28 Soft tissue sarcomas of the extremities in adults

Soft TIssue Sarcomas 567

The tubes are loaded with Ir192 on day 2-4 in the IGR technique (15,17) and on day 6 - 8 in the MSKCC technique. (18,19)

9 Dose, Dose Rate, Fractionation If LDR brachytherapy is usedalone a total dose of 60 - 75 Gy at a dose rate of 40 - 60 cGy/hour is delivered depending on the surgical and pathologic resuts. (15,17,37) If LDR brachytherapy is combined with external beam therapy the dose of brachytherapy is dependant on the dose of external beam therapy. The overall total dose varies from 70 - 80 Gy with a brachytherapy dose of 25 - 35 Gy. When the dose of brachytherapy is more than 65 Gy (brachytherapy alone), or more than 30 Gy (in combination treatments), the volume receiving more than 65/30 Gy is reduced. (15,17). The loading should be adjusted to focus this boost volume on the area at highest risk of local recurrence. This optimisation of dose distribution can also be easily applied using the stepping source technology. For HDR brachytherapy the reccomendations from the ABS: for intraoperative HDR rachytherapy the doses range from 10 to 15 Gy (prescribed at a 0.5 cm depth of this brachytherapy is used as a boost to EBRT). 10 Monitoring In perioperative brachytherapy specific care must be taken in relation to the early side effects of to the surgical procedure and brachytherapy and their interaction. Typical surgical complications are haemorrhage, infection, haematoma and wound dehiscence. In these cases, it is essential to check with the geometry of the implant compared to the initial plan by X rays, and if there is displacement to recalculate the dosimetry. Systematic prophylactic antibiotics are not mandatory but are used if there are local or general symptoms. 11 Results Most treatments have been with low dose rate but there is some experience with high or pulsed dose rates. 11.1 Results of surgery The results of surgery are dependent on tumour and patient related factors. In addition, different types of surgery carry a characteristic risk of local recurrence: intralesional procedure 100%, marginal procedure 50 - 80%, wide excision 30 - 60%, radical excision 10 - 20% (Enneking et al. 1981?). These results underline the fact that a high local control rate can only be achieved by performing a radical procedure which will be associated with significant morbidity. (2,9,13,16,26,35) 11.2 Results of external beam therapy combined with surgery Conservative limb sparing treatment including nonradical surgery and adjuvant radiotherapy for localised extremity sarcomas has been shown to be as effective as radical surgery alone in a prospective randomised NCI trial comparing amputation vs a limb-sparing operation followed by