Therapeutic strategies for mobile spine chordoma: en bloc Versus intralesional surgery with adjuvant charged-particle therapy.

Purpose: The aim of this retrospective study is to analyze the impact of en bloc resection with negative margins versus intralesional resection plus adjuvant hadron-therapy (HT) on local control (LC) and overall survival (OS) in patients with mobile spine chordomas. Mechanical complications incidence as well as risk factors, and outcome differences are investigated as secondary endpoints.

Methods: 33 patients in a period from January 2013 to December 2021 were enrolled for the final analysis. The inclusion criteria were: lesions located in the mobile spine (C1-L5), age ≥ 15 years, minimum follow-up of 2 years, en bloc or intralesional surgical resection, virgin or recurrent chordomas, with only one previous surgical treatment.

Results: No difference was found in terms of LC between the two groups. The presence of pathologic fracture at pre-operative imaging and the presence of macroscopic residual tumor after surgery, independently from its entity, seemed to be associated with an increased risk of LR. No difference was found between planned en bloc and planned intralesional surgery in terms of mechanical complications occurrence. Eight patients (24.24%) had mechanical complications during the follow up period: male sex, presence of pathologic fracture at baseline, a combined surgical approach, the use of carbon fiber-only hardware appeared to be associated with an increased risk of mechanical complications after the primary surgery.

Conclusions: En bloc resection, whenever possible, is always to be preferred for its widely recognized potential in LC and OS improvement. However, technology advances in high-dose conformal charged-particle therapy have allowed improvement of local control rates as an adjuvant therapy of intralesional surgery for mobile spine chordoma, with acceptable acute and chronic toxicity.