Positron emission tomography scan for predicting clinical outcome of patients with recurrent cervical carcinoma following radiation therapy

Abstract

To evaluate the role of positron emission tomography (PET) for predicting the clinical outcome of patients with recurrent cervical carcinoma following definitive radiation therapy (RT). Twenty two patients of post irradiated recurrent cervical carcinoma (PIRCC) were enrolled in this prospective study. 18-fluorodeoxyglucose (FDG) PET imaging was performed in each patient before the salvage therapy. The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) were measured and correlated with cumulative progression free survival (PFS). Median age of patients was 42 years. Majority of patients had stage III disease at the initial presentation and all 22 patients had received prior definitive RT. The median recurrence free period was 11 months. Salvage therapy consisted of surgical resection or re-irradiation depending upon the various clinical and radiological factors. Median SUVmax was 5.8 (range 1.8-50.6) and median MTV was 43 cm³ (range 5.8-243). The cumulative PFS for all patients was 20% at 30 months. The one-year PFS was 28% for patients with SUVmax value of >5.8 versus 42% for those with SUVmax value of <5.8 (P value 0.01). The one-year PFS was 43% for patients with MTV value of >43 cm³ versus 45% for those with MTV value of <43 cm³ (P value 0.8). Our preliminary experience has suggested that FDG uptake on PET scan can predict the clinical outcome of PIRCC patients. Further randomized studies may be conducted with large sample size and longer follow up to establish its definite predictive value.