105 CMR 120.574
Safety Precautions for Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic
Radiosurgery Units
(A) A licensee shall control access to the treatment room by a door at each entrance.
(B) A licensee shall equip each entrance to the treatment room with an electrical interlock
system that will:
(1) Prevent the operator from initiating the treatment cycle unless each treatment room
entrance door is closed;
(2) Cause the source(s) to be shielded promptly when an entrance door is opened; and
(3) Prevent the source(s) from being exposed following an interlock interruption until all
treatment room entrance doors are closed and the source(s) on-off control is reset at the
console.
(C) A licensee shall require any individual entering the treatment room to assure, through the
use of appropriate radiation monitors, that radiation levels have returned to ambient levels.
(D) Except for low-dose remote afterloader units, a licensee shall construct or equip each
treatment room with viewing and intercom systems to permit continuous observation of the
patient or the human research subject from the treatment console during irradiation.
(E) For licensed activities where sources are placed within the patient's or human research
subject's body, a licensee shall only conduct treatments which allow for expeditious removal of
a decoupled or jammed source.
(F) In addition to the requirements specified in 105 CMR 120.574(A) through (E), a licensee
shall:
(1) For low dose-rate, medium dose-rate, and pulsed dose-rate remote afterloader units,
require:
(a) An authorized medical physicist and either an authorized user or a physician, under
the supervision of an authorized user, who has been trained in the operation and
emergency response for the unit to be physically present during the initiation of all
patient treatments involving the unit; and,
(b) An authorized medical physicist and either an authorized user or an individual,
under the supervision of an authorized user, who has been trained to remove the source
applicator(s) in the event of an emergency involving the unit, to be immediately available
during continuation of all patient treatments involving the unit.
(2) For high dose-rate remote afterloader units, require:
(a) An authorized user and an authorized medical physicist to be physically present
during the initiation of all patient treatments involving the unit; and
(b) An authorized medical physicist and either an authorized user or a physician, under
the supervision of an authorized user, who has been trained in the operation and
emergency response for the unit, to be physically present during continuation of all
patient treatments involving the unit.
(3) For gamma stereotactic radiosurgery units, require an authorized user and an authorized
medical physicist to be physically present throughout all patient treatments involving the
unit.
(4) Notify the Radiation Safety Officer, or his or her designee, and an authorized user as
soon as possible, if the patient or human research subject has a medical emergency and,
immediately, if the patient dies.
(G) A licensee shall have emergency response equipment available near each treatment room,
to respond to a source that inadvertently:
(1) Remains in the unshielded position; or
(2) Lodges within the patient following completion of the treatment.