Pre-ablative diagnostic whole-body scan following total thyroidectomy for well-differentiated thyroid cancer: is it necessary?
OBJECTIVE
This study reviewed the incidence of positive pre-ablative diagnostic scan after total thyroidectomy and the efficacy of the current ablative dose. The predictive factors for outcome using a standard ablative dose and postoperative complications of total thyroidectomy were also examined.


METHODS
This was a retrospective review of patients referred for radioiodine ablation after total thyroidectomy between September 1997 and September 2001.


RESULTS
Forty patients were included in this study, of whom 95% had a positive scan after total thyroidectomy. Of the 30 patients who underwent standard 80-mCi radioiodine ablation, 21 (70%) had successful single ablation while the remaining nine patients needed a higher ablative dose. There were no significant differences between patients who had successful ablation with the standard dose and those who did not in terms of tumour size, patient age, lymph node status and extra-thyroidal extension. Fifteen percent suffered from permanent hypoparathyroidism requiring calcium supplementation. Three patients had documented recurrent laryngeal nerve paralysis.


CONCLUSIONS
Bypassing the pre-ablative diagnostic scan is feasible. The present ablation dose of 80 mCi of radioiodine is effective. The relatively high postoperative morbidity after difficult total thyroidectomy suggests less aggressive excision and postoperative radioiodine ablation of the remnant tissue.
Teoh
Choon Meng
CM
Department of Surgery, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia. cmteoh@mail.hukm.ukm.my
Rohaizak
Muhammad
M
Chan
Kin Yoong
KY
Jasmi
Ali Yaakub
AY
Fuad
Ismail
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy*; D011182:Postoperative Care; D011183:Postoperative Complications; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy*; D013965:Thyroidectomy; D014826:Vocal Cord Paralysis
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals