Use of Metabolic Parameters as Prognostic Factors During Concomitant Chemoradiotherapy for Locally Advanced Cervical...

To investigate the use of metabolic parameters as early prognostic factors during concomitant chemoradiotherapy for locally advanced cervix carcinoma (LACC).

Between February 2008 and January 2012, 34 consecutive patients treated for LACC (International Federation of Gynecology and Obstetrics Staging System stage IB2-IVA) were included in a retrospective study. Treatment was standard of care: total dose of 45 Gy in 1.8 Gy per fraction with concurrent cisplatin followed by brachytherapy. 18F-FDG PET-CT modalities were performed before treatment and per-treatment (at 40 Gy). The analyzed parameters were: maximum standardized uptake value (SUVmax), SUVmax variations of the primary tumor between the 2 investigations (DSUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Survival was assessed according to early metabolic changes during chemoradiotherapy.

Median follow-up was 16 months (range, 5.3 to 32.4 mo). Median SUVmax before treatment was 13.15 (5.9 to 31) and was 5.05 (0 to 12) per-treatment. Median DSUVmax was 63.97% (0% to 100%). Median MTV before treatment was 44.16 mL (3.392 to 252.768 mL) and was 5.44 mL (0 to 69.88 mL) per-treatment. Median TLG before treatment was 249.82 mL (13.40 to 1931.10 mL) and was 20.14 mL (0 to 349.99 mL) per-treatment. At 40 Gy, SUVmax≥6, DSUVmax≤40%, MTV≥5.6 mL, and TLG≥21.6 mL were significantly associated with overall survival and progression-free survival reduction. MTV predicted progression with a sensitivity of 80% and a specificity of 87.5% and TLG with a sensitivity of 80% and a specificity of 83.3%.

PET-CT imaging could be useful as an early prognostic factor during treatment for LACC. MTV and TLG seem to provide better prognostic information than SUVmax and DSUVmax.