Assessment of minimum target dose as a predictor of local failure after spine SBRT.

OBJECTIVES: Metastasis-directed stereotactic body radiation therapy (SBRT) has demonstrated robust clinical benefits in carefully selected patients, improving local control and even overall survival (OS). We assess a large database to determine clinical and dosimetric predictors of local failure after spine SBRT. METHODS: Spine SBRT treatments with imaging follow-up were identified. Patients were treated with a simultaneous integrated boost technique using 1 or 3 fractions, delivering 20-24 Gy in 1 fraction to the gross tumor volume (GTV) and 16 Gy to the low dose volume (or 27-36 Gy and 21-24 Gy for 3 fraction treatments). Exclusions included: lack of imaging follow-up, proton therapy, and benign primary histologies. RESULTS: 522 eligible spine SBRT treatments (68 % single fraction) were identified in 377 unique patients. Patients had a median OS of 43.7 months (95 % confidence interval: 34.3-54.4). The cumulative incidence of local failure was 10.5 % (7.4-13.4) at 1 year and 16.3 % (12.6-19.9) at 2 years. Local control was maximized at 15.3 Gy minimum dose for single-fraction treatment (HR = 0.31, 95 % CI: 0.17 - 0.56, p < 0.0001) and confirmed via multivariable analyses. Cumulative incidence of local failure was 6.1 % (2.6-9.4) vs. 14.2 % (8.3-19.8) at 1 year using this cut-off, with comparable findings for minimum 14 Gy. Additionally, epidural and soft tissue involvement were predictive of local failure (HR = 1.77 and 2.30). CONCLUSIONS: Spine SBRT offers favorable local control; however, minimum dose to the GTV has a strong association with local control. Achieving GTV minimum dose of 14-15.3 Gy with single fraction SBRT is recommended whenever possible.

Cost and clinical outcomes of postoperative intensive care unit versus general floor management in head and neck free flap reconstructive surgery patients.

PURPOSE: To compare clinical, surgical, and cost outcomes in patients undergoing head and neck free-flap reconstructive surgery in the setting of postoperative intensive care unit (ICU) against general floor management. METHODS: Retrospective analysis of head and neck free-flap reconstructive surgery patients at a single tertiary academic medical center. Clinical data was obtained from medical records. Cost data was obtained via the Mayo Clinic Rochester Cost Data Warehouse, which assigns Medicare reimbursement rates to all professional billed services. RESULTS: A total of 502 patients were included, with 82 managed postoperatively in the ICU and 420 on the general floor. Major postoperative outcomes did not differ significantly between groups (Odds Ratio[OR] 1.54; p = 0.41). After covariate adjustments, patients managed in the ICU had a 3.29 day increased average length of hospital stay (Standard Error 0.71; p < 0.0001) and increased need for take-back surgery (OR 2.35; p = 0.02) when compared to the general floor. No significant differences were noted between groups in terms of early free-flap complications (OR 1.38;p = 0.35) or late free-flap complications (Hazard Ratio 0.81; p = 0.61). Short-term cost was $8772 higher in the ICU (range = $5640-$11,903; p < 0.01). Long-term cost did not differ significantly. CONCLUSION: Postoperative management of head and neck oncologic free-flap patients in the ICU does not significantly improve major postoperative outcomes or free-flap complications when compared to general floor care, but does increase short-term costs. General floor management may be appropriate when cardiopulmonary compromise is not present.