HALT - Targeted Therapy with or without Dose-Intensified Radiotherapy in Oligo-Progressive Disease in Oncogene Addicted Lung Tumours

Introduction: Following initial response to TKI, advanced NSCLC patients with actionable mutations ultimately develop treatment resistance. In a proportion of patients (15-40%), initial, limited progression (≤5 lesions) is observed, termed oligoprogressive disease (OPD). SBRT offers hypofractionated, targeted radiotherapy treatment hypothesised to prolong clinical benefit from TKI prior to widespread disease development. With limited evidence to date, and poor clinical/biological selection criteria, the potential benefit offered by SBRT to ablate OPD sites prior to change in systemic therapy is an important question to address. Methods: HALT is a randomised, multi-centre, phase II/III international trial with seamless transition to phase III incorporated. Eligible patients (stage IV NSCLC, actionable mutation, TKI response prior to OPD) are randomised 2:1 to SBRT/continued TKI or continued TKI alone. Eligibility is confirmed by a virtual MDT (vMDT) comprising trial clinicians and radiologists (confirmation of OPD, SBRT suitability). Follow-up assessments are aligned with routine care at 3-monthly intervals until change in systemic therapy is clinically indicated, with imaging and toxicity assessment at each visit. Results: Recruitment commenced November 2017 with 25 centres (17 UK;8 non-UK) open to date. Following the COVID-19 pandemic, recruitment is recovering with 129 registered and 74 randomised patients. Over the last 4 years, little evidence has emerged to confirm any potential benefit of SBRT in this patient group and the impact on patient toxicity remains unknown. Therefore, with persisting questions around clinical equipoise, HALT remains highly relevant. With an 18-month extension and a recent amendment to the HALT inclusion criteria (≤5 OPD lesions, ≤7cm and OPD assessments by PET-avidity), the target of 110 randomised patients remains achievable. Conclusions: As the first randomised trial assessing SBRT benefit in this mutation-positive NSCLC patient population, HALT will provide valuable treatment efficacy and safety information, informing subsequent trial design and contribute to the development of international guidelines for the identification and clinical management of oligoprogression in mutation positive lung cancer. Keywords: Stereotactic body radiotherapy, NSCLC, Phase II

Impact on quality of life from multi-modality treatment for lung cancer: a randomised controlled feasibility trial of surgery versus no surgery as part of multi-modality treatment in potentially resectable stage III-N2 NSCLC (the PIONEER trial)

Introduction: Optimal treatment of stage III-N2 NSCLC requires multi-modality treatment: local treatment (surgery or radiotherapy) and systemic anti-cancer therapy. There is no clear evidence of superiority for survival between surgical and non-surgical approaches and little research has explored quality of life as an endpoint (QOL). Methods: Randomised controlled feasibility study. Patients are randomised to receive multi-modality treatment 1) with surgery OR 2) without surgery. Eligible patients have ‘potentially resectable’ N2 NSCLC and have received an MDT recommendation for multimodality treatment. Sixty-six patients and their carers will be recruited from 8 UK centres. Patient/carer QOL questionnaires will be administered at baseline, weeks 6, 9, 12 and month 6, data will be analysed descriptively. Semi-structured interviews will be conducted and framework analysis applied. Results: Recruitment is ongoing (opened November 2020). Despite COVID-19 related challenges, we have opened six sites, approached 14 patients and successfully recruited nine patients (64% consent rate) and five carers. Four patients and two carers have completed the trial. Five patients (55%) have completed all outcome data to date and eight patients (89%) have received their allocated treatment. NSCLC N2 patients being assessed at MDTs at recruiting sites are being assessed for eligibility. Forty-seven N2 patients have been identified as ineligible. Reasons for ineligibility include: not suitable for surgery;referred for best supportive care;MDT decision regarding most appropriate treatment;patient choice regarding treatment;other. Conclusion: There have been challenges to site opening due to sites focusing on COVID related studies only. Three sites have only opened in the past 6 months and a further two are due to open which should increase recruitment. Despite delays we have successfully recruited nine participants and all but one have received their allocated treatment. Results will inform the design of a future fully powered randomised trial with QOL as the primary outcome.

171 HALT: targeted therapy with or without dose-intensified radiotherapy in oligo-progressive disease in oncogene addicted lung tumours

Background: Following initial response to TKI, advanced NSCLC patients with actionable mutations ultimately develop treatment resistance. In a proportion of patients (15-40%), initial, limited progression (<3 lesions) is observed, termed oligoprogressive disease (OPD). SBRT offers hypofractionated, targeted radiotherapy treatment hypothesised to prolong clinical benefit from TKI prior to widespread disease development. The potential benefit offered by SBRT to ablate OPD sites prior to change in systemic therapy is an important question to address, particularly during the current pandemic, where reducing clinic visits is particularly advantageous. Method: HALT is a randomised, multi-centre, phase II/III international trial with seamless transition to phase III incorporated. Eligible patients (stage IV NSCLC, actionable mutation, TKI response prior to OPD) are randomised 2:1 to SBRT/continued TKI or continued TKI alone. Eligibility is confirmed by a virtual MDT comprising trial clinicians and radiologists (OPD, SBRT suitability). Follow-up assessments aligned with routine care at 3-monthly intervals until change in systemic therapy is clinically indicated, imaging and toxicity assessment at each visit. Current status: Recruitment commenced November 2017;27 centres (16 UK;11 non-UK) open to date (09/03/2021), 94 patients registered and 50 randomised. Because of the COVID-19 pandemic, recruitment was temporarily paused on 20/03/2020 and restarted in accordance with national guidelines on 16/06/2020. Of 94 patients registered, vMDT review performed for 74 patients (18 screen fails prior to vMDT);50 randomised, 22 confirmed ineligible via vMDT (inc. >3 lesions, lesion >5cm, intracranial disease identified). Conclusion: The vMDT remains an important, novel aspect of the trial, ensuring robust patient selection ahead of randomisation. As the first randomised trial assessing SBRT benefit in this patient population, HALT will provide valuable treatment efficacy and safety information, informing subsequent trial design and contribute to the development of international guidelines for the identification and clinical management of oligoprogression in mutation positive lung cancer. Disclosure: No significant relationships.

Changes in the Management of Patients having Radical Radiotherapy for Lung Cancer during the First Wave of the COVID-19 Pandemic in the UK.

AIMS: In response to the COVID-19 pandemic, guidelines on reduced fractionation for patients treated with curative-intent radiotherapy were published, aimed at reducing the number of hospital attendances and potential exposure of vulnerable patients to minimise the risk of COVID-19 infection. We describe the changes that took place in the management of patients with stage I-III lung cancer from April to October 2020. MATERIALS AND METHODS: Lung Radiotherapy during the COVID-19 Pandemic (COVID-RT Lung) is a prospective multicentre UK cohort study. The inclusion criteria were: patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between 2nd April and 2nd October 2020. Patients who had had a change in their management and those who continued with standard management were included. Data on demographics, COVID-19 diagnosis, diagnostic work-up, radiotherapy and systemic treatment were collected and reported as counts and percentages. Patient characteristics associated with a change in treatment were analysed using multivariable binary logistic regression. RESULTS: In total, 1553 patients were included (median age 72 years, 49% female); 93 (12%) had a change to their diagnostic investigation and 528 (34%) had a change to their treatment from their centre's standard of care as a result of the COVID-19 pandemic. Age ≥70 years, male gender and stage III disease were associated with a change in treatment on multivariable analysis. Patients who had their treatment changed had a median of 15 fractions of radiotherapy compared with a median of 20 fractions in those who did not have their treatment changed. Low rates of COVID-19 infection were seen during or after radiotherapy, with only 21 patients (1.4%) developing the disease. CONCLUSIONS: The COVID-19 pandemic resulted in changes to patient treatment in line with national recommendations. The main change was an increase in hypofractionation. Further work is ongoing to analyse the impact of these changes on patient outcomes.

A novel use for routine CBCT imaging during radiotherapy to detect COVID-19.

INTRODUCTION: Thoracic CT is a useful tool in the early diagnosis of patients with COVID-19. Typical appearances include patchy ground glass shadowing. Thoracic radiotherapy uses daily cone beam CT imaging (CBCT) to check for changes in patient positioning and anatomy prior to treatment through a qualitative assessment of lung appearance by radiographers. Observation of changes related to COVID-19 infection during this process may facilitate earlier testing improving patient management and staff protection. METHODS: A tool was developed to create overview reports for all CBCTs for each patient throughout their treatment. Reports contain coronal maximum intensity projection (MIP's) of all CBCTs and plots of lung density over time. A single therapeutic radiographer undertook a blinded off-line audit that reviewed 150 patient datasets for tool optimisation in which medical notes were compared to image findings. This cohort included 75 patients treated during the pandemic and 75 patients treated between 2014 and 2017. The process was repeated retrospectively on a subset of the 285 thoracic radiotherapy patients treated between January-June 2020 to assess the efficiency of the tool and process. RESULTS: Three patients in the n = 150 optimisation cohort had confirmed COVID-19 infections during their radiotherapy. Two of these were detected by the reported image assessment process. The third case was not detected on CBCT due to minimal density changes in the visible part of the lungs. Within the retrospective cohort four patients had confirmed COVID-19 based on RT-PCR tests, three of which were retrospectively detected by the reported process. CONCLUSION: The preliminary results indicate that the presence of COVID-19 can be detected on CBCT by therapeutic radiographers. IMPLICATIONS FOR PRACTICE: This process has now been extended to clinical service with daily assessments of all thoracic CBCTs. Changes noted are referred for oncologist review.

Reduced Fractionation in Lung Cancer Patients Treated with Curative-intent Radiotherapy during the COVID-19 Pandemic.

Patients treated with curative-intent lung radiotherapy are in the group at highest risk of severe complications and death from COVID-19. There is therefore an urgent need to reduce the risks associated with multiple hospital visits and their anti-cancer treatment. One recommendation is to consider alternative dose-fractionation schedules or radiotherapy techniques. This would also increase radiotherapy service capacity for operable patients with stage I-III lung cancer, who might be unable to have surgery during the pandemic. Here we identify reduced-fractionation for curative-intent radiotherapy regimes in lung cancer, from a literature search carried out between 20/03/2020 and 30/03/2020 as well as published and unpublished audits of hypofractionated regimes from UK centres. Evidence, practical considerations and limitations are discussed for early-stage NSCLC, stage III NSCLC, early-stage and locally advanced SCLC. We recommend discussion of this guidance document with other specialist lung MDT members to disseminate the potential changes to radiotherapy practices that could be made to reduce pressure on other departments such as thoracic surgery. It is also a crucial part of the consent process to ensure that the risks and benefits of undergoing cancer treatment during the COVID-19 pandemic and the uncertainties surrounding toxicity from reduced fractionation have been adequately discussed with patients. Furthermore, centres should document all deviations from standard protocols, and we urge all colleagues, where possible, to join national/international data collection initiatives (such as COVID-RT Lung) aimed at recording the impact of the COVID-19 pandemic on lung cancer treatment and outcomes.