Can Metabolic Activity Predict Response in Early-Stage Lung Cancer Treated with Stereotactic Body Radiation Therapy?

Abstract

165 ISSN 1758-1966 10.2217/LMT.13.17 © 2013 Future Medicine Ltd Lung Cancer Manage. (2013) 2(3), 165–167 Lung cancer has been and continues to be a devastating disease, with projections for 2013 estimating 228,190 new cases, while 159,480 individuals will succumb to their disease [101]. Although intensive molecular studies have identified novel target therapies, such as that for ALK-mutated metastatic disease, there is relatively little new information for patients diagnosed with early-stage disease. This is especially important with the increased utilization of screening protocols to detect early-stage disease and the now relatively widespread implementation of stereotactic body radiation therapy (SBRT) for patients who are medically inoperable or elect for this promising treatment over that of more invasive therapies. With fluorodeoxyglucose-PET scanning being a part of the standard staging protocols [1], there is additional information on the metabolic activity of tumors, which, beyond diagnostic and planning purposes, is largely ignored. The question that has been asked is: can this information be used to identify a high-risk cohort that may potentially benefit from more aggressive initial therapy? This question can in part be answered by extrapolating from the surgical literature, as both modalities are often used to treat early-stage disease. In a 2010 metaanalysis sanctioned by the International Association for the Study of Lung Cancer (IASLC), the maximum standardized uptake value (SUV max ) was found to be a useful marker for predicting overall survival in definitive surgical lung cancer patients [2]. Patients who receive SBRT as therapy, however, often lack a histological diagnosis and are treated based on interval changes in radiographic and PET findings, leaving the multidisciplinary team with relatively little information about the patient’s disease compared with those with pathological findings. Because it is expected that the patients have a similar disease process, a projection from the surgical literature would indicate that SUV max may be a useful marker for patients treated with SBRT.