POSTOPERATIVE RADIOTHERAPY FOR MALIGNANT FIBROUS HISTIOCYTOMA

Between 1974 and 1989, 49 patients with histologically confirmed malignant fibrous histiocytoma received post-operative radiotherapy at the Mallinckrodt Institute of Radiology for primary (41) or recurrent (8) disease. Median age of the patients was 63 years, and the median follow-up period was 41 months. Patients were grouped according to the 1988 AJC staging classification: stage IA (one patient), stage IIA (4 patients), stage IIB (9 patients), stage IIIA (15 patients), stage IIIB (18 patients), and stage IVA (2 patients). Eight tumors (16%) were in the pelvis, 8 (16%) in the trunk, 4 (8%) in the head and neck, and 29 (60%) in the extremities. Primary surgical procedures included incisional biopsy (4 patients), excisional biopsy (19), narrow margin excision (14), wide local excision (9), and removal of the entire compartment (3). Based on pathology reports, the margins of resection were classified as positive in 23 (5 gross, 18 microscopic), 5 close, 11 negative, and 10 unknown. Patients were irradiated with shrinking field technique; the median radiation dose was 6000 cGy, with more than 95% of patients receiving at least 4500 cGy. In addition, seven patients received postoperative chemotherapy. The 5-years overall survival rate was 62%, disease-free survival 64%, local control 68%, and freedom-from-distant metastasis 85%. Thirteen patients had local recurrences, with > 75% recurring within 3 years. Sites of local recurrence were as follows: trunk (3), pelvis (3), lower extremities (4), and head and neck (3). There appears to be a correlation of local failure with positive surgical margin: of 23 patients with positive margins, 9 (39%) had local recurrences, whereas 1 of 11 patients (9%) with negative margins had local recurrence. Three of 13 patients or recurrent disease were salvaged by additional treatment, rendering ultimate local control in 80% (39/49). Thirty-four of 36 patients with local control obtained good to excellent function. Two patients were found to have grade 3 complications: 1 patient had edema of the extremity, and the other developed necrotic skin ulcer that was successfully treated with hyperbaric oxygen. Five patients developed distant metastases, with 80% occurring within 2 years. In summary, adequate but conservative surgery with postoperative radiotherapy for malignant fibrous histiocytoma can achieve local tumor control as well as preservation of functional limbs with acceptable morbidity in a large proportion of patients.