Re-irradiation spine stereotactic body radiotherapy following high-dose conventional radiotherapy for metastatic epidural spinal cord compression: a retrospective study

Yutaro Koide; Shoichi Haimoto; Hidetoshi Shimizu; Takahiro Aoyama; Tomoki Kitagawa; Yurika Shindo; Naoya Nagai; Shingo Hashimoto; Hiroyuki Tachibana; Takeshi Kodaira

doi:10.1007/s11604-024-01539-x

Re-irradiation spine stereotactic body radiotherapy following high-dose conventional radiotherapy for metastatic epidural spinal cord compression: a retrospective study

Jpn J Radiol. 2024 Feb 28. doi: 10.1007/s11604-024-01539-x. Online ahead of print.

Affiliations

¹ Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-Ku, Nagoya, Aichi, Japan. ykoide@aichi-cc.jp.
² Department of Neurosurgery, Aichi Cancer Center Hospital, Chikusa-Ku, Nagoya, Japan.
³ Department of Radiation Oncology, Aichi Cancer Center Hospital, Kanokoden 1-1, Chikusa-Ku, Nagoya, Aichi, Japan.

PMID: 38413551
DOI: 10.1007/s11604-024-01539-x

Abstract

Purpose: We aimed to evaluate the efficacy and safety of re-irradiation stereotactic body radiation therapy (SBRT) in patients with metastatic epidural spinal cord compression (MESCC) following high-dose conventional radiotherapy.

Materials and methods: Twenty-one patients met the following eligibility criteria: with an irradiation history of 50 Gy₂ equivalent dose in 2-Gy fractions (EQD2) or more, diagnosed MESCC in the cervical or thoracic spines, and treated with re-irradiation SBRT of 24 Gy in 2 fractions between April 2018 and March 2023. Prior treatment was radiotherapy alone, not including surgery. The primary endpoint was a 1-year local failure rate. Overall survival (OS) and treatment-related adverse events were assessed as the secondary endpoints. Since our cohort includes one treatment-related death (TRD) of esophageal perforation, the cumulative esophageal dose was evaluated to find the dose constraints related to severe toxicities.

Results: The median age was 68, and 14 males were included. The primary tumor sites (esophagus/lung/head and neck/others) were 6/6/7/2, and the median initial radiotherapy dose was 60 Gy₂ EQD2 (range: 50-105 Gy₂, 60-70/ > 70 Gy₂ were 11/4). Ten patients underwent surgery followed by SBRT and 11 SBRT alone. At the median follow-up time of 10.4 months, 17 patients died of systemic disease progression including one TRD. No radiation-induced myelopathy or nerve root injuries occurred. Local failure occurred in six patients, with a 1-year local failure rate of 29.3% and a 1-year OS of 55.0%. Other toxicities included five cases of vertebral compression fractures (23.8%) and one radiation pneumonitis. The cumulative esophageal dose was recommended as follows: D_max < 203, D_{0.035 cc} < 187, and D_1cc < 167 (Gy₃ in biological effective dose).

Conclusion: Re-irradiation spine SBRT may be effective for selected patients with cervical or thoracic MESCC, even with high-dose irradiation histories. The cumulative dose assessment across the original and re-irradiated esophagus was recommended to decrease the risk of severe esophageal toxicities.

Keywords: Re-irradiation; Spinal cord compression; Spinal metastases; Stereotactic radiotherapy.

Grants and funding

23K14669/Japan Society for the Promotion of Science