Cumulative doses of adjunct 131I treatment depend on location of residual thyroid tissue after total thyroidectomy in differentiated thyroid cancer.
OBJECTIVE
The aim of this study was to review the outcome after adjunct postoperative 131I therapy in patients with differentiated thyroid carcinoma (DTC) treated with total thyroidectomy (excluding medullary thyroid carcinoma).


METHODS
Retrospective chart review: Management protocol is total thyroidectomy with cervical node sampling, 131I whole-body scan 3 weeks postoperatively to document residual thyroid tissue or metastatic lesions. Adjunct treatment consists of one or more 131I (100-200 mci/1.73 m2). Patients are considered disease free if 2 consecutive 131I whole-body scan are negative with undetectable thyroglobulin level.


RESULTS
Twenty-one patients, 14 females and 7 males, with a mean age of 13.6 years were treated. Whole-body scan postoperatively revealed uptake in the thyroid bed (TB) in 10 patients, in cervical lymph nodes (CLN) in 9 patients, and in CLN and lungs in 2 patients. Patients with residual uptake in TB received a significantly lesser dose of 131I (mean, 122 +/- 53 mci) than those with metastatic CLN (357 +/- 182 mci) (P < .004) (t test) or lung mets (523.5 mci). With a mean follow-up of 7.8 years (range, 1-16 years), overall survival is 100% but disease-free survival is 100%, 66%, and 0% respectively for patients with residual disease in TB, CLN, and lungs.


CONCLUSIONS
Patient with residual thyroid tissue in the TB required a significantly lesser number of treatments and doses of 131I compared to patients with cervical node metastases with a 100% disease-free survival. The best management of immediate postoperative residual cervical nodes (surgical excision vs 131I) remains to be defined. The efficacy of 131I therapy in patients with lung metastases remains controversial with complete remission unlikely.
Saint-Vil
Dickens
D
Division of Pediatric General Surgery, CHU Sainte Justine, Montreal, Quebec, Canada H3T 1C5. dickens_saint-vil@ssss.gouv.qc.ca
Emran
Mohammad Ali
MA
Lambert
Raymond
R
Alos
Nathalie
N
Turpin
Sophie
S
Huot
Céline
C
D000293:Adolescent; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D018365:Neoplasm, Residual / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome; D014915:Whole-Body Counting
D007457:Iodine Radioisotopes