Investigation of Alopecia for Nasopharyngeal Carcinoma Patient Treated with IMRT and Tomotherapy
WYC Kong*, FKH Lee, RMC Chau, Queen Elizabeth Hospital, Hong KongSU-E-T-273 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: A nasopharyngeal carcinoma patient treated with Tomotherapy was presented with severe alopecia in the follow up clinic 8 weeks post treatment. Dosimetric investigation was carried out on a group of NPC patients to look at scalp follicle doses using IMRT and Tomotherapy techniques.
Methods: Scalp follicle and upper neck follicle structures were defined in treatment planning system. Total of 16 Tomotherapy and 16 IMRT NPC patients were investigated, all patients were at different stage through treatment. The median dose for each structure was compared between IMRT and Tomotherapy techniques. The degree of alopecia for each patient was graded with reference to Cancer Therapy Evaluation Program CTCAE V3.0.
Results: The mean median dose for scalp follicle structure was recorded as 1635.6±213.4cGy for Tomotherapy, and 1604.4±448.9cGy for IMRT. The mean median dose for upper neck follicle was recorded as 3744.8±352.0cGy for Tomotherapy, and 3539.5±512.3cGy for IMRT. A 2 tailed t test was performed on the results, at 95% significant level, the results show no significant difference in median doses for both follicles regions between Tomotherapy and IMRT treatment for NPC patients. Most patients on treatment for NPC started to experience some degree of alopecia from the last 2 weeks of treatment. Patients from the follow up clinic who had completed treatment over 20 weeks were not presented with alopecia symptoms. These results suggest alopecia is a temporary side effect.
Conclusion: There is no significant difference in median doses to the follicles regions between IMRT and Tomotherapy techniques. With reference to Lawenda BD study, and the results from this study suggests the risk of permanent alopecia is low for our current planning techniques.