Posters— Surgical Treatment of Sarcomas

COMBINED SURGERY, BRACHYTHERAPY AND EXTERNAL IRRADIATION OF LOCALLY ADVANCED SOFT TISSUE SARCOMAS: A FEASIBLE APPROACH

Pedersen JG¹, Krarup-Hansen A², Daugaard S³, Hojlund B⁴, Rosendal F, Larsen JS², Lund B¹ & Engelholm SA². Departments of: Orthopaedic Surg¹, Radiation Oncology², Pathology³ & Radiology⁴, National University Hospital (Rigshospitalet), DK-2100 Copenhagen, Denmark

Background: Locally advanced disease of soft tissue sarcomas (STS) is a major surgical task: Maximum local control vs. minimum surgery and disability. Aim: To reduce the amount of extensive surgery, to improve local control by immediate use of postoperative tumour (T) bed brachytherapy (brt) followed by external beam irradiation (RT), and to reduce morbidity.

Material & Methods: 16 patients (pts) median age 60 Years (29-75), F/M 9/7 with a blank chest X-ray had an MR/CT-scan and a diagnostic biopsy. 15 pts had a primary T larger than 5 cm; 1 less than 5 cm; 9 located at the lower and 4 at the upper extremity and 3 superficial at the thorax: 2 had a grade (gr) I T; 10 a gr II and 3 a gr III; S had liposarcoma; 3 myxofibrosarcoma; 2 leio- myosarcoma; 1 myogenic sarcoma; 1 synovial sarcoma and 1 malignant haemangioperi-cytoma. All pts underwent surgical procedure (10 intralesional excision, 4 marginal, 2 wide) and intra- opererative implantation of microSelectron (mSr) flexible applicators (median 6 (3-18)), each tube with a maximal loading length of 23 cm. The following day the tubes were connected to the PDR-mSr treatment unit and a mean dose of 22 Gy (20-30) was applied, dose rate 0.6 Gy/hr; one pulse/hr with a CT-scan calculated 100% at reference points 5 mm from the catheters. The tubes were extracted immediately after finishing the brt. The volume implants were recon-structed from orthogonal radiographs and the 3D-dose distribution calculated in CADPLAN using a geometric optimisation algorithm for stepping source implants. The mean treatment volume was 104 ml (45-200). Conventional fractionated compartmental external beam RT was initiated at day 22 (9-34) and a total cumulated mean dose of 49 Gy (44-50) in 2 Gy-fractions was given.

Results: 15 pts are alive, 14 with no sign of local recurrence at a median follow-up of 16 months (12-49); 1 pt died of lung metastases at 27 months; 1 pt with intralesional excision had multi- focal local recurrence of dedifferentiated liposarcoma (gr II -> III); 1 pt is alive with lung metastases. One pt (brt 30 Gy, external RT 50 Gy) had quite a severe RT-induced damage and needed skin-transplantation after which the pt recovered. Brt was reduced to 20 Gy and no further events of RT damage were observed. Overall only minimal disability was observed.

Conclusion: Combined modality treatment of locally advanced STS is a safe and feasible approach. This early report needs further confirmation in a long-time observation large-scale study.