XBeam (v2)

XBeam is dose calculation software for Xstrahl's superficial and orthovoltage radiotherapy and surface electronic brachytherapy systems. It can validate monitor units or radiation doses calculated by hand or other treatment planning systems, or serve as the primary means of calculating monitor units and doses for external beam radiation treatments. The software is intended for use by authorized medical physics personnel only.

XBeam uses the same fundamental dose calculation algorithm as its predicate device RADCalc, based on percent dose depth (PDD) curves and absolute dose output for specified applicator-filter combinations. Both support single or two parallel-opposed beams. XBeam does not support brachytherapy, tomotherapy, photons (MV), or electrons, whereas RADCalc supports these; however, XBeam includes all required features for supported treatment types (superficial/orthovoltage).

IEC 62366 (usability engineering), IEC 62304 (software life cycle processes), and ISO 14971 (risk management). The submission also references FDA guidance on software-contained medical devices.

XBeam and RADCalc share identical product codes (MUJ), regulatory class (II), and regulatory numbers (21 CFR 892.5050). Both calculate monitor units and radiation doses for the same device platforms using the same scientific principles. Validation testing confirmed XBeam output matched RADCalc results within 0.7% (attributed to rounding), and delivered doses agreed with planned doses to within 1.8-3.6%, demonstrating equivalent dosimetric accuracy. The narrower feature set (supporting only superficial/orthovoltage treatments rather than brachytherapy or photons) does not raise safety or effectiveness concerns for the indicated uses.