18Fluorodeoxyglucose PET Is Prognostic of Progression-Free and Overall Survival in Locally Advanced Pancreas Cancer Treated With Stereotactic Radiotherapy

ArticleinInternational journal of radiation oncology, biology, physics 77(5):1420-5 · August 2010with10 Reads
Impact Factor: 4.26 · DOI: 10.1016/j.ijrobp.2009.06.049 · Source: PubMed

    Abstract

    This study analyzed the prognostic value of positron emission tomography (PET) for locally advanced pancreas cancer patients undergoing stereotactic body radiotherapy (SBRT).
    Fifty-five previously untreated, unresectable pancreas cancer patients received a single fraction of 25-Gy SBRT sequentially with gemcitabine-based chemotherapy. On the preradiation PET-CT, the tumor was contoured and the maximum standardized uptake value (SUVmax) and metabolic tumor burden (MTB) were calculated using an in-house software application. High-SUVmax and low-SUVmax subgroups were created by categorizing patients above or below the median SUVmax. The analysis was repeated to form high-MTB and low-MTB subgroups as well as clinically relevant subgroups with SUVmax values of <5, 5-10, or >10. Multivariate analysis analyzing SUVmax, MTB, age, chemotherapy cycles, and pretreatment carbohydrate antigen (CA)19-9 was performed.
    For the entire population, median survival was 12.7 months. Median survival was 9.8 vs.15.3 months for the high- and low- SUVmax subgroups (p <0.01). Similarly, median survival was 10.1 vs. 18.0 months for the high MTB and low MTB subgroups (p <0.01). When clinical SUVmax cutoffs were used, median survival was 6.4 months in those with SUVmax >10, 9.5 months with SUVmax 5.0-10.0, and 17.7 months in those with SUVmax <5 (p <0.01). On multivariate analysis, clinical SUVmax was an independent predictor for overall survival (p = 0.03) and progression-free survival (p = 0.03).
    PET scan parameters can predict for length of survival in locally advanced pancreas cancer patients.