Influence of Fractionation Scheme and Tumor Location on Toxicities Following Stereotactic Body Radiotherapy for Large (≥5 Centimeter) Non-Small Cell Lung Cancer: A Multi-Institutional Analysis

Publication date: Available online 2 December 2016
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Vivek Verma, Valerie K. Shostrom, Weining Zhen, Mutian Zhang, Steve E. Braunstein, John Holland, Christopher L. Hallemeier, Matthew M. Harkenrider, Adrian Iskhanian, Salma K. Jabbour, Albert Attia, Percy Lee, Kyle Wang, Roy H. Decker, Ronald C. McGarry, Charles B. Simone
PurposeStereotactic body radiotherapy (SBRT) for ≥5cm non-small cell lung cancer (NSCLC) has been understudied. There are concerns regarding toxicities from irradiating higher volumes with ablative doses. We describe the impact of fractionation scheme and tumor location on toxicities as part of a multi-institutional analysis.MethodsPatients with primary ≥5cm N0 M0 NSCLC that underwent ≤5-fraction SBRT were examined across multiple high-volume SBRT centers. Collected data included clinical/treatment parameters; toxicities were prospectively assessed at each institution according to CTCAE. Patients treated daily were compared to those treated every other day (QOD)/other nondaily regimens. Stratification between central and peripheral tumors was also performed.ResultsNinety-two patients from 12 institutions were evaluated (2004-2016) with median follow-up of 12 months. In total, there were 23 (25%) and six (7%) grade ≥2 and grade ≥3 toxicities, respectively. Grades 2 and 3 pulmonary toxicities occurred in 9%, and 4%, respectively; one patient treated daily experienced grade 5 radiation pneumonitis. Patients experiencing pulmonary toxicities had greater smoking history (median 70 vs. 53 pack-years, p=0.009). Of the entire cohort, 46 patients underwent daily SBRT and 46 received every other day (QOD, n=40)/other nondaily (n=6) regimens. Clinical/treatment parameters were similar between groups; the QOD/other group was more likely to receive 3-/4-fraction schemas. Patients treated QOD/other experienced significantly fewer grade ≥2 toxicities as compared to daily treatment (7% vs. 43%, p<0.001). Patients treated daily also had higher rates of grade ≥2 pulmonary toxicities (p=0.014) and any toxicities (p<0.001). Patients with peripheral tumors (N=66) were more likely to receive 3-/4-fraction regimens than those with central tumors (N=26). No significant differences in grade ≥2 toxicities were identified according to tumor location (p>0.05).ConclusionsFrom this multi-institutional study, toxicity of SBRT for ≥5cm lesions is acceptable, and daily treatment was associated with a higher rate of toxicities.

Teaser

There are toxicity concerns from irradiating large (≥5cm) non-small cell lung cancers with stereotactic body radiotherapy (≤5-fractions). We describe the impact of fractionation scheme and tumor location on toxicities as part of a multi-institutional analysis. Although there was no association with tumor location (central versus peripheral), receipt of daily radiotherapy (as opposed to every other day/other regimens) was associated with a higher rate of toxicity.


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