Is 131I ablation necessary for patients with low-risk papillary thyroid carcinoma and slightly elevated stimulated thyroglobulin after thyroidectomy?

Abstract

Objective: This prospective study evaluated the recurrence rate in low-risk patients with papillary thyroid cancer (PTC) who presented slightly elevated thyroglobulin (Tg) after thyroidectomy and who did not undergo ablation with 131 I. Subjects and methods: The study included 53 low-risk patients (nonaggressive histology; pT1b-3, cN0pNx, M0) with slightly elevated Tg after thyroidectomy (> 1 ng/mL, but ≤ 5 ng/mL after levothyroxine withdrawal or ≤ 2 ng/mL after recombinant human TSH). Results: The time of follow-up ranged from 36 to 96 months. Lymph node metastases were detected in only one patient (1.9%). Fifty-two patients continued to present negative neck ultrasound. None of these patients without apparent disease presented an increase in Tg. Conclusions: Low-risk patients with PTC who present slightly elevated Tg after thyroidectomy do not require ablation with 131 I. Arch Endocrinol Metab. 2016;60(1):5-8

Iodine-131: An Effective Method for Treating Lymph Node Metastases of Differentiated Thyroid Cancer

“…Of the confounding factors, thyroid tissue remnants and distant metastasis were found to be important in influencing the efficacy of treatment, likely because both remnant thyroid tissues and metastasis have the ability to uptake iodine, and thus reduce the effectiveness of iodine uptake of metastatic lymph nodes, especially under conditions where the iodine-uptake ability of remnant thyroid tissues is over 1,000 times that of metastatic tissue [16]. The HTG level is a specific marker used to identify the recurrence or metastasis of DTC [17–20]. It has also been proven to be an important factor influencing 131 I treatment efficacy on metastasis of DTC, which is in line with the thyroid tissue remnants and distant metastasis.…”

Thyroid remnant ablation with radioiodine activity of 30, 60, and 100 mCi in patients with differentiated thyroid cancer – a prospective comparison of long-term outcomes

“…The authors of the current ATA guidelines allow the non-performance of RAI ablation in low-risk DTC. However, the quality of evidence is low [ 1 , 14 , 15 ]. Currently ongoing studies probably will justify the lack of RAI ablation in a low-risk group [ 16 ].…”

Radioiodine for thyroid cancer: sometimes, less is best

“…However, only two previous studies evaluated the follow-up of low risk patients who were not submitted to ablation because of low postoperative Tg (4,7). This remark emphasizes the importance of this prospective study by Rosario and Mourão (1), which also showed a low recurrence rate (approximately 2%) in a large number of low risk patients who, following total thyroidectomy without central neck dissection, remained with slightly elevated stimulated Tg and were not submitted do RAI ablation.…”

“…Another point to be raised in this study is the inclusion of intermediate risk patients [26 patients presented tumors > 4 cm or minimal extra thyroid invasion (pT3, cN0pNx, M0)] in the selected group of patients classified as low risk (1,9). By including these patients, the author also evaluated the recurrence rate of this intermediate risk group that remained with slightly elevated stimulated Tg after surgery.…”