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
4506 - Single intravenous preoperative administration of the oncolytic virus Pexa-Vec to prime anti-tumor immunity
Presenter: Adel Samson
Session: Poster Display session 3
Resources:
Abstract
1631 - Randomized phase 2 clinical trial of NY-ESO-1 protein vaccine combined with cholesteryl pullulan (CHP-NY-ESO-1) in resected esophageal cancer patients
Presenter: Shinichi Kageyama
Session: Poster Display session 3
Resources:
Abstract
4244 - T cell repertoire sequencing reveals dynamics of response to dendritic cell vaccine plus dasatinib for checkpoint blockade resistant metastatic melanoma
Presenter: Luca Quagliata
Session: Poster Display session 3
Resources:
Abstract
5791 - Ixovex, a novel oncolytic E1B-mutated adenovirus
Presenter: Mohiemen Anwar
Session: Poster Display session 3
Resources:
Abstract
4170 - Anti-CSPG4 DNA vaccination as a promising strategy for the treatment of CSPG4+ tumors: a comparative oncology trial
Presenter: Federica Riccardo
Session: Poster Display session 3
Resources:
Abstract
5780 - Antitumor activity, immunogenicity and safety of a novel PD-1 vaccine in combination with two chimeric HER-2 peptide vaccine in syngeneic Balb/c, C57Bl/6 models and in beagle dogs
Presenter: Pravin Kaumaya
Session: Poster Display session 3
Resources:
Abstract
5860 - Maternal immunization against ALK as a weapon to fight neuroblastoma
Presenter: Giuseppina Barutello
Session: Poster Display session 3
Resources:
Abstract
4720 - Phase 1 study evaluating safety, pharmacokinetics (PK), pharmacodynamics, and preliminary efficacy of ABBV-428, first-in-class mesothelin (MSLN)-CD40 bispecific, in patients (pts) with advanced solid tumors
Presenter: Jason Luke
Session: Poster Display session 3
Resources:
Abstract
5717 - Anti-PD-L1/IL-15 fusion protein generates robust adaptive immune gene signatures in tumors leading to tumor inhibition and memory responses
Presenter: Stella Martomo
Session: Poster Display session 3
Resources:
Abstract
1802 - Evaluation of the anti-tumor efficacy and immune effects of N-809, a novel IL-15 superagonist/anti-PD-L1 bispecific agent
Presenter: Kristin Hicks
Session: Poster Display session 3
Resources:
Abstract