Task Group 76 Report on 'The management of respiratory motion in radiation oncology' (Med. Phys. 33, 3874-3900 (2006))

摘要

In 2006, the AAPM Task Group 76, on respiratory motion in radiation oncology, produced a generally very useful report.1 Mostly in Sec. V.C of this report, an "interplay" issue between motion from the MLC leaves in dynamic IMRT (such as sliding jaw, tomotherapy, and types of VMAT, for example) and organ (or tumor) motion is considered. However, the clinical implications for such interplay, or perhaps more precisely termed "interference," are somewhat minimized based mainly on fraction averaging considerations. These implications are specifically minimized in the discussion of the effects of the 5 mm criterion that is to be used for the central decision of whether motion management should be used. We believe that this criterion should be expanded to include a consideration of the frequency coherence between the fluence modulation and the tumor motion. The faience modulation pattern is unique to any particular modality and may vary between treatment plans. The current 5 mm criterion includes only the tumor motion amplitude; essentially, it is based on the assumption that this factor always dominates, and it may not have been evidence-based to a high enough degree. In addition, the effects of fractionation are very likely to reduce dose errors, but as stated in Sec. V.C, one should not rely on fractionation alone.