# A Targeted Radionuclide Therapy Facility at a University Teaching Hospital in Singapore

## TL;DR

This paper describes a specialized facility in Singapore for high-dose radioactive iodine therapy, designed to ensure radiation safety for patients and the public.

## Contribution

The paper presents a detailed design and implementation of a radiation safety facility for targeted radionuclide therapy at a university hospital.

## Key findings

- The facility includes anterooms, shielded patient rooms, and dedicated waste storage to minimize radiation exposure.
- Lead shielding and HEPA ventilation systems effectively manage radiation and airborne contamination.
- Radiation detectors and decay tanks ensure safe handling and disposal of radioactive waste.

## Abstract

High-dose radioactive iodine is used for the ablation of residual thyroid tissue after thyroidectomy. Patients undergoing such treatment should stay at a purpose-built facility to minimise radiation exposure to the patient’s family, staff, and the general public.

We present our facility, supporting equipment, and measured radiation doses to demonstrate the effectiveness of the radiation safety design.

Our facility comprises an anteroom and two single rooms with ensuite toilets and inter-room shielding. Lead shielding thickness ranges from 5 mm to 25 mm. The emergency shower, hand-foot contamination monitor, survey meter, radiation spill kit, and personal protective equipment are sited in the anteroom. Urine from the hot toilets is collected in dedicated decay tanks before discharge into the main sewage. A high-efficiency particulate air (HEPA) filter-fitted ventilation system with 12 air changes per hour is used to reduce the presence of airborne particulate matter. Radiation detectors are installed directly above the patient beds to enable remote measurement of patient dose rates.

Contaminated items are divided into linen and waste bags before being brought to a waste storage area for radiation decay. These radiation “hot” bags are stored until their projected date of reaching background radiation, after which they are returned to housekeeping or disposed of appropriately.

The waste storage area, built with 5 mm lead lining on top of existing reinforced concrete walls, is sited below the patient rooms. It houses the decay tanks, lead-lined storage bins, and a freezer for contaminated items.

Area monitors are installed in both the anteroom and in the storage area.