Statistics of dose homogeneity indices in the target when planning irradiation for various nosologies

Any technological solution then has the right to be applicable and widely distributed when it is justified from a clinical point of view. That is, when as a result of the application of the technology the survival rate of patients increases in comparison with the previous one. The purpose of the work is to systematize the results accumulated over the past eight years on the statistics of dose homogeneity indices in the target when planning irradiation for several nosologies. When reaching tolerant values of the homogeneity index, the probability of tumor recurrence decreases, which entails an increase in the life expectancy of patients. Homogeneity indices in the target were calculated when planning irradiation of patients. Dependences of the HI dose homogeneity indices within the target on the irradiation technology were obtained. Taking into account the prognostic capabilities of the HI index for relapse-free survival, the optimal technology for irradiating patients for each nosology was selected. It has been shown that when irradiating cervical cancer, it is desirable to use 3D conformal radiation therapy 3DCRT and intensity-modulated radiation therapy IMRT, and for lung and prostate cancer, intensitymodulated radiation therapy in the RapidArc rotational mode. It is desirable to irradiate breast cancer using 3D CRT technology. It is also shown that the length of the irradiated targets has a pronounced effect on the homogeneity index and its tolerance values. It is possible to optimize irradiation plans by selecting the irradiation technology to achieve HI within the tolerance limits. The considered technologies of conformal radiation therapy 3D CRT, IMRT, Rapid Arc can be considered viable, since in most cases they allow achieving the desired homogeneity in the target and, thus, significantly reduce the likelihood of relapses in cancer patients.

1. Belikova AA, Gerasimov VA, Ivanov SA, et al. Risk factors for local and distant progression in patients with non-small cell lung and breast cancer after whole-brain irradiation. Medical Physics. 2021;90(2):29-38 (in Russian).

2. Lebedenko IM, Bykova YuB, Boldyreva VA, et al. Estimation of dose distribution in the planned target volume using the homogeneity index. Medical Physics. 2017;73(1):34-38 (in Russian).

3. Lebedenko IM, Kravets OA, Bykova YuB, et al. Quantitative assessment of the quality of planning the remote radiotherapy in cervical cancer patients. Issues of Oncology. 2016;(6):827-830 (in Russian).

4. Lebedenko IM, Romanova EA, Belova AA, et al. Quantitative assessment of the quality of treatment planning for patients with advanced cervical cancer. Biomedical Engineering. 2018;52(4):263-266 (in English).

5. International Commission on Radiation Unitsand Measurements. Prescribing, Recording аnd Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). ICRU Report 83. 2010 (in English).

6. Lebedenko IM, Kudashkina YuA, Gromushkina EV, et al. Quantitative assessment of the quality of planning remote irradiation of cancer patients. Medical Technology. 2022;(2):31-34 (in Russian).

7. Lazareva YuA, Lebedenko IM. Quantitative assessment of the quality of external radiotherapy planning for patients with prostate cancer. Medical Physics. 2022;94(2):12-19. DOI: 10.52775/1810-200X-2022-94-2-12-19 (in Russian).

8. Gumbatova AE, Ovsyannikov AV, Lebedenko IM, et al. Evaluation of the quality and comparison of dosimetric parameters of plans for craniospinal irradiation using VMAT method at Varian TrueBeam and Varian Halcyon accelerators. Medical Physics. 2022;96(4):30-36. DOI: 10.52775/1810-200X-2022-96-4-30-36 (in Russian).