Purpose: Total skin electron therapy (TSET) has proven to be one of the most effective treatments for advanced-stage cutaneous T-cell lymphoma. Many techniques have been developed to deliver a uniform dose to skin. Two most used techniques are the Stanford six-field and rotational techniques. This study compares patient skin dose distributions as function of depth between these two techniques.
Methods: The Monte Carlo code BEAM/DOSXYZnrc was used to simulate a 6 MeV HDTSe beam from a Varian Linac. The simulated beams were benchmarked and validated against experiments. The simulated dual-field beams passed a 3 mm thick of Acrylic scattering plate of 50 cm x 200 cm before incident on the patient at extended distance. The dual-field beams were then used to calculate the patient dose distributions on a CT-based patient images. The calculations assumed the same patient standing on a platform and the patient’s different postures were ignored for the Stanford six-field technique in the dose calculation for direct comparison of the two techniques. The resultant patient doses were analyzed as a function of skin depth-dose coverage and evaluated using dose-volume-histograms (DVH).
Results: Although small dose differences were observed in some local areas, no clinically significant differences were found in the patient 3D dose distributions between the Stanford six-field and rotational techniques. When dose coverage DVH curves were compared, they are visually the same between these two irradiation techniques for mean dose to skin depth of 0-5 mm, 5-10 mm and 10-15 mm from the skin surface, respectively.
Conclusion: Both the Stanford six-field and rotational techniques provide similar dose distributions to patient skin with only small differences in some local areas. The comparison did not consider different patient postures in the Stanford technique, which could affect the comparison of the doses to the limbs.
Not Applicable / None Entered.