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Tian Rui Siow



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    P2.01 - Advanced NSCLC (Not CME Accredited Session) (ID 950)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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      P2.01-63 - Are Heart Doses Associated with Survival in NSCLC Treated with Post-Operative Radiotherapy? A National Population-Based Study (ID 11304)

      16:45 - 18:00  |  Author(s): Tian Rui Siow

      • Abstract
      • Slides

      Background

      Some early studies suggested that post-operative thoracic radiotherapy (PORT) using non-modern radiation techniques in non-small cell lung cancer (NSCLC) might cause significant treatment-related toxicities. Higher radiation doses to the heart have been recently linked to more cardiac events and worse overall survival (OS) in patients with locally-advanced NSCLC treated with thoracic irradiation. We embarked on a national population-based study to assess the association between radiation heart doses, acute myocardial infarct (AMI) rates and OS in NSCLC patients treated with PORT using contemporary radiation techniques.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Study eligibility criteria included stage I to III NSCLC treated with PORT from 2007 to 2014 in our public hospitals which comprised about 80% of national caseload. The clinical and dosimetric data were collected from the institutional electronic medical records and linked to the national death and AMI registries. Univariate Cox regression was performed using STATA version 13.

      4c3880bb027f159e801041b1021e88e8 Result

      43 eligible patients were identified. Median follow-up duration was 36.6 months. Characteristics of study population are summarized in Table 1. There were no AMI events. The 1- and 2-year OS were 74% and 65%. Univariate Cox regression analysis showed that age (hazard ratio, 1.06; 95% confidence interval, 1.01 to 1.10; P= 0.008) was the only significant factor associated with OS. Radiation heart doses, including mean heart dose, volume of heart receiving at least 5, 25, 30, 40, 50 Gy and dose to 30% of heart volume, were not associated with OS.

      Table 1: Characteristics of Study Population
      Characteristics N= 43
      Sociodemographic and Clinical Characteristics
      Age at lung cancer diagnosis, year, median (IQR) 63.6 (54.2-67.0)
      Gender
      Male
      Female

      18 (41.9%)
      25 (58.1%)
      Eastern Cooperative Oncology Group performance status
      0 and 1
      2

      41 (95.4%)
      2 (4.6%)
      Smoking status
      Current and former smoker
      Never smoker

      14 (32.6%)
      29 (67.4%)
      Diabetes mellitus
      Yes
      No

      7 (16.3%)
      36 (83.7%)
      Pre-existing ischaemic heart disease
      Yes
      No

      6 (14.0%)
      37 (86.0%)
      Chronic obstructive pulmonary disease
      Yes
      No

      1 (2.3%)
      41 (97.7%)
      Use of positron emission tomography-computed tomography for staging
      Yes
      No

      19 (44.2%)
      24 (55.8%)
      Use of brain magnetic resonance or contrast computed tomography for staging
      Yes
      No

      35 (81.4%)
      8 (18.6%)
      Tumour Characteristics
      Histology
      Adenocarcinoma
      Squamous cell carcinoma
      Non-small-cell lung cancer, not otherwise specified

      31 (72.1%)
      5 (11.6%)
      7 (16.3%)
      Tumour laterality
      Left
      Right

      16 (37.2%)
      27 (62.8%)
      Lobar location of tumour
      Upper
      Middle
      Lower

      25 (58.1%)
      5 (11.6%)
      13 (30.2%)
      Pathological T stage
      T1
      T2
      T3
      T4

      15 (34.9%)
      19 (44.2%)
      6 (13.9%)
      3 (7.0%)
      Pathological N stage
      N0
      N1
      N2

      10 (23.3%)
      4 (9.3%)
      29 (67.4%)
      Overall pathological stage
      Stage I
      Stage II
      Stage III

      3 (7.0%)
      9 (20.9%)
      31 (72.1%)
      Resection margin status
      R0
      R1
      R2

      28 (65.1%)
      13 (30.2%)
      2 (4.7%)
      Treatment Characteristics
      Type of surgery
      Lobectomy
      Pneumonectomy

      36 (83.7%)
      7 (16.3%)
      Use of concurrent or sequential chemotherapy
      Yes
      No
      Unknown

      31 (72.1%)
      11 (25.6%)
      1 (2.3%)
      Type of chemotherapy used
      Cisplatin + vinorelbine
      Cisplatin + gemcitabine
      Cisplatin + pemetrexed
      Carboplatin + vinorelbine
      Carboplatin + gemcitabine
      Carboplatin + pemetrexed
      Carboplatin + paclitaxel

      13 (30.2%)
      6 (14.0%)
      4 (9.3%)
      2 (4.7%)
      2 (4.7%)
      2 (4.7%)
      2 (4.7%)
      Thoracic radiation technique
      3D-conformal
      Intensity-modulated radiation therapy or Arc therapy

      30 (69.8%)
      13 (30.2%)
      Prescribed thoracic radiation dose, Gy, median (IQR)* 60.0 (50.0-60.0)
      Dosimetric Characteristics
      Mean heart dose, Gy, median (IQR) 9.4 (2.3-14.6)
      Heart volume received at least 5 Gy (heart V5), percentage, median (IQR) 34.0 (9.7-46.0)
      Heart volume received at least 25 Gy (heart V5), percentage, median (IQR) 15.0 (2.0-24.0)
      Heart volume received at least 30 Gy (heart V5), percentage, median (IQR) 12.3 (1.0-20.0)
      Heart volume received at least 40 Gy (heart V5), percentage, median (IQR) 4.6 (0.0-14.5)
      Heart volume received at least 50 Gy (heart V5), percentage, median (IQR) 2.0 (0.0-6.0)
      Dose to 30% of heart volume (heart D30), Gy, median (IQR) 7.4 (1.5-17.5)
      Mean lung dose, Gy, median (IQR) 11.2 (10.1-13.6)
      Lung volume received at least 5 Gy (lung V5), percentage, median (IQR) 48.0 (40.0-56.0)
      Lung volume received at least 20 Gy (lung V20), percentage, median (IQR) 20.4 (16.0-26.0)
      Planning target volume in 10 cc, median (IQR) 20.8 (15.1-38.8)
      Abbreviation:
      1. IQR, interquartile range
      *All doses are in equivalent dose in 2-Gy fraction

      8eea62084ca7e541d918e823422bd82e Conclusion

      This study found that various radiation heart doses were not significantly associated with OS in patients with NSCLC treated with PORT. Studies with larger sample size and longer term follow-up are needed to assess cardiac outcome, given the possibility of late occurrence of AMI events.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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    P3.08 - Oligometastatic NSCLC (Not CME Accredited Session) (ID 974)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall
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      P3.08-07 - An Institution Review of Outcomes of Lung Stereotactic Body Radiotherapy in Various Oligometastatic Disease States (ID 12340)

      12:00 - 13:30  |  Author(s): Tian Rui Siow

      • Abstract
      • Slides

      Background

      There is growing interest to use ablative techniques in patients with limited metastases to improve on local control (LC) and possibly survival outcomes. We review the outcomes of metastatic patients treated with pulmonary stereotactic body radiotherapy (SBRT) at our centre and analyse variables that might have affected outcomes.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Institutional review board approval was obtained before a retrospective review of patients treated at our centre from Jan 2010 to Dec 2016 was conducted. The data of patients treated with lung SBRT in the oligometastatic (≤3 lesions) setting was obtained from electronic medical records. The data was analysed using SPSS ver23. Survival was calculated from start of SBRT.

      4c3880bb027f159e801041b1021e88e8 Result

      A total of 46 patients with 53 lung lesions were treated with SBRT. All patients had ECOG of 0-2. Primary cancers were varied with majority from lung (n=18, 39.1%) and colorectal cancers (n=13, 28.3%). There were 33 oligorecurrent, 10 oligoprogressive and 3 oligometastatic cases. Median age at SBRT was 66.8 years. Median lesion diameter was 18mm (range 7-57mm). Median SBRT biological effective dose (BED) was 105.6Gy (range 78.6 – 132.0Gy). The median follow-up was 26.9 months (range 4.5 – 59.6 months). There were 12 (22.6%) local failures at last follow-up. Median progression free survival (PFS) was 13.7 months (95% CI: 3.9 -23.5 months). Median overall survival (OS) was 42.2 months (95% CI: 30.8 - 53.5 months). The 2 year PFS and OS was 32.6% and 81.9% respectively. There were 3 (6.5%) likely radiotherapy related grade 3-4 pulmonary toxicities. On univariate analysis, a higher BED and squamous cell histology predicted for better LC. Oligorecurrent cases, higher BED, radical treatment to primary, single active/enlarging lesion and single metastatic involved organ, previous lung interventions, biopsy of lung lesion and radical treatment to all metastatic lesions predicted for better PFS. Local failure and progression predicted for worst OS. On multivariate analysis no variable had a significant impact on survival outcomes.

      8eea62084ca7e541d918e823422bd82e Conclusion

      The patients in this study are heterogeneous. Target lesion control after lung SBRT for metastatic disease is comparable to that of primary lung cancer. The excellent survival outcomes in this group of metastatic patients may be due to selection of patients with indolent disease biology. Better disease control outcomes were seen in oligorecurrent cases and when radical treatment to all lesions and higher BEDs were used. Further studies are needed to select for patients that are most likely to benefit from local ablative therapies.

      6f8b794f3246b0c1e1780bb4d4d5dc53

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