Biological Effective Dose (BED) in modelling the risk of radiation-induced cardiac toxicity.

D'Avino V., Palma G., Liuzzi R., Pacelli R., Cella L.
  Lunedì 11/09   14:30 - 18:30   Aula A209   V - Biofisica e fisica medica
Our aim was to develop a Normal Tissue Complication Probability (NTCP) model independent of the radiotherapy fractionation scheme and based on the Biological Effective Dose (BED) concept. We recast the formalism of the Lyman-Kutcher-Burman (LKB) NTCP model for the radiation-induced cardiac valve dysfunction using 3D-BED distributions. Heart BED-Volume Histograms (BED-VHs) were calculated from treatment plans of 90 Hodgkin's Lymphoma patients undergoing radiotherapy with different fractionation schedules. The LKB model best-estimated parameters were computed. The BED-NTCP showed a good predictive power independently of the fraction-size sensitivity of the heart $(\alpha / \beta$ range 1--3 Gy). This approach is generally applicable to different radiation toxicity endpoints.