Pelvic Recurrence After Definitive Surgery For Locally Advanced Rectal Cancer: A Retrospective Investigation Of Implications For Precision Radiotherapy Field Design

Background: To analyze the local distribution of pelvic recurrence after total mesorectal excision, with a view to simplifying the formulation of optimal individualized radiotherapy plans.Methods: We retrospectively investigated the data of 168 patients diagnosed with recurrent pelvic cancer treated at Fudan University Shanghai Cancer Center between January 2008 and December 2012. The following were collected depending on availability: operative report, histological report, specimen photographs, initial preoperative images, images confirming local recurrence, and clinical history.Results: A total of 203 lesions of local recurrence were identified. The most common sites of pelvic recurrence were the mesorectum, including the anastomotic stoma in 53.0% of cases; presacral space in 27.4%, and pelvic floor and perineum in 21.4% the cases. Recurrence was most common in the lower pelvic region (i. e., below the upper border of the acetabulum), accounting for approximately 76.2% (128 cases) of cases. In patients with mid-rectal and distal rectal carcinoma, < 5% had relapse in the upper pelvis, and in those with distal rectal cancer, no recurrence occurred in the external iliac and inguinal area.Conclusions: Patients with pelvic cancer may benefit by individualized treatment plans aimed at achieving a balance between tumor control and minimal risk of irradiation-induced toxicity.