Gamma Knife Management of Skull Base Chordomas: Is it a Choice?

Systematic Review Comparing Open versus Endoscopic Surgery in Clival Chordomas and a 10-Year Single-Center Experience

Objectives Chordomas are rare, slow-growing, and osteo-destructive tumors of the primitive notochord. There is still contention in the literature as to the optimal management of chordoma. We conducted a systematic review of the surgical management of chordoma along with our 10-year institutional experience.

Design A systematic search of the literature was performed in October 2020 by using MEDLINE and EMBASE for articles relating to the surgical management of clival chordomas. We also searched for all adult patients surgically treated for primary clival chordomas at our institute between 2009 and 2019.

Participants Only articles describing chordomas arising from the clivus were included in the analysis. For our institution experience, only adult primary clival chordoma cases were included.

Main Outcome Measures Patients were divided into endoscopic or open surgery. Rate of gross total resection (GTR), recurrence, and complications were measured.

Results Our literature search yielded 24 articles to include in the study. Mean GTR rate among endoscopic cases was 51.9% versus 41.7% for open surgery. Among the eight cases in our institutional experience, we found similar GTR rates between endoscopic and open surgery.

Conclusion Although there is clear evidence in the literature that endoscopic approaches provide better rates of GTR with fewer overall complications compared to open surgery. However, there are still situations where endoscopy is not viable, and thus, open surgery should still be considered if required.

Less common extracerebral tumors

This chapter examines the results of GKNS on a variety of extraparenchymal skull base tumors some benign and some malignant. For the benign tumors there is good evidence on the effectiveness of the method for pretty much all diagnoses. For malignant extraparenchymal tumors the results are more limited and GKNS only has a supportive role in these lesions.

Midterm prognosis and surgical implication for clival chordomas after extended transsphenoidal tumor removal and gamma knife radiosurgery

Background

Treating chordoma through surgery alone is often ineffective. Thus, surgery often performed with irradiation, with a reported 5-year survival rate of 60–75%. The clinical course varies, and disease rarity prevents larger number of clinical investigations.

Methods

In total, 19 patients with clival chordomas were retrospectively extracted from our institutional database. They were initially treated with maximal tumor removal using the extended transsphenoidal approach between March 2006 and January 2021. When total tumor removal was achieved, prophylactic irradiation was not performed. If tumor remnants or recurrence were confirmed, Gamma Knife (GK) radiosurgery was performed. The mean follow-up period was 106.7 months (ranged 27–224 months). The clinical course and prognostic factors were investigated.

Results

Total removal was achieved in 10 patients, whereas 4 patients suffered recurrence and required GK. GK was applied to 11 patients with a 50% isodose of 13–18 Gy (mean: 15.4 Gy), and eight patients remained progression free, whereas three patients suffered repeated local recurrence and died of tumor-related complications. The mean overall progression-free interval was 57.2 months (range: 6–169 months). One male patient died of tumor un-related lung cancer 36 months after the initial treatment, and other patients survived throughout the observational periods. The mean overall survival was 106.7 months (range: 27–224 months). Thus, the 5-year survival rate was 94.7%. Statistical analysis indicated that sex (men), > 15 Gy of 50% isodose by GK, and screening brain examinations as prophylactic medicine were significant favorable prognostic factors.

Conclusions

The favorable outcomes in this investigation suggest the importance of early detection and treatment. Surgery may enable better conditions for sufficient GK doses.

Proton therapy for brain tumours in the area of evidence-based medicine

ADVANCES IN KNOWLEDGE

This review details the indication of brain tumors for proton therapy and give a list of the open prospective trials for these challenging tumors.