Impact of a standardized extended curettage technique on recurrence rate in patients with giant cell tumor of bone

Introduction. Giant cell tumor of bone is characterized by high risk of local recurrence, especially during denosumab therapy complicating visual control of the radicalness of surgical intervention. Despite constant improvement of tumor excochleation technique, consensus on the optimal surgical technique has not yet been reached as the results of comparative studies are often contradictory.

Aim. To compare oncological outcomes and determine risk factors in patients with giant tumor of bone after standard and extended excochleations against the background of neoadjuvant therapy with denosumab.

Materials and methods. During single-center prospective-retrospective study, data of 83 patients with giant cell tumor of bone were analyzed. The extended excochleation group (n = 33) was formed according to compliance with a strict protocol (length of cortical window >70 % of tumor length, combination use of local adjuvants). The group included 23 patients recruited prospectively since 01.01.2024 and 10 patients included retrospectively from earlier period according to the same criteria. The group of standard excochleation (historic control group) (p = 50) included patients who underwent surgery between 01.01.2014 and 31.12.2023 without strict protocol per the surgeon’s decision. The primary endpoint was the rate of local recurrences.

Results. During the follow-up, local recurrence developed in 31 (62 %) patients of the control group and 4 (12.1 %) patients of the extended excochleation group (p < 0.001). The risk of recurrence for standard technique was 3.7-fold higher (hazard ratio 3.71; 95 % confidence interval 1.31–10.53; p = 0.014). ROC analysis showed that the ratio between cortical window and tumor length ≤69 % is a significant predictor of recurrence (area under curve (AUC) = 0.674; p = 0.012). The use of high-speed burr was statistically significantly associated with decreased risk of local recurrence (p = 0.019).

Conclusion. Implementation of standardized protocol of extended excochleation based on formation of a wide cortical window and combination administration of adjuvants into clinical practice significantly reduces the risk of local recurrence of giant cell tumor of bone in patients receiving denosumab. A quantitative criterion of “cortical window length >69 % of tumor length” can serve as an intraoperative landmark for reaching appropriate surgical radicalness.