The Role of Radiotherapy in the Different Cancer of Tiroides: Case Series and Literature Review

Original Research

Abstract

Introduction: The initial management of differentiated thyroid cancer (DTC) usually includes surgery that can be accompanied according to the risk of recurrence of the administration of radioactive iodine (I-131). However, there is a small group of patients who are classified as refractory to I-131, which directly affects their prognosis and life expectancy, making it necessary to evaluate local treatment options before advancing to systemic therapies and, in these conditions, radiotherapy (RTP) represents a local option for primary or palliative treatment purposes.

Methods: An epidemiological, descriptive, retrospective, single-center study was carried out, involving 49 patients with DTC and indication for radiotherapy.

Results:  In 80% of the cases the age was over 45 years, with a 74% predominance in the female sex, all with a diagnosis of DTC undergoing surgery, 88% with a non-aggressive variant, 57% with a tumor size between 1 at 4cm, 71% with extrathyroid extension, 71% with cervical lymph node metastases, 45% TNM stage I, and 71% with a high risk of recurrence. 96% received  I-131, requiring reoperations for up to 5 or more occasions (8%). 57% received RTP for curative purposes and 43% palliative. The radiotherapy technique used in 69% of the patients was IMRT / VMAT, and the most frequently used dose was ?60Gy in the cervical region (61%). Of the 49 patients, 90% had an incomplete structural response and 12% died from DTC.

Conclusions: Radiation therapy should be considered in locally advanced disease with extrathyroid extension, macroscopic residual disease and unresectable or recurrent tumor that fails conventional therapy for DTC.