Abstract 5645
Background
Radiation induced CT changes may be apparent following completion of TRT. We sought to quantify differences in radiation-associated densities on serial CT scans of patients with ES-SCLC treated with TRT alone versus TRT followed by combined IPI and NIVO.
Methods
Between 2016 and 2018, patients at a single institution with ES-SCLC who achieved stable disease or better following initial treatment with platinum doublet chemotherapy were offered TRT and prescribed a total dose of 30Gy in 10 fractions targeting initially involved thoracic tumor sites. Combined IPI 3mg/kg and NIVO 1mg/kg was administered every 3 weeks for up to 4 doses. We evaluated an irradiated region of interest (ROI) within the lungs and a volume of lung (outside the Planning Target Volume) receiving > 20 Gy. Within the ROI, we calculated the Hounsfield unit (HU) mean for each patient prior to therapy and at subsequent follow-up CT thorax at least 60 days and closest to 120 days after commencing TRT. To quantify CT density change, we measured the difference in HU mean within the irradiated ROI before and after treatment.
Results
Seventeen patients enrolled on NCT03043599 received TRT followed by combined IPI/NIVO. Two additional patients received the same treatment off protocol. Eleven patients received TRT alone (no IPI/NIVO). The average increase in HU mean within 20Gy irradiated ROI before and after treatment was 9% (max 59%, min -19%) across the study cohort (n = 30). CTCAE grade 3 or higher pulmonary toxicity (N = 8 of 30) was significantly associated with increased CT density change within the ROI (mean 28% vs 2%, p = 0.001). Treatment with TRT and IPI/NIVO (N = 19 of 30) demonstrated a trend towards increased mean CT density change within the ROI compared to patients treated with TRT alone (mean 13% vs. 0%, p = 0.1).
Conclusions
Quantifying CT density change within irradiated lung parenchyma may offer a novel approach to predict radiation associated pulmonary toxicities. Measuring density changes across patient cohorts receiving TRT with novel systemic therapies may help to identify combined treatment strategies likely to be associated with diminished risk of toxicity.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Bristol-Myers Squibb.
Disclosure
S. Kim: Research grant / Funding (institution): Bristol-Myers Squibb. S.A. Rosenberg: Advisory / Consultancy: Novocure. J.E. Gray: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): AstraZeneca; Honoraria (self), Advisory / Consultancy: Celgene; Honoraria (self), Advisory / Consultancy: Takeda; Honoraria (self), Advisory / Consultancy: Janssen; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Genentech; Honoraria (self), Advisory / Consultancy: Eli Lilly; Honoraria (self), Advisory / Consultancy: Triptych Health Partners. S.J. Antonia: Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy: Merck; Advisory / Consultancy: CBMG; Advisory / Consultancy: Boehringer Ingelheim; Advisory / Consultancy: AstraZeneca/MedImmune; Advisory / Consultancy: Memgen; Advisory / Consultancy: FLX Bio; Advisory / Consultancy: Nektar; Advisory / Consultancy: Venn. B. Perez: Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy: AstraZeneca. All other authors have declared no conflicts of interest.
Resources from the same session
2152 - Inferring the correlation between incidence rates of melanoma and the average tumor-specific epitope binding ability of HLA class I molecules in different populations
Presenter: Istvan Miklos
Session: Poster Display session 3
Resources:
Abstract
4382 - Thermal Liquid Biopsy as a Valuable Tool in Lung Cancer Screening Programs
Presenter: Alberto Rodrigo
Session: Poster Display session 3
Resources:
Abstract
2465 - Towards a screening test for cancer by circulating DNA analysis
Presenter: Rita Tanos
Session: Poster Display session 3
Resources:
Abstract
3788 - Evaluation of a successful launch of the MammaPrint and BluePrint NGS kit
Presenter: Leonie Delahaye
Session: Poster Display session 3
Resources:
Abstract
3863 - Analysis of prognostic factors on overall survival in elderly women treated for early breast cancer using data mining and machine learning
Presenter: Pierre Heudel
Session: Poster Display session 3
Resources:
Abstract
1993 - Circulating tumor cell detection in epithelial ovarian cancer using dual-component antibodies targeting EpCAM and FRα
Presenter: Na Li
Session: Poster Display session 3
Resources:
Abstract
4281 - CEUS of the breast: Is it feasible in improved performance of BI-RADS evaluation of critical breast lesions?——A multi-center prospective study in China
Presenter: Jun Luo
Session: Poster Display session 3
Resources:
Abstract
2268 - Classification of abnormal findings on ring-type dedicated breast PET for detecting breast cancer
Presenter: Shinsuke Sasada
Session: Poster Display session 3
Resources:
Abstract
4035 - Prediction of benign and malignant breast masses using digital mammograms texture features
Presenter: Cui Yanhua
Session: Poster Display session 3
Resources:
Abstract
5678 - Nanomaterials Augmented LDI-TOF-MS for Hepatocellular Carcinoma Diagnosis and Classification
Presenter: Jian Zhou
Session: Poster Display session 3
Resources:
Abstract