Increasing radiation therapy dose is associated with improved survival in patients undergoing stereotactic body radiation therapy for stage I non-small-cell lung cancer.

To determine the comparative effectiveness of different stereotactic body radiation therapy (SBRT) dosing regimens for early-stage non-small-cell lung cancer, using a large national database, focusing on the relative impact of dose as a function of tumor stage. The study included patients in the National Cancer Database from 2003 to 2006 with T1-T2N0M0 inoperable lung cancer (n=498). The biologically effective dose (BED) was calculated according to the linear quadratic formula using an α/β ratio of 10. High versus lower-dose (HD vs LD) SBRT was defined as a calculated BED above or below 150 Gy. Overall survival was estimated using Kaplan-Meier methods and Cox proportional hazard regression. The 5 most common dose fractionation schemes (percentage of cohort) used were 20 Gy × 3 (34%), 12 Gy × 4 (16%), 18 Gy × 3 (10%), 15 Gy × 3 (10%), and 16 Gy × 3 (4%). The median calculated BED was 150 Gy (interquartile range 106-166 Gy). The 3-year overall survival (OS) for patients who received HD versus LD was 55% versus 46% (log-rank P=.03). On subset analysis of the T1 cohort there was no association between calculated BED and 3-year OS (61% vs 60% with HD vs LD, P=.9). Among the T2 cohort, patients receiving HD experienced superior 3-year OS (37% vs 24%, P=.01). On multivariable analysis, factors independently prognostic for mortality were female gender (hazard ratio [HR] 0.76, P=.01), T2 tumor (HR 1.99, P=.0001), and HD (HR 0.68, P=.001). This comparative effectiveness analysis of SBRT dose for patients with stage I non-small-cell lung cancer suggests that higher doses (>150 Gy BED) are associated with a significant survival benefit in patients with T2 tumors.

Koshy M ，Malik R ，Weichselbaum RR ，Sher DJ ... -  《-》

The Effect of Biologically Effective Dose and Radiation Treatment Schedule on Overall Survival in Stage I Non-Small Cell Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy.

To determine the effect of biologically effective dose (BED10) and radiation treatment schedule on overall survival (OS) in patients with early-stage non-small cell lung cancer (NSCLC) undergoing stereotactic body radiation therapy (SBRT). Using data from 65 treatment centers in the United States, we retrospectively reviewed the records of T1-2 N0 NSCLC patients undergoing SBRT alone from 2006 to 2014. Biologically relevant covariates, including dose per fraction, number of fractions, and time between fractions, were used to quantify BED10 and radiation treatment schedule. The linear-quadratic equation was used to calculate BED10 and to generate a dichotomous dose variable of <105 Gy versus ≥105 Gy BED10. The primary outcome was OS. We used the Kaplan-Meier method, the log-rank test, and Cox proportional hazards regression with propensity score matching to determine whether prescription BED10 was associated with OS. We identified 747 patients who met inclusion criteria. The median BED10 was 132 Gy, and 59 (7.7%) had consecutive-day fractions. Median follow-up was 41 months, and 452 patients (60.5%) had died by the conclusion of the study. The 581 patients receiving ≥105 Gy BED10 had a median survival of 28 months, whereas the 166 patients receiving <105 Gy BED10 had a median survival of 22 months (log-rank, P=.01). Radiation treatment schedule was not a significant predictor of OS on univariable analysis. After adjusting for T stage, sex, tumor histology, and Eastern Cooperative Oncology Group performance status, BED10 ≥105 Gy versus <105 Gy remained significantly associated with improved OS (hazard ratio 0.78, 95% confidence interval 0.62-0.98, P=.03). Propensity score matching on imbalanced variables within high- and low-dose cohorts confirmed a survival benefit with higher prescription dose. We found that dose escalation to 105 Gy BED10 and beyond may improve survival in NSCLC patients treated with SBRT.

Stahl JM ，Ross R ，Harder EM ，Mancini BR ，Soulos PR ，Finkelstein SE ，Shafman TD ，Dosoretz AP ，Evans SB ，Husain ZA ，Yu JB ，Gross CP ，Decker RH ... -  《-》

Stereotactic body radiotherapy for centrally located early-stage non-small cell lung cancer or lung metastases from the RSSearch(®) patient registry.

Davis JN ，Medbery C ，Sharma S ，Pablo J ，Kimsey F ，Perry D ，Muacevic A ，Mahadevan A ... -  《Radiation Oncology》

Size matters: a comparison of T1 and T2 peripheral non-small-cell lung cancers treated with stereotactic body radiation therapy (SBRT).

The purpose of this study was to compare the outcomes and local control rates of patients with peripheral T1 and T2 non-small-cell lung cancer treated with stereotactic body radiation therapy. The records of 40 consecutive patients treated with 3- or 5-fraction lung stereotactic body radiation therapy for peripheral, clinical stage I non-small-cell lung cancer were reviewed. Stereotactic body radiation therapy was delivered at a median dose of 60 Gy. Doses to organs at risk were limited based on the Radiation Therapy Oncology Group 0236 treatment protocol. Patients were staged clinically. Median follow was 12.5 months. Twenty-seven (67%) patients and 13 (33%) patients had T1 and T2 tumors, respectively. Thirty-seven (94%) patients were medically inoperable. Nine (23%) patients had chest wall pain after stereotactic body radiation therapy. Symptomatic pneumonitis developed in 4 (10%) patients. Increasing tumor size correlated with worse local control and overall survival. The median recurrence-free survival for T1 and T2 tumors was 30.6 months (95% confidence interval [CI], 26.9-34.2) and 20.5 months (95% CI, 14.3-26.5), respectively (P = .038). Local control at 2 years was 90% and 70% in T1 and T2 tumors, respectively (P = .03). The median survival for T1 and T2 tumors was 20 months (95% CI, 20.1-31.6) and 16.7 months (95% CI, 10.8-21.2), respectively (P = .073). Stereotactic body radiation therapy for T2 non-small-cell lung cancer has a higher local recurrence rate and trended toward a worse survival than did T1 lesions. Tumor size is an important predictor of response to stereotactic body radiation therapy and should be considered in treatment planning.

Dunlap NE ，Larner JM ，Read PW ，Kozower BD ，Lau CL ，Sheng K ，Jones DR ... -  《-》

30 Gy or 34 Gy? Comparing 2 single-fraction SBRT dose schedules for stage I medically inoperable non-small cell lung cancer.

To review outcomes of 2 single-fraction lung stereotactic body radiation therapy (SBRT) schedules used for medically inoperable early stage lung cancer. Patients in our institution have been treated on and off protocols using single-fraction SBRT (30 Gy and 34 Gy, respectively). All patients had node-negative lung cancer measuring ≤5 cm and lying ≥2 cm beyond the trachea-bronchial tree and were treated on a Novalis/BrainLAB system with the ExactTrac positioning system for daily image guidance. For the interval from 2009 to 2012, 80 patients with 82 lesions were treated with single-fraction lung SBRT. Fifty-five patients (69%) and 25 patients (31%) received 30 Gy and 34 Gy, respectively. In a comparison of 30 Gy and 34 Gy cohorts, patient and tumor characteristics were balanced and median follow-up in months was 18.7 and 17.8, respectively. The average heterogeneity-corrected mean doses to the target were 33.75 Gy and 37.94 Gy for the 30-Gy and 34-Gy prescriptions, respectively. Comparing 30-Gy and 34-Gy cohorts, 92.7% and 84.0% of patients, respectively, experienced no toxicity (P was not significant), and had neither grade 3 nor higher toxicities. For the 30-Gy and 34-Gy patients, rates of 1-year local failure, overall survival, and lung cancer-specific mortality were 2.0% versus 13.8%, 75.0% versus 64.0%, and 2. 1% versus 16.0%, respectively (P values for differences were not significant). This is the largest single-fraction lung SBRT series yet reported. and it confirms the safety, efficacy, and minimal toxicity of this schedule for inoperable early stage lung cancer.

Videtic GM ，Stephans KL ，Woody NM ，Reddy CA ，Zhuang T ，Magnelli A ，Djemil T ... -  《-》