Use of Spreadsheets to Manipulate Field Scanning Data

Computerized field scanning systems are now standard tools in most radiotherapy departments. These systems can easily measure central axis depth dose curves and beam profiles. Data acquired from these systems forms the basis of what is used for machine calibrations and patient dosimetry. Unfortunately, the data is often not in the best format for these applications. Each data point is often acquired in a fraction of a second with a small volume ionization chamber resulting in “noisy” data. Many dosimetric applications require tissue maximum ratio data which is technically difficult to directly measure with these scanning systems. And finally, it is desirable to have the data clearly organized in tables according to the specific needs of the department. Commercial spreadsheets can be used to solve these problems. We have used Lotus 1-2-3@ to smooth the central axis data, calculate additional data points, calculate tissue maximum ratios, and clearly present this data in neatly organized tables.