Radiat Oncol J.  2018 Jun;36(2):103-113. 10.3857/roj.2018.00045.

Treatment outcomes of radiotherapy for anaplastic thyroid cancer

• Park JW
• Choi SH
• Yoon HI
• Lee J
• Kim TH
• Kim JW
• Lee IJ

• KMID: 2418870
• DOI: http://doi.org/10.3857/roj.2018.00045

Abstract

PURPOSE
Anaplastic thyroid cancer (ATC) is a rare tumor with a lethal clinical course despite aggressive multimodal therapy. Intensity-modulated radiotherapy (IMRT) may achieve a good therapeutic outcome in ATC patients, and the role of IMRT should be assessed. We retrospectively reviewed outcomes for ATC treated with three-dimensional conformal radiotherapy (3D-CRT) or IMRT to determine the optimal treatment option and explore the role of radiotherapy (RT).
MATERIALS AND METHODS
Between December 2000 and December 2015, 41 patients with pathologically proven ATC received RT with a sufficient dose of ≥40 Gy. Among them, 21 patients (51%) underwent surgery before RT. Twenty-eight patients received IMRT, and 13 received 3D-CRT. Overall survival (OS) and progression-free survival (PFS), patterns of failure, and toxicity were examined.
RESULTS
The median follow-up time for survivors was 38.0 months. The median and 1-year OS and PFS rates were 7.2 months and 29%, 4.5 months and 15%, respectively. Surgery significantly improved the prognosis (median OS: 10.7 vs. 3.9 months, p = 0.001; median PFS: 5.9 vs. 2.5 months, p = 0.007). IMRT showed significantly better PFS and OS than 3D-CRT, even in multivariate analysis (OS: hazard ratio [HR] = 0.30, p = 0.005; PFS: HR = 0.33, p = 0.005). Significantly higher radiation dose could be delivered with IMRT than 3D-CRT (EQD210 66 vs. 60 Gy, p = 0.005). Only 2 patients had grade III dermatitis after IMRT. No other severe toxicity ≥grade III occurred.
CONCLUSION
Patients with ATC showed better prognosis through multimodal treatment. Furthermore, IMRT could achieve favorable survival rates by safely delivering higher dose than 3D-CRT.

Keyword

Anaplastic thyroid carcinoma; Radiotherapy; Intensity-modulated radiotherapy; Surgery; Progression-free survival

MeSH Terms

Combined Modality Therapy
Dermatitis
Disease-Free Survival
Follow-Up Studies
Humans
Multivariate Analysis
Prognosis
Radiotherapy*
Radiotherapy, Conformal
Radiotherapy, Intensity-Modulated
Retrospective Studies
Survival Rate
Survivors
Thyroid Carcinoma, Anaplastic*