Session Item

Assessment of clinical and economic efficiency of 3DCRT and IMRT techniques for palliative radiotherapy (RT) of patients with symptomatic bone metastasis.assessment of clinical and economic efficiency of 3DCRT and IMRT techniques for palliative radiotherapy (RT) of patients with symptomatic bone metastasis.

A retrospective cost – effectiveness analysis of 143 patients received palliative RT 4 Gy to 20 Gy on symptomatic bone metastasis on TrueBeam STx. Median follow – up was 10.5 month. Compliance with the ethical principles 83 (58%) 3DCRT patients, 60 (42%) IMRT patients. The criterion for the choice of the irradiation technique, was a discussion with an evaluation of treatment plans for the dose to critical organs and a comparison of all pros and cons. IGRT by CBCT was used in every fraction and did not take into account the direct cost. Incremental cost-effectiveness ratio - quality adjusted life-year (QALY) per direct costs. QALY -  multiplication of median survival time in year and quality of life index (QoL index) calculated according to the ratio of pain relief to the degree of radiation complications. Assessment of pain relief using a 10-point Brief Pain Inventory (BPI) scale, the difference in scores before the onset of RT and 1 month after the end of RT. Radiation reactions were assessed using a four degree RTOG scale 1 month after the end of RT. Survival curves were constructed according of Kaplan and Meier method. Comparison of survival curves using Log rank test by Pearson chi – square (χ2) using IBM software SPSS statistics version 23.0.

For IMRT patients mean BPI scores were 7.6 before RT, and 2.3 after RT; pain relief by 5.3 points was estimated. For 3DCRT patients mean BPI scores were 7.1 before RT, and 2.5 after RT; pain relief by 4.6 points was estimated. Radiation reactions by RTOG scale was 1.17 and 1.52 for IMRT and 3DCRT techniques respectively. Mean direct costs was 288.7 and 145.2 Euro per patient for IMRT and 3DCRT techniques respectively. Mean QoL index was 4.88 (n= 60, SD =1.55) and 3.40 (n= 83, SD =1.41) for IMRT and 3DCRT respectively. IMRT technique showed significantly better survival results overall survival 70.0% compared to 3DCRT overall survival 51.8%, differences are statistically significant χ2 = 5.36, df = 1, p = 0.021 (Figure 1).

Figure 1 – Techniques survival curves by the method of Kaplan and Meier

For IMRT patients, the median survival time was 21.9 months, SE 1.8 months, 95% CI (18.4 - 25.5), For 3DCRT patients, the median survival time was 15.6 months, SE 1.4 months, 95% CI (12.9 - 18.4). Quality-adjusted survival was 1.8 and 1.3 years for IMRT and 3DCRT respectively.  Quality-adjusted life year (QALY)  0.89 gained for IMRT and 0.44 for and 3DCRT respectively. Per 1 QALY was 324.1 euro for IMRT and 328.5 euro for 3DCRT techniques. This resulted in an incremental cost-effectiveness ratio 3.2 euro

IMRT was cost-effective beneficial compared to 3DCRT in the palliative treatment of symptomatic bone metastasis.