Session Item

Tuesday
August 31
11:00 - 12:15
Room 2.1
Proving the clinical benefit of 15 years of IGRT
Ludvig Muren, Denmark;
Marcel van Herk, United Kingdom
4230
Symposium
Physics
09:01 - 09:09
Palliative radiotherapy for bone metastases at the end of life: an Australian population-based study
PH-0523

Abstract

Palliative radiotherapy for bone metastases at the end of life: an Australian population-based study
Authors: Ong|, Wee Loon(1)*[weeloonong@cantab.net];Foroudi|, Farshad(1);Milne|, Roger(2);Millar|, Jeremy(3);
(1)Olivia Newton John Cancer Center, Department of Radiation Oncology, Heidelberg, Australia;(2)Cancer Council Victoria, Cancer Epidemiology Division, Melbourne, Australia;(3)Alfred Health, Radiation Oncology Services, Melbourne, Australia;
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Purpose or Objective

To evaluate the pattern of use of radiation therapy (RT) for bone metastases (BM) at the end of life (EOL) in Victoria, Australia

Material and Methods

This is a population-based cohort of cancer patients who received RT for BM between 2013 and 2016, as captured in the statewide Victorian Radiotherapy Minimum Data Set. Data linkage was performed with the Victorian Cancer Registry to capture mortality data. The final cohort comprised patients who had RT for BM at the EOL (defined as death within 30 days of commencing RT). The primary outcome was the proportion of patients who received single fraction RT (SFRT) and multi-fraction RT (MFRT). The Cochrane Armitage test for trend was used to evaluate changes in SFRT use over time. Multivariable logistic regression was used to assess factors associated with SFRT use.

Results

A total of 8,153 patients received 13,947 courses of palliative RT between 2013 and 2016, of which 1,359 courses of RT were delivered at the EOL. Of these, 396 courses of RT (29%) were SFRT and 963 (71%) were MFRT.  There was no significant change in the use of SFRT over time from 30% in 2013 to 32% in 2016 (P=0.07). Patients who had SFRT were older (mean age 71.7 who had SFRT vs. 70.1 who had MFRT; P=0.02). There were no differences in SFRT use for different primary cancer type (P=0.9). SFRT were less commonly given to the skull (6%) compared to other body sites e.g. rib (51%) and extremities (52%) (P<0.001). There was higher use of SFRT in patients who had died shortly after commencing RT – 49%, 29% and 25% in patients who died within 7 days, 8-14 days, and 15-30 days of starting RT respectively (P<0.001). There were large institutional provider variations in SFRT use – 34% SFRT use in public compared to 19% in private institutions (P<0.001), and 35% SFRT use in regional compared to 27% in metropolitan centres (P=0.008). In multivariate analyses, the target RT sites, time between starting RT and death, and institutional type (public/ private) were independently associated with SFRT use.

Conclusion

This large Australian population-based study showed that less than one-third of palliative RT for BM at the EOL was SFRT. There is variation in SFRT use at the EOL depending on the target body sites, and institutional provider factors. Future work is needed to increase uptake of SFRT use especially in cancer patients with limited prognosis who may require palliative RT for symptom management for BM.