[Locoregional recurrence of differentiated thyroid cancers: diagnosis-treatment]

To evaluate the improvement of the diagnosis and the treatment of local recurrences (LR) in patients with differentiated thyroid carcinoma.

Among a total of 57 patients, two groups were compared: group I: 31 patients operated on from 1974 to 1990; group II: 26 patients operated on from 1991 to 2000. In the group I, the diagnosis of the cervical recurrence was supported by imaging study (ultrasonography, tomodensitometry), in the group II by radioiodinescan and serum thyroglobuline (Tg) measurement. The main difference was the consideration of Tg measurement to detect the recurrence in the group II. A high level of Tg was the only abnormality for 9 patients of the group II.

A nodal recurrence was respectively present in the group I and II in 88.8% and 92% of the cases. Re-operation consisting in thyroid totalisation and bilateral lymphadenectomy was respectively performed in 71% and 100% of the cases. Surgery associated with iodine 131 therapy was respectively the treatment for 45.1% and 88.4% of the cases. After a median follow up of 66.2 months; results of the group I were as follow: normal or undetectable Tg: 10 (33.3%), second or more cervical recurrences: 7, distant metastases: 11, death in relation to thyroid cancer: 11. After a median follow up of 36.3 months, results of the group II were as follow: normal or undetectable Tg: 17 (65.4%), second or more cervical recurrences: 6, distant metastasis: 5, death in relation to thyroid cancer: 1. The best results concerned patients with an isolated elevated Tg without anatomical location of the first LR.

LR diagnosis is difficult and needs imaging study, radioiodine-scan and serum Tg determination together. Re-operation associated with radioiodine-therapy is the treatment of choice. Elevated serum Tg is suffisant to indicate re-operation even if no anatomical substrate is found. Iodine-radiotherapy alone is generally unable to obtain undetectable serum Tg.