High Intensity Focused Ultrasound (HIFU) for Parathyroid Adenoma

This study aims to determine whether HIFU treatment is a safe and effective alternative to an operation to remove all or part of the affected gland. The objective is to achieve biochemical cure (assessed by normal calcium level in the blood at six weeks, six months and one year after therapy) without affecting the patient's voice or ability to swallow.

Primary hyperparathyroidism is a common endocrine condition in which one or more of the four parathyroid glands in the neck releases too much parathyroid hormone (PTH). this leads to excess calcium in the blood and if untreated it can cause osteoporosis, kidney stone formation, deterioration of kidney function and disturbance in heart rhythm. Surgery to remove all or part of the affected gland(s) is expected to cure 95% of such patients. In current practice all such patients undergo localisation techniques using sestamibi scanning and neck ultrasonography to demonstrate the position of the enlarged/overactive parathyroid gland. These radiological tests are positive in some two thirds of patients, who can be operated through a minimally invasive procedure focused on the exact localisation pinpointed by the scans. This study uses a procedure that does not require a surgical incision. Precise imaging of the parathyroid glands allows the exact position of the tumour to be found from outside the body. A High Intensity Focused Ultrasound beam produces heat, but only in a small specific area. Exact positioning of the ultrasound beam targets the tumour cells and kills them without harming the surrounding healthy tissues.

Six weeks post-treatment.Six month data were also intended to be reported, however, six month data were not analyzed because only one subject was entered and this subject was withdrawn from the study before six months after treatment.

Voice Handicap Index. 30 questions rated on a five point scale from 'never' to 'always' and an overall score from 1 'normal' to 10 'severely impaired'

Inclusion Criteria: Primary Hyperparathyroidism (PHPT) Moderate/severe hypercalcaemia (Ca>2.8mmol/L) Positive sestamibi scan demonstrating a cervical parathyroid adenoma Adenoma visible on ultrasound scan Exclusion Criteria: Large adenoma (>15mm) Deep adenoma (>20mm from skin surface Familial disease (eg members of MEN-1 families) Inability to complete questionnaires in English without making mistakes or needing help with translation