Prevalence of Palliative Radiotherapy Abstracts Presented at Annual Scientific Meetings of the Canadian Association of Radiation Oncology: 2009-2020

Abstract

<h3>Purpose/Objective(s)</h3> Approximately half of all radiotherapy is delivered with palliative intent. Clinical research in palliative radiotherapy (PRT) aims to manage symptoms, improve quality of life (QoL), evaluate supportive care interventions, and determine optimal dose-fractionation schedules, amongst other goals. The Canadian Association of Radiation Oncology (CARO) Annual Scientific Meeting (ASM) provides opportunities to discuss new developments and disseminate knowledge. Our aim was to expand on a previous study describing the prevalence of palliative research at the CARO ASM. <h3>Materials/Methods</h3> Published abstracts (2009-2020) were independently reviewed by two authors who categorized each as: curative-intent; palliative-intent; pertaining to or including both populations; or neither. Abstracts were considered palliative if they described a population with incurable malignancy receiving interventions primarily for symptom control or QoL. Studies evaluating ablative-intent stereotactic RT were not considered palliative. Type of study, primary, site treated, symptoms palliated and regions of authorship were recorded. Descriptive and summary statistics were calculated including one-way ANOVA and chi-square test for trend. <h3>Results</h3> 222/2995 abstracts (7.4%, range 2.4-13.9% per year) were classified as palliative. 22/222 (9.9%) described phase I-III trials while 83/222 (37.4%) were retrospective. Primary sites were mainly lung (31/222) and genitourinary (16/222); 64.9% (144/222) aggregated multiple primaries. Most commonly treated metastases were bone (36.0%) and brain (12.6%); 22.1% of abstracts grouped multiple sites. QoL, symptom and toxicity outcomes were reported in 32.4% (72/222), 27.0% (60/222) and 17.1% (38/222), respectively. The most common specific symptom palliated was pain (23/222) but reporting multiple symptoms was common (30/222). One third were authored by investigators from Ontario and 33/222 were from a dedicated PRT program. This proportion of palliative abstracts is not significantly different from previous reports: 7.6% presented from 2003 to 2008 (<i>P</i> = 0.99), and 6.7% from 1992 to 2002 (<i>P</i> = 0.77) were palliative, confirmed by trend analysis examining all years 1992-2020 (<i>P</i> = 0.47). <h3>Conclusion</h3> Despite the prevalence of PRT in clinical practice, the proportion of palliative-focused abstracts presented at the CARO ASM has not significantly changed in almost 30 years. Acknowledging the challenges of conducting studies in a population with limited life expectancy, PRT research represents an essential way to advance comprehensive personalized patient care.