Design and beam characteristics of the Siemens Stabilipan Orthovoltage Unit for intraoperative radiation therapy.

A 250 KVP Siemens Stabilipan Orthovoltage Therapy machine has been permanently installed in a new operating suite for delivery of intraoperative radiation therapy (IORT). A discussion of the choice of effective energy and half-value layer (HVL), as well as description of the physical aspects of the treatment system including applicator design, radiation data, dosimetry and radiation shielding of the OR suite will be presented.