Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Choline PET based dose-painting in prostate cancer - Modelling of dose effects. | Niyazi et al. Radiation Oncology 2010 5 23 http content 5 1 23 RADIATION ONCOLOGY RESEARCH Open Access Choline PET based dose-painting in prostate cancer - Modelling of dose effects Maximilian Niyazi1 Peter Bartenstein2 Claus Belka1 Ute Ganswindt1 Abstract Background Several randomized trials have documented the value of radiation dose escalation in patients with prostate cancer especially in patients with intermediate risk profile. Up to now dose escalation is usually applied to the whole prostate. IMRT and related techniques currently allow for dose escalation in sub-volumes of the organ. However the sensitivity of the imaging modality and the fact that small islands of cancer are often dispersed within the whole organ may limit these approaches with regard to a clear clinical benefit. In order to assess potential effects of a dose escalation in certain sub-volumes based on choline PET imaging a mathematical doseresponse model was developed. Methods Based on different assumptions for a p g50 sensitivity and specificity of choline PET the influence of the whole prostate and simultaneous integrated boost SIB dose on tumor control probability TCP was calculated. Based on the given heterogeneity of all potential variables certain representative permutations of the parameters were chosen and subsequently the influence on TCP was assessed. Results Using schedules with 74 Gy within the whole prostate and a SIB dose of 90 Gy the TCP increase ranged from high detection rate of choline PET low whole prostate dose high g50 ASTRO definition for tumor control to TCP gain low sensitivity of PET high whole prostate dose CN 2 definition for tumor control or even 0 in selected cases. The corresponding initial TCP values without integrated boost ranged from to 100 . According to a large data set of intermediate-risk prostate cancer patients the resulting TCP gains ranged from to ASTRO definition or from to CN 2 definition . .
