1. (a) Therapy systems shall be provided with radiation detectors in the radiation head.
2. (b) New equipment shall be provided with at least two radiation detectors incorporated into two separate dose monitoring systems.
3. (c) Existing equipment shall be provided with at least one radiation detector incorporated into a primary dose monitoring system.

4. (d) The detector in a dose monitoring system shall be:

   1. (1) Permanently installed and interlocked to prevent incorrect positioning.
   2. (2) Part of a dose monitoring system that provides readings in dose monitor units which can be used to calculate the absorbed dose at a reference point in the treatment volume.
   3. (3) Capable of independently monitoring and controlling the useful beam.

5. (e) For new equipment, the design of dose monitoring systems shall assure that:

   1. (1) The malfunctioning of one system does not affect the correct functioning of the second system.
   2. (2) The failure of an element common to both systems which could affect the correct function of both systems terminates irradiation.

6. (f) A dose monitoring system shall have a legible display at the control panel. For new equipment, a display shall:

   1. (1) Maintain a reading until intentionally reset to zero.
   2. (2) Have only one scale and no scale multiplying factors.
   3. (3) Utilize a design so that increasing dose is displayed by increasing numbers and that the absorbed dose may be accurately determined under all conditions of use.
   4. (4) Provide that, in the event of a power failure, the dose monitoring information required in this subsection displayed at the control panel at the time of failure shall be retrievable.

Source

The provisions of this § 228.66 adopted October 2, 1998, effective October 3, 1998, 28 Pa.B. 4894.

Cross References

This section cited in 25 Pa. Code § 228.74 (relating to absorbed dose rate).