PT - JOURNAL ARTICLE AU - Victor Kalff AU - Cuong Duong AU - Elizabeth G. Drummond AU - Jane P. Matthews AU - Rodney J. Hicks TI - Findings on <sup>18</sup>F-FDG PET Scans After Neoadjuvant Chemoradiation Provides Prognostic Stratification in Patients with Locally Advanced Rectal Carcinoma Subsequently Treated by Radical Surgery DP - 2006 Jan 01 TA - Journal of Nuclear Medicine PG - 14--22 VI - 47 IP - 1 4099 - http://jnm.snmjournals.org/content/47/1/14.short 4100 - http://jnm.snmjournals.org/content/47/1/14.full SO - J Nucl Med2006 Jan 01; 47 AB - Predicting outcome after aggressive therapy for advanced rectal cancer remains difficult. 18F-FDG PET has emerged as a valid method for predicting patient outcomes after therapy in an increasing number of cancers. We evaluated the prognostic information obtained from the degree of change in tumor 18F-FDG PET uptake induced by chemoradiation before radical curative surgery in patients with T3/T4 rectal cancer. Methods: The study included 34 consecutive patients with T3/T4 Nx M0 rectal cancer on structural imaging, who underwent staging and postchemoradiation 18F-FDG PET before planned curative surgery. Change in 18F-FDG uptake was graded visually as complete (CMR), partial (PMR), or no (NoMR) metabolic response. Pre- and postchemoradiation 18F-FDG PET–derived standardized uptake values (SUVs) were then obtained for PMR patients to determine whether SUV further stratified this subgroup. Operative findings were available in 30 patients (3 excluded because of 18F-FDG PET–defined M1 disease, 1 refused surgery). Clinical status at study closeout (alive free from disease, FFD; alive with disease, AWD; or died of disease, DOD) was available for all patients. Results: A pathologic complete response was found in only 6 of 30 patients (5 CMR, 1 false-positive PMR). However, after an estimated median 3.1 y of follow-up, all 17 CMR patients were FFD, 6 of 10 PMR patients were FFD, 2 of 10 had DOD, and 2 of 10 were AWD. All 3 NoMR patients DOD. PET response was highly significantly associated with overall survival duration (P &lt; 0.0001) and time to progression (P &lt; 0.0001). Pathologic complete response was the only other statistically significant prognostic factor (P &lt; 0.03). The percentage of maximum SUV change after chemoradiation was not predictive of survival in PMR patients. Conclusion: Using a simple qualitative assessment, postchemoradiation 18F-FDG PET scintigraphy provides good medium-term prognostic information in patients with advanced rectal cancer undergoing radical surgery with curative intent.