Keywords:
Breast, Radioprotection / Radiation dose, Cardiac, CT, CT-High Resolution, Radiation therapy / Oncology, Complications, Radiation effects, Cancer, Dosimetric comparison, Image guided radiotherapy
Authors:
A. Parasuramar, M. Borg, A. DeSmit; SA/AU
DOI:
10.1594/ranzcr2017/R-0124
Results
The Shapiro-Wilk test of normality is summarised in Tables 1 and 2.
This indicates that a substantial number of variables listed in Table 1 and 2 cannot be assumed to be from a normally distributed population (as the p-value of the Shapiro-Wilk statistic is less than .001).
Therefore,
subsequently,
non-parametric statistics (i.e.
Medians and Inter-quartile range) and techniques (e.g.
Mann-Whitney U test) have been used to address the aims of the data analysis.
The Wilcoxon signed-rank test was used to compare the median values of the patient’s clinical characteristics for DIBH and Free breathing as both the techniques were used on the same set of patients.
These results are illustrated in Table 3.
The Mann-Whitney U test was used to compare the patient’s median values of the clinical characteristics for the ABC and the VBH techniques as both the techniques were used on a different set of patients.
Only the statistically significant results have been reported.
These results are illustrated in Table 4.
Clinical characteristics have been described using summary statistics (median and standard deviation (SD) or median and inter-quartile range (IQR)) depending on the distribution of the variable.
These have been summarized in the tables below.
The results of the data analysis indicated that the Ipsilateral Lung maximum (cm) is significantly higher for the DIBH group implying DIBH to be a better technique compared to Free Breathing.
This assertion is further supported by the following clinical characteristics being significantly lower for the Free breathing technique group: Ipsitlateral Lung V20 (%),
Lung V20 (%),
Heart V25 (%),
Heart (Gy),
and LAD mean (Gy).
This indicates that DIBH is superior to FB when measuring irradiation to innocent structures.
Additionally,
the results of the data analysis indicated that the Heart (Gy) and the Contralateral Breast V3 (%) values were significantly higher for the VBH technique group compared to the ABC technique group.
This indicates that ABC (with Elekta equipment) is a more effective technique compared to VBH as far as these clinical characteristics are concerned.