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

Journal Article · Thu Dec 01 04:00:00 EST 2016 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2016.08.033· OSTI ID:22645723

Stahl, John M. ^[1]; Ross, Rudi ^[2]; Harder, Eileen M.; Mancini, Brandon R. ^[1]; Soulos, Pamela R. ^[3]; Finkelstein, Steven E.; Shafman, Timothy D.; Dosoretz, Arie P. ^[2]; Evans, Suzanne B.; Husain, Zain A.; Yu, James B. ^[1]; Gross, Cary P. ^[3]

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1. Department of Therapeutic Radiology, Yale School of Medicine, New Haven, Connecticut (United States)
2. 21st Century Oncology, Fort Myers, Florida (United States)
3. Cancer Outcomes, Public Policy and Effectiveness Research (COPPER) Center, Yale School of Medicine, New Haven, Connecticut (United States)

Purpose: To determine the effect of biologically effective dose (BED{sub 10}) 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). Methods and Materials: 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 BED{sub 10} and radiation treatment schedule. The linear-quadratic equation was used to calculate BED{sub 10} and to generate a dichotomous dose variable of <105 Gy versus ≥105 Gy BED{sub 10}. 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 BED{sub 10} was associated with OS. Results: We identified 747 patients who met inclusion criteria. The median BED{sub 10} 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 BED{sub 10} had a median survival of 28 months, whereas the 166 patients receiving <105 Gy BED{sub 10} 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, BED{sub 10} ≥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. Conclusions: We found that dose escalation to 105 Gy BED{sub 10} and beyond may improve survival in NSCLC patients treated with SBRT.

• OSTI ID: 22645723
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 96; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
GY RANGE 100-1000
LUNGS
NEOPLASMS
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SCHEDULES