Users Manual Part 2

IBA | 15-2 | Clinical User’s Guide
Volume 1 - Treatment Session
|Part II - Using Treatment Room Equipment Resetting a Dose Counter Electronic Unit |
The Proteus PLUS has one measuring function: the measurement of the Monitor
Units (MU). The accuracy of the measurement of the MU is 1%.
The proton radiation dose delivered to the patient is measured in Ionization
Chambers. The Ion Chamber Electronic Unit (ICEU) and/or scanning controller
communicate(s) dose information to the DCEU.
The DCEU allows the irradiation as long as the radiation dose delivered to the patient
is less than the upper preset limit entered on the DCEU by the RTT. The dose count
is displayed on the front panel of the DCEU.
The DCEU is a backup in case of an IC software communication failure. You typically
set the value to 105% of the required dose.
WARNING As a Radiation Therapy Technologist (RTT), when the treatment is
interrupted (e.g., the treatment is stopped after a pause, the software
crashes, etc.), you have to manually record the value reported by the
hardware Monitor Unit (MU) counter, which is located on the front
panel of the Dose Counter Electronic Unit (DCEU).
If applicable, i.e., in the Single Scattering, Double Scattering, and
Uniform Scanning treatment modes ONLY, a correction shall manually
be applied to this value to take into account the dose correction
parameters encoded in the Dosimetry Manager (ambient temperature,
atmospheric pressure, and dose correction factor).
Check that the value reported by the hardware MU counter (after
correction) matches the delivered MU value recorded in the Oncology
Information System (OIS) for this irradiation.
When the irradiation is resumed, if the system (Oncology Information
System or Proton Therapy System) proposes a MU value for the
delivered dose (MUd), you shall verify that this value matches the value
reported by the hardware MU counter (after correction), within the
foreseen precision. If the values are not in agreement, you shall use the
value reported by the hardware MU counter (after correction).