Role of conventional and diffusion weighted MRI in predicting treatment response after low dose radiation and chemotherapy in locally advanced carcinoma cervix.

Background And Purpose: To assess the diagnostic performance of conventional and diffusion weighted (DWI) magnetic resonance imaging (MRI) in predicting response in locally advanced cervical cancer.

Materials And Methods: Total 24 patients with stage IIB-IIIB squamous cell carcinoma cervix were treated with initial two cycles of paclitaxel and carboplatin and concurrent low dose radiotherapy prior to standard chemoradiation. Response was assessed clinically and radiologically after 3 weeks of initial treatment. Volumetric and functional parameters derived from conventional and diffusion weighted MRI, due to treatment were measured.

Results: Significant reduction of GTV was noted in MRI (54 cm(3) vs. 11 cm(3), p < 0.01) and DWI (44 cm(3) vs. 6 cm(3), p < 0.01, ΔADC = 0.49 × 10(-3)mm(2)/sec, p < 0.01) after treatment. Tumor volume reduction rate (TVRR) in DWI was significantly higher in pathological good responders (p = 0.03). In this group both mean post treatment apparent diffusion coefficient (ADC) value and ΔADC were significantly higher (p = 0.01 and p = 0.03). ADC was a good predictor for pathological response (area under receiver operating characteristic curve (ROC) 0.814).

Conclusion: TVRR (DWI) and ΔADC can be used as a predictor of early pathological response. Complete response based on DWI, could be a useful predictor of long term disease control.