[Patients treated for differentiated thyroid cancer with negative 131I whole-body scans and elevated thyroglobulin levels: a possible course].
OBJECTIVE
To verify the existence of patients with treated differentiated thyroid cancer (DTC) with negative 131I whole-body scanning (WBS) and high serum thyroglobulin (Tg) in the follow-up who evolve towards normalization without other therapy interventions.


METHODS
Retrospective revision of the periodic examinations established in the protocol for patients with DTC, analyzing the levels of Tg found with IRMA annually in those with hormonal treatment and every 1-5 years in absence of previous hormonal treatment to WBS. Minimum surveillance of 2 years. Those who had elevated levels of Tg and WBS and other negative imaging tests in their course were selected. The characteristics of the patients selected were analysed in those whose Tg levels evolved to normalization without specific medical or surgical treatment (Group I) and those who did not reach normalization of Tg (Group II).


RESULTS
A total of 130 patients (17.93 %) with high levels of Tg and negative WBS were detected. Group I: 31 patients (4.28 %), 11 men and 20 women; average age at the moment of the diagnosis of 33.4 years (rank: 5-60); average surveillance: 12.4 years (+/- 7.4).


RESULTS
27 papillary and 4 follicular carcinoma. Average ablation dose: 3.260 GBq (88,1 mCi); average total I131 dose: 6.850 GBq (185.13 mCi). Tg normalization average time: 8.2 years. Group II: 99 patients (13.65 %), 27 men and 72 women. Average age of 40.4 years (rank: 7-76). Average surveillance: 9.8 years.


RESULTS
86 papillary and 13 follicular carcinoma. Average ablation dose: 3.266 GBq (88.28 mCi); average total 131I dose: 9.363 GBq (253,06 mCi). Two of the patients in group I had negative PET-FDG. There were 13 patients in whom progressive reduction of the levels of thyroglobulin without reaching normalization with negative PET-FDG was detected.


CONCLUSIONS
In patients with radiated DTC, deferred normalization of the levels of the serum thyroglobulin is possible. Empirical treatments cannot be considered the only factor that contributes to this result, which can occur without the administration of high-doses of 131I.
Gutiérrez Cardo
A L
AL
Servicio de Medicina Nuclear, Hospital Universitario Virgen del Rocío, Sevilla, Spain. antoniol.gutierrez.sspa@juntadeandalucia.es
Rodríguez Rodríguez
J R
JR
Borrego Dorado
I
I
Navarro González
E
E
Tirado Hospital
J L
JL
Vázquez Albertino
R
R
D018263:Adenocarcinoma, Follicular / Q000097:blood* / Q000000981:diagnostic imaging* / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D002291:Carcinoma, Papillary / Q000097:blood* / Q000000981:diagnostic imaging* / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D002454:Cell Differentiation; D002648:Child; D003131:Combined Modality Therapy; D019468:Disease Management; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D011184:Postoperative Period; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging* / Q000532:radiotherapy / Q000601:surgery; D013965:Thyroidectomy; D051598:Whole Body Imaging
D014408:Biomarkers, Tumor; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D013954:Thyroglobulin