Functional and oncological outcome of petroclival chondrosarcoma operated on through an extradural anterior petrosectomy approach. A single center experience.

BACKGROUND: Management of skull base chondrosarcoma (SBC) remains challenging due to its deep location and complex growth pattern. Non-total resection and postoperative residual mass are common features, with controversy regarding the need to offer systematic postoperative radiation therapy or additional surgery.

METHODS: A single-center retrospective cohort study was conducted on 10 consecutive patients harboring petroclival chondrosarcomas that were operated on between May 2007 and March 2019. After resection, the patients were allocated to a wait-and-rescan policy.

RESULTS: Patients were operated on through an extradural anterior petrosectomy (EAP). Subtotal tumor resection was achieved in all patients. The mean duration of follow-up was 70 months (range 25-137/median 67 months). Clinical outcomes dramatically improved in three (30%) patients, while five patients retained preoperative cranial nerve (CN) disturbances after surgery (50%). Two patients reported transient postoperative worsening of their symptoms (20%). All of the postoperative CN new deficits improved within one year, except in one patient who showed permanent facial nerve palsy. The preoperative median Karnofsky Performance Scale (KPS) score was 80 (range 70-100), and then it became 90 (range 70-100) postoperatively. Patients harboring a tumor residue were included in a wait-and-rescan policy. With this regimen, tumor control was obtained in seven patients (70% of cases until the last follow-up). Three patients (30%) showed progression of the residual; two of them were treated with adjuvant therapy, while an extra cranial growth residue was observed in the third.

CONCLUSION: Optimal and reasonable surgical resection of petroclival chondrosarcomas could be achieved with good to excellent functional outcomes through an EAP. In spite of a significant percentage of regrowth, only one patient required additional salvage surgery.