Commissioning of Scalp-Sparing Rotational Total Skin Electron Therapy (TSET)
Abstract
Purpose
Alopecia from rotational total skin electron therapy (TSET) poses severe psychological challenges for patients with special social needs. Depending on the location of the disease, some patients may be candidates for scalp-sparing TSET. We herein present the commissioning of a modified-TSET setup with added shielding using lead sheets and a lead-covered helmet that was shown to effectively shield the scalp area to prevent significant hair loss.
Methods
The TSET setup was modified to shield the head region of patients using two sheets of 3-mm lead suspended from the top of the rotational treatment platform. Additionally, a lead helmet specifically for shielding the scalp region was fabricated by uniformly covering a helmet with 3-mm lead. To test the shielding of the lead helmet, radiochromic films were wrapped inside the helmet to detect potential locations for insufficient shielding. An end-to-end test was performed using an anthropomorphic phantom with TLD measurements at 13 locations for the scalp-sparing TSET. To test the effectiveness of the lead helmet, an additional setup with the anthropomorphic phantom was performed using only the lead sheets for shielding without the lead helmet.
Results
Film results confirmed the shielding integrity of the lead helmet. TLD measurements of the anthropomorphic phantom using the scalp-sparing TSET setup revealed significant dose reduction to the scalp area of the phantom with the greatest sparing occurring when both the helmet and the lead sheets were implemented. This setup reduced the dose by 98.5% for vertex, 88.9% for forehead and 97.4% for back of head. The special design did not significantly affect the dose for other areas of the body intended for treatment.
Conclusion
The scalp-sparing TSET setup with added lead shielding from lead sheets and helmet can significantly decrease absorbed dose in the scalp to effectively reduce the occurrence and severity of alopecia.