Technetium-99m-furifosmin in the follow-up of differentiated thyroid carcinoma.
Tumor scintigraphy with flow tracers, such as 201TI-chloride, has an established role in the follow-up of differentiated thyroid cancer. We investigated a new tracer, 99mTc-furifosmin (Technescan Q12, Mallinckrodt Diagnostika, Hennef, Germany), in patients with elevated thyroglobulin levels or sonographic suspicion of lymph node metastases or recurrent disease.


METHODS
In a prospective study, we examined 20 patients with 99mTc-furifosmin. All patients underwent a 18F-fluorodeoxyglucose (FDG) PET scan of the neck and chest. Positive 99mTc-furifosmin findings were validated by biopsy, (131)I scan, CT or 18F-FDG PET examinations.


RESULTS
In three patients with cervical lymph node metastases detected on a planar 99mTc-furifosmin scan, we found a rapid tracer accumulation in the tumor (maximum < 2 min) and a significant washout in 2 of 3 patients after 4 hr. The visual contrast and the tumor-to-nontumor ratio was rather poor (average 1.2:1). In 3 additional patients, 3 pulmonary and 2 mediastinal lymph node metastases were detected by the 99mTc-furifosmin SPECT scan. Two patients were true-negative, and in 13 of 18 patients, the tumor could be localized by 18F-FDG PET (10 cervical, 6 mediastinal, 4 pulmonary metastases, 1 bone metastasis); 5 patients were false-negative. In 3 of these false-negative cases we could not localize the tumor with other diagnostic methods. Two patients had a true-negative PET examination.


CONCLUSIONS
The statistical analysis of our data on 99mTc-furifosmin reveals that the sensitivity and 95% confidence interval of 33% (11%-56%) on a patient-by-patient basis and of 34% (17%-57%) for the lesion-by-lesion analysis is significantly lower than the sensitivity and 95% confidence interval of 72% (50%-89%) on a patient-by-patient basis and of 91% (78%-100%) on lesion-by-lesion basis for 18F-FDG. The sensitivity of 99mTc-furifosmin appears to be poor, even for cervical and mediastinal tumor manifestations where the value of 201TI-chloride is established.
Brandt-Mainz
K
K
Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Essen, Germany.
Müller
S P
SP
Sonnenschein
W
W
Bockisch
A
A
D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D005462:Fluorine Radioisotopes; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C114153:technescan Q12; D019788:Fluorodeoxyglucose F18