Efficacy and toxicity of primary re-irradiation for malignant spinal cord compression based on radiobiological modelling: a phase II clinical trial

• Published in: British journal of cancer Vol. 128; no. 4; pp. 576 - 585
• Main Authors: Wallace, Neil D., Dunne, Mary T., McArdle, Orla, Small, Cormac, Parker, Imelda, Shannon, Aoife M., Clayton-Lea, Angela, Parker, Michael, Collins, Conor D., Armstrong, John G., Gillham, Charles, Coffey, Jerome, Fitzpatrick, David, Salib, Osama, Moriarty, Michael, Stevenson, Michael R., Alvarez-Iglesias, Alberto, McCague, Michael, Thirion, Pierre G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.02.2023; Nature Publishing Group
• Subjects: 631/67/1059/485; 692/4028/67/322/803; Biomedical and Life Sciences; Biomedicine; Cancer Research; Central nervous system diseases; Clinical trials; Compression; Decompression; Dose Fractionation, Radiation; Drug Resistance; Epidemiology; Humans; Molecular Medicine; Oncology; Patients; Radiation Injuries; Radiation therapy; Radiotherapy Dosage; Re-Irradiation; Spinal cord; Spinal Cord Compression - radiotherapy; Spinal Cord Neoplasms - radiotherapy; Spine; Toxicity; Treatment Outcome
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/s41416-022-02078-w

Background The efficacy and safety of primary re-irradiation for MSCC are not known. Our aim was to establish the efficacy and safety of biologically effective dose-based re-irradiation. Methods Patients presenting with MSCC at a previously irradiated spine segment, and not proceeding with surgical decompression, were eligible. A 3 Gray per fraction experimental schedule (minimum 18 Gy/6 fractions, maximum 30 Gy/10 fractions) was used, delivering a maximum cumulative spinal dose of 100 Gy 2 if the interval since the last radiotherapy was within 6 months, or 130 Gy 2 if longer. The primary outcome was a change in mobility from week 1 to week 5 post-treatment, as assessed by the Tomita score. The RTOG SOMA score was used to screen for spinal toxicity, and an MRI performed to assess for radiation-induced myelopathy (RIM). Results Twenty-two patients were enroled, of whom eleven were evaluable for the primary outcome. Nine of eleven (81.8%) had stable or improved Tomita scores at 5 weeks. One of eight (12.5%) evaluable for late toxicity developed RIM. Conclusions Re-irradiation is an efficacious treatment for MSCC. There is a risk of RIM with a cumulative dose of 120 Gy 2 . Clinical Trial Registration Cancer Trials Ireland (ICORG 07-11); NCT00974168.