TomoDirect: An efficient means to deliver radiation at static angles with tomotherapy

Aims and background. The TomoTherapy Hi-Art II system is able to deliver dynamic intensity-modulated radiation therapy within a helical geometry providing robust conformality and modulation, abrupt dose falloff, and reliable accuracy. A new upgrade named TomoDirect was introduced recently, allowing delivery of radiation at discrete angles with a fixed gantry. We present our preliminary clinical experience with TomoDirect.Methods. Three specific clinical contexts were chosen for the implementation of TomoDirect, namely palliation of bone metastasis pain (BP), whole brain radiation therapy for intracranial secondary lesions (WBRT), and adjuvant whole breast radiation therapy after conservative surgery for early stage breast cancer (AWBRT). After appropriate positioning, planning CT, contouring, and plan generation, all patients were treated with the TomoDirect upgrade of the TomoTherapy Hi-Art II system with different doses and fractionation according to clinical decision-making.Results. Between May and December 2010, 41 patients were treated with TomoDirect. Eighteen patients were treated for BP (mainly vertebral metastases) with a predominant posterior field arrangement. Seven patients were treated for WBRT (multiple brain lesions) with a parallel-opposed latero-lateral approach and 16 patients were treated for conventionally fractionated AWBRT mainly with a 2-field tangential approach. Radiation treatments were generally well tolerated and the acute toxicity was mild.Conclusions. While helical tomotherapy allows the delivery of very sophisticated treatment plans, in certain anatomical sites and clinical contexts where the number of beam directions is constrained and supposed not to affect plan quality, TomoDirect might be an efficient means to deliver radiation at static angles with consistent dosimetric and clinical results

TomoDirect: an efficient means to deliver radiation at static angles with tomotherapy

Aims and background. The TomoTherapy Hi-Art II system is able to deliver dynamic intensity-modulated radiation therapy within a helical geometry providing robust conformality and modulation, abrupt dose falloff, and reliable accuracy. A new upgrade named TomoDirect was introduced recently, allowing delivery of radiation at discrete angles with a fixed gantry. We present our preliminary clinical experience with TomoDirect.Methods. Three specific clinical contexts were chosen for the implementation of TomoDirect, namely palliation of bone metastasis pain (BP), whole brain radiation therapy for intracranial secondary lesions (WBRT), and adjuvant whole breast radiation therapy after conservative surgery for early stage breast cancer (AWBRT). After appropriate positioning, planning CT, contouring, and plan generation, all patients were treated with the TomoDirect upgrade of the TomoTherapy Hi-Art II system with different doses and fractionation according to clinical decision-making.Results. Between May and December 2010, 41 patients were treated with TomoDirect. Eighteen patients were treated for BP (mainly vertebral metastases) with a predominant posterior field arrangement. Seven patients were treated for WBRT (multiple brain lesions) with a parallel-opposed latero-lateral approach and 16 patients were treated for conventionally fractionated AWBRT mainly with a 2-field tangential approach. Radiation treatments were generally well tolerated and the acute toxicity was mild.Conclusions. While helical tomotherapy allows the delivery of very sophisticated treatment plans, in certain anatomical sites and clinical contexts where the number of beam directions is constrained and supposed not to affect plan quality, TomoDirect might be an efficient means to deliver radiation at static angles with consistent dosimetric and clinical results

Practical IMRT QA dosimetry using Gafchromic film: a quick start guide

This work outlines a method for using Gafchromic film for dosimetry purposes, by scanning it with currently available commercial scanners. The scanners used were: Epson V800, Epson V700, Epson V37 series, specifically a V370 and a Canon multi-function office printer/scanner. The Epson scanners have 16 bit RGB resolution, the Canon has 8 bit RGB (Red Green Blue) resolution, and the V800 and V700 allow scanning in transmission mode. The V700 uses an Epson White Cold Cathode Florescent Lamp; the recently released V800 uses an Epson light emitting diode (LED) light source, while the V37 series uses a reflective mode and the Epson LED light source. The Epson V37 series scanners are designed for non-professional use so the cost has been kept at a low entry level point, so they would be a suitable option for a department wanting to use Gafchromic film or with limited needs that did not justify a more sophisticated and expensive unit. Note that the V800 or V700 scanners are not expensive in context, costing approximately the same as a 25 sheet box of Gafchromic film. The Canon was included to demonstrate that a scanner with 8 bit RGB resolution can be used for dosimetry. These general multi-function units are available in most departments, and they would allow Gafchromic film to be evaluated as a dosimetry tool without a significant investment. Furthermore, they are generally capable of scanning large format film (425 x 350 mm) in one part. Although this is not necessary for dosimetry, it is often useful for machine QA, where dividing the film into two parts to ensure accurate measurements is not practical. Moreover, this analytical method uses software that is freely or commonly available, particularly the image processing package ImageJ. Note ImageJ v1.48 was the version used. The results demonstrate that this method used with the scanners evaluated is a practical method of using Gafchromic film as a dosimeter for IMRT QA