Pre-operative stereotactic radiosurgery for cerebral metastatic disease: A retrospective dose-volume study.
Radiother Oncol
; 184: 109314, 2023 07.
Article
em En
| MEDLINE
| ID: mdl-35905780
ABSTRACT
BACKGROUND AND PURPOSE:
Stereotactic radiosurgery (SRS) after maximal safe resection is an accepted treatment strategy for patients with cerebral metastatic disease. Despite its high conformality profile, the incidence of radionecrosis (RN) remains high. SRS delivered pre-operatively could be associated with a reduced incidence of RN. We sought to evaluate whether neoadjuvant SRS could reduce radiotherapy doses in a cohort of patients treated with post-operative SRS.METHODS:
A cohort of 47 brain metastases (BM) treated at 2 academic institutions was retrospectively analyzed. Subjects underwent surgical extirpation of BMs and subsequent SRS to surgical bed. Post-operative volumetric and dosimetric data was collected from records or recreations of delivered plans; pre-operative data were derived from hypothetical radiotherapy courses and compared using Wilcoxon signed-rank tests.RESULTS:
Higher planned tumor volume post-operatively (median[IQR] 12.28 [6.54, 18.69]cc vs 10.20 [4.53, 21.70]cc respectively, pâ¯=â¯0.4150) was observed. The median prescribed radiotherapy dose (DRx) was 16â¯Gy pre-operatively and 24â¯Gy post-operatively (pâ¯<â¯0.0001). Further investigations revealed improved pre-operative conformity index (1.23[1.20, 1.29] vs 1.29[1.23, 1.39], pâ¯=â¯0.0098) and gradient index (2.72[2.59, 2.98] vs 2.94[2.69, 3.47], pâ¯=â¯0.0004). A significant difference was found in normal brain tissue exposed to 10â¯Gy (12.97[6.78, 25.54]cc vs 32.13[19.42, 48.40]cc, pâ¯<â¯0.0001), 12â¯Gy (9.31[4.56, 17.43]cc vs 23.80[14.74, 36.56]cc, pâ¯<â¯0.0001), and 14â¯Gy (5.62[3.23, 11.61]cc vs 17.47[9.00, 28.31]cc, pâ¯<â¯0.0001), favoring pre-operative SRS.CONCLUSIONS:
Neoadjuvant SRS is associated reduced DRx, better conformality profile and decreased radiation to normal tissue. These findings could support the use of neoadjuvant SRS for the treatment of BMs.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lesões por Radiação
/
Neoplasias Encefálicas
/
Neoplasias Supratentoriais
/
Radiocirurgia
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Radiother Oncol
Ano de publicação:
2023
Tipo de documento:
Article