Skull base chordoma treated with proton therapy: A systematic review

Abstract

Background: Chordoma located in the skull base is usually a challenging surgical condition. It is often not possible to achieve gross total resection. Residual tumors have been treated with adjuvant focal radiation therapy employing high-energy particles most commonly through proton beam. In this review, we systematically analyzed indications and outcomes of this treatment with respect to local control rates of the lesion and factors determining recurrence of skull base chordomas. In addition, we collected data on treatment-associated radiation-induced side effects. Methods: In line with the PRISMA guidelines, the authors performed a literature search algorithm for relevant articles using three databases: PubMed, Embase, and Cochrane. Inclusion and exclusion criteria were applied to evaluate all identified studies published between 1980 and 2018. Results: Our review included 11 studies for analysis (n = 511 patients). The mean age of the study population was 47.3 ± 5.8 years. The mean dose of postsurgical irradiation at the time of initial treatment was 71.1 ± 3.1 Gy. The mean follow-up duration was 45.0 ± 17.5 months. Within this follow-up duration, recurrence occurred in 26.8% of the patients. The mean time to recurrence was 34.5 ± 15.2 months. A significant number of patients experienced side effects varying from Grade 1 (mild dermatitis) to Grade 4 (temporal lobe necrosis and visual disorders). Conclusion: Despite advances in proton therapy, recurrence rates in skull base chordoma remain high. The toxicity of proton therapy may be more prevalent than generally thought. Unfortunately, there is substantial variation in the methods of data reporting.

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

“…There is ongoing research regarding prognostic factors and optimal post-surgical radiation strategies with further evaluation needed regarding tumor biology and PBT versus radiosurgery. 13,14 Despite continuing improvements of surgical techniques, there is still considerable variation in the literature as to the optimal management technique. As such, we decided to perform a systematic review of surgical management in clival chordomas, particularly focusing on open versus endoscopic surgery with the aim to compare this against our own 10-year clinical experience of clival chordomas at our regional skull base unit in London (January 2009-October 2019) along with a couple of highlighted cases.…”

The Role of Adjuvant Treatment in Craniofacial Malignancy: A Critical Review

“…In contrast, postoperative radiotherapy is suggested for most patients with chondrosarcomas and chordomas as complete resection of the tumor is difficult and recurrent tumors are associated with poorer prognosis (84,85). Proton-beam therapy may be particularly useful as photon therapy is associated with a high rate of local failure and carries a significant risk of brainstem and cranial nerve damage (187)(188)(189).…”

Role of Proton Beam Therapy in Current Day Radiation Oncology Practice

“…76 Another review conducted in 2018 concluded that despite advances in proton therapy, recurrence rates in skull base chordoma remain high. 77 Large case series demonstrated that unfavorable tumor control was often linked to high residual volumes (>23 cm 3 ) and brainstem involvement. [78][79][80] Authors recommended that due to the radioresistant behavior of this neoplasm, a delivery of a dose of at least 74 Gy (RBE) to the tumor bed and other sites of gross disease is recommended.…”