Objective To explore the value of diffusion weighted imaging (DWI) in presurgical planning of pelvic bone neoplasms.

Methods The clinical, imaging and pathological data of patients pathologically confirmed as pelvic chondrosarcoma and osteosarcoma from December 2014 to October 2021 were retrospectively analyzed. Thirteen patients with osteosarcoma and 22 patients with chondrosarcoma were included in the osteosarcoma group and chondrosarcoma group. Through the registration of CT and corresponding DWI images, the tumor boundary was drawn by the Medraw software to form a three-dimensional pelvis model to design the osteotomy distance. The magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC), postoperative pathological results and short-term recurrence rate of two groups were compared.

Results Of the 35 patients, 26 involved the ilium and 16 involved the acetabulum, of which 8 involved the ilium alone and 15 involved three or more sites simultaneously. The average ADC value in chondrosarcoma group was (1.21±0.17), which was higher than (0.97±0.21) in the osteosarcoma group (P < 0.000 1). The resection margins of the tumor were negative in all cases, and there was no recurrence within 6 months of clinical follow-up.

Conclusion DWI is helpful to judge the pelvic malignant bone tumors boundaries, and the presurgical planning of osteotomy range based on DWI and ADC value can help individualized operation design.