Radioiodine treatment (RAI-T) of differentiated thyroid carcinoma (DTC) is important to avoid disease progression, in particular in pediatric patients. For these reasons, a diagnostic scan may be useful to assess therapeutic tailored activity. The purpose of our study was to evaluate the usefulness of diagnostic whole-body scan (WBS) with iodine-123 (123I) in combination with recombinant human thyroid-stimulating hormone (rh-TSH; Thyrogen) (rh-TSH-Dx-WBS), in planning RAI-T or further surgery before RAI-T in pediatric DTC.
Among 101 rh-TSH-Dx-WBS of 55 patients (21 males, mean age: 15 years, range: 5–18 years) followed at the Bambino Gesù Pediatric Hospital for DTC from February 2004 to December 2016, 41 rh-TSH-Dx-WBS scans of 41 patients (20 male and 21 female, mean age: 14 years, range: 5–18 years) performed for staging before RAI-T were retrospectively evaluated. Thyroglobulin was determined at baseline and on day 5.
Receiver operating characteristic curve analysis showed that thyroglobulin alone is not a good predictor for staging modification (area under the curve=0.6855). rh-TSH-Dx-WBS showed both remnant and lymph node in 11 (27%), lymph node localization alone in one (2.5%), lung alone in 1/41 (2.5%), both lymph node and lungs in 2/41 (5%), and thyroid remnant alone in 26/41 (63%) patients. rh-TSH-Dx-WBS modified staging in 12/41 (29%): in 3/12 (25%) for the presence of lung metastases and in 9/12 (75%) for lymph node involvement. In all these patients, administered activity for RAI-T was then modified or further surgery was planned.
Although further studies are needed, our data showed that combined use of rh-TSH and 123I-Dx-WBS allows an accurate and complete staging of disease, to implement the best therapeutic plan.
aDepartment of Imaging, Nuclear Medicine Unit
bMedical Physics Unit
cEndocrine Unit, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
Correspondence to Maria F. Villani, MD, Department of Imaging, Nuclear Medicine Unit, Bambino Gesù Paediatric Hospital IRCCS, Piazza Sant’Onofrio, 4, 00165 Rome, Italy Tel: +39 668 592 759; fax: +39 668 592 767; e-mail: email@example.com
Received July 6, 2018
Received in revised form September 21, 2018
Accepted September 5, 2018