First Local Experience of Intra-Cavitary Yttrium-90 Citrate Colloid Irradiation via Ommaya Reservoir for Refractory Cystic Craniopharyngioma: a Case Report.

Craniopharyngioma is uncommon benign intracranial tumour that can be cured by surgical resection followed by conventional radiotherapy. However, its anatomical localisation makes the treatment hazardous or impossible. This case report aims to discuss the first local experience of using beta-emitting Yttrium-90 radioisotope in treating a patient with refractory cystic craniopharyngioma. A 43-year-old male who has underlying refractory cystic craniopharyngioma complicated with visual impairment and panhypopituitarism was referred to our nuclear medicine department for intra-cavitary irradiation therapy. Initially, he was presented with blurring of vision and headache which he had two previous resection surgeries of cystic craniopharyngioma. However, due to persistent symptoms, he had Ommaya reservoir shunt inserted for regular aspiration. Despite regular aspiration, his symptoms worsen. He was unsuitable for radiotherapy thus was considered for intra-cystic irradiation with radioisotope. Prior to the therapy, he had pre-therapy assessment with Tc-99 m MAA. He subsequently received Ytrrium-90 citrate colloid of 300 Gy radiation dose to the inner surface of the tumour which complicated with post therapy inflammatory reaction. This first local experience highlights the role of radioisotope as the valuable minimally invasive adjuvant therapy in treating a patient with refractory cystic craniopharyngioma. Further follow-up is necessary to assess the outcome and possible late complications.

Concurrent Benign Iodine-Avid Thymic and Liver Cysts Mimicking Metastatic Disease on 131I Whole-Body Scintigraphy.

ABSTRACT: A 57-year-old woman received radioiodine therapy post total thyroidectomy for pT3aNxMx follicular thyroid carcinoma. Posttherapy 131I whole-body scan showed 131I concentration in the chest, mediastinum, and left upper thigh with stimulated thyroglobulin (Tg) of 89 µg/L. Subsequent radioiodine therapies showed persistent 131I accumulation in the anterior mediastinal soft tissue lesions and a hypodense segment VII liver lesion visualized on SPECT/CT, suggestive of iodine-avid metastatic disease despite the undetectable serum Tg (<1.0 µg/L) with no Tg antibody interference. Biopsy of the liver lesion revealed liver cyst, and consequent removal of the mediastinal lesions showed benign thymic cysts.