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).
