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Alexander Louie



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    FP02 - Health Services Research/Health Economics (ID 120)

    • Event: WCLC 2020
    • Type: Posters (Featured)
    • Track: Health Services Research/Health Economics
    • Presentations: 1
    • Moderators:
    • Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
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      FP02.10 - Predictors of Moderate-to-Severe Symptoms in Stage IV NSCLC: A Population-Based Study of Patient Reported Outcomes (ID 3525)

      00:00 - 00:00  |  Author(s): Alexander Louie

      • Abstract
      • Presentation
      • Slides

      Introduction

      Patients with metastatic NSCLC have significant disease and treatment-related morbidity. In Ontario, Canada, cancer patients complete Edmonton Symptom Assessment System (ESAS) questionnaires, a tool that elicits patients’ self-reported severity of common cancer-associated symptoms at clinical encounters. ESAS domains are: anxiety, depression, drowsiness, appetite, nausea, pain, shortness of breath, tiredness and well-being. The purpose of this study is to examine moderate-to-severe symptom burden in the 12 months following a diagnosis of stage IV NSCLC.

      Methods

      Using administrative databases and unique encoded identifiers, stage IV NSCLC diagnosed between January 2007 and September 2018 were evaluated for symptom screening with ESAS in the 12 months following diagnosis. Proportion of patients reporting moderate-to-severe score (i.e. ESAS ≥4) in each domain within 12 months were calculated. Patients reporting moderate-to-severe within the different ESAS domains of were plotted over time. Multivariable (MV) Poisson regression models with potential covariates such as age, sex, Elixhauser comorbidity index, socioeconomic factors, and cumulative cancer treatments received were constructed to identify factors associated with moderate-to-severe symptoms.

      Results

      Of the 22,799 stage IV NSCLC patients identified, 13,593 (59.6%) had at least 1 completed ESAS recorded (87,791 unique assessments) in the year following diagnosis. Majority (94.6%) reported at least 1 moderate-to-severe score. Tiredness (peak: 67.4%, overall: 84.3%), lack of wellbeing (peak: 62.1%, overall: 80.9%), low appetite (peak: 50.4%, overall: 72.1%), and shortness of breath (peak: 51.0%, overall: 68.1%) were the most prevalent moderate-to-severe symptoms reported by patients within 12 months after diagnosis (these peaked at diagnosis), while nausea (34.92%) was the least common.
      Patients receiving chemotherapy alone (17.5%, n= 2,380), radiotherapy alone (36.3%, n=4,936), or both (24.8%, n=3,369) reported more moderate-to-severe symptoms compared to patients receiving no treatment (risk ratio [RR]: 1.04, 1.04, and 1.06 respectively [all p-values<0.0001). Receiving chemotherapy alone or chemotherapy and radiotherapy combinations was associated with score≥4 in all individual ESAS domains (p-values <0.05), while receiving radiotherapy alone was associated with score≥4 in all domains but shortness of breath (RR: 0.98, p=0.26). Immigrants and patients with worst socioeconomic deprivation index were less likely to report moderate-to-severe symptoms.

      Conclusion

      Moderate-to-severe symptoms were prevalent throughout the first year following stage IV NSCLC diagnosis at the population-level. Patients receiving chemotherapy and/or radiotherapy were at increased risk of moderate-to-severe symptoms and may require more supportive care. Further analyses on predictors of severe-to-moderate score on each ESAS domain will be discussed in the presentation.

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    P05 - Early Stage/Localized Disease - Radiotherapy (ID 114)

    • Event: WCLC 2020
    • Type: Posters
    • Track: Early Stage/Localized Disease
    • Presentations: 1
    • Moderators:
    • Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
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      P05.02 - International Delphi Consensus on Radical Thoracic Re-Irradiation for Non-Small Cell Lung Cancer (NSCLC) (ID 1647)

      00:00 - 00:00  |  Author(s): Alexander Louie

      • Abstract
      • Slides

      Introduction

      Local recurrence or second lung primaries are common indications for radical thoracic re-irradiation (re-RT), affecting approximately 700 patients in the UK annually. Re-RT is usually the only suitable curative-intent treatment but prospective evidence on toxicity, dose constraints, and optimal treatment technique is lacking. We performed a Delphi process to identify areas of consensus in re-RT for NSCLC.

      Methods

      An international panel of 15 radiation oncologists specialising in lung cancer participated in an initial survey on 23/09/2019 to capture their definition of re-RT, suitable patients, re-RT technique and dose constraints used. The most common responses to questions from the first survey were used to make statements which participants voted on in subsequent rounds using a 5-point Likert scale. Consensus was achieved once 75% of participants agreed with a statement. For the statements which did not reach consensus, respondents provided additional evidence/comments to refine them. In total, four surveys were performed using a web-based survey programme.

      Results

      All respondents completed three rounds of the survey, with the final round currently in progress. Consensus was achieved within two rounds regarding re-RT indications, patient eligibility and work-up (Table 1). In addition, agreement was reached to use stereotactic ablative body radiotherapy (SABR) if possible for re-RT. Dose constraints, due to the lack of supportive data, required three rounds to develop agreement. Several volumetric lung constraints were suggested, but due to post-radiotherapy fibrosis, it was concluded that there was insufficient evidence to form recommendations (Table 2).

      Areas of controversy were how much overlap was significant when performing re-RT, what were the minimum lung function requirements and the minimum safe interval between treatments.

      Table 1
      Statement Degree of Consensus
      Indications
      Re-RT can be considered for suspected new lung primaries with minimal overlap with previous radiotherapy fields. 93%
      Re-RT can be considered for lung tumours which develop new nodal disease after an initial course of radiotherapy only to the primary tumour (therefore minimal overlap). 100%
      Re-RT can be considered where a lung tumour relapses locally (or develops a suspected second primary tumour with >50% overlap with the original primary tumour), but low overlap with serial structures in the thorax. 93%
      Patient eligibility
      In general, patients should have an ECOG PS of 0 - 2 to be considered for re-RT, with exceptions being made for selected PS 3 patients (e.g. SABR re-RT, or PS 3 due to non-respiratory issues). 93%
      Re-irradiation should be avoided in patients with interstitial lung disease. 86%
      Surgery should be considered in all appropriate patients being assessed for re-irradiation. 93%
      Work-up
      Essential investigations prior to commencing re-RT are: Whole body PET-CT, CT chest + contrast, and CT/MRI brain. 93-100%

      Table 2
      Statement Degree of consensus
      Dose constraints
      For radical re-irradiation, the desirable cumulative maximum point dose constraint to the oesophagus is an EQD2 of 75Gy, although up to 100Gy is acceptable (using an a/b=3), with the volume of the oesophagus getting 55 Gray should be less than 35% (V55Gy<35%). 86%
      For radical re-irradiation, the desirable cumulative maximum point dose constraint to the spinal cord is an EQD2 of 60Gy (using a/b=2), provided that the initial irradiation dose to the cord did not exceed 50Gy and the interval between treatments is greater than 6 months. 80%
      For radical re-irradiation, the desirable cumulative maximum dose (Dmax) constraint to the aorta is an EQD2 of 115Gy (a/b=3). The desirable cumulative Dmax to the pulmonary artery is an EQD2 of 110Gy. 80%
      There is insufficient evidence to suggest volumetric cumulative dose constraints for the lung due to the changes in anatomy and function of the lung after an initial course of radiotherapy. 80%
      Technique
      Radical re-irradiation should be performed using highly conformal radiotherapy techniques (e.g. VMAT, Tomotherapy, Cyberknife). 100%
      Acceptable doses for conventionally fractionated re-RT include 60Gy in 30 fractions or 55Gy in 20 fractions once daily for NSCLC 93%
      SABR is the preferred re-RT technique where the tumour is not ultra-central, no nodal disease and the tumour volume is small with minimal overlap with OARs. 87%
      Any dose and fractionation that can safely deliver a BED >100Gy to the tumour is acceptable for radical re-irradiation with SABR. 87%

      Conclusion

      This Delphi process with international experts has developed key recommendations on the criteria for suitable re-RT patients, dose constraints and preferred technique. These statements can be used to develop prospective trials to provide better evidence for re-RT.

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    P52 - Staging - Prognosis and Staging (ID 186)

    • Event: WCLC 2020
    • Type: Posters
    • Track: Staging
    • Presentations: 1
    • Moderators:
    • Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
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      P52.03 - Concordance of PET Scan and EBUS-TBNA for Mediastinal Staging of Stage 3 Non-Small Cell Lung Cancer (ID 1593)

      00:00 - 00:00  |  Author(s): Alexander Louie

      • Abstract
      • Slides

      Introduction

      Mediastinal staging is essential to plan adequate treatment for patients with stage 3 non-small cell lung cancer (NSCLC). Curative-intent radiation fields are often planned based on positron-emission tomography (PET) scan results, despite the fact that this imaging modality has limitations. Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has been shown to have higher sensitivity and specificity. The objective of this study is to evaluate the concordance of PET scan and EBUS-TBNA in mediastinal staging.

      Methods

      We conducted a retrospective cohort study of patients diagnosed with NSCLC at Sunnybrook Health Sciences Centre, Toronto, Canada, between September 2017 and November 2019. From an institutional database of all lung cancer patients who underwent EBUS-TBNA for lung cancer, patients with stage 3 NSCLC with both EBUS-TBNA and PET scan for mediastinal staging were included. EBUS results were considered the gold standard for nodal staging based on previous publications. Indeterminate PET scan results were reviewed independently by a PET radiologist. Analyses of sensitivity and specificity were conducted on a per-node basis.

      Results

      Thirty-two patients were included in the analysis. The median number of nodes biopsied per patient was 3 (range 1- 5). Ten patients (31%) had at least one discordant lymph node station. The sensitivity and specificity of PET scan were 78.7% and 79.3%, respectively. Six positive lymph nodes on PET scan were downstaged by EBUS-TBNA, including a patient who was downstaged from cN2 to pN0. The five patients with false positive results did not have any known inflammatory or infectious disease at the time of the PET study. Ten lymph node metastases in five patients were PET-occult. Two patients were upstaged from cN2 to pN3, and one from cN0 to pN2. The size of PET-occult metastases compared to false positive lymph nodes was not significantly different (p=0.65). Seventeen patients (65%) went on to be treated with concurrent chemoradiation, and 6 had radical-intent radiation only. Other patients were treated with chemotherapy only (n=1), targeted therapy (n=3), or lost to follow-up (n=5).

      Conclusion

      Our study shows there is clinically significant discordance in the extent of nodal metastases between PET scan and EBUS-TBNA among patients with stage 3 NSCLC. Routine systematic EBUS-TBNA may improve radiation treatment planning by including all affected areas while sparing disease-free lymph nodes. This reinforces the recommendation that patients with high risk of N2 or N3 disease should get mediastinal staging prior to definitive therapy. The impact of discordant results on radiotherapy treatment plans will be reviewed in the next phase of our study.

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