Endocrine Abstracts

JOINT1069

Introduction: The risk stratification for recurrence of differentiated thyroid carcinomas, as outlined by the 2015 American Thyroid Association (ATA) guidelines, has enabled a therapeutic de-escalation, particularly for patients classified as low-risk for recurrence.

Materials and Methods: This monocentric retrospective study held within the Nuclear Medicine Unit of the Central Military Hospital of Algiers, follows a total of 280 patients, initially classified as low-risk according to the 2015 ATA criteria (pT1bN0/NxMx, pT2N0/NxMx), who after total thyroidectomy, received 1.1 GBq (30 mCi) of iodine-131 after thyrotropin stimulation (with either of the follwoing processes: rhTSH or thyroid hormone withdrawal) for ablation purposes. Thyroglobulin (Tg) and anti-thyroglobulin antibodies (ATg) levels were measured after thyrotropin stimulation, along with a cervical ultrasound, conducted 9 to 12 months post-treatment for all patients.

Results: Out of the 280 patients, 265 showed a complete biological response and a normal cervical ultrasound, resulting in a success rate of 94.6%.

- A cranial metastasis was identified in one patient.

- Four patients presented loco-regional metastasis (metastatic cervical adeonpathies).

- Ten patients presented an incomplete biochemical response with a negative cervical ultrasound and responded well to a second course of iodine-131 treatment.

Discussion: The results of our study are consistent with those of the ESTIMABL 1 study (98% remission), which allowed us to avoid overtreatment in more than 97% of patients. Additionally, dose reduction minimizes treatment-related side effects and has a considerable economic and organizational impact.

Conclusion: The use of low-dose iodine 131 (1.1Gbq), demonstrate excellent outcomes, yielding comparable results to higher dose treatment in low-risk differentiated thyroid carcinoma, ensuring optimal patient care, all the while reducing the economic and the organizational burden associated with former protocols.