Daşu Alexandru
Department of Radiation Physics, Norrlands University Hospital, 901 85 Umeå, Sweden.
Acta Oncol. 2008;47(7):1221-8. doi: 10.1080/02841860802251583.
Functional imaging could provide valuable information on the distribution of biological factors that influence the outcome of radiation therapy. Tumour proliferation and cell density in particular could be imaged with dedicated metabolic tracers and could thus be used for the biological optimisation of the treatment plans. The feasibility of individualising treatment planning using proliferation and density information has been investigated through simulations of heterogeneous tumours taking into account the cell density and proliferation rates. The predicted outcome was used to estimate the success of the individualisation of dose distributions. The results have shown that tumour control could be increased through the escalation of doses to proliferating foci with a relative reduction of doses to slowly proliferating regions of the tumour. This suggests that individualisation of treatment planning taking into account proliferation information creates the premises for further reduction of the doses to the surrounding regions which would consequently lead to an increased sparing of the normal tissues. Cell density has been shown to be another important factor that could be used for optimisation, albeit of a lower weight than proliferation. However, associated with proliferation it could lead to treatment failure if the trouble foci are underdosed. In conclusion, treatment optimisation based on imaged proliferation could improve both tumour control and normal tissue sparing.
功能成像可以提供有关影响放射治疗结果的生物因素分布的有价值信息。特别是肿瘤增殖和细胞密度可以用专用的代谢示踪剂进行成像，因此可用于治疗计划的生物优化。通过考虑细胞密度和增殖率的异质性肿瘤模拟，研究了使用增殖和密度信息个性化治疗计划的可行性。预测结果用于估计剂量分布个体化的成功率。结果表明，通过增加对增殖灶的剂量并相对减少对肿瘤缓慢增殖区域的剂量，可以提高肿瘤控制率。这表明考虑增殖信息的治疗计划个体化创造了进一步降低周围区域剂量的前提条件，从而导致对正常组织的更多保护。细胞密度已被证明是另一个可用于优化的重要因素，尽管其权重低于增殖。然而，如果病变灶剂量不足，与增殖相关可能导致治疗失败。总之，基于成像增殖的治疗优化可以改善肿瘤控制和正常组织保护。
