Author of

• 10692

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  P1.08 - Poster Session 1 - Radiotherapy (ID 195)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10704

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    P1.08-012 - Significant association between radiation induced oesophagitis, neutropenia and V20 in patients with non-small cell lung cancer (ID 1518)

    09:30 - 16:30  |  Author(s): C. Russell
    • Abstract

    Background
    Radiation induced oesophagitis (RIO) is frequently associated with high dose thoracic radiation therapy (RT). Although RIO is uncommonly life threatening, it is a distressing toxicity associated with pain, decreased oral intake and can significantly impact on patient’s quality of life. The aim of this retrospective analysis was to assess the rates of acute and late RIO and investigate the association of RIO with radiation dosimetrics and neutropenia.

    Methods
    Criteria for inclusion of patient data included a pathological confirmation of non-small cell lung cancer (NSCLC), treatment with concurrent chemotherapy and radical or high dose palliative RT at our centre between 03/04 and 08/07. Exclusion criteria included previous thoracic RT, RT alone, treatment breaks of > five days, inconsistent radiation dose per fraction and hyper-fractionated RT. Acute and late RIO and neutropenia were scored using the Common Toxicity Criteria for Adverse Events (CTCAE v3.0) criteria. Using Focal (Computerized Medical Systems CMS, St Louis, MO, USA), the outer muscular border of the oesophagus was delineated from the cricoid (superior border) to the gastro-oesophageal junction (inferior border) on CT derived images, using pre-defined soft-tissue window/level settings. Dosimetric data was derived from Xio (CMS) plans (three-dimensional conformal RT (3DCRT) with 6MV photons), including the oesophageal length and volume, maximum and mean doses, percentage of oesophagus receiving 20 to 60 Gy (in 5 Gy increments) and percentage length of oesophagus (whole and partial circumference) receiving 20 to 60 Gy (10 Gy increments). Assessment of potential prognostic factors with respect to acute oesophagitis was done using Wilcoxon rank sum test and Spearman’s correlation. Acute oesophagitis and acute neutropenia reaction were dichotomised as grade 0+1 vs. grade 2+3+4. The association of acute oesophagitis with acute neutropenia was examined using Barnard’s test.

    Results
    The data of 54 patients were eligible for inclusion in this trial. 48 (89%) patients had acute RIO of at least grade 1 (95% CI [78% to 95%]) and five patients (9%) had late RIO of at least grade 1 (95% CI [4% to 20%]). There was a statistically significant correlation between the grade of acute RIO, oesophagus V20 (r=0.303, p=0.026) and length oesophagus receiving 20Gy (whole circumference) (r=0.319, p=0.019). The mean (SD) maximum dose to the oesophagus was 50.2 Gy (18) (r=0.143, p=0.302) and the mean (SD) mean oesophageal dose was 20.8 Gy (10.8) (r=0.269, p=0.049). The maximum grade of acute oesophagitis was significantly associated with acute neutropenia (p=0.035).

    Conclusion
    Acute neutropenia, mean oesophageal dose and the volume and length of oesophagus receiving low radiation doses were significantly associated with acute RIO in our patient cohort. No association was demonstrated between RIO and maximum radiation dose.