Posters— Surgical Treatment of Sarcomas

GIANT CELL TUMOR OF THE PELVIS AND SACRUM: REVIEW OF SEVENTEEN CASES AND META-ANALYSIS

Leggon RE, Berry BH, Zlotecki R, Reith J, Wood D, Vlasak R, Scarborough MT. (University of Florida, Gainesville, Florida, 32610-0246)

Seventeen patients with giant cell tumor (GCT) of the pelvis and sacrum were reviewed. The mean patient age was 33 years and average follow-up was 8.0 years. Sixteen of 17 lesions were stage 3 (benign, aggressive). Symptom duration averaged 12 months. The average largest tumor dimension was 11 cm, and one developed benign pulmonary metastases. The treatment was radiation therapy (RT) alone in 9 patients, surgery with intralesional margins alone (S(IL)) in 2, surgery with wide margins S (W) in 4. Primary RT in 8 sacral lesions resulted in 1 local recurrence of tumor, 4 cases in which the tumor involuted and the bone reformed, and 3 cases that were stable but without ossification. Wide surgical margins for pelvic lesions resulted in no local recurrences. Two of 12 patients treated with RT developed radiation-induced sarcoma (RIS). Local recurrence occurred in 23% of patients in this series.

Meta-analysis yielded 239 lesions (73 pelvis, 166 sacrum). Recurrence rates were 49% for RT (32 of 65 patients),47% for S(IL) (32 of 68 patients), 46% for S(IL) - RT (38 of 83 patients), 60% for S(IL) + cryosurgery (6 of 10 patients), and 0% for S(W) (0 of 23 patients). Benign lung metastases developed in 6 %, secondary malignancies in 2%, perioperative death in 2%, and multicentricity in < 1%. The average dose of RT was 4780 cGy. Radiation dosage studies of 122 cases, including 34 cases of primary RT alone, were reviewed. Increasing doses of RT (<4500 cGy vs. 4500-5500 cGy vs. >5500 cGy) did not appear to decrease the rate of local recurrence. RIS developed in 11% of patients with >5-year follow-up. There did not appear to be a benefit to RT in addition to intralesional surgery. Disease status was worse for sacral GCT (ANED-90%, AWD-1%, DOD-6%, DOC-3%) at an average follow-up of 8.7 years.

Surgery with wide margins should be considered for GCT of the ilium, pubis, or lower sacrum to decrease the chance of local recurrence and the potential for radiation-induced sarcoma. Treatment of acetabular lesions must be individualized. Primary RT alone is most strongly indicated for large lesions of the sacrum.