Background: There are no large-scale analyses of canine calvarial multilobular tumor of bone (MLT); the majority are single case reports or small case series describing novel surgical techniques. Exclusion of mandibular, maxillary, and zygomatic-derived MLT when considering survival time, risk of tumor recurrence, disease morbidity, and metastasis is critical when considering surgical challenges of calvarial neoplasm.
Objective: To evaluate survival time, time to recurrence, and determine possible prognostic factors of calvarial multilobular tumor of bone in treated patients Animals: client-owned companion canines who underwent surgical debulking and stereotactic radiation therapy or surgical debulking alone with histologic diagnosis
Methods: retrospective cohort study, single center, cases referred between 2012-2024
Results: Histologic grade, duration of clinical signs prior to surgery, and neurologic status prior to surgery had no significant effect on median survival time. Radiation therapy post-operatively was the only factor evaluated which significantly prolonged both survival time (p=0.0279) and disease-free interval (p=0.0195). Median survival time with surgery alone 291 days (n=14). Median survival time with surgery and radiation therapy 1543 days (n=5). 78% of patients with surgery alone had tumor regrowth; median days post-operative regrowth was diagnosed 311 days (98-1651). 1/19 patients diagnosed with metastasis. Median weight 23.7kg (4.3-42.5). Clinical Importance: Median time to recurrence and median survival time with surgery alone shorter than previously reported literature which grouped all locations of MLT of the skull, though rates of metastasis are significantly lower. Radiation therapy following surgical debulking significantly prolongs survival time and disease-free interval.