Adjuvant stereotactic radiosurgery with or without postoperative fractionated radiation therapy in adults with skull base chordomas: a systematic review

Abstract

OBJECTIVE The objective of this retrospective study was to compare the survival of patients with biopsy-proven skull base chordoma who had undergone stereotactic radiosurgery (SRS) with versus without prior fractionated radiation therapy (RT). METHODS Relevant articles from database inception to September 2021 were retrieved from the PubMed, Scopus, Web of Science, and Cochrane databases for a systematic review of treatment protocols. Studies were included if they 1) involved adult patients (age ≥ 18 years) with histologically and radiologically confirmed chordomas located within the clival skull base region and treated with SRS; 2) reported data on clinical features, SRS protocols, and outcomes; and 3) were written in the English language. Studies were excluded if they 1) were literature reviews, case reports, technical notes, abstracts, or autopsy reports; 2) did not clearly differentiate the data of patients with chordomas from the data of patients with different tumors or the data of patients with chordomas in locations other than the skull base; or 3) lacked histological confirmation or treatment and outcome data. Extracted data included the following: study author and publication year, patient age and sex, symptoms, cranial nerve involvement, invaded structures, lesion size, treatment modality, surgical details, histopathological type, RT modality, SRS parameters, complications, postradiosurgery outcomes, complications, and survival outcomes. RESULTS After the selection process, 15 articles describing 130 patients met the study eligibility criteria, including 94 patients who had undergone postresection SRS (NoRT group) and 36 who had undergone postresection fractionated RT and subsequent SRS (RT group). The NoRT and RT groups were comparable in age (51.3 vs 47.4 years, respectively), sex (57.1% vs 58.3% male), tumor volume (9.5 vs 11.2 cm3), SRS treatment parameters (maximum dose: 35.4 vs 42.2 Gy, marginal dose: 19.6 vs 20.6 Gy, treatment isodose line: 60.2% vs 65.2%), and SRS adverse effects (10.9% vs 17.6%). For the entire cohort, the 3-, 5-, and 10-year progression-free survival (PFS) rates were 23%, 9%, and 3%, respectively, and the overall survival (OS) rates were 94%, 82%, and 76%, respectively. In the NoRT group, SRS was adjuvant treatment after resection in 38 patients (40.4%), salvage treatment for recurrent tumor treated with resection alone in 10 (10.6%), and not specified in 46 (48.9%). In the RT group, SRS was boost treatment in 9 patients (25.0%), salvage treatment after recurrence in 22 (61.1%), and not specified in 5 (13.9%). There was no difference between the two groups in terms of median PFS (24.0 months [Q1 34.0, Q3 15.0] vs 23.8 months [34.0, 18.0], respectively; p = 0.8) or median OS (293.0 months [not reached, 137.4] vs not reached [not reached, 48.0], respectively; p = 0.36). The adverse radiation effect rates were comparable between the groups (10.9% vs 17.6%, respectively; p = 0.4). CONCLUSIONS The role of SRS in the management of skull base chordomas is still evolving. This systematic literature review of biopsy-proven chordoma revealed that tumor control and survival rates for SRS alone after chordoma surgery were not inferior to those encountered after SRS plus fractionated RT.

Endoscopic Endonasal Approach for Clival Chordomas in Elderly Patients: Clinical Characteristics, Patient Outcome, and Recurrence Rate

“…Considering this significant recurrence rate also in elderlies, we can suggest that postoperative radiation therapy should be advised also in this population to prevent early progression and increase their overall survival. [24][25][26] It has been reported that radiotherapy could increase the risk of delayed CSF leak in patients already operated trough an EEA, therefore we used to fill the surgical field with abdominal fat, covered with mucoperiosteum even whether no intra-operative leak is observed. [24][25][26] This maneuver could also be particularly useful in elderlies, which could be more severely affected by the development of delayed leak with meningitis.…”

“…[24][25][26] It has been reported that radiotherapy could increase the risk of delayed CSF leak in patients already operated trough an EEA, therefore we used to fill the surgical field with abdominal fat, covered with mucoperiosteum even whether no intra-operative leak is observed. [24][25][26] This maneuver could also be particularly useful in elderlies, which could be more severely affected by the development of delayed leak with meningitis.…”

Adjuvant Stereotactic Radiosurgery With or Without Postresection Fractionated Radiation Therapy for the Management of Clival Chordomas in Adults: An International Multicenter Case Series

“…26,28 Similarly, in a metaanalysis, Di Maio et al 29 did not detect any statistically significant difference in tumor control rates between various radiation treatment modalities. Similarly, in a meta-analysis of SRS for primary and recurrent skull base chordomas, comparing SRS with or without prior FRT, Bin-Alamer et al 30 did not detect any difference in neither overall survival nor tumor control between the 2 groups. Our results propose that adjuvant postoperative SRS alone is a potential alternative to conventional postresection FRT modalities and may reduce unnecessary risk related to additional radiation and need for additional treatment.…”

“…The median tumor volume was nonsignificantly higher in the SRS group (6.0 cc [IQR, 3.3-12.1]) compared with the FRT+SRS group (3.0 cc [IQR, 1.6-8.6]; P = .06), whereas the median prescription volume was significantly higher in the SRS group (6.6 cc [IQR, 3.3-15.2]) compared with the FRT+SRS group (3 cc [IQR, 1.6-8.6]; P = .03; Table 2). The SRS group had a significantly higher median marginal dose (18 Gy [IQR, [16][17][18]) compared with the FRT+SRS group (16 Gy [IQR, [13][14][15][16][17][18]; P = .01) and a significantly higher median maximum dose (36 Gy [IQR, 32-40]) compared with the FRT+SRS group (32 Gy [IQR, [27][28][29][30][31][32][33][34][35][36]; P = .01), and both groups had a similar median isodose line (50%).…”

Proton beam therapy for clival chordoma: Optimising rare cancer treatments in Australia

“…Several excellent reviews of the literature for proton therapy in skull base chordomas have been published recently including systematic reviews. [42][43][44][45][46] Other significant series are summarised in Table 1. 15,37,[47][48][49] To date, there have been no randomised studies comparing proton therapy and photon therapy.…”