Contrast enhanced dynamic MRI of cervical carcinoma during radiotherapy: early prediction of tumour regression rate

This prospective study investigated the relationship between changes in the MRI dynamic enhancement of cervical carcinoma early during radiotherapy, and tumour regression rate throughout radiotherapy. A total of 36 MRI examinations was performed in seven patients with cervical carcinoma, including a T2 weighted sequence weekly during radiotherapy and also a multislice dynamic Gd-DTPA enhanced sequence before and after the first 2 weeks of radiotherapy. Tumour enhancement was determined on dynamic images using a region of interest and signal-to-noise ratio method. Serial tumour volumes over time on T2 weighted images were estimated using the Cavalieri method of modern design-based stereology to obtain tumour regression rate. It was found that peak and mean enhancement prior to radiotherapy ranged from 3.0 to 13.3, and from 1.9 to 12.2, respectively. After 2 weeks of radiotherapy, peak and mean enhancement ranged from 7.5 to 13.0, and from 6.3 to 10.6, respectively. The change in peak and mean tumour enhanc...