Histogram analysis of apparent diffusion coefficient for the assessment of local aggressiveness of cervical cancer

Purpose To retrospectively explore the value of apparent diffusion coefficient (ADC) histogram in assessing local aggressiveness of cervical cancer. Methods 53 patients with cervical cancer, including 7 cases at stage IB1, 17 cases at stage IB2 and 29 cases at stage IIA, were subjected to preoperative MRI including diffusion-weighted imaging with b values of 0 and 800 s/mm 2 . The average of mean ADC values (ADC mean ), minimum ADC values (ADC min ) and the 5th to 85th percentile ADC values every 10 % (ADC 5 % , ADC 15 % , ADC 85 % ) were measured. ADC values were compared between subgroups according to pathologic subtype, histological differentiation, depth of cervical infiltration, and lymph node metastases. Results ADC mean and ADC min for adenocarcinoma were 1,170.3 ± 97.8 × 10 −6 and 748.7 ± 157.5 × 10 −6 mm 2 s −1 , respectively, significantly higher than that of squamous cell carcinoma (SCC) (1,053.8 ± 134.3 × 10 −6 and 615.6 ± 170.2 × 10 −6 mm 2 s −1 , respectively). ADC mean and ADC 5 % –ADC 85 % of well or moderately tumor were significantly higher than poorly differentiated tumor, but ADC min was not significantly different among different differentiated cervical cancer. Only ADC 5 % –ADC 45 % could discriminate well or moderately differentiated SCC from poorly differentiated SCC. ADC 5 % for distinguishing well/moderately from poorly differentiated cervical cancer had a largest AUC (0.83). There was no statistical difference in ADC value for different depth of cervical infiltration or lymph node metastases. Conclusions ADC values are helpful in assessing pathologic subtype and the differentiation of cervical cancer.