(P 258) COMPARING OUTCOMES FOLLOWING INTRALESIONAL VERSUS WIDE RESECTION PROCEDURES IN THE TREATMENT OF RENAL CELL CARCINOMA BONE METASTASES

Objective: Bone metastases from renal cell carcinoma (RCC) are associated with poor prognosis, high rates of recurrence, and revision surgery following surgical fixation. Among orthopedic oncologists, there are differences in practice patterns regarding whether to manage RCC bone metastases with intralesional procedures such as intramedullary nailing or curettage and cementation, or larger procedures involving wide resection and megaprosthetic reconstruction. While intralesional procedures generally enable reduced surgical morbidity and faster recovery, they may pose an increased risk for disease recurrence and/or progression, and the need for revision surgery. This is especially germane to RCC metastases, which demonstrate variable sensitivity to adjuvant radiation. Our goal is to synthesize data from all long bone RCC metastases treated at our institution since 2005 to compare post-operative complications among patients who initially underwent intralesional vs. wide resection procedures, specifically the need for additional surgery. We hypothesized that patients who initially underwent intralesional procedures experienced higher rates of revision surgery.

Methods: A list of patients who experienced renal cell carcinoma metastases to bone treated at our institution’s orthopedic oncology practice from 2005-2024 was obtained from pathology reports (n=191). Metastases that were not treated with surgery or were not located in long bones were excluded. An additional patient was excluded because their medical record was incomplete. Each patient’s record was reviewed to collect data on mortality, anatomical location, and the type of procedure(s) they had for the treatment of RCC bone metastases. Additional data will be collected on patients’ chemotherapy histories, radiation histories, and other clinical parameters. Descriptive statistics were computed to compare location of metastasis, mortality, and average survival between the intralesional and resection and reconstruction groups. The need for subsequent surgery in the same location as the initial operation due to recurrence, disease progression, or implant failure was compared between the two groups using a two-sample t-test. Subsequent surgeries for infections or wound complications were not considered in the initial review.

Results: Of 126 identified long bone metastases that were treated with surgical fixation, 89 were treated with intralesional procedures and 37 with resection and reconstruction. 66 of the intralesional procedures involved IM nailing while 23 involved other procedures including hemiarthroplasty and ORIF with cementation, curettage, and plate fixation. Differences in location of metastasis, the need for additional procedures, and mortality between the intralesional and resection groups are summarized in Table 1. The difference in proportion of patients who required a subsequent procedure at the same location due to recurrence of cancer or repeated fracture between the intralesional and resection groups was not significant (0.19 vs. 0.08, p=0.12). The difference in mean survival time after first operation between the two groups was not significant (514 days vs. 719 days, p=0.09).

Conclusion: These data suggest that there is no significant difference in the proportion of patients who require subsequent operations between patients who were initially treated with intralesional versus wide resection and reconstruction procedures for RCC long bone metastases. We did not appreciate a difference in mortality or average time of survival after first operation between the two groups. These results suggest that there may be no advantage to treating RCC long bone metastases with initial wide resection and reconstruction. Additional data will be collected pertaining to chemotherapy history, radiation history, and surgical complications that may demonstrate factors that are associated with higher rates of revision surgery or surgical complications.