Intra-operative implant brachytherapy in the management of soft-tissue sarcomas

SURGICAL MARGIN AND ITS INFLUENCE ON SURVIVAL IN SOFT TISSUE SARCOMA

BACKGROUND

The goal of surgeons treating soft tissue sarcoma is to gain local control, to avoid risk of local recurrence and to avoid compromise of the patient's potential survival. The aim of the investigation was to assess the significance of the extent of surgical margin on the chance of death, metastasis and local recurrence.

METHODS

Two hundred and seventy-nine patients who presented with soft tissue sarcoma without metastatic disease were analysed.

RESULTS

The extent of the surgical margin was not clinically or statistically significant in the development of metastatic disease. The presence of a contaminated surgical margin led to a significantly higher rate of local recurrence (as did a narrow surgical margin less than 1 mm). A margin greater than 1 mm allowed a satisfactory outcome in terms of low local recurrence rates. In terms of overall survival, the failure to achieve a wide surgical margin (wide contaminated margin) led to an increased relative death rate. However, when the margin was not contaminated (even if the margin was very close, less than 1 mm), the overall survival rate was similar across all groups. Patients who had radical resections did poorly; they generally belonged to a group in which palliative surgery was carried out, and they showed very high relative metastasis and death rates.

CONCLUSION

The present study provides statistically significant evidence that increasing the width of resection improves local control and overall survival.

Current results of brachytherapy for soft tissue sarcoma

Perioperative brachytherapy results in a better local control rate than surgery alone for extremity soft tissue sarcoma. Brachytherapy enables the delivery of a high radiation dose to a limited volume of tissue, allows the reduction of radiation treatment time, enables direct visualization of the tumor bed and surrounding critical structures, and costs less than external beam radiotherapy. The literature seems to regard the effectiveness of brachytherapy as comparable to that of external beam radiotherapy, and the side effect profile is acceptable. Traditional low-dose-rate brachytherapy methods require extended periods of patient isolation, but recent technologic advances may obviate this necessity. Newer high-dose-rate (HDR) brachytherapy delivery methods allow for the fractionation of radiation delivery and outpatient treatment in some cases. Furthermore, with HDR brachytherapy, the radiation dose distribution can be tailored around critical anatomic structures. Although the application of HDR brachytherapy to soft tissue sarcoma is relatively new, it seems to result in a satisfactory local control rate and may replace traditional low-dose-rate techniques.

The American Brachytherapy Society recommendations for brachytherapy of soft tissue sarcomas

PURPOSE

This report presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with soft tissue sarcoma.

METHODS AND MATERIALS

Members of the ABS with expertise in soft tissue sarcoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report.

RESULTS

Brachytherapy used alone or in combination with external beam irradiation is an established means of safely providing adjuvant local treatment after resection for soft tissue sarcomas in adults and in children. Brachytherapy options include low dose rate techniques with iridium 192 or iodine 125, fractionated high dose rate brachytherapy, or intraoperative high dose rate therapy. Recommendations are made for patient selection, techniques, dose rates, and dosages. Complications and possible interventions to minimize their occurrence and severity are reviewed.

CONCLUSION

Brachytherapy represents an effective means of enhancing the therapeutic ratio, offering both biologic and dosimetric advantage in the treatment of patients with soft tissue sarcoma. The treatment approach used depends upon the institution, physician expertise, and the clinical situation. Guidelines are established for the use of brachytherapy in the treatment of soft tissue sarcomas in adults and in children. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose-reporting policies. These guidelines will be modified, as further clinical results become available.