Objective:To explore the correlation of apparent diffusion coefficient (ADC) of magnetic resonance diffusion weighted imaging (DWI) examination before radiotherapy in patients with advanced cervical squamous cell carcinoma with clinicopathological characteristics and radiotherapy efficacy.Methods:The clinical data of 80 patients with advanced cervical cancer who were admitted to the Second Hospital of Nanjing from September 2019 to March 2022 were retrospectively analyzed. All patients underwent magnetic resonance imaging (MRI) DWI examination. The differences in ADC values among cervical squamous cell carcinoma patients with different clinicopathological characteristics were analyzed. The patients were divided into the effective group (complete remission+partial remission) and the ineffective group (stable disease+progressive disease) based on the radiotherapy effect, and the differences in ADC values between the two groups were compared. The logistic regression model was used to analyze the factors affecting the radiotherapy efficacy of patients with advanced cervical squamous cell carcinoma.Results:Among 80 patients with advanced cervical squamous cell carcinoma, 21 achieved complete remission, 31 achieved partial remission, 25 achieved stable disease, and 3 achieved progressive disease after radiotherapy; there were 52 cases in the effective group and 28 cases in the ineffective group. The ADC value of the effective group before radiotherapy was higher than that of the ineffective group [(0.99±0.14)×10 -3mm 2/s vs. (0.76±0.20)×10 -3mm 2/s], and the difference was statistically significant ( t = 6.01, P < 0.001); after radiotherapy, the ADC value of the effective group was also higher than that of the ineffective group [(1.43±0.25)×10 -3mm 2/s vs. (1.11±0.23)×10 -3mm 2/s), and the difference was statistically significant ( t = 5.61, P < 0.001); the ADC values of both the effective and ineffective groups increased after radiotherapy compared to before radiotherapy (both P < 0.05). The ADC values of patients with different International Federation of Obstetrics and Gynecology (FIGO) stage, degree of pathological differentiation, depth of lesion infiltration, Ki-67 expression, lymph node metastasis, and distant metastasis were statistically significant (all P < 0.05). The results of multivariate logistic regression analysis showed that ≥FIGO stage Ⅲ, low differentiation, lymph node metastasis, lymphatic vessel infiltration, distant metastasis, and low ADC value before radiotherapy were independent risk factors for efficacy of radiotherapy in patients with advanced cervical squamous cell carcinoma (all P < 0.05). Conclusions:The ADC value before radiotherapy is a factor that affects the radiotherapy effect of patients with advanced cervical squamous cell carcinoma. The lower the ADC value before radiotherapy is, the worse the radiotherapy effect of patients will be.