Factors affecting the stability of deep inspiration breath-holding in radiotherapy for left-sided breast cancers

The purpose of this study was to explore the factors affecting the stability of deep inspiration breath-hold for left-sided breast cancer radiotherapy and provide directional suggestions for clinicians to consider whether patients with left-sided breast cancer were fit for this technique.

Using optical body surface monitoring system, 100 patients with left-sided breast cancer were trained for deep inspiration breath-hold before computed tomography positioning. The patients' age, height, weight, vital capacity, type of surgery (modified radical or breast-conserving operation) were recorded. According to the duration and fluctuation of each inspiration, the patients were divided into five categories. The statistical methods of Spearman and Kendall were used to calculate correlation coefficients, and the p values of these factors and breath-holding stability grades were calculated using the Spss software; the correlation heat map was drawn by Origin software, reflecting which of the above factors had significant correlation with breath-holding stability and their correlation strength.

Values of p inferior to 0.05 were obtained for vital capacity, body mass index, age and surgical method, and values of p greater than 0.05 were obtained for adjuvant chemotherapy and targeted treatment. According to the value of correlation coefficient and correlation heat map, the order of strength is vital capacity>body mass index>age>surgical method.

The patient's age, vital capacity, body mass index and operation method significantly affect the stability of breath-holding. For breast cancer radiotherapy, clinicians can select patients by considering these factors related with the stability of holding their breath.