Radiotherapy of aggressive fibromatosis

The long term results of 24 patients treated with postoperative irradiation for aggressive fibromatosis are presented. Tumour sites were the pelvis (8), chest wall (5), shoulder (5), extremities (4) and head and neck (2). Macroscopic complete resection (R1) was performed in 3 cases. 17 patients presented postoperatively with gross disease (R2), 8 of which were recurrent tumours. 4 patients with inoperable disease had biopsies only. Radiation doses ranged from 28 to 64 Gy at a fractionation of 5 x 2 or 4 x 2.5 Gy/week. 4 patients had external irradiation in combination with 192Ir implants, 2 were irradiated with implants alone. In the combined treatment group, external doses ranged from 28 to 52 Gy and additional interstitial doses from 35 to 50 Gy. 192Ir treatment alone was given with 45 and 57 Gy to the contour of the target volume. The 10 year recurrence free survival rate is 75%. A dose response relationship has been established in the dose range of 30-60 Gy revealing an expected 80% persistent tumour control rate at 60 Gy. A dose volume relationship however, could not be derived from our data. Moderate fibrosis without functional impairment developed in 5 patients (21%). These data support a policy of postoperative radiotherapy with 60 Gy in patients with incompletely excised or gross residual tumour following surgery.