Head and Neck Cancer
PV QA 2 - Poster Viewing Q&A 2
MO_36_2853 - Hypofractionated Radiation Therapy for Anaplastic Thyroid Carcinoma: 15 Years of Experience in a Single Institution
Monday, October 22
10:45 AM - 12:15 PM
Location: Innovation Hub, Exhibit Hall 3
Hypofractionated Radiation Therapy for Anaplastic Thyroid Carcinoma: 15 Years of Experience in a Single Institution
N. Takahashi1, H. Matsushita1, R. Umezawa1, T. Yamamoto1, Y. Ishikawa1, Y. Katagiri1, S. Tasaka1, K. Takeda1, K. Fukui2, N. Kadoya1, K. Ito1, and K. Jingu1; 1Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan, 2Tohoku University Graduate School of Medicine, Sendai, Japan
Purpose/Objective(s): Anaplastic thyroid carcinoma is a rare cancer and has a poor prognosis. Several radiation protocols have been reported, but the results were not satisfactory. The aim of this study was to determine the effect of hypofractionated radiotherapy.
Materials/Methods: Thirty-three patients (21 male patients and 12 female patients) who received radiotherapy for ATC between 2000 and 2014 in our institution were included in this study.
Results: Nineteen patients were treated with ≥ 5 Gy per fraction (Gy/fr), and 18 of those patients received 5 Gy/fr. Twenty-eight patients died, and 27 of those patients died from ATC. Sixteen patients died from distance metastasis and 6 patients died from local recurrence. In the ≥ 5 Gy/fr group, local recurrence occurred in 5 patients and 1 of them died from active bleeding from a local tumor. There was local recurrence in 7 patients who received the other protocol, and 5 of them died from asphyxiation, active bleeding or uncontrollable growth of a local tumor on the neck. The median overall survival (OS) period in all patients was 5 months. In multivariate analysis, patients who received an equivalent dose in 2 Gy fractions (EQD2) ≥ 50 Gy had significantly better OS (p = 0.016). In univariate analysis, patients who received ≥ 5 Gy/fr did not have significantly better OS (p = 0.872) or LC (p = 0.090). The chi-squared test showed that significantly fewer patients died from local recurrence in the ≥ 5 Gy/fr group (p = 0.025).
Conclusion: Multivariate analysis showed that EQD2 ≥ 50 Gy resulted in better OS, and ≥ 5 Gy/fr decreased the rate of mortality from local recurrence.
| Multivariate analysis for OS. |
| || HR || 95 % CI || p value |
| Male vs female || 2.14 || 0.96-5.13 || 0.064 |
| EQD2 (≥ 50 Gy vs < 50 Gy) || 0.26 || 0.097-0.76 || 0.016 |
| Note: OS = overall survival, HR = Hazard ratio, CI = confidence interval, EQD2 = equivalent dose in 2 Gy fractions. Factors with p < 0.01 in univariate analysis were included in multivariate analysis. |
Author Disclosure: N. Takahashi: None. H. Matsushita: None. R. Umezawa: None. T. Yamamoto: None. S. Tasaka: None. K. Fukui: None. K. Ito: None.