The treatment outcome depending on the extent of resection in skull base and spinal chordomas

Abstract

The authors tried to assess the treatment outcomes depending on the extent of resection in axial chordomas and compare the outcome of two adjunctive therapies (external beam radiation therapy vs. stereotactic radiosurgery) following incomplete tumour resection in terms of local tumour control. We retrospectively reviewed 30 consecutive patients with chordoma involving skull base, sacrum and mobile spine between 1993 and 2008. Their initial treatments had different extent of resection. Wide resection was performed for 12 (40%), subtotal resection and adjunctive radiotherapy/radiosurgery for 12 (40%), while six patients (20%) were solely treated with radiotherapy/radiosurgery. For these three groups, overall and progression-free survival rate were compared. The overall survival rate was 96% at 5years and 67% at 10years. Tumour progression-free survival (PFS) rates were 73% and 43% at 5 and 10years, respectively. Local tumour progression was seen in 67% in all patients, 58% in wide resection group, 67% in subtotal resection plus radiotherapy/radiosurgery group, and 75% in radiotherapy/radiosurgery group; however, this was not statistically significant (P = 0.69). Neither the extent of resection nor tumour location significantly influenced overall and progression-free survival (P > 0.05). With regard to the type of radiotherapy, tumour progression occurred in all lesions treated with external photon beam radiation therapy (EBRT) but only 38% of lesions treated with stereotactic radiosurgery (SRS) (P = 0.003). Adjunctive radiotherapy/radiosurgery following subtotal resection showed comparable local control and survival to wide resection. SRS offered superior local tumour control compared to EBRT.