Positron Emission Tomography with 18Fluorodeoxyglucose in Radiation Treatment Planning for Non-small Cell Lung Cancer: A Systematic Review

Introduction:This article summarizes the available evidence on the role of 18fluorodeoxy-d-glucose positron emission tomography (PET) and PET-computed tomography in radiation treatment (RT) planning for non-small cell lung cancer.Methods:Relevant studies were identified through a systematic review of the medical literature between January 1996 and May 2010. Medline, EMBASE, and the Cochrane databases were searched.Results:Twenty-eight nonrandomized prospective and retrospective studies and one randomized trial reported in abstract form were identified. There were no guidelines, systematic reviews, or meta-analyses found in the search. There are no data available that demonstrate an impact of PET-based RT planning on survival or local recurrence rates. Nineteen studies reported changes in gross tumor volume, and 11 studies reported changes in planning target volume. The limited data suggest that PET in RT planning is more likely to decrease the dose to the esophagus, but the data on the dose to lung tissue are mixed. In two studies that evaluated the effect of PET on total RT dose administered to patients, the RT dose increased by approximately 15 Gy and tumor control probability increased by 8.6% and 17.7% (p = 0.026). In 12 studies, PET detected distant metastases in 8 to 25% of patients and resulted in a change from curative to palliative RT intent in 8 to 41% of patients.Conclusions:The inclusion of PET imaging in the planning process produces modifications in RT planning that may be beneficial. These changes include a change in treatment intent from radical to palliative and substantial modifications of the gross tumor volume and planning target volume. It is not certain that these changes result in better clinical outcomes, but ongoing evaluation of PET for this purpose is warranted.