Colorectal Histology Is Associated With an Increased Risk of Local Failure in Lung Metastases Treated With Stereotactic Ablative Radiation Therapy

Journal Article · Sat Aug 01 04:00:00 UTC 2015 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2015.04.004· OSTI ID:22462400

Binkley, Michael S. ^[1]; Trakul, Nicholas ^[2]; Jacobs, Lisa Rose; Eyben, Rie von; Le, Quynh-Thu; Maxim, Peter G.; Loo, Billy W. ^[1]; Diehn, Maximilian ^[1]

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1. Department of Radiation Oncology and Cancer Institute, Stanford University School of Medicine, Stanford, California (United States)
2. Department of Radiation Oncology, University of Southern California Keck School of Medicine, Los Angeles, California (United States)

Purpose: Stereotactic ablative radiation therapy (SABR) is increasingly used to treat lung oligometastases. We set out to determine the safety and efficacy of this approach and to identify factors associated with outcomes. Methods and Materials: We conducted a retrospective study of patients treated with SABR for metastatic lung tumors at our institution from 2003 to 2014. We assessed the association between various patient and treatment factors with local failure (LF), progression, subsequent treatment, systemic treatment, and overall survival (OS), using univariate and multivariate analyses. Results: We identified 122 tumors in 77 patients meeting inclusion criteria for this study. Median follow-up was 22 months. The 12- and 24-month cumulative incidence rates of LF were 8.7% and 16.2%, respectively; the 24-month cumulative incidence rates of progression, subsequent treatment, and subsequent systemic treatment were 75.2%, 64.5%, and 35.1%, respectively. Twenty-four-month OS was 74.6%, and median OS was 36 months. Colorectal metastases had a significantly higher cumulative incidence of LF at 12 and 24 months (25.5% and 42.2%, respectively), than all other histologies (4.4% and 9.9%, respectively; P<.0004). The 24-month cumulative incidences of LF for colorectal metastases treated with a biologically effective dose at α/β = 10 (BED{sub 10}) of <100 Gy versus BED{sub 10} of ≥100 Gy were 62.5% and 16.7%, respectively (P=.08). Toxicity was minimal, with only a single grade 3 or higher event observed. Conclusions: SABR for metastatic lung tumors appears to be safe and effective with excellent local control, treatment-free intervals, and OS. An exception is metastases from colorectal cancer, which have a high LF rate consistent with a radioresistant phenotype, suggesting a potential role for dose escalation.

• OSTI ID: 22462400
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 92; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
HISTOLOGY
LUNGS
METASTASES
MULTIVARIATE ANALYSIS
NEOPLASMS
PATIENTS
PHENOTYPE
RADIATION DOSES
RADIOSENSITIVITY
RADIOTHERAPY
TOXICITY