The impact of intra-thoracic anatomical changes upon the delivery of lung SABR

Sean Brown, Matthew Beasley, Robert Chuter, Gareth Price, Corinne Faivre-Finn, Kevin Franks, Louise Murray, Marcel van Herk, Ann Henry

Research output: Contribution to journalMeeting Abstractpeer-review


Category: New radiotherapy techniques/implementation/QA. Purpose(s): The study aim was to describe the occurrence of intra-thoracic anatomical changes (ITACs) on cone beam computed tomography (CBCT), and the impact on patients, with early non-small cell lung cancer (NSCLC) treated with (stereotactic ablative radiotherapy (SABR). These have potential to disrupt the workflow. The impact of ITACs on this population is unknown. This study was conducted on behalf of the UK Advanced Radiotherapy Technologies Network (ART-NET) at The Christie and Leeds Cancer Centre. Methods and materials: CBCTs from 100 patients treated with SABR for early NSCLC were reviewed. The presence of the following ITACs was assessed: atelectasis, infiltrative change, pleural effusion, baseline shift, gross tumour volume (GTV) increase and GTV decrease. These were graded using a traffic light score adopted from Kwint et al, to assess potential target under-coverage or organ at risk (OAR) over-dose. The frequency of physics or clinician review was noted. A linear mixed effects model was used to assess the relationship between set-up time (time from first CBCT to beam delivery) and ITAC grade. Result(s): ITACs were seen in 22% of patients. 21% were graded as 'red' implying a risk of under-dosage to the PTV or OAR over-dose. Most were 'yellow' (51%) with minimal impact. Physics or clinician review occurred in 10% of all treatment fractions. Three patients needed their treatment re-planned. Mixed model analysis demonstrates that ITACs have a significant effect on set-up time (X2(3)=9.22, p=0.02). Conclusion(s): The majority of ITACs were minor but associated with unplanned physics or clinician review, representing a potential resource burden. ITACs also have a significant impact upon set-up time with consequences for the workflow. Detailed guidance on the management of ITACs is needed to provide support for therapeutic radiographers delivering lung SABR.Copyright © 2019
Original languageEnglish
Pages (from-to)e14-e15
JournalClinical Oncology
Publication statusPublished - Oct 2019

Research Beacons, Institutes and Platforms

  • Manchester Cancer Research Centre


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