FACILITIES DESIGN AT RADIOTHERAPY DEPARTMENT

The location and siting of a radiotherapy facility within the hospital environment requires careful consideration because of the role of radiation oncology in multidisciplinary cancer management, including the requirement for diagnosis, coordinated referral and long term follow-up of patients. The construction of specialized bunkers (shielded rooms) for housing the treatment equipment is technically an engineering challenge and need professional oversight to ensure long term structural integrity. A generic design is important to cater for future requires and advances in technology.

This post provides information on the environmental, legal, technical and professional aspects related to developing a master plan for the construction of a radiotherapy facility.

An overall concept design should therefore consist of the five key functional areas which expedite radiotherapy workflow. These functional areas in radiotherapy are the reception and clinical consulting areas, the imaging and treatment planning area, and the two treatment suites (teletherapy and brachytherapy).

The design of the radiotherapy department is taken consideration of:

·         The placement of the treatment unit

·         The direction(s) of the primary beam

·         The location of the operator

·         Surrounding areas to ensure low occupancy

·         Costs

RECEPTION, ADMINISTRATION AND WAITING AREAS

The reception and main waiting areas should be located at the main entrance to the department and act as distribution point for all the different sections in the department (Fig. 1). Colour coded lines on the floor can be considered to direct patients to a specific area in the department, e.g. imaging and planning, brachytherapy, EBRT, etc. The reception station staff should be sufficient to service the number of oncologists and medical officers for new and follow-up patients; a typical ratio would be one per team of two clinicians. Administration consists of separate offices for financial matters, for instance, which are generally more private and where matters can be discussed confidentially.

CLINICAL CONSULTING AREA

To assess and review patient

IMAGING AND TREATMENT PLANNING

The IAEA guidelines describing the buildings for the essential equipment of a basic radiotherapy clinic recommend an imaging area (required for treatment planning) consisting of a simulator room. Two X ray bunkers, each with an associated control room, to house a fluoroscopic simulator and a CT scanner or CT simulator (Fig. 6) are suggested here.

EXTERNAL BEAM RADIOTHERAPY

It is advisable to place bunkers above ground, together with the rest of the facility. Two alternative layouts (options A and B) for maximum energy 10 MV linear accelerators (LINACs) are shown in Fig. 3. Sizes are given in millimetres and all thicknesses are given for 2.35 g/cm3 concrete. The workload used assumes 1000 Gy/week delivered at the isocentre.

BRACHYTHERAPY

A brachytherapy suite should include the shielded treatment room, a control area, a procedure/

preparation room, a recovery area, a sluice room and an imager or film processing area (Fig. 5).

Shielding is needed to restrict radiation doses to staff, patients, visitors and the public to acceptable levels. The requirements are met with walls of thickness equivalent to 230 mm of solid brick or concrete, and lead-lined sliding entrance doors, which is standard for diagnostic X ray facilities. Viewing windows for the operators should be lead glass and embedded into the wall structure. The inner room dimensions should be the same as for the EBRT bunkers (structurally 7 m × 7 m × 4 m high) because manoeuvrability of a simulator and the storage space needed are the same as for a teletherapy system.

Safety considerations:

·         Clear warning signs are required

·         Patient and visitor is not allowed to enter treatment area without permission

·         Shielding must be provided with the public dose llimits.

·         Interlocks door with specific criteria.

·         Emergency off buttons

Reference:

INTERNATIONAL ATOMIC ENERGY AGENCY, Planning National Radiotherapy Services: A Practical Tool, IAEA Human

Health Series No. 14, IAEA, Vienna (2011).