Palliative Diagnostic CT RT Lowers Time in Center Without Harming Efficacy

"[Diagnostic CT-based planning] workflow has patient benefits that are tangible, [including] fewer appointments, less travel, and less waiting," according to Melissa O’Neil, MRT.

It was reported that diagnostic CT-based planning appears to be a feasible workflow worth considering for patients with cancer who have had a diagnostic CT scan and will receive simple palliative radiation therapy, according to a presentation on the DART study (NCT05233904) given at the 2023 American Society for Therapeutic Radiology and Oncology (ASTRO) Annual Meeting.

In the conventional workflow arm (arm 1) and experimental workflow arm (arm 2), respectively, the median time in center (TIC) was 4.8 months (IQR, 3.8-5.8; SD, 4.7±1.1) and 0.4 months (IQR, 0.3-0.5; SD, 0.4±0.1; P <.001). Moreover, all plans included in the study were deliverable in each cohort, and there was no difference between cohorts in terms of blinded plan acceptability scores.

In arms 1 and 2, respectively, the plan was primarily considered to be acceptable (80% vs 82%), and a small potion ranked the plan as acceptable with minor deviation (20% vs 19%). Neither plan was ranked as having a deficiency that may affect clinical outcome.

Additionally, 32 of 33 patients completed questionnaires, in which patient acceptability was comparable between cohorts; of note, time burden was an exception, with 50% of patients in arm 1 reporting an acceptable time spent receiving treatment compared with 90% in arm 2 (P = .025). Moreover, when assessing clinician acceptability using a 5-point acceptability scale, 90% of 93 responders reported a score of 4 or higher in arm 2; the mean score was 4.6/5 ± 0.5.

“This workflow has patient benefits that are tangible, [including] fewer appointments, less travel, and less waiting,” according to presenting author Melissa O’Neil, MRT, of the Department of Radiation Oncology at the London Regional Cancer Program, Western University, London, Canada. “If this workflow allows someone to circumvent an often-busy CT sim schedule, [patients will have] faster relief resulting from faster access to treatment. This is huge in a symptomatic patient population.”

The DART study was intended to examine the potential effect of diagnostic CT-based planning on “patient experience, plan deliverability, adequacy of target coverage, and staff workflows.” Investigators included patients with bone, soft tissue, lung, abdominal, and pelvis tumors or metastases in the palliative care setting. Patients were randomized 1:2 to either arm 1—CT sim planning—or arm 2—diagnostic CT-based planning. In arm 2, no CT sim was conducted, and the most recent diagnostic CT was pulled for patient setup in lieu of anatomical landmarking to plan for surface-guided radiation therapy.

The study included patients who were receiving palliative radiation via simple planning technique at a dose of up to 30 Gy in up to 10 fractions. Eligible patients had either bone or soft tissue metastases or primary disease in the thorax, abdomen, pelvis, or proximal limbs. Previous and recent diagnostic CT with full visualization of region of interest plus reproducible positioning were also required; this needed to be done within 28 days of enrollment to reduce the potential risk of significant interval radiographic change.

The study’s primary end point was TIC, with key secondary end points including plan deliverability and acceptability, as well as stakeholder acceptability.

A total of 33 patients were included in the study, 11 of whom were in the conventional workflow arm and 22 were in the experimental workflow arm. Overall, patients had a median age of 72 years (IQR, 67-78), and most patients were male (72.7%). The most common disease types were lung (33.3%), prostate (24.2%), and breast cancer (12.1%). Additionally, the median time from diagnostic CT scan to enrollment was 18 days in arm 1 vs 13 days in arm 2.

Reference

O’Neil M, Laba JM, Lock MI, et al. Diagnostic CT-enabled radiation therapy (DART): results of a randomized trial for palliative radiation therapy. Presented at 2023 American Society for Therapeutic Radiology and Oncology (ASTRO) Annual Meeting; October 1-4, 2023; San Diego, CA. Abstract LBA14.