Ultrasensitive serum thyroglobulin measurement is useful for the follow-up of patients treated with total thyroidectomy without radioactive iodine ablation.
BACKGROUND
Thyroglobulin (Tg) measurement is a major tool for the follow-up of differentiated thyroid cancer (DTC) patients; however, in patients who do not undergo radioactive iodine (RAI) ablation, normal ultrasensitive Tg levels measured under levothyroxine treatment (usTg/l-T4) are not well defined.


OBJECTIVE
This single-center retrospective study assessed usTg/l-T4 level in 86 consecutive patients treated with total thyroidectomy without RAI ablation for low-risk DTC (n=77) or for tumors of uncertain malignant potential (TUMP) (n=9).


RESULTS
DTCS were classified as PT1, PT2, and PT3 in 75, 1, and 1 case respectively and PN0, PN1, and PNX in 40, 6, and 31 respectively. following surgery, ten patients had TG antibodieS (TGAB). Among those without TGAB, the first USTG/L-T4 determination obtained at a mean time of 9 months after surgery was 0.1NG/ML in 62% of cases, 0.3NG/ML in 82% of cases, 1NG/ML in 91%, and 2NG/ML in 96% of cases. after a median follow-up of 2.5 years (range: 0.6-7.2 years), one patient had persistent disease with an usTg/l-T4 at 11 ng/ml and an abnormal neck ultrasonography (US) and two patients had usTg/l-T4 level >2 ng/ml (3.9 and 4.9 ng/ml) with a normal neck US. Within the first 2 years following total thyroidectomy without RAI ablation, usTg/l-T4 level is ≤2 ng/ml in 96% of the cases.


CONCLUSIONS
After total thyroidectomy, sensitive serum Tg/l-T4 level is ≤2 ng/ml in most patients and can be used for patient follow-up.
Departments of Nuclear Medicine and Endocrine Oncology.
C
C
Nascimento
I
I
Borget
F
F
Troalen
A
A
Al Ghuzlan
D
D
Deandreis
D
D
Hartl
J
J
Lumbroso
C N
CN
Chougnet
E
E
Baudin
M
M
Schlumberger
S
S
Leboulleux
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000601:surgery*; D013965:Thyroidectomy; D013974:Thyroxine / Q000097:blood; D014463:Ultrasonography; D055815:Young Adult
D007457:Iodine Radioisotopes; D013954:Thyroglobulin; D013974:Thyroxine