Combination Therapy with 3D-Guided Hypophysectomy and Radiation Therapy for a Non-Functioning Sellar Mass in a Dog

Abstract

A 10-year-old, 7.05 kg, neutered male mongrel dog presented with non-ambulatory tetraparesis and a history of tonic-clonic seizures occurring once or twice a year over the past 2 years. Neurological examination revealed the absence of postural reactions in all limbs, with no cranial nerve abnormalities. Magnetic resonance imaging (MRI) identified a 7.6 × 8.5 × 9.4 mm mass in the sellar region. Subsequent endocrine tests and physical examinations revealed no hormonal abnormalities, leading to the diagnosis of a nonfunctioning sellar mass. The objective of the surgery was to achieve safe and efficient access to the pituitary fossa using a 3D-printed, patient-specific guide for transsphenoidal hypophysectomy. Postoperatively, the patient developed central diabetes insipidus, which was managed with desmopressin. The medication was successfully discontinued after 1 month. Following surgery, the patient received adjuvant radiation therapy beginning 8 weeks postoperatively. At the 3-month follow-up, the patient exhibited normal gait with no recurrence of tetraparesis or seizures. This is the first reported case of transsphenoidal hypophysectomy for a nonfunctioning sellar mass in Korea. Unlike conventional surgical methods, the use of a 3D-printed, patient-specific guide enabled accurate localization of the bone cutting site and surgical trajectory to the sellar region, thereby facilitating safe access and minimizing complications. This approach may offer a viable treatment option for dogs with pituitary tumors requiring surgical intervention.