Petroclival Chondrosarcoma: A Multicenter Review of 55 Cases and New Staging System

OBJECTIVE:To analyze clinical outcomes after treatment of petroclival chondrosarcoma and to propose a novel staging system. STUDY DESIGN:Retrospective case review, 1995 to 2015. SETTING:Multicenter study. PATIENTS:Consecutive patients with histopathologically proven petroclival chondrosarcoma. INTERVENTION(S):Microsurgery, endoscopic endonasal surgery, radiation therapy, observation. MAIN OUTCOME MEASURES:Disease- and treatment-associated morbidity, recurrence, mortality. RESULTS:Fifty-five patients (mean age 42 years; 56% women) presenting with primary or recurrent petroclival chondrosarcoma were analyzed. The mean duration of follow-up was 74 months. Among 47 primary cases, the most common presenting symptoms were headache (55%) and diplopia (49%) and the mean tumor size at diagnosis was 3.3 cm. Subtotal resection was performed in 33 (73%) patients and gross total resection in 12 (27%). Adjuvant postoperative radiation was administered in 30 (64%) cases. Preoperative cranial neuropathy improved in 13 (29%), worsened in 11 (24%), and remained stable in 21 (47%) patients; notably, 11 preoperative sixth nerve palsies resolved after treatment. Nine recurrences occurred at a mean of 42 months. The 1-, 3-, 5- and 10-year recurrence-free survival rate for all 45 patients who underwent primary microsurgery with or without adjuvant radiation therapy was 97%, 89%, 70%, and 56%, respectively. Higher tumor stage, larger categorical size (