The influence of the α/β ratio on treatment time iso-effect relationships in the central nervous system.

Conclusions: It is reasonable to use an α/β ratio of 2 Gy for CNS tissue, with the same repair half-times as published in the original publication by Pop et al (2000), in situations where the assessment of the BED in radiosurgery is used with other form of radiotherapy. In radio-surgery, the variation in BED with treatment duration (for a fixed physical dose) is very similar, but absolute BED values depend on the α/β value. In radiosurgery, clinical recommendations obtained using BED calculations using the originally proposed α/β ratio of 2.47 Gy are still appropriate. For calculations involving a combination of radio-surgery and other modalities, such as fractionated radiotherapy, it would be appropriate in all cases to apply a value of 2 Gy, the accepted norm in neuro-oncology, without significant loss of accuracy in the radio-surgical component. This may have important applications in retreatment situations. PMID: 32243225 [PubMed - as supplied by publisher]
Source: International Journal of Radiation Biology - Category: Radiology Tags: Int J Radiat Biol Source Type: research