FDG PET/CT in monitoring neoadjuvant chemotherapy response in cervical cancer patients

Objectives To Evaluate FDG PET/CT in predicting the response of neoadjuvant chemotherapy(NAC) with palclitaxel combining cisplatin in cervical cancer patients.

Methods Eleven new diagnosed cervical cancer patients (mean age 50.5±5.8 years) with FIGO stage Ib2 to IIA, who received 3 cycles of NAC, underwent PET/CT scans at baseline, after 2nd cycles, and the end of NAC. SUVmax of FDG PET/CT was calculated. SUVmax percentage changes between baseline and after 2nd cycles (ΔSUVmax(2nd cycle-baseline)), and between baseline and the end (ΔSUVmax(end-baseline))of NAC were compared with the pathologic response.

Results 3 patients were considered pathologic response group (1 no residual tumor and 2 only microscopic diseases), and 8 patients were pathologic macroscopic disease. Cutoff ΔSUVmax(2nd cycle-baseline) value was 35% for predicting pathologic macroscopic disease from pathologic response group, with a sensitivity of 75%, a specificity of 100%, a positive predictive value of 100%, negative predictive value of 60%, and accuracy of 81.2%. And 75% cutoff ΔSUVmax(end-baseline) value for predicting pathologic macroscopic disease showed a sensitivity of 100%, a specificity of 33.3%, a positive predictive value of 80%, negative predictive value of 100%, and accuracy of 81.2%.

Conclusions Metabolic response by FDG PET/CT at early stage can predict the pathologic macroscopic disease group, who ΔSUVmax(baseline-2nd cycle) < 35% was unable to obtain pathologic complete response or only microscopic disease after completely neoadjuvant chemotherapy.

Research Support This study was supported by grants CMRPG381121 from Chang Gung Memorial Hospital at Linko