Normal Lung Tissue CT Density Changes after Volumetric-Arc Radiotherapy (VMAT) for Lung Cancer

Journal of Personalized Medicine

Marek Konkol¹  Piotr Milecki¹  Marek Fechner²  Paweł Śniatała³  Krzysztof Matuszewski⁴  Maciej Bryl⁵ 

[1] Electroradiology Department, Poznan University of Medical Sciences, 61-866 Poznan, Poland;Independent Researcher, 60-965 Poznan, Poland;Institute of Computing Science, Poznan University of Technology, 60-965 Poznan, Poland;Medical Physics Department, Greater Poland Cancer Center, 61-866 Poznan, Poland;Oncology Department, Greater Poland Center of Pulmonology and Thoracic Surgery, 60-569 Poznan, Poland;

关键词: radiation-induced lung injury;    density changes;    radiodensity;    radiation pneumonitis;    radiotherapy;    lung cancer;   

DOI  :  10.3390/jpm12030485

来源: DOAJ

【 摘 要 】

Radiation-induced lung injury remains a significant toxicity in thoracic radiotherapy. Because a precise diagnosis is difficult and commonly used assessment scales are unclear and subjective, there is a need to establish quantitative and sensitive grading methods. The lung tissue density change expressed in Hounsfield units (HUs) derived from CT scans seems a useful numeric surrogate. The study aimed to confirm a dose-response effect on HU value changes (ΔHU), their evolution in time, and the impact of selected clinical and demographic factors. We used dedicated, self-developed software to register and analyze 120 pairs of initial and follow-up CT scans of 47 lung cancer patients treated with dynamic arc radiotherapy. The differences in HU values between CT scans were calculated within discretized dose-bins limited by isodose lines. We have proved the dose-effect relationship, which is well described with a sigmoid model. We found the time evolution of HU changes to suit a typical clinical presentation of radiation-induced toxicity. Some clinical factors were found to correlate with ΔHU degree: planning target volume (PTV), V35 in the lung, patient’s age and a history of arterial hypertension, and initial lung ventilation intensity. Lung density change assessment turned out to be a sensitive and valuable method of grading post-RT lung toxicity.

【 授权许可】

Unknown