## 3 Results
### Individual Anatomical Characteristics of the Patient
#### 3.4.2 Cardiovascular Risk Factors  
Diabetes  
Diabetes are a special group of patients who have an increased risk of myocardial dysfunction after radiation therapy [34]. A study by [PERSON] et al. evaluated the EAR [10-year absolute risk of cardiovascular disease (CVD)] after left-breast radiotherapy [33]. In the first group of 200 patients without diabetes, the baseline risk was 0.031-0.035; after irradiation, the excess relative risk (ERR) increased to 0.11. This allowed for a final estimate of the EAR over the next 10 years of 0.003-0.004 in this group of patients. In contrast, 10 patients with left-breast cancer and diabetes had a baseline risk of 0.1-0.2, so the EAR over the next 10 years was 0.01-0.03. Also, [PERSON] et al. described and pointed out the positive aspects of applying the DIBH method to patients with diabetes. The mean doses to the heart and left anterior descending artery (LAD) were considerably lower in the DIBH group, measuring 2.10 \(\pm\) 0.39 Gy and 6.16 \(\pm\) 0.18 Gy, respectively, compared to 4.29 \(\pm\) 0.60 Gy and 12.69 \(\pm\) 0.93 Gy in the FB group. However, the frequency of cardiac events was greater in the FB group than in the DIBH group [32]. A study carried out by [PERSON] et al. reported that patients with diabetes should be closely monitored by multidisciplinary teams of physicians after irradiation [34]. Diagnosed diabetes mellitus was considered an important factor that can significantly affect the risk of CVD in study subjects. The aforementioned studies show that patients with diabetes will have a 10-year excess absolute risk of cardiovascular disease, on average, five times higher [33]. Smoking  
A study by [PERSON] et al., where the smoking group accounted for 19.2% of all patients undergoing DIBH, showed that this is a risk group with a significantly increased incidence of late cardiac complications [32]. [PERSON] et al. found this to be the most important factor influencing the risk of cardiovascular disease after using the DIBH method in female patients. From a group of 210 patients, 28 smokers were selected who had a cumulative cardiovascular disease risk (taking into account the initial risk and excess absolute risk EAR) of 6.07%. Compared to non-smokers (182 patients), this risk was 3.55% [33]. [PERSON] et al. also identified cigarette smoking as a very important factor with toxic effects on the heart after radiotherapy. They confirmed that smokers have a higher mortality rate from radiation therapy than non-smokers [35]. Smoking significantly increases the occurrence of ischemic heart disease (IHD) [5]. At the same time, it is the most important factor affecting the risk of cardiovascular disease after DIBH in female patients. It is easy to see that compulsive cigarette smoking almost doubles the risk of CVD [33]. Hypertension  
[PERSON] et al. showed that hypertensive patients are more likely to have cardiac events after DIBH [32]. Similar conclusions were reached by [PERSON] et al. who indicated that hypertensive patients have an increased incidence of coronary artery disease after receiving left-sided radiotherapy [33]. [PERSON] and colleagues emphasized the importance of thorough diagnostics in patients with arterial hypertension prior to radiation therapy [34]. [PERSON] et al., in patients undergoing left-sided adjuvant radiotherapy for breast cancer, assessed the impact of arterial hypertension, smoking, and hypercholesterolemia on mortality due to ischemic heart disease (IHD). In the study, they evaluated two patients of the same age undergoing radiation therapy using DIBH. One was a smoker with systolic blood pressure above 157 mmHg and elevated cholesterol levels of 246 mg/dL, with a baseline relative risk for IHD of 3, while the other was a non-smoker with a systolic blood pressure of 104 mmHg and cholesterol level of 165 mg/dL with a baseline relative risk for IHD of 0.3. What is to be taken from this information is that the risk of ischemic heart disease in the future for the first patient was nine times higher compared to the second patient.