Five months' follow-up of patients with and without iodine-positive lymph node metastases of thyroid carcinoma as disclosed by (131)I-SPECT/CT at the first radioablation.
OBJECTIVE
In differentiated thyroid carcinoma (DTC), (131)I-SPECT/CT is more accurate in identifying radioiodine-positive lymph node metastases (LNM) than planar whole-body scans (WBS). The purpose of this study was to investigate the value of (131)I-SPECT/CT performed at the first radioablation to predict the occurrence and/or persistence of cervical radioiodine-positive LNM 5 months later.


METHODS
The study included 81 DTC patients that had had SPECT/ spiral CT after radioablation of thyroid remnants after thyroidectomy. The patients were re-examined 5 months later using (131)I-WBS performed at TSH stimulation. In addition, SPECT/CT of the neck was performed in patients with iodine-positive cervical foci to distinguish between thyroid remnant and LNM. The outcome variable of the study was the detection or exclusion of iodine-positive cervical LNM.


RESULTS
Of 61 patients without a SPECT/CT diagnosis of (131)I-positive LNM at radioablation, 60 had no (131)I-positive LNM at follow-up. In the remaining patient of this group, a new radioiodine-positive LNM was detected. In 17 of 20 patients with a SPECT/CT diagnosis of (131)I-positive LNM (n = 19) or an indeterminate lesion (n = 1) at first radioablation, no (131)I-positive LNM were detected 5 months later. Radioiodine-positive LNM persisted in three patients of this group.


CONCLUSIONS
(131)I-SPECT/CT has a high negative predictive value with regard to the occurrence of radioiodine-positive cervical LNM 5 months after initial therapy. The majority of iodine-positive LNM diagnosed by SPECT/CT at radioablation disappear within 5 months. These findings motivate further research into the value of (131)I-SPECT/CT of the neck for predicting recurrence and planning surgical reintervention in DTC.
Schmidt
Daniela
D
Clinic of Nuclear Medicine, University of Erlangen-Nürnberg, Krankenhausstr. 12, 91054 Erlangen, Germany. Daniela.Schmidt@uk-erlangen.de
Linke
Rainer
R
Uder
Michael
M
Kuwert
Torsten
T
D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D018365:Neoplasm, Residual; D010347:Patient Care Planning; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000627:therapeutic use*; D012086:Reoperation; D013964:Thyroid Neoplasms / Q000473:pathology*; D013965:Thyroidectomy; D015899:Tomography, Emission-Computed, Single-Photon; D036542:Tomography, Spiral Computed; D051598:Whole Body Imaging; D055815:Young Adult
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals