Conventional external radiotherapy in the management of clivus chordomas with overt residual disease

Abstract

Cranial chordomas are uncommon tumors accounting for less than 1% of all intracranial neoplasms. Although they are slowly growing, rarely metastasizing tumors, cranial chordomas are challenging to treat due to their critical location, invasive nature and aggressive recurrence. The aim of this retrospective study was to evaluate the role of conventional irradiation in the treatment of clival chordomas with overt residual disease after incomplete surgery. Between January 1979 and December 1997, 18 patients with histologically confirmed clival chordoma were treated with radiotherapy. Median age at the time of diagnosis was 32 years. The mean duration of the symptoms before diagnosis was 33.9 months. Median tumor diameter at initial presentation was 5 cm (range, 3-7 cm). The type of surgical procedure was subtotal excision in 11 patients and biopsy in 7. Radiation treatment was delivered with megavoltage units, and total doses between 50 Gy and 64 Gy (median, 60 Gy) were administered with conventional daily fractions. One patient received additional 12.50 Gy with linear accelerator-based stereotactic radiosurgery after subtotal excision and external irradiation. The mean follow-up time was 43.2 months. Overall survival at 5 years was 35%. Eleven patients showed progression after radiotherapy. The median time to progression after radiotherapy was 40.8 months (38.4-43.2) with a 5-year progression-free survival of 23%. Five patients (29.4%) showed symptomatic relief after radiotherapy while persistent symptoms were recorded for 6 patients. Incomplete surgery and conventional external radiotherapy with a dose of around 60 Gy seem to be inadequate in the treatment of clival chordomas.

Hypofractionated Stereotactic Radiation Therapy for Skull Base and Upper Cervical Chordoma and Chondrosarcoma: Preliminary Results

“…Zorlu et al [25] reported that in the case of overt residual tumor, the 5-year survival rate was 35% with clival chordoma when 60 Gy of adjuvant conventional radiotherapy was given. But when maximum surgical cytoreduction was tried, the control rate of adjuvant radiotherapy was greatly improved.…”

Review of photon and proton radiotherapy for skull base tumours

“…Results are summarized in Table 3. [58][59][60][61][62][63][64][65][66][67][68] For these diseases, particle therapy has been historically employed, results in terms of local control and progression free survival with photons RT are acceptable for chondrosarcoma but were on average rather disappointing for chordomas with only one series reporting 5-year local control in excess of 80% and other series reporting local control or progression free survival from 15% to 66%. It is difficult to draw any conclusions from these scarce and heterogeneous data; nevertheless, outcome appears not to be equivalent to that of particles and these findings may suggest that even modern advanced photons cannot achieve adequate target coverage in the skull base for prescription doses in excess of 70 Gy.…”

Fractionated Stereotactic Radiosurgery Treatment Results for Skull Base Chordomas

“…The recommended dose was more than 65-70 Gy (25,26). Previously, we reported our treatment results of skull base chordomas treated with conventional radiotherapy (27). The five-year PFS and OS rates were found to be 23% and 35%, respectively.…”