방사선의학 웹진

바로가기  >

Abstract
Background: One important determinant in choosing a treatment modality is spinal instability. Clear management guidelines are suggested for stable and unstable spinal metastatic lesions, but lesions in the intermediate instability category (SINS [spinal instability neoplastic score] score of 7-12) remain a clinical dilemma. This study aims to analyze the risk factors necessitating surgical intervention after radiotherapy (RT) in patients with those lesions.

Methods: A multicenter cohort of 469 patients with spinal metastases of intermediate instability who received radiotherapy (RT) as the initial treatment between 2019 and 2021 were retrospectively enrolled. All patients were neurologically intact at the time of RT. According to the performance of surgical intervention after RT, various clinical and radiographic risk factors for surgical intervention were compared between surgery and non-surgery groups using uni- and multivariate analyses. A recursive partitioning analysis (RPA) was performed using significant determinants identified in multivariate analysis.

Results: The mean age at the time of RT was 59.9 years and there were 198 females. The lung was the most common primary site. During the mean follow-up duration of 18.2 months, surgical treatment was required in 79 (17.9%) of patients. The most common surgical method was decompressive laminectomy with stabilization (62.0%), followed by vertebrectomy with stabilization (22.8%) and stabilization only (15.2%). The mean SINS for the total cohort was 9.0. Multivariate regression analyses revealed that the primary tumor site of the lung, liver, and kidney, higher Bilsky grades of ESCC, lytic bone lesions, and higher EQD210 were significant risk factors for surgical intervention after RT. Among them, Bilsky grade, primary tumor type of the lung, liver, and kidney, and EQD210 were the most important determinants for expecting the probability of surgical intervention on RPA.

Conclusions: Surgical intervention was performed in 17.9% of patients with intermediate instability after RT as the initial treatment. The primary tumor site of the lung, liver, and kidney, higher Bilsky grade of ESCC, and EQD210 were the most important determinants for expecting the probability of surgical intervention. Therefore, the optimal treatment strategy needs to be devised by carefully evaluating the risk of surgical intervention.

Affiliations

Se-Jun Park 1, Jin Ho Kim 2, Yong Chan Ahn 3, Woong Sub Koom 4, Hwa Kyung Byun 5, Young-Hoon Kim 6, Sang-Il Kim 6, Dong-Ho Kang 1, On Behalf Of The Korean Society Of Spinal Tumor
1Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University, Seoul 06351, Republic of Korea.
2Department of Radiation Oncology, Seoul National University Hospital, Seoul National University, Seoul 03080, Republic of Korea.
3Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University, Seoul 06351, Republic of Korea.
4Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University, Seoul 03722, Republic of Korea.
5Department of Radiation Oncology, Yongin Severance Hospital, College of Medicine, Yonsei University, Yongin 16995, Republic of Korea.
6Department of Orthopedic Surgery, Seoul St. Mary's Hospital, Catholic University, Seoul 06591, Republic of Korea.