interest were 1-year and 2-year local control (LC) and Grade 3-5 toxicities. Secondary outcomes were 1-year overall survival (OS) and 2-year OS. Weighted random effects meta-analyses using the DerSimonian and Laird methods were performed to calculate effect sizes.

Results: Thirteen studies were identified with 533 patients and 940 lung metastases. The median prescription dose was 50 Gy (range: 48-60 Gy) in 5 fractions (range: 4-10). Following SABR, 1- and 2-year pooled LC rates were 97% (95% CI: 95-98%) and 91% (95% CI: 88-95%), respectively. Pooled 1- and 2-year OS rates were 85% (95% CI: 80-90%) and 68% (95% CI: 57-80%), respectively. The estimated incidence of Grade 3-5 toxicities following SABR was 0.1% (95% CI: 0-0.5%).

Conclusion: SABR for sarcoma pulmonary metastases resulted in excellent LC with minimal toxicities.

Background: Secondary trigeminal neuralgia (TN) is often associated with benign meningiomas and schwannomas. For patients who are unable to undergo surgical resection, Gamma Knife radiosurgery (GKRS) is a well-established alternative for tumor control. There is limited data on the pain outcomes in these patients undergoing tumor-targeted GKRS.

Methods: Patients receiving tumor-targeted GKRS for a benign tumor causing secondary TN between 2005 and 2021 were identified. The Barrow Neurological Institute (BNI) pain score was documented at baseline and over the course of clinical follow-up. The study endpoint was defined as either last documented follow-up or date of additional pain procedure.

Results: Seventeen patients were identified with 12 meningiomas (71%), 4 vestibular schwannomas (24%), and 1 trigeminal schwannoma (6%). Patients received either a single fraction of 12-13 Gy in 14 patients (82%) or 25 Gy in 5 fractions for 3 patients (18%). At a mean time to study endpoint of 29.5 months, 6 patients (35%) were pain free. Median time to BNI pain improvement was 4.6 months post-GKRS. One patient (6%) experienced new onset facial numbness. After the study endpoint, five patients (29%) underwent at least one subsequent balloon compression procedure for pain control. Mean total follow-up time was 61.9 months.

Conclusion: For patients with secondary TN due to benign lesions who are poor candidates for surgical resection, tumor-targeted GKRS has a modest effect on pain outcomes. Complication rates are also comparatively very low.

Purpose: This systematic review evaluated variability in study endpoints among stereotactic body radiation therapy (SBRT) studies for bone metastases. Heterogeneity in endpoint definitions and reporting may hinder cross-study comparability and the establishment of consistent treatment protocols.

Methods: A comprehensive search of Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials identified prospective studies, including cohort studies, phase I/II trials, and randomised controlled trials (RCTs), published between 2014-01-01 and 2024-11-12. Studies were eligible if they: (1) included adult patients with bone metastases treated with SBRT, (2) were prospective, and (3) reported pre-defined clinical endpoints.

Results: A total of 58 studies were included: eight cohort studies, 37 phase I/II trials, and 13 RCTs. Pain-related endpoints were the most frequently reported primary endpoints, with pain response reported in 28% (16 studies). Other primary endpoints included toxicities (22%, 13 studies), survival metrics (12%, seven studies), and local control (9%, five studies). Secondary endpoints varied, with survival-related endpoints reported in 60% (35 studies) and toxicity in 41% (24 studies). Endpoint selection differed by clinical scenario, reflecting distinct objectives such as symptom relief, local control, and progression-free survival. Variability in definitions for endpoints, particularly pain flare and vertebral compression fracture, along with inconsistent radiological response criteria, was noted.

Conclusion: Considerable heterogeneity in endpoint selection, definitions, and measurement tools across SBRT reflects diverse clinical objectives. Consensus-driven standardisation of endpoints, response criteria, and follow-up schedules is essential to enhance comparability, facilitate evidence synthesis, and support integration of SBRT research findings into clinical practice.

Background and purpose: Precise urethral delineation is critical for minimizing genitourinary (GU) toxicity in prostate SBRT. This study compares acute toxicity outcomes between catheter-based and MRI-based urethral delineation methods.

Materials and methods: In this prospective study (2023-2024), 40 patients were randomized to catheter-based (n = 20) or MRI-based (n = 20) urethral delineation prior to SBRT. IPSS, QOL scores, and RTOG toxicity were assessed at baseline, treatment completion, and 1/3-month follow-ups. Dosimetric analysis included urethral BED and bladder V _18 Gy.

Results: Both methods achieved comparable dosimetric precision (urethral BED: 128 ± 12 Gy catheter vs 130 ± 10 Gy MRI, p = 0.42). Acute grade ≥2 GU toxicity rates were similar (40% catheter vs 30% MRI, p = 0.54). The catheter group showed transient QOL deterioration likely attributable to procedural discomfort, with all patients returning to baseline by 3 months. Multivariate analysis identified urethral BED ≥130 Gy (OR: 2.1, p = 0.03) and bladder V _18 Gy ≥ 30% (OR: 1.9, p = 0.04) as independent predictors of toxicity.

Conclusion: Catheter-based and MRI-based delineation demonstrate equivalent dosimetric and clinical outcomes in prostate SBRT. While catheterization may cause temporary discomfort, both methods are equally effective when adhering to dose constraints (urethral BED: <130 Gy, bladder V _18 Gy < 30%). The choice between techniques may consider patient tolerance and institutional protocols, as both approaches provide excellent therapeutic outcomes.

Objective: To report on local control (LC), toxicity, and overall survival (OS) following stereotactic ablative radiation therapy (SABR) for extracranial metastases from malignant melanoma.

Methods: The RSSearch^® Patient Registry was searched for patients with extracranial melanoma metastases treated with SABR. LC was defined as the time from completion of SABR to the date of last radiographic follow-up with either stability or decrease in size of the treated metastasis or the date at which lesion growth was radiographically confirmed per RECIST criteria. Kaplan-Meier analyses were utilized to evaluate potential prognostic factors on univariate analyses (UVA) with log-rank tests followed by use of a Cox proportional hazards multivariate (MVA) model.

Results: There were 45 patients with 52 extracranial melanoma metastases treated with SABR. One- and 2-year LC rates were both 85.3% (95% CI: 67.9-93.7%) following SABR. On UVA, BED10 < 60 Gy was associated with poorer 1-year and 2-year LC (96% vs. 61.9%), which remained significant on MVA (hazard ratio [HR] = 7.06; p = 0.03). On UVA, pulmonary vs. non-pulmonary metastases were correlated with 1-year OS (84.5% vs. 57.4%; p = 0.05) and non-spinal vs. spinal metastases (74.3% vs. 56.3%; p = 0.02), though neither were significant on MVA. The incidence of treatment-related toxicity was 18.9%, all Grade 1-2.

Conclusion: We recommend dose/fractionation schedules that meet or exceed BED10 ≥ 60 Gy when treating extracranial melanoma metastases with SABR.

Aims: To assess the suitability of CBCT images for dose calculation using the convolution algorithm.

Methods: A CT to electron density curve was produced for the Gamma Knife ICON CBCT scanner. A three-level stepwise curve with fixed electron densities for air, brain tissue and bone was also produced. For 10 patients, the beam on time for shots in 11 locations within the brain was calculated using each of these curves and compared to beam on times calculated using the TMR10 algorithm, and the convolution algorithm with CT images.

Results: The ratios of the average beam on time for convolution versus TMR10 were 1.058, 1.216 and 1.052 for CT images, CBCT images (Hounsfield unit electron density curve) and CBCT images (three-level stepwise curve with fixed electron densities) respectively.

Conclusions: Using ICON CBCT images for dose calculation can result in an underestimation of the dose compared to convolution using CT images. However, using CBCT images along with a three-level stepwise electron density curve with fixed electron densities can provide good agreement with doses calculated using convolution with CT images.