Association Between Perinasal Uptake on Radioactive Iodine Whole-Body Scan and Nasolacrimal Duct Obstruction.

Background and

Objectives

This study reports an association between nasolacrimal duct obstruction (NLDO) and perinasal uptake on radioactive iodine (RAI) whole-body scan. Materials and

Methods

This is a retrospective study of 37 patients from May to November 2017 who underwent thyroidectomy and I-131 ablation for papillary thyroid cancer (PTC) and had a follow-up I-123 diagnostic WBS and dacryoscintigraphy. Ophthalmic examinations assessed punctal stenosis, NLDO, tear film break-up time, Schirmer's test, punctate keratopathy, tear meniscus height, epiphora, and ocular dryness. Perinasal and nasal uptake on whole-body scans (WBSs) were assessed as negative (no uptake) or positive (focal uptake). The associations between perinasal uptake on WBS, dacryoscintigraphy findings, and ophthalmic assessments were assessed.

Results

Nasal uptake on I-131 post-ablation WBS were observed in 60 eyes (81%); perinasal uptake was observed in 8 eyes (11%). Nasal uptake on I-123 post-ablation WBS were observed in all eyes; perinasal uptake was observed in 15 eyes (20%). Perinasal and nasal uptake on I-131 post-ablation WBS were significantly associated with delayed excretion on dacryoscintigraphy (p < 0.001 and p = 0.03, respectively). Perinasal uptake on I-123 WBS was associated with both abnormal dacryoscintigraphy findings and ocular dryness (p < 0.001 and p = 0.02, respectively).

Conclusions

Perinasal uptake on I-131 post-ablation and I-123 diagnostic WBS was significantly associated with delayed excretion on dacryoscintigraphy, suggesting NLDO.