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G. Defraene
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P3.09 - Mesothelioma (ID 725)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Mesothelioma
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.09-003 - Heart Radiation Dose as a Risk Factor for Dyspnea Worsening After Multimodality Treatment for NSCLC and MPM: An Exploratory Analysis (ID 10496)
09:30 - 09:30 | Author(s): G. Defraene
- Abstract
Background:
The purpose of our study was to quantify the influence of heart dose on the early and late onset of dyspnea in a cohort of non-small cancer (NSCLC) and malignant pleural mesothelioma (MPM) patients having multimodality treatment including radiotherapy (RT).
Method:
In 121 patients with multimodality-treated NSCLC and MPM the maximal dyspnea score (CTCAE 4.0) before RT, at an early (<6 months) and a late (7-12 months) time point were obtained. Included patients needed to be clinically and radiologically progression-free 9 months after the end of RT. The difference (Δ) between the maximal dyspnea at <6 months and at 7-12 months with the pre-RT dyspnea was calculated.
Result:
Forty-four percent (50/113) of the patients developed an early worsening of at least 1 point in their dyspnea score (Δdyspnea >1) after the end of RT. Independent predictors of an early worsening were the mean heart dose (MHD) (for Δdyspnea >1: OR=1.03, p=0.04) and the dyspnea score before RT (for Δdyspnea >1: OR=0.40, p=0.0001; for Δdyspnea >2: OR=0.35, p=0.05). At the later time point, only the dyspnea score before RT (OR: 0.40, p=0.001) was identified as predictor of Δdyspnea >1.
Conclusion:
Our results, albeit exploratory, suggest that heart dose may play a role in the early worsening of the dyspnea in a heterogeneous cohort of patients having multimodality treatment including RT, whereas baseline dyspnea plays a major role for both early and later worsening.
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P3.14 - Radiotherapy (ID 730)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Radiotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.14-011 - Mean Heart Dose Is an Independent Risk Factor for Early Mortality After Chemoradiotherapy Treatment for Lung Cancer (ID 10342)
09:30 - 09:30 | Author(s): G. Defraene
- Abstract
Background:
Early mortality after (chemo)radiotherapy can be caused by treatment-related toxicities and thus by delivered doses to normal lung and heart tissues. However, prediction models for mortality incorporating dosimetry are lacking. This study explores the prognostic value of common dosimetric features.
Method:
Two prospective cohorts containing 218 and 181 curatively treated stage I-III lung cancer patients from 2003-2007 and 2013-2016 periods, respectively, were studied. Prescribed dose was 66Gy/2Gy (concurrent chemotherapy), 66Gy/2.75Gy (sequential or no chemotherapy) or a similar schedule. Clinical (WHO performance status, age, T stage, N stage and primary gross tumor volume (GTV)) and dosimetric (mean lung dose (MLD) and mean heart dose (MHD)) covariates were analysed. Cox regression models of survival and a logistic regression model for the 12 month mortality endpoint were optimized using forward stepwise selection (p<0.05).
Result:
Median follow-up time was 80.2 and 20.2 months in dataset 1 and 2, respectively. MHD (HR=1.023, p=0.001) and WHO performance status (HR=1.25, p=0.03) were selected in the Cox model for dataset 1. Tumor volume (HR=1.0015, p=0.001), WHO performance status (HR=1.023, p=0.02) and MHD (HR=1.0030, p=0.03) were selected in dataset 2. Adding time-dependent covariates revealed a decreasing GTV HR over time in dataset 1 (p=0.02), while MHD risk did not significantly change with time. Worse survival observed in a high MHD subgroup indeed only starts after 8 months (Figure 1). 12 month survival modeling included the covariates MHD (optimal cut-off 22Gy) and GTV (AUC=0.71). In dataset 2, these covariates and cut-off resulted in a model with AUC=0.63. Figure 1
Conclusion:
Mean heart dose is an independent risk factor for early mortality in two cohorts with different treatment periods and techniques. The best classifier for 12 month mortality risk was obtained with the MHD<22Gy constraint, which could be used in model-based implementation of proton therapy.
