Patterns of failure in anaplastic and differentiated thyroid carcinoma treated with intensity-modulated radiotherapy

  • H. Vulpe Princess Margaret Cancer Centre
  • J.Y.Y. Kwan Princess Margaret Cancer Centre
  • A. McNiven Princess Margaret Cancer Centre
  • J.D. Brierley Princess Margaret Cancer Centre
  • R. Tsang Princess Margaret Cancer Centre
  • B. Chan Princess Margaret Cancer Centre
  • D.P. Goldstein Princess Margaret Cancer Centre, University of Toronto
  • L.W. Le Princess Margaret Cancer Centre, University of Toronto
  • A. Hope Princess Margaret Cancer Centre
  • M. Giuliani Princess Margaret Cancer Centre
Keywords: Thyroid neoplasms, recurrence, radiotherapy, anaplastic thyroid carcinoma, papillary carcinoma

Abstract

Background

The radiotherapy (rt) volumes in anaplastic (atc) and differentiated thyroid carcinoma (dtc) are controversial.

Methods

We retrospectively examined the patterns of failure after postoperative intensity-modulated rt for atc and dtc. Computed tomography images were rigidly registered with the original rt plans. Recurrences were considered in-field if more than 95% of the recurrence volume received 95% of the prescribed dose, out-of-field if less than 20% received 95% of the dose, and marginal otherwise.

Results

Of 30 dtc patients, 4 developed regional recurrence: 1 being in-field (level iii), and 3 being out-of-field (all level ii). Of 5 atc patients, all 5 recurred at 7 sites: 2 recurrences being local, and 5 being regional [2 marginal (intramuscular to the digastric and sternocleidomastoid), 3 out-of-field (retropharyngeal, soft tissues near the manubrium, and lateral to the sternocleidomastoid)].

Conclusions

In dtc, locoregional recurrence is unusual after rt. Out-of-field dtc recurrences infrequently occurred in level ii. Enlarged treatment volumes to level ii must be balanced against a potentially greater risk of toxicity.

Author Biographies

H. Vulpe, Princess Margaret Cancer Centre
Department of Radiation Oncology
J.Y.Y. Kwan, Princess Margaret Cancer Centre
Department of Radiation Oncology
A. McNiven, Princess Margaret Cancer Centre
Department of Radiation Oncology
J.D. Brierley, Princess Margaret Cancer Centre
Department of Radiation Oncology
R. Tsang, Princess Margaret Cancer Centre
Department of Radiation Oncology
B. Chan, Princess Margaret Cancer Centre
Radiation Medicine Program
D.P. Goldstein, Princess Margaret Cancer Centre, University of Toronto
Department of Otolaryngology–Head and Neck Surgery
L.W. Le, Princess Margaret Cancer Centre, University of Toronto
Department of Biostatistics
A. Hope, Princess Margaret Cancer Centre
Department of Radiation Oncology
M. Giuliani, Princess Margaret Cancer Centre
Department of Radiation Oncology
Published
2017-06-28
How to Cite
Vulpe, H., Kwan, J., McNiven, A., Brierley, J., Tsang, R., Chan, B., Goldstein, D., Le, L., Hope, A., & Giuliani, M. (2017). Patterns of failure in anaplastic and differentiated thyroid carcinoma treated with intensity-modulated radiotherapy. Current Oncology, 24(3), e226-e232. https://doi.org/10.3747/co.24.3551
Section
Radiation Oncology