Journal of radiosurgery and SBRT最新文献

Objectives: To perform a systematic review and meta-analysis of outcomes for patients with locally recurrent brain metastases treated with a repeat course of stereotactic radiosurgery (rSRS).

Method: Primary outcomes were 1-year local control(LC) and radionecrosis (RN). Secondary outcomes were 1-year overall survival (OS) and 1-year distant brain control (DBC). Weighted random effects meta-analyses utilizing the DerSimonian and Laird methods were conducted to characterize summary effect sizes. Mixed effects regression models were utilized to analyze potential correlations between prognostic factors and outcomes.

Results: In total, 347 patients with 462 brain metastases treated with rSRS were included. Estimated 1-year LC, OS, and DBC rates were 69.0% (95% CI: 61.0-77.0%), 49.7% (95% CI: 28.9-70.6%), and 41.6% (95% CI: 33.0-50.4%), respectively. The estimated RN rate was 16.1% (95% CI: 6.3-25.9%). Every 1 Gy increase in prescription dose was estimated to result in roughly 5% increase in 1-year LC (p = 0.14).

Conclusions: rSRS was well-tolerated with reasonable 1-year LC and OS. Dose escalation may result in improved LC.

Objective: To evaluate the efficacy and safety of stereotactic body radiotherapy (SBRT) in patients with adrenal gland metastasis (AGM) of oligometastatic lung cancer.

Methods: Between June 2013 and May 2021, 44 patients with oligometastatic lung cancer (51 AGMs) were treated with SBRT. Forty-six (90%) lesions received a biological effective dose (BED₁₀, α/β = 10) of 100 Gy. The primary endpoint was local control (LC). Local control (LC), overall survival (OS), and progression-free survival (PFS) curves were calculated by the Kaplan-Meier method.

Results: The median follow-up was 23 months. The most common histology was non-small cell lung cancer (88.6%). The 1- and 2-year LC rates were both 95% and 91%, respectively. Overall survival was better in patients with solitary AGMs in univariate analysis.

Conclusion: This study demonstrated that SBRT with higher BED is associated with satisfactory LC and low toxicity rates in patients with AGM of oligometastatic lung cancer.

Purpose: Optimal timing of SRS after surgical resection of brain metastases (BMs) remains debated but is generally advocated to occur within 4 weeks of surgery to account for cavity remodeling. Our study assesses this recommendation by examining cavity dynamics and any downstream effects on outcome.

Methods: Post-operative MRIs were used to compare target lesion volumes to target volume at time of SRS. Spearman's analysis identified a relationship between the time to SRS (ttSRS) and target remodeling. The Mann-Whitney-U test compared median remodeling between groups receiving standard (≤4 weeks) and late (>4 weeks) adjuvant SRS. Kaplan Meier functions estimated probabilities of local recurrence (LR) and survival (OS). A Cox proportional hazards model (CPH) identified predictors of OS, LR, and leptomeningeal disease (LMD).

Results: Median ttSRS was 32 days (3-72). A positive correlation exists when comparing ttSRS to reduction in cavity volume (0-10 weeks; p = 0.01) with no difference in median cavity remodeling between standard and late SRS groups. OS and LR rates were respectively 53.3% and 70.2% at 12 months with no difference in OS (p = 0.16) or LR (p = 0.54) between standard and late SRS groups. Subtotal resection predicted LMD (HR: 6.37; p = 0.03). No grade 3 or higher toxicity was seen in follow-up.

Conclusion: Resection cavities may continue to shrink well after resection. There is no significant difference in OS or LR based on ttSRS, however, treatment factors such as the extent of resection may account for outcomes such as LMD.

Introduction: Stereotactic body radiation therapy (SBRT) is increasingly utilized for patients with recurrent and metastatic sarcoma. SBRT affords the potential to overcome the relative radioresistance of sarcomas through delivery of a focused high biological effective dose (BED) as an alternative to invasive surgery. We report local control outcomes after metastatic sarcoma SBRT based on radiation dose and histology.

Methods: From our IRB-approved single-institution registry, all patients treated with SBRT for metastatic sarcoma between 2014 and 2020 were identified. Kaplan-Meier analysis was used to estimate local control and overall survival at 1 and 2 years. A receiver operating characteristic (ROC) curve was generated to determine optimal BED using an α/β ratio of 3. Local control was compared by SBRT dose using the BED cut point and evaluated by histology.

Results: Forty-two patients with a total of 138 lesions met inclusion criteria. Median imaging follow up was 7.73 months (range 0.5-35.0). Patients were heavily pre-treated with systemic therapy. Median SBRT prescription was 116.70 Gy BED (range 66.70-419.30). Desmoplastic small round cell tumor, Ewing sarcoma, rhabdomyosarcoma, and small round blue cell sarcomas were classified as radiosensitive (n = 63), and all other histologies were classified as radioresistant (n = 75). Local control for all lesions was 66.7% (95% CI, 56.6-78.5) at 1 year and 50.2% (95% CI, 38.2-66.1) at 2 years. Stratifying by histology, 1- and 2-year local control rates were 65.3% and 55.0%, respectively, for radiosensitive, and 68.6% and 44.5%, respectively, for radioresistant histologies (p = 0.49). The ROC cut point for BED was 95 Gy. Local control rates at 1- and 2-years were 75% and 61.6%, respectively, for lesions receiving >95 Gy BED, and 46.2% and 0%, respectively, for lesions receiving <95 Gy BED (p = 0.01). On subgroup analysis, local control by BED > 95 Gy was significant for radiosensitive histologies (p = 0.013), and trended toward significance for radioresistant histologies (p = 0.25).

Conclusion: There is a significant local control benefit for sarcoma SBRT when a BED > 95 Gy is used. Further investigation into the dose-response relationship is warranted to maximize the therapeutic index.

In Gamma Knife (GK) radiosurgery, dose rate decreases during the life cycle of its radiation source, extending treatment times. Prolonged treatments influence the amount of sublethal radiation injury that is repaired during exposure, and is associated with decreased biologically-equivalent dose (BED). We assessed the impact of treatment times on clinical outcomes following GK of the trigeminal nerve - a rare clinical model to isolate the effects of treatment times. This is a retrospective analysis of 192 patients with facial pain treated across three source exchanges. All patients were treated to 80 Gy with a single isocenter. Treatment time was analyzed in terms of patient anatomy-specific dose rate, as well as BED calculated from individual patient beam-on times. An outcome tool measuring pain in three distinct domains (pain intensity, interference with general and oro-facial activities of daily living), was administered before and after intervention. Multivariate linear regression was performed with dose rate/BED, brainstem dose, sex, age, diagnosis, and prior intervention as predictors. BED was an independent predictor of the degree of improvement in all three dimensions of pain severity. A decrease in dose rate by 1.5 Gy/min corresponded to 31.8% less improvement in the overall severity of pain. Post-radiosurgery incidence of facial numbness was increased for BEDs in the highest quartile. Treatment time is an independent predictor of pain outcomes, suggesting that prescription dose should be customized to ensure iso-effective treatments, while accounting for the possible increase in adverse effects at the highest BEDs.

Objectives: Stereotactic body radiotherapy (SBRT) can sterilize the portal vein tumour thrombus (PVTT) and may make the patient eligible for liver transplant. We assessed the radiological response of PVTT after SBRT and check incidence of radiation induced liver disease (RILD).

Methods: PVTT treatment response was measured at 4-6 weeks as per mRECIST criteria, volume of PVTT and its enhancement in arterial phase. Biochemical data and Child-Pugh scoring (CPC) were evaluated to determine RILD incidence.

Results: 31 Patients were included. Complete response was seen in 5 patients (16.1%), partial response in 13 patients (41.9%), stable disease in 12 patients (38.7%). Mean volume of PVTT was 15.05 cc before SBRT and 7.83 cc afterwards (p = 0.001). The mean enhancement of the lesion was 86.19HU before SBRT vs 58.58HU after SBRT (p = 0.000). Two patients had grade 3 adverse events.

Conclusion: Volume, enhancement, and major axis length of PVTT showed statistically significant improvement after SBRT. No case had RILD after SBRT.