Dosimetrist/Physicist Training Guide - UCSF Radiation Oncology

MOSAIQ Dosimetrist/Physicist Training Guide Module III
Copyright 2009, IMPAC Medical Systems 104
LTGRAD0005C/1.0/31-Mar-2009
Appendix B Dose
Calculation
Cases can arise in which it is advantageous to track partial dose contribution to
secondary dose sites. An example is dose to mid-axilla from a superclavicular field or
total body treatment plans and off-axis treatment plans in which the dose site
coefficients for the contributing fields may not be equal to 1. Refer to the dose
calculations implemented in MOSAIQ below so that you can understand how Total
Dose is determined.
Definitions
The definitions are used in the dose calculation are follows:
Field Dose
Coefficient (FDC)
Dose Site
Coefficient (DSC)
Historical
Treatment MU
(TMU)
Dose Site Dose
(DSD)
The field dose divided by the field MU. FDC is a calculated
value and appears in the MU/Dose Specification dialog
box, Dose/MU field.
The coefficient that equals the dose delivered to the site
from that field when multiplied by the dose contributed to
the field. The DSC is defined in the Dose Site Coefficient
dialog box, Coefficient field, when you complete dosimetry
setup.
The MU recorded for each treatment field or portal image
exposure.
The Dose delivered to a site per treatment as determined by
the MU delivered multiplied by the FDC and DSC.
Session A specific time period over which any delivered dose is
combined into a single fraction, which is configurable.
The above coefficients are saved to 3 decimal places.