A Prospective Analysis of Quality of Life Data and Clinical Toxicity as a Function of Radiation Dose and Volume in Stage I Lung Cancer Patients after SBRT
Feldman A, Devpura S, Movsas B, Chetty I, Cook A, Rusu S, Brown S, Kim J, Sun Z, Ajlouni M, mayyas E, Liu J, Liu C, and Snell D. A Prospective Analysis of Quality of Life Data and Clinical Toxicity as a Function of Radiation Dose and Volume in Stage I Lung Cancer Patients after SBRT. International Journal of Radiation Oncology Biology Physics 2020; 108(2):E64.
International Journal of Radiation Oncology Biology Physics
Background: Stereotactic body radiation therapy (SBRT) is an appropriate treatment option for patients with stage I non-small cell lung cancer (NSCLC) who are not surgical candidates. As these patients often present with significant co-morbidities, quality of life (QOL) outcomes are especially important.
Objectives: To use a validated patient reported quality of life (QOL) assessment tool to measure clinical toxicity and patient reported quality of life (QOL) outcomes up to 36 months after SBRT in stage I NSCLC patients based on pre-treatment dosimetric parameters and tumor volumes.
Methods: Fifty-six stage I NSCLC patients treated with SBRT (12 Gy x 4) were prospectively monitored for symptoms including cough, dyspnea, fatigue, and pneumonitis. Symptoms were measured at baseline (before treatment), immediately after treatment and 3, 6, 12, 18, 24, and 36 months post-treatment. Toxicity was graded from zero to five following the Charlson comorbidity and toxicity index. Quality of life was determined using the previously-validated Functional Assessment of Cancer Therapy-Trial Outcome Index (FACT-TOI) Lung questionnaire which incorporated three subscale endpoints: lung subscale (LSC), physical well-being (PWB) and functional well-being (FWB). Dosimetric parameters, including the mean lung radiation dose (MLD), and the volume of normal lung receiving at least 5, 10, 13 or 20 Gy (V5, V10, V13, and V20) were obtained from the treatment plan. Pearson correlation and student t-test analyses were used to measure correlations and distinguish between lung metrics with QOL and clinical toxicities.
Results: SBRT produced minimal toxicities. QOL (TOI, LSC, PWB, or FWB) at 3, 6, 12 and 24 months post-treatment were significantly correlated with V5, V10, V13, V20, or MLD. Radiation pneumonitis showed mild positive but statistically significant (P < 0.05) correlation with V20. Moreover, FWB at 3 months showed mild negative correlation with dyspnea.
Conclusions: Lung SBRT treatment for patients with NSCLC, using a 12 Gy x 4 dose regimen, was well tolerated with minimal toxicity observed. A validated patient related quality of life assessment tool was used to identify the dosimetric parameters most crucial for treatment planning. Further follow-up is recommended.