ESTRO 2024 - Abstract Book

S1735

Clinical - Lung

ESTRO 2024

We have introduced a dose limit to the base of the heart in the routine setting at our centre in April 2023. The RAPID-RT study (REC approval granted 02/02/2023 [22/NW/0390]), aims to demonstrate that new a methodology called rapid-learning [1], using RWD can be used to demonstrate the impact of such change on survival. When introducing new dose limits, it is also important to characterise the impact on toxicity profiles. In this study we reviewed toxicity frequency and data quality and for a baseline cohort of patients treated with lung radiotherapy before introduction of the dose limit to the base of the heart.

Material/Methods:

As part of a Quality Improvement Audit, we retrospectively reviewed patients treated from February-October 2022 (inclusive), prior to the introduction of the dose limit to the base of the heart in March 2023. We manually reviewed the records of all eligible patients receiving curative (non-SABR) radiotherapy for lung cancer, from day 1 radiotherapy until 6 months post- treatment, through our site’s radiotherapy delivery system (MOSAIQ).

Exclusion criteria: lung lesions other than primary lung cancer, treatment with palliative radiotherapy or SABR, patients who opted out via the NHS National opt-out system were excluded.

Toxicity data is collected by clinicians through structured electronic forms at each out-patient review using the Common Terminology Criteria for Adverse Events (CTCAE v5). We focused on oesophagitis and pneumonitis.

Structured data were compared to that recorded in free text annotations, imaging reports, or clinical letters. A structured algorithm was used to define episodes of oesophagitis and pneumonitis and aid grading. The clinical record for each patient was considered to have ‘good’ data quality if all toxicity experienced by the patient was recorded in a structured format, which is amenable to data extraction. In cases where some information was not clear, such as the impact of symptoms on a patient’s activities of daily living (ADLs), patients were contacted by phone, using a script to guide the collection of information. Any toxicity found that was confirmed to have occurred but not recorded in a structured format was retrospectively converted into a structured format, graded according to CTCAE v5.

Results:

At The Christie NHS Foundation Trust, 409 patients with primary lung cancer and treated with curative-intent radiotherapy were identified. Of these, 61 were excluded based on the exclusion criteria listed above. The remaining 348 patients comprised approximately 68% receiving RT alone, 17% sequential, and 16% concurrent treatments. These were reviewed manually to identify episodes of oesophagitis or pneumonitis. 214 patients (61%) had ‘good’ toxicity data quality. 58 patients (17%) had toxicity that was recorded in the electronic clinical notes, but that was not captured in a structured format. 77 patients (22%) were contacted by phone to identify the impact of symptoms on their activities of daily living (ADLs). Upon completion of the manual review; in 349 patients, 111 (31.9%) experienced G2 Oesophagitis, 3 (0.86%) G3 Oesophagitis, 2 (0.57%) G4 Pneumonitis. Additionally, there was 1 patient (0.29%) whose death could be attributed directly to Pneumonitis and therefore was a G5.

Table 1 – toxicities uncovered after 9-months of manual review of clinical notes in Stage I-III patients receiving radiotherapy (prior to heart-sparing introduction).