Obstacles to receiving postoperative radiation therapy following separation surgery for metastatic spine disease
Authors: Dugan John E. , Long Connor C. , Chanbour Hani , Bendfeldt Gabriel A. , Suryateja Gangavarapu Lakshmi , Younus Iyan , Jonzzon Soren , Ahmed Mahmoud , Luo Leo Y. , Berkman Richard A. , Lugo-Pico Julian G. , Abtahi Amir M. , Stephens Byron F. , Zuckerman Scott L. 
Published: June 2024

OBJECTIVE
Obtaining timely postoperative radiotherapy (RT) following separation surgery is critical to avoid local recurrence of disease yet can be a challenge due to scheduling conflicts, insurance denials, and travel arrangements. In patients undergoing metastatic spine surgery for spinal cord compression, the authors sought to: 1) report the rate of postoperative RT, 2) describe reasons for patients not receiving postoperative RT, and 3) investigate factors that may predict whether a patient receives postoperative RT.

METHODS
A single-center retrospective case series was undertaken of all patients who underwent metastatic spine surgery for extradural disease between January 2010 and January 2021. Inclusion criteria were patients with intermediate or radioresistant tumors with evidence of spinal cord compression who underwent surgery. The primary outcome was the occurrence of RT within 3 months following surgery. Multivariable logistic regression analysis was performed controlling for age, BMI, race, total number of decompressed levels, tumor size, other organ metastasis, and preoperative RT or chemotherapy to predict patients receiving postoperative RT.

RESULTS
Of 239 patients undergoing spine surgery for metastatic disease, 113 (47.3%) received postoperative RT while 126 (52.7%) did not. In the postoperative RT group, 24 (21.2%) received stereotactic body radiation therapy while 89 (78.8%) received conventional external-beam radiation therapy. The most common reasons for patients not receiving postoperative RT included death or transfer to hospice (31.0%), RT not being recommended by radiation oncology (30.2%), and loss to follow-up (23.8%). On critical review with the radiation oncology department, the authors estimated that 101 of 126 (80.2%) patients who did not receive postoperative RT were potential candidates for postoperative RT. Patients who received postoperative RT had more documented inpatient (48.7% vs 32.5%, p < 0.001) and outpatient (100.0% vs 65.1%, p < 0.001) radiation oncology consultations than those who did not. Additionally, patients who received postoperative RT had a higher rate of postoperative chemotherapy (53.1% vs 25.4%, p < 0.001), while patients who did not receive postoperative RT had a higher rate of preoperative RT (7.1% vs 31.0%, p < 0.001). Multivariable analysis confirmed that patients who received preoperative RT had lower odds of undergoing postoperative RT (OR 0.14, 95% CI 0.06–0.34; p < 0.001), and patients who underwent postoperative chemotherapy had higher odds of undergoing postoperative RT (OR 3.83, 95% CI 2.05–7.17; p < 0.001).

CONCLUSIONS
In the current study reflecting real-world care of patients with metastatic spine disease after undergoing separation surgery, 47% of patients did not receive postoperative RT, and 80% of those patients were potential candidates for postoperative RT. Radiation oncology consultation and postoperative chemotherapy were significantly associated with receiving postoperative RT, whereas preoperative RT was significantly associated with not receiving postoperative RT. The lack of timely postoperative RT highlights a potential gap in metastatic spine tumor care and underscores the necessity for prompt radiation oncology consultation and effective planning.