Stereotactic Body Radiation Therapy for Stage IIA to IIIA Inoperable Non-Small Cell Lung Cancer: A Phase 1 Dose-Escalation Trial

PURPOSE

Larger tumors are underrepresented in most prospective trials on stereotactic body radiation therapy (SBRT) for inoperable non-small cell lung cancer (NSCLC). We performed this phase 1 trial to specifically study the maximum tolerated dose (MTD) of SBRT for NSCLC >3 cm.

METHODS AND MATERIALS

A 3 + 3 dose-escalation design (cohort A) with an expansion cohort at the MTD (cohort B) was used. Patients with inoperable NSCLC >3 cm (T2-4) were eligible. Select ipsilateral hilar and single-station mediastinal nodes were permitted. The initial SBRT dose was 40 Gy in 5 fractions, with planned escalation to 50 and 60 Gy in 5 fractions. Adjuvant chemotherapy was mandatory for cohort A and optional for cohort B, but no patients in cohort B received chemotherapy. The primary endpoint was SBRT-related acute grade (G) 4+ or persistent G3 toxicities (Common Terminology Criteria for Adverse Events version 4.03). Secondary endpoints included local failure (LF), distant metastases, disease progression, and overall survival.

RESULTS

The median age was 80 years; tumor size was >3 cm and ≤5 cm in 20 (59%) and >5 cm in 14 patients (41%). In cohort A (n = 9), 3 patients treated to 50 Gy experienced G3 radiation pneumonitis (RP), thus defining the MTD. In the larger dose-expansion cohort B (n = 25), no radiation therapy-related G4+ toxicities and no G3 RP occurred; only 2 patients experienced G2 RP. The 2-year cumulative incidence of LF was 20.2%, distant failure was 34.7%, and disease progression was 54.4%. Two-year overall survival was 53%. A biologically effective dose (BED) <100 Gy was associated with higher LF (P = .006); advanced stage and higher neutrophil/lymphocyte ratio were associated with greater disease progression (both P = .004).

CONCLUSIONS

Fifty Gy in 5 fractions is the MTD for SBRT to tumors >3 cm. A higher BED is associated with fewer LFs even in larger tumors. Cohort B appears to have had less toxicity, possibly due to the omission of chemotherapy.

Biomarkers associated with pulmonary exacerbations in a randomized trial of nintedanib for radiation pneumonitis

BACKGROUND AND PURPOSE

Radiation pneumonitis (RP) is a common side effect of thoracic radiotherapy and often has a long course characterized by acute exacerbations and progression to permanent lung fibrosis. There are no validated biomarkers of prognosis in patients diagnosed with RP.

MATERIALS AND METHODS

We analyzed a time course of serum chemokines, cytokines, and other proteins from patients with grade 2+ RP in a randomized clinical trial of a steroid taper plus nintedanib, a multiple tyrosine kinase inhibitor, versus placebo plus a steroid taper for the treatment of RP. Weighted gene correlation network analysis (WGCNA) and univariable zero inflated Poisson models were used to identify groups of correlated analytes and their associations with clinical outcomes.

RESULTS

Thirty enrolled patients had biomarker data available, and 17 patients had enough analytes tested for network analysis. WGNCA identified ten analytes, including transforming growth factor beta-1 (TGF-β1), monocyte chemoattractant protein-1 (MCP-1), and platelet-derived growth factor (PDGF), that in aggregate were correlated with the occurrence of pulmonary exacerbations (p = 0.008), the total number of acute pulmonary exacerbations (p = 0.002), and treatment arm (p = 0.036). By univariable analysis, an increase in rate of change of two components of the RP module were associated with an increased incidence rate of pulmonary exacerbations: interleukin 5 (IL-5, incidence rate ratio (IRR) 1.02, 95% CI 1.01-1.04, p = 0.002), and tumor necrosis factor superfamily 12 (TNFSF12, IRR 1.06, CI 1-1.11, p = 0.036). An increased slope of epidermal growth factor (EGF) was associated with a decreased incidence rate of exacerbations (IRR 0.94, CI 0.89-1, p = 0.036).

CONCLUSION

We identified a panel of serum biomarkers that showed association with nintedanib treatment and acute pulmonary exacerbations in patients with RP. A confirmatory study will be needed to validate this panel for use as a prognostic tool in patients with RP.

Insurance Denials and Patient Treatment in a Large Academic Radiation Oncology Center

Importance

Insurance barriers to cancer care can cause significant patient and clinician burden.

Objective

To investigate the association of insurance denial with changes in technique, dose, and time to delivery of radiation oncology treatment.

Design, Setting, and Participants

In this single-institution cohort analysis, data were collected from patients with payer-denied authorization for radiation therapy (RT) from November 1, 2021, to December 8, 2022. Data were analyzed from December 15, 2022, to December 31, 2023.

Exposure

Insurance denial for RT.

Main Outcomes and Measures

Association of these denials with changes in RT technique, dose, and time to treatment delivery was assessed using χ2 tests.

Results

A total of 206 cases (118 women [57.3%]; median age, 58 [range, 26-91] years) were identified. Most insurers (199 [96.6%]) were commercial payers, while 7 (3.4%) were Medicare or Medicare Advantage. One hundred sixty-one patients (78.2%) were younger than 65 years. Of 206 cases, 127 (61.7%) were ultimately authorized without any change to the requested RT technique or prescription dose; 56 (27.2%) were authorized after modification to RT technique and/or prescription dose required by the payer. Of 21 cases with required prescription dose change, the median decrease in dose was 24.0 (range, 2.3-51.0) Gy. Of 202 cases (98.1%) with RT delivered, 72 (34.9%) were delayed for a mean (SD) of 7.8 (9.1) days and median of 5 (range, 1-49) days. Four cases (1.9%) ultimately did not receive any authorization, with 3 (1.5%) not undergoing RT, and 1 (0.5%) seeking treatment at another institution.

Conclusions and Relevance

In this cohort study of patients with payer-denied cases, most insurance denials in radiation oncology were ultimately approved on appeal; however, RT technique and/or effectiveness may be compromised by payer-mandated changes. Further investigation and action to recognize the time and financial burdens on clinicians and clinical effects on patients caused by insurance denials of RT is needed.

Perioperative and oncologic outcomes of pulmonary resection for synchronous oligometastatic non-small cell lung cancer: Evidence for surgery in advanced disease

OBJECTIVES

Recent randomized trials have demonstrated a survival advantage with the use of local consolidative therapy in oligometastatic non-small cell lung cancer; however, the indications for and outcomes after pulmonary resection as a component of local consolidative therapy remain ill defined. We sought to characterize the perioperative and long-term survival outcomes among patients with resected oligometastatic non-small cell lung cancer.

METHODS

Patients presenting to a single center (2000-2017) with oligometastatic non-small cell lung cancer (≤3 synchronous metastases, intrathoracic nodal disease counted as a single site) who underwent resection of the primary tumor were retrospectively identified. Charts were reviewed, and demographic, clinical, pathologic, oncologic, and survival outcomes were recorded. Survival outcomes were analyzed from the date of surgery.

RESULTS

A total of 52 patients met inclusion criteria, among whom most (38, 73.1%) were ever smokers, had nonsquamous tumors (48, 92.3%), had no intrathoracic nodal disease (33, 63.5%), and had 1 to 2 sites of metastases (49, 94.2%). The majority (41, 78.9%) received systemic therapy, predominantly in the neoadjuvant setting (24/41, 58.5%). After resection, there were no 30- or 90-day deaths. After a median follow-up of 94.6 months (95% CI, 69.0-139.1), 37 patients (71.2%) progressed and 38 patients (73.1%) died. Median postoperative progression-free survival and overall survival were 9.4 (5.5-11.6) months and 51.7 (22.3-65.3) months, respectively.

CONCLUSIONS

Pulmonary resection as a means of maximum locoregional control in oligometastatic non-small cell lung cancer is feasible and safe, and may be associated with durable long-term survival benefits. The frequency of systemic postoperative progression highlights an urgent need to characterize perioperative and oncologic outcomes after pulmonary resection in the current era of novel systemic therapies.

Evaluating a Physician Audit and Feedback Intervention to Increase Clinical Trial Enrollment in Radiation Oncology in a Multisite Tertiary Cancer Center: A Randomized Study

PURPOSE

Clinical trial participation continues to be low, slowing new cancer therapy development. Few strategies have been prospectively tested to address barriers to enrollment. We investigated the effectiveness of a physician audit and feedback report to improve clinical trial enrollment.

METHODS AND MATERIALS

We conducted a randomized quality improvement study among radiation oncologists at a multisite tertiary cancer network. Physicians in the intervention group received quarterly audit and feedback reports comparing the physician's trial enrollments with those of their peers. The primary outcome was trial enrollments.

RESULTS

Among physicians randomized to receive the feedback report (n = 30), the median proportion of patients enrolled during the study period increased to 6.1% (IQR, 2.6%-9.3%) from 3.2% (IQR, 1.1%-10%) at baseline. Among those not receiving the feedback report (n = 29), the median proportion of patients enrolled increased to 4.1% (IQR, 1.3%-7.6%) from 1.6% (IQR, 0%-4.1%) at baseline. There was a nonsignificant change in the proportion of enrollments associated with receiving the feedback report (-0.6%; 95% CI, -3.0% to 1.8%; P = .6). Notably, there was an interaction between baseline trial accrual and receipt of feedback reports (P = .005), with enrollment declining among high accruers. There was an increase in enrollment throughout the study, regardless of study group (P = .001).

CONCLUSIONS

In this study, a positive effect of physician audit and feedback on clinical trial enrollment was not observed. Future efforts should avoid disincentivizing high accruers and might consider pairing feedback with other patient- or physician-level strategies. The increase in trial enrollment in both groups over time highlights the importance of including a comparison group in quality improvement studies to reduce confounding from secular trends.

An 18F-FDG PET/CT and Mean Lung Dose Model to Predict Early Radiation Pneumonitis in Stage III Non-Small Cell Lung Cancer Patients Treated with Chemoradiation and Immunotherapy

Radiation pneumonitis (RP) that develops early (i.e., within 3 mo) (RPEarly) after completion of concurrent chemoradiation (cCRT) leads to treatment discontinuation and poorer survival for patients with stage III non-small cell lung cancer. Since no RPEarly risk model exists, we explored whether published RP models and pretreatment 18F-FDG PET/CT-derived features predict RPEarly Methods: One hundred sixty patients with stage III non-small cell lung cancer treated with cCRT and consolidative immunotherapy were analyzed for RPEarly Three published RP models that included the mean lung dose (MLD) and patient characteristics were examined. Pretreatment 18F-FDG PET/CT normal-lung SUV featured included the following: 10th percentile of SUV (SUVP10), 90th percentile of SUV (SUVP90), SUVmax, SUVmean, minimum SUV, and SD. Associations between models/features and RPEarly were assessed using area under the receiver-operating characteristic curve (AUC), P values, and the Hosmer-Lemeshow test (pHL). The cohort was randomly split, with similar RPEarly rates, into a 70%/30% derivation/internal validation subset. Results: Twenty (13%) patients developed RPEarly Predictors for RPEarly were MLD alone (AUC, 0.72; P = 0.02; pHL, 0.87), SUVP10, SUVP90, and SUVmean (AUC, 0.70-0.74; P = 0.003-0.006; pHL, 0.67-0.70). The combined MLD and SUVP90 model generalized in the validation subset and was deemed the final RPEarly model (RPEarly risk = 1/[1+e(- x )]; x = -6.08 + [0.17 × MLD] + [1.63 × SUVP90]). The final model refitted in the 160 patients indicated improvement over the published MLD-alone model (AUC, 0.77 vs. 0.72; P = 0.0001 vs. 0.02; pHL, 0.65 vs. 0.87). Conclusion: Patients at risk for RPEarly can be detected with high certainty by combining the normal lung's MLD and pretreatment 18F-FDG PET/CT SUVP90 This refined model can be used to identify patients at an elevated risk for premature immunotherapy discontinuation due to RPEarly and could allow for interventions to improve treatment outcomes.

Disparities in Stage at Presentation Among Hispanic and Latinx Patients With Non-Small-Cell Lung Cancer in the United States

PURPOSE

Hispanic and Latinx people in the United States are the fastest-growing ethnic group. However, previous studies in non-small-cell lung cancer (NSCLC) often analyze these diverse communities in aggregate. We aimed to identify differences in NSCLC stage at diagnosis in the US population, focusing on disaggregated Hispanic/Latinx individuals.

METHODS

Data from the National Cancer Database from 2004 to 2018 identified patients with primary NSCLC. Individuals were disaggregated by racial and ethnic subgroup and Hispanic country of origin. Ordinal logistic regression adjusting for age, facility type, income, educational attainment, comorbidity index, insurance, and year of diagnosis was used to create adjusted odds ratios (aORs), with higher odds representing diagnosis at later-stage NSCLC.

RESULTS

Of 1,565,159 patients with NSCLC, 46,616 were Hispanic/Latinx (3.0%). When analyzed in the setting of race and ethnicity, Hispanic patients were more likely to be diagnosed with metastatic disease compared with non-Hispanic White (NHW) patients: 47.0% for Hispanic Black, 46.0% Hispanic White, and 44.3% of Hispanic other patients versus 39.1% of non-Hispanic White patients (P < .001 for all). By country of origin, 51.4% of Mexican, 41.7% of Puerto Rican, 44.6% of Cuban, 50.8% of South or Central American, 48.4% of Dominican, and 45.6% of other Hispanic patients were diagnosed with metastatic disease, compared with 39.1% of NHWs. Conversely, 20.2% of Mexican, 26.9% of Puerto Rican, 24.2% of Cuban, 22.5% of South or Central American, 23.7% of Dominican, and 24.5% of other Hispanic patients were diagnosed with stage I disease, compared with 30.0% of NHWs. All Hispanic groups were more likely to present with later-stage NSCLC than NHW patients (greatest odds for Mexican patients, aOR, 1.44; P < .001).

CONCLUSION

Hispanic/Latinx patients with non-small-cell lung cancer were more likely to be diagnosed with advanced disease compared with NHWs. Disparities persisted upon disaggregation by both race and country of origin, with over half of Mexican patients with metastatic disease at diagnosis. Disparities among Hispanic/Latinx groups by race and by country of origin highlight the shortcomings of treating these groups as a monolith and underscore the need for disaggregated research and targeted interventions.

Clinical outcomes of stereotactic body radiation therapy for malignant pleural mesothelioma

BACKGROUND

The objective of this study is to determine the outcomes and toxicities of patients with malignant pleural mesothelioma (MPM) treated with stereotactic body radiotherapy (SBRT).

MATERIALS AND METHODS

Data were extracted from an institutional tumor registry for patients diagnosed with mesothelioma and treated with SBRT. Kaplan-Meier and Cox regression analyses were employed to determine local control (LC) and overall survival (OS).

RESULTS

Forty-four patients with 59 total treated tumors from December 2006 to April 2022 were identified. Fifty-one (86.4 %) cases had oligoprogressive disease (five sites or less). The median prescription dose delivered was 3000 cGy in 5 fractions (range: 2700-6000 cGy in 3-8 fractions). Fifty-one (86.4 %) tumors were in the pleura, 4 (6.8 %) spine, 2 (3.4 %) bone, 1 (1.7 %) brain, and 1 (1.7 %) pancreas. The median follow-up from SBRT completion for those alive at last follow-up was 28 months (range: 14-52 months). The most common toxicities were fatigue (50.8 %), nausea (22.0 %), pain flare (15.3 %), esophagitis (6.8 %), dermatitis (6.8 %), and pneumonitis (5.1 %). There were no grade ≥ 3 acute or late toxicities. There were 2 (3.4 %) local failures, one of the pleura and another of the spine. One-year LC was 92.9 % (95 % CI: 74.6-98.2 %) for all lesions and 96.3 % (95 % CI: 76.5-99.5 %) for pleural tumors. One-year LC was 90.9 % (95 % CI: 68.1-97.6 %) for epithelioid tumors and 92.1 % (95 % CI: 72.1-98.0 %) for oligoprogressive tumors. One-year OS from time of SBRT completion was 36.4 % (95 % CI: 22.6-50.3 %). On multivariable analysis, KPS was the lone significant predictor for OS (p = 0.029).

CONCLUSIONS

Our single-institutional experience on patients with MPM suggests that SBRT is safe with a low toxicity profile and potentially achieve good local control.

Standard-of-care systemic therapy with or without stereotactic body radiotherapy in patients with oligoprogressive breast cancer or non-small-cell lung cancer (Consolidative Use of Radiotherapy to Block [CURB] oligoprogression): an open-label, randomised, controlled, phase 2 study

BACKGROUND

Most patients with metastatic cancer eventually develop resistance to systemic therapy, with some having limited disease progression (ie, oligoprogression). We aimed to assess whether stereotactic body radiotherapy (SBRT) targeting oligoprogressive sites could improve patient outcomes.

METHODS

We did a phase 2, open-label, randomised controlled trial of SBRT in patients with oligoprogressive metastatic breast cancer or non-small-cell lung cancer (NSCLC) after having received at least first-line systemic therapy, with oligoprogression defined as five or less progressive lesions on PET-CT or CT. Patients aged 18 years or older were enrolled from a tertiary cancer centre in New York, NY, USA, and six affiliated regional centres in the states of New York and New Jersey, with a 1:1 randomisation between standard of care (standard-of-care group) and SBRT plus standard of care (SBRT group). Randomisation was done with a computer-based algorithm with stratification by number of progressive sites of metastasis, receptor or driver genetic alteration status, primary site, and type of systemic therapy previously received. Patients and investigators were not masked to treatment allocation. The primary endpoint was progression-free survival, measured up to 12 months. We did a prespecified subgroup analysis of the primary endpoint by disease site. All analyses were done in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03808662, and is complete.

FINDINGS

From Jan 1, 2019, to July 31, 2021, 106 patients were randomly assigned to standard of care (n=51; 23 patients with breast cancer and 28 patients with NSCLC) or SBRT plus standard of care (n=55; 24 patients with breast cancer and 31 patients with NSCLC). 16 (34%) of 47 patients with breast cancer had triple-negative disease, and 51 (86%) of 59 patients with NSCLC had no actionable driver mutation. The study was closed to accrual before reaching the targeted sample size, after the primary efficacy endpoint was met during a preplanned interim analysis. The median follow-up was 11·6 months for patients in the standard-of-care group and 12·1 months for patients in the SBRT group. The median progression-free survival was 3·2 months (95% CI 2·0-4·5) for patients in the standard-of-care group versus 7·2 months (4·5-10·0) for patients in the SBRT group (hazard ratio [HR] 0·53, 95% CI 0·35-0·81; p=0·0035). The median progression-free survival was higher for patients with NSCLC in the SBRT group than for those with NSCLC in the standard-of-care group (10·0 months [7·2-not reached] vs 2·2 months [95% CI 2·0-4·5]; HR 0·41, 95% CI 0·22-0·75; p=0·0039), but no difference was found for patients with breast cancer (4·4 months [2·5-8·7] vs 4·2 months [1·8-5·5]; 0·78, 0·43-1·43; p=0·43). Grade 2 or worse adverse events occurred in 21 (41%) patients in the standard-of-care group and 34 (62%) patients in the SBRT group. Nine (16%) patients in the SBRT group had grade 2 or worse toxicities related to SBRT, including gastrointestinal reflux disease, pain exacerbation, radiation pneumonitis, brachial plexopathy, and low blood counts.

INTERPRETATION

The trial showed that progression-free survival was increased in the SBRT plus standard-of-care group compared with standard of care only. Oligoprogression in patients with metastatic NSCLC could be effectively treated with SBRT plus standard of care, leading to more than a four-times increase in progression-free survival compared with standard of care only. By contrast, no benefit was observed in patients with oligoprogressive breast cancer. Further studies to validate these findings and understand the differential benefits are warranted.

FUNDING

National Cancer Institute.

Clinical and Dosimetric Risk Factors Associated With Radiation-Induced Lung Toxicities After Multiple Courses of Lung Stereotactic Body Radiation Therapy

Purpose

Data are limited on radiation-induced lung toxicities (RILT) after multiple courses of lung stereotactic body radiation therapy (SBRT). We herein analyze a large cohort of patients to explore the clinical and dosimetric risk factors associated with RILT in such settings.

Methods and Materials

A single institutional database of patients treated with multiple courses of lung SBRT between January 2014 and December 2019 was analyzed. Grade 2 or higher (G2+) RILT after the last course of SBRT was the primary endpoint. Composite plans were generated with advanced algorithms including deformable registration and equivalent dose adjustment. Logistic regression analyses were performed to examine correlations between patient or treatment factors including dosimetry and G2+ RILT. Risk stratification of patients and lung constraints based on acceptable normal tissue complication probability were calculated based on risk factors identified.

Results

Among 110 eligible patients (56 female and 54 male), there were 64 synchronous (58.2%; defined as 2 courses of SBRT delivered within 30 days) and 46 metachronous (41.8%) courses of SBRT. The composite median lung V20, lung V5, and mean lung dose were 9.9% (interquartile range [IQR], 7.3%-12.4%), 32.2% (IQR, 25.5%-40.1%), and 7.0 Gy (IQR, 5.5 Gy-8.6 Gy), respectively. With a median follow-up of 21.1 months, 30 patients (27.3%) experienced G2+ RILT. Five patients (4.5%) developed G3 RILT, and 1 patient (0.9%) developed G4 RILT, and no patients developed G5 RILT. On multivariable regression analysis, female sex (odds ratio [OR], 4.35; 95% CI, 1.49%-14.3%; P = .01), synchronous SBRT (OR, 8.78; 95% CI, 2.27%-47.8%; P = .004), prior G2+ RILT (OR, 29.8; 95% CI, 2.93%-437%; P = .007) and higher composite lung V20 (OR, 1.18; 95% CI, 1.02%-1.38%; P = .030) were associated with significantly higher likelihood of G2+ RILT.

Conclusions

Our data suggest an acceptable incidence of G2+ RILT after multiple courses of lung SBRT. Female sex, synchronous SBRT, prior G2+ RILT, and higher composite lung V20 may be risk factors for G2+ RILT.

Multi-institutional analysis of aneuploidy and outcomes to chemoradiation and durvalumab in stage III non-small cell lung cancer

There is a need to identify predictive biomarkers to guide treatment strategies in stage III non-small cell lung cancer (NSCLCs). In this multi-institutional cohort of 197 patients with stage III NSCLC treated with concurrent chemoradiation (cCRT) and durvalumab consolidation, we identify that low tumor aneuploidy is independently associated with prolonged progression-free survival (HR 0.63; p=0.03) and overall survival (HR 0.50; p=0.03). Tumors with high aneuploidy had a significantly greater incidence of distant metastasis and shorter median distant-metastasis free survival (p=0.04 and p=0.048, respectively), but aneuploidy level did not associate with local-regional outcomes. Multiplexed immunofluorescence analysis in a cohort of NSCLC found increased intratumoral CD8-positive, PD-1-positive cells, double-positive PD-1 CD8 cells, and FOXP3-positive T-cell in low aneuploid tumors. Additionally, in a cohort of 101 patients treated with cCRT alone, tumor aneuploidy did not associate with disease outcomes. These data support the need for upfront treatment intensification strategies in stage III NSCLC patients with high aneuploid tumors and suggest that tumor aneuploidy is a promising predictive biomarker.

Tumor-Targeted Nonablative Radiation Promotes Solid Tumor CAR T-cell Therapy Efficacy

Infiltration of tumor by T cells is a prerequisite for successful immunotherapy of solid tumors. In this study, we investigate the influence of tumor-targeted radiation on chimeric antigen receptor (CAR) T-cell therapy tumor infiltration, accumulation, and efficacy in clinically relevant models of pleural mesothelioma and non-small cell lung cancers. We use a nonablative dose of tumor-targeted radiation prior to systemic administration of mesothelin-targeted CAR T cells to assess infiltration, proliferation, antitumor efficacy, and functional persistence of CAR T cells at primary and distant sites of tumor. A tumor-targeted, nonablative dose of radiation promotes early and high infiltration, proliferation, and functional persistence of CAR T cells. Tumor-targeted radiation promotes tumor-chemokine expression and chemokine-receptor expression in infiltrating T cells and results in a subpopulation of higher-intensity CAR-expressing T cells with high coexpression of chemokine receptors that further infiltrate distant sites of disease, enhancing CAR T-cell antitumor efficacy. Enhanced CAR T-cell efficacy is evident in models of both high-mesothelin-expressing mesothelioma and mixed-mesothelin-expressing lung cancer-two thoracic cancers for which radiotherapy is part of the standard of care. Our results strongly suggest that the use of tumor-targeted radiation prior to systemic administration of CAR T cells may substantially improve CAR T-cell therapy efficacy for solid tumors. Building on our observations, we describe a translational strategy of "sandwich" cell therapy for solid tumors that combines sequential metastatic site-targeted radiation and CAR T cells-a regional solution to overcome barriers to systemic delivery of CAR T cells.

The Impact of Co-Alterations on Outcomes after Local Therapy for Patients with KRAS-Mutant Lung Adenocarcinoma Brain Metastases

PURPOSE/OBJECTIVE(S)

Brain metastases are common in NSCLC with up to 25% of patients having brain metastases (BMs) at the time of diagnosis and 30% developing BMs during their disease course. KRAS is an oncogenic driver in approximately 25% of lung adenocarcinomas. Genomic alterations co-occurring with KRAS are associated with distinct biological landscapes which may influence prognosis. Herein, we sought to identify correlations between genomic profiles, intracranial progression free survival (iPFS), and overall survival (OS).

MATERIALS/METHODS

We retrospectively reviewed 156 patients with KRAS-mutant lung adenocarcinoma BM who underwent SRS for their BMs at MSKCC from 2010-2022. Each patient had at least one tumor sample profiled with MSK-IMPACT, a custom FDA-cleared next-generation sequencing. Mutations, copy number alterations, and fusions were filtered for driver alterations using OncoKB. Survival outcomes were calculated from date of MRI indicating metastatic brain disease.

RESULTS

Of the 156 patients, 80 patients presented with BMs at diagnosis whereas 76 developed BMs during their disease course, with a median 2 lines of therapy prior to BM diagnosis. The most common KRAS mutation was G12C (n = 64; 41%), G12V (n = 26, 17%), G12D (n = 17; 11%), and G12A (n = 11; 7%). The most frequently co-altered genes were TP53 (n = 71, 46%), STK11 (n = 51, 33%), CDKN2A (n = 27, 17%), KEAP1 (n = 17, 11%), and SMARCA4 (n = 10, 6%). The presence of a KEAP1 co-occurring alteration was associated with inferior iPFS (HR 1.95, 95% CI 1.05 - 3.59, p = 0.035) and the presence of SMARCA4 was also associated with inferior iPFS (HR 2.28, 95% CI 1.05 - 4.95, p = 0.038). The presence of an STK11 mutation was associated with worse OS (HR 1.57, 95% 1.01 - 2.43, p = 0.045). In a multi-variate clinico-genomic model, KEAP1 and STK11 co-occurring alterations remained significantly associated with iPFS. Patients with KEAP1-altered tumors had an increased incidence of intracranial regional progression. The 24-month cumulative incidence of regional progression amongst KEAP1-altered tumors was 57% (95% CI, 29%-77%) compared with 37% (95% CI, 29%-46%) among KEAP1-wildtype tumors (P = 0.041). Patients with CDKN2A-altered tumors had an increased incidence of leptomeningeal disease (LMD) as a form of intracranial progression. The 24-month cumulative incidence of LMD amongst CDKN2A-altered tumors was 11% (95% CI, 2.7%-27%) compared with 4.1% (95% CI, 1.5%-8.8%) among CDKN2A-wildtype tumors (P = 0.023).

CONCLUSION

In our cohort of molecularly profiled KRAS-mutant lung adenocarcinoma BM patients treated with SRS, we found that co-occurring KEAP1 and STK11 were significantly associated with worse iPFS. We also observed that CDKN2A co-altered tumors had an increased incidence of LMD. These findings have implications for future efforts to personalize brain metastasis management based on comprehensive genomic profiling.

Peripheral T-Cell Priming and Micrometastatic Disease Control with Metastasis-Directed Therapy: Multidimensional Immunogenomic Profiling of Oligometastatic Prostate Cancer in the EXTEND Trial

PURPOSE/OBJECTIVE(S)

Comprehensive metastasis-directed therapy (MDT) for oligometastatic prostate cancer extended progression-free survival (PFS) and time to new lesion formation in the intermittent hormone therapy (HT) basket of EXTEND. To better understand the mechanism of MDT benefit, we pooled the intermittent and continuous HT baskets of EXTEND and tested the hypothesis that adding MDT to HT would program systemic T-cells to control micrometastatic disease.

MATERIALS/METHODS

A total of 174 men were randomized to HT with or without MDT to up to 5 sites of metastases. HT was given for 6 months (intermittent basket, n = 87) or indefinitely (continuous basket, n = 87). Peripheral blood samples were drawn at enrollment, at the end of MDT, at 3 months follow-up (3 mo F/U), and at progression and then analyzed by flow cytometry, T-cell receptor (TCR)-β CDR3 variable region sequencing, multiplex cytokine profiling, and next-generation circulating tumor DNA (ctDNA) sequencing. TCR clonal expansion was determined using a published betabinomial model. Repertoire changes were assessed by Morisita's index, and dominant TCR repertoire motifs were characterized with ImmunoMap. Associations between blood markers and PFS were evaluated with Cox regression adjusted hazard ratios (aHR) accounting for randomization arm and stratifying for intermittent vs continuous HT.

RESULTS

Randomization to MDT+HT was associated with T-cell activation, proliferation, and clonal expansion. This response was first observed at end-MDT as upregulated expression of T-cell activation and inhibition markers (i.e., ICOS, Tim-3, and LAG-3) and increases in highly proliferative CD4+ and CD8+ Ki67hi T-cells (all P<0.05). TCR sequencing of 7,678,911 T-cells revealed that MDT+HT was associated with TCR clonal expansion, remodeling of the TCR repertoire, and changes in dominant TCR motifs at end-MDT and 3 mo F/U (all P<0.05). Observed T-cell priming could be driven by signaling networks of canonical T-cell stimulatory cytokines (IL-2, IL-12, and IL-15), which were upregulated at end-MDT and persisted at 3 mo F/U (all P<0.05). This modulation of T-cell phenotype, clonotype, and cytokine concentrations was not observed in the HT-monotherapy arm. At end-MDT, systemic T-cell responses were associated with improved PFS, most notably CD8+ T-cell expression of LAG-3 (aHR 0.22, 95% CI 0.03-0.91) and high TCR clonal expansion (aHR 0.13, 95% CI 0.02-0.52). High ctDNA burden at end-MDT correlated with worse PFS (aHR 1.41, 95% CI 1.04-2.54), as did CD8+ T-cell expression of inhibitory receptor TIGIT at 3 mo F/U (aHR 1.03, 95% CI 1.01-1.06).

CONCLUSION

The addition of MDT to HT induced systemic T-cell activation and expansion, which was not observed in the HT-only arm. This systemic immune response was independently associated with improved PFS. In addition to cytoreduction of macroscopic disease, MDT-induced immune education may be an important complementary mechanism of micrometastatic control in oligometastatic prostate cancer.

Phase II Study of Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) for Patients with Pleural Metastases from Thymic Malignancies

PURPOSE/OBJECTIVE(S)

Pleural metastases are common sites for recurrence and progression in patients with thymic malignancies. The management of pleural metastases typically involves surgical resection with or without neoadjuvant or adjuvant systemic therapy. After surgical resection of pleural metastases, the 5-year progression-free survival (PFS) rate is about 29-45%. While radiation therapy (RT) is standardly used in the management of locally-advanced thymic malignancies, the role of RT in patients with pleural metastases in unclear. Intensity-modulated pleural radiation therapy (IMPRINT) is a RT technique currently being used to treat malignant pleural mesothelioma (MPM) patients with 2 intact lungs at centers that specialize in MPM treatment. This IMPRINT technique can potentially be extrapolated to thymic patients with pleural metastases. Because the risk of toxicity is of greater concern for thymic patients given their overall relatively favorable prognosis, the rate of toxicity, particularly radiation pneumonitis, needs to be established in the thymic patient population.

MATERIALS/METHODS

This is a single-arm, single institution Phase II study of hemithoracic IMPRINT for patients with pleural metastases from thymic malignancies. The primary endpoint of this study is grade 3 or higher radiation pneumonitis within 4 months of completing RT. Secondary endpoints include any toxicity, progression-free survival, patterns of failure and overall survival. Patients must have a pathologically confirmed diagnosis of a thymic malignancy with radiologic or pathologic evidence of pleural metastases. Thymoma or thymic carcinoma are allowed. Patients may have de novo stage IVA disease or recurrent disease in the pleura. There must be no evidence of extrathoracic metastatic disease or contralateral pleural/pericardial disease. Surgical resection of the pleural nodules (ex: pleurectomy/decortication, debulking/metastasectomy) are allowed. Extrapleural pneumonectomy is not allowed. Patients are excluded if they have undergone prior thoracic radiation therapy preventing hemithoracic pleural IMRT, whereas prior thymic bed radiation and/or prior pleural SBRT are allowed. RT will be administered to the ipsilateral pleura to 50.4 Gy in 28 fractions. An optional dose-painting boost to gross disease up to 60 Gy while respecting normal tissue constraints is allowed. Patients can be treated with photon or proton therapy. Simulation, contouring and RT planning guidelines have been developed. Patients will be followed per protocol at regular intervals for at least 12 months following RT. The expected accrual is 36 patients over 4 years. Further information can be found on clinicaltrials.gov (NCT05354570).

RESULTS

To be determined.

CONCLUSION

To be determined.

Inpatient Simulation Resource Utilization for Inpatient Radiation Oncology Consults

PURPOSE/OBJECTIVE(S)

Previous data have shown that inpatient radiation oncology consult services result in high-value care, with decreased length of stay, adoption and delivery of shorter fractionation schedules, and lower hospital costs. As such, institutions are increasingly creating inpatient radiation oncology services, although little is known about the allocation of limited resources for patients who may have limited prognosis, complex simulation requirements, and may have difficulty tolerating treatment. Thus, we sought to examine the utilization of simulation appointments for inpatient emergencies.

MATERIALS/METHODS

At our institution, inpatient consults are placed to a specialized inpatient palliative radiation oncology service, consisting of radiation oncologists specialized in metastatic and palliative RT, dedicated advanced practitioners, and nurses who specifically assess patients for medical appropriateness prior to simulation, including changes in disposition, medical stability, and adequate premedication. Electronic health record data was used to explore utilization trends of a single-institution inpatient radiation oncology consult service in 2020. Data regarding the nature and timing of consults, subsequent simulations and treatments, and patient outcomes including 14-day mortality and 30-day mortality from radiation (RT) start were assessed. Descriptive statistics are presented.

RESULTS

From 1/1/2020-12/31/2020, 1557 consults were placed. These consults led to 220 (14.1%) inpatient simulations. Of these planned simulations, 210 (95.5%) simulations occurred (of which 10 [4.8%] were rescheduled and eventually completed) and 179 (85.2%) completed treatment. Of 169 with mortality data available, 16 (9.5%) died within 14 days of RT start, and 41 (24.5%) died within 30 days of RT start. Of those with scheduling data (N = 193), 122 were same-day simulations (63.2%), and 507 (93.8%) occurred within 7 days or fewer.

CONCLUSION

Of 1557 inpatient consultations in one year, with appropriate metastatic and palliative experience, only a minority of consultations required inpatient simulation (14.1%). With appropriate nursing assessment, over 95% were able to complete simulation, with nearly two-thirds completing simulation on the same day, and nearly all patients completing simulation within a week of consultation. Most of these patients completed treatment and survived 30 days from treatment start. Thus, with highly specialized radiation oncologist clinical judgment in conjunction with appropriate nursing assessment prior to simulation scheduling, patients booked for simulation represent high-value utilization of resources.

Clinical Sequalae of Initial Insurance Denials in a Large Academic Radiation Oncology Center

PURPOSE/OBJECTIVE(S)

The objective of this study is to investigate the clinical sequalae of initial radiation oncology insurance denials. The hypothesis is that while the majority of initial insurance case denials are ultimately overturned, there are potential clinical implications to these initial denials.

MATERIALS/METHODS

Data were extracted from an institutional registry of patient cases initially denied authorization by their insurers from January 2022 to December 2022. Chi-Square tests using statistical software were employed.

RESULTS

Two hundred six cases from November 2021 to December 2022 were identified. The majority (n = 199 [96.6%]) of insurers were commercial payers, while 7 (3.4%) were Medicare/Medicare Advantage. 161 (78.1%) patients were <65 years of age, and 45 (21.8%) 65 or older. One hundred forty-one (68.4%) cases were metastatic, 60 (29.1%) definitive, and 5 (2.4%) were recurrent. Of the 206 cases, 127 (61.6%) cases were ultimately successful in authorization of the ordered treatment without any change to the requested treatment technique or prescription dose after P2P (Peer to Peer review), second-level appeal, comparison plan submission, employer request, insurance carrier change, and/or external appeal, and 56 (27.2%) cases were authorized though with insurer-requested modification to radiation treatment technique and/or prescription dose. Of 21 cases with a requested change in prescription dose, the median decrease in biologically effective dose (BED) was 24 Gy (range: 2.3-51). Of 58 cases with requested change in RT technique, 20 (34.5%) changed from IMRT to 3D-CRT, 16 (27.6%) SBRT to 3D, 15 (25.9%) SBRT to IMRT, 6 (10.3%) SBRT to 2D, and 1 (1.7%) 3D-CRT to 2D. 19 (9.2%) cases remained unauthorized by the insurer but proceeded with treatment via departmental administrative clearance. Of 196 cases which went on to treatment, 72 (36.7%) cases were delayed for a mean of 7.8 days and median of 5 days (range: 1-49). P2P was performed by the treating radiation oncologist in 169 (82.0%) cases, of which 78 (46.1%) were successful in authorization of the ordered treatment. Of the 91 unsuccessful cases, 62 (68.1%) second-level appeals were performed, of which 39 (62.9%) were successful in overturning denied authorization. Of the 23 cases not authorized either through P2P or second-level appeal, 3 (13.0%) cases were successful in authorization of the requested treatment via employer request, external appeal through an independent review organization, or insurance carrier change.

CONCLUSION

Our institutional analysis suggests that while the majority of initial insurance case denials are ultimately overturned without any change to the requested treatment technique or prescription dose through a number of requests made by the insurer to the radiation oncologist, there are clinical implications with a significant percentage of case denials leading to treatment delays, decrease in prescription BED, and less conformal treatment technique.

Prospective, Cell-Free Circulating Tumor DNA (ctDNA) Profiling in Locally Advanced Lung Cancer Treated with Chemoradiation

PURPOSE/OBJECTIVE(S)

Liquid biopsy for cell-free circulating tumor DNA (ctDNA) allows for non-invasive, comprehensive genomic profiling. We explored the utility prospective liquid biopsy for (ctDNA) in among non-small cell lung cancer (NSCLC) patients treated with definitive chemoradiation.

MATERIALS/METHODS

This prospective clinical cohort consists of unresectable, locally advanced NSCLC patients who had liquid biopsy testing prior to initiation of cancer therapy. Liquid biopsy testing was performed using a next-generation sequencing assay (MSK-ACCESS) which includes 129 genes and paired white blood cell sequencing. An FDA-recognized database (OncoKB) was utilized to classify alterations associated with radiation resistance (including KEAP1, NFE2L2, STK11, and PIK3CA) and radiation sensitivity (including ATM, ATR, BRCA1/2, ARID1A, MLH1 and other DNA Damage Repair Pathway alterations). We evaluated progression-free survival (PFS) from the completion of chemoradiation using the Log-rank test.

RESULTS

Among 25 patients with prospective ctDNA testing prior to therapy initiation, 17 patients had stage III disease (68%), 8 patients had stage II disease (32%), 18 patients had adenocarcinoma (72%), 7 patients had squamous cell carcinoma (28%), and 23 (92%) were former or current smokers. The median radiation dose was 60 Gy in 30 fractions (range: 55 to 66 Gy in 20 to 33 fractions). 76% of patients (n = 18) had one or more alterations detected (median: 3 alterations, range: 1 - 8) including genomic markers of radiation response in 2 patients in BRCA1/2 (n = 2) and radiation resistance in 1 patient in KEAP1. The most common driver alteration detected was KRAS in 24% of the cohort (n = 6). Among patients with baseline detectable ctDNA, the median PFS was 21.3 months and was not reached among patients without baseline ctDNA detection (HR 4.54, p = 0.04).

CONCLUSION

Using an institutional assay, the presence of baseline cell-free ctDNA appeared prognostic in patients with unresectable, locally advanced NSCLC treated with definitive chemoradiation. We also detected driver alterations and potential markers of radiation resistance and response using ctDNA testing. Prospective cell-free ctDNA profiling may offer pathways to therapy personalization among patients with locally advanced unresectable lung cancer.

Addition of Metastasis-Directed Therapy to Standard of Care Systemic Therapy for Oligometastatic Breast Cancer (EXTEND): A Multicenter, Randomized Phase II Trial

PURPOSE/OBJECTIVE(S)

Prior retrospective and prospective evidence have suggested a potential survival benefit of adding metastasis-directed therapy (MDT) to standard of care systemic therapy for oligometastatic breast cancer. This has led to the increased utilization of MDT in this setting despite the lack of randomized evidence to support this approach. Furthermore, the recent presentation of NRG-BR002 has questioned the value of MDT. Thus, we evaluated whether the addition of MDT to systemic therapy improves PFS in oligometastatic breast cancer.

MATERIALS/METHODS

EXTEND (NCT03599765) is a phase II randomized basket trial for multiple solid tumors testing whether the addition of MDT improves PFS. The primary endpoint was pre-specified to be independently assessed and reported for the breast basket when a minimum of 6 months of follow-up had been reached. Patients with ≤5 metastases were randomized to standard of care systemic therapy with or without MDT. The choice of systemic therapy was at the discretion of the treating medical oncologist. Number of metastatic lesions and prior lines of systemic therapy for metastatic disease were used as stratification variables pre-randomization. The primary endpoint was progression-free survival (PFS) defined as time to randomization to date of clinical or radiographic progression or death. The study was designed to have 80% power to detect an improvement in median PFS from 18 to 36 months, with a type I error of 0.1.

RESULTS

Between September 2018 to July 2022, 43 patients were randomized. 22 patients were assigned to the MDT arm, and 21 patients to the no MDT arm. Three patients were not evaluable. The MDT arm patients were older vs the no-MDT arm patients (median 61.5 years vs 48 years, p = 0.01). Otherwise, the arms were well-balanced. Overall, 8 patients had triple negative disease (18.6%), and 12 patients (30%) had de novo metastatic disease. Of those patients with de novo presentation randomized to MDT, all except one had the primary tumor treated with surgery and radiation. At a median follow-up of 19.4 months, 20 events were observed. Among the 40 evaluable patients, there were 5 deaths (3 in the MDT arm and 2 in the no MDT arm). There was no difference in PFS between the MDT and no MDT arms (median 15.6 v 24.9 months, p = 0.66). Similarly, there was no difference in the secondary endpoint of time to new metastatic lesion appearance between the MDT and no MDT arms (median 15.6 months vs not reached, p = 0.09). Two grade 3 toxicities were observed in the MDT arm, and 1 in the no MDT arm. Further analysis of correlative translational biomarkers, including immune markers and ctDNA, are ongoing.

CONCLUSION

The addition of MDT to standard of care systemic therapy did not improve PFS or time to new metastatic lesion in patients with oligometastatic breast cancer. This data coupled with the recently presented NRG-BR002 results, suggests there is no benefit to MDT in an otherwise unselected oligometastatic breast cancer population.

Harnessing Electronic Patient-Reported Outcomes (ePRO) in Routine Care to Promote Clinical Trial Enrollment: A Randomized Study

PURPOSE/OBJECTIVE(S)

Only approximately 5% of adult cancer patients participate in clinical trials. While collection of patient-reported outcomes (PRO) is now routine in clinical trials, their role in actively improving care is evolving, particularly in radiation oncology. At our single multi-site institution, weekly electronic patient reported outcomes (ePRO) questionnaires regarding acute toxicity are routinely sent to all patients undergoing breast radiation We hypothesized that using ePROs to prompt recruitment to a clinical trial assessing a supportive intervention would increase enrollment.

MATERIALS/METHODS

An automated weekly query of ePRO survey responses was generated to identify patients with moderate or greater fatigue, the primary eligibility criterion for an ongoing randomized clinical trial testing an integrative medicine intervention. 23 radiation oncologists treating breast cancer were randomized to have their patients potentially eligible by ePRO receive a direct portal message about the trial, or to usual care (physician-based referral). Physician randomization was stratified by patient caseload and assigned in a 1:1 ratio. Secondarily, every other patient in the portal message group was assigned to receive the message either from their radiation oncologist or integrative medicine. Statistical analysis included two-sample, two-sided proportion tests.

RESULTS

From September 5, 2022, to December 19, 2022, among 776 patients completing ePROs during radiation treatment, 252 patients (32%) screened positive for fatigue. Of those who screened positive, 135 were randomized to the ePRO-prompted portal message group and 117 to the usual care group (physician-based referral). Among patients in the portal message group, 52 responded (39%) and 27 enrolled (20%), compared to 1 patient referred (0.8%) and 0 enrolled with physician-based referral alone (p < 0.001). In the portal message group, there were 21 responses (30%) and 12 enrollments (17%) among those messaged by their radiation oncologist, compared to 31 responses (48%) and 15 enrollments (23%) among those messaged by integrative medicine. When evaluating the source of the portal message, there was a significant difference in response rate favoring integrative medicine (p = 0.03), but no difference in enrollments (p = 0.39).

CONCLUSION

Utilization of ePROs to prompt recruitment to a trial testing a symptom intervention resulted in increased enrollment compared to standard physician-based referral, suggesting a promising new role for ePROs. Importantly, messaging from the supportive care service directly did not result in a difference in enrollments and may help reduce oncology physician-level barriers to studies testing supportive interventions. Future directions should investigate this method to reduce disparities in patients enrolling on clinical trials and facilitate access to symptom support services in routine cancer care.

Stereotactic body radiation therapy for sarcoma pulmonary metastases

BACKGROUND/PURPOSE

Stereotactic body radiation therapy (SBRT) is standard for patients with inoperable early-stage NSCLC. We hypothesized that SBRT for sarcoma pulmonary metastases would achieve high rates of local control with acceptable toxicity and that patients with oligometastatic disease may achieve prolonged survival following SBRT.

MATERIALS/METHODS

This retrospective review included consecutive patients at our institution treated with SBRT for sarcoma pulmonary metastases. Cumulative incidence of local failure (LF) was estimated using a competing risks framework.

RESULTS

We identified 66 patients treated to 95 pulmonary metastases with SBRT. The median follow-up from the time of SBRT was 36 months (95% CI 34 - 53 months). The cumulative incidence of LF at 12 and 24 months was 3.1% (95% CI 0.9 - 10.6%) and 7.4% (95% CI 4.0% - 13.9%), respectively. The 12- and 24-month overall survival was 74% (95% CI 64 - 86%) and 49% (38 - 63%), respectively. Oligometastatic disease, intrathoracic only disease, and performance status were associated with improved survival on univariable analysis. Three patients had grade 2 pneumonitis, and one patient had grade 2 esophagitis. No patients had ≥ grade 3+ toxicities.

CONCLUSION

To the best of our knowledge, this is the largest series of patients treated with SBRT for pulmonary sarcoma metastases. We observed that SBRT offers an effective alternative to surgical resection with excellent local control and low proportions of toxicity.

AI Serial Image Prediction of Progression-Free Survival (PFS) for Locally Advanced Non-Small Cell Lung Cancer (LA-NSCLC) Patients Treated with Chemoradiation (CRT) and Durvalumab Consolidation

PURPOSE/OBJECTIVE(S)

Patient outcomes with definitive CRT for LA-NSCLC remain poor, with no imaging biomarkers to predict benefit. Hence, we developed a serial image AI model using paired planning CT (pCT) and first week cone-beam CT (CBCT) to predict PFS and measured AI model fairness defined as the bias in the classification with respect to gender as a protected attribute.

MATERIALS/METHODS

Sixty-four consecutive patients with LA-NSCLC treated with concurrent CRT to 60 Gy in 30 fractions and durvalumab consolidation were analyzed. Three prediction models were created. A previously developed AI image foundation model [1] was pre-trained with unlabeled 6,402 3D CT scans sourced from institutional and the Cancer Imaging Archive and modified to predict PFS as a binarized outcome (high PFS > 6 months and low PFS < 6 months) using pCT scans. Serial image AI model was created by adding the first week CBCT scan. The third model measured tumor growth rate (TGR) as relative change in tumor and nodal volume from pCT to CBCT derived using a different published AI model [2]. Association with PFS using univariable and multivariable Cox regression after adjusting for age, gender, planning tumor volume, and smoking status were measured using TGR and the two AI model predictions using a cutoff of > 50% probability for low PFS. AI model fairness metrics area under receiver operating curve (AUROC), precision, sensitivity, and specificity were computed.

RESULTS

TGR was not associated with PFS on univariate (Hazard ratio [HR] of 1.515, 95% confidence interval [CI] of 0.32 to 7.26, p = 0.60) or multivariate analysis (HR: 1.58, 95% CI: 0.32 to 7.80, p = 0.58) and resulted in a Harrell's C-index of 54.7%. The serial image AI model prediction was associated with PFS in both univariable (HR: 2.12, 95% CI: 1.02 to 4.40, p = 0.045) and multivariable analysis (HR 2.39, 95% CI of 1.09 to 5.25, p = 0.029), and a C-index of 62.5%. The pCT AI model was associated with PFS in univariate (HR 2.06, 95% CI of 1.06 to 4.01, p = 0.034) but not in multivariable analysis (HR 1.89, 95% CI of 0.93 to 3.87, p = 0.08), and a C-index of 59.9%. The serial image AI model reduced the parity in classification compared to pCT AI model indicating higher fairness (Table I).

CONCLUSION

The multi-image AI model predicted PFS with slightly higher accuracy and resulted in higher fairness than the pCT AI model. These results underscore the potential for incorporating multi-imaging biomarkers to predict treatment response.

A Novel FDG PET and Mean Lung Dose Model to Identify Stage III NSCLC Patients at High Risk of Developing Early Radiation Pneumonitis

PURPOSE/OBJECTIVE(S)

Early radiation pneumonitis (RPEarly) is a primary reason for the premature discontinuation of durvalumab consolidation and can lead to poor survival in patients with stage III non-small cell lung cancer (NSCLC). Currently, there are no RP risk models specifically tested for RPEarly. Here, we tested the applicability of published RP models for predicting RPEarly and explored the value of integrating pretreatment FDG-PET parameters.

MATERIALS/METHODS

The cohort consisted of all 178 LA-NSCLC patients treated with concurrent chemoradiation (cCRT) and durvalumab between May 2017 and December 2021. RPEarly was defined as RP occurring within three months of cCRT completion; late RP (RPLate) was defined as any later occurring RP. The three published RP models analyzed included: 1) Mean lung dose (MLD), 2) MLD, age, pulmonary comorbidity, smoking status, and tumor location, and 3) MLD, age and pulmonary comorbidity. In addition, pretreatment FDG PET-CT scans were used to calculate SUV parameters from auto-segmented normal lung contours: 10th- and 90th percentile (SUVP10, SUVP90), maximum, mean (SUVmean), minimum, and standard deviation. The RP models were fit to RPEarly, RPLate, and RPEarly+Late in the 178 patients. To assess the association between FDG PET parameters and RP unbiasedly, the cohort was then randomly split, but enforcing similar RP rates, into a two-thirds derivation and a one-third validation subset. Model performance was assessed by AUC, p-values and the Hosmer-Lemeshow test (pHL; ideally ∼0.50).

RESULTS

The rates of RPEarly, RPLate, and RPEarly+Late were 12%, 11%, and 23%, respectively (corresponding to 21, 20, and 41 events). Only the MLD model significantly predicted RPEarly (AUC = 0.70; p = 0.04; pHL = 0.84); none of the three models predicted RPLate or RPEarly+Late. Among the FDG PET parameters, SUVP10, SUVP90 and SUVmean predicted RPEarly with similar performance (AUC = 0.69-0.73; p = 0.005-0.01; pHL = 0.68-0.72), and, therefore, bivariate models were built between MLD and each of SUVP10, SUVP90 and SUVmean. Only the MLD + SUVP90 model generalized in the validation subset (AUC = 0.63; p = 0.03; pHL = 0.89) and was thus deemed the final model for RPEarly. A final re-fitting of all model coefficients to the whole cohort indicated improvement over using the published MLD alone model (AUC = 0.75 vs. 0.70; p-value = 0.0006 vs. 0.04; pHL = 0.67 vs. 0.84). Risk of RPEarly is thus estimated as: RPEarly = 1/(1 = e-x); x = -5.79 + (1.57*MLD) + (0.14* SUVP90).

CONCLUSION

Patients at risk for RPEarly can be accurately identified prior to treatment by combining a re-fitted version of the published Mean Lung Dose model and pre-treatment FDG PET SUVP90 of the normal lung. This refined model can be used to identify patients with an exacerbated risk for premature durvalumab discontinuation due to RPEarly and could allow for interventions and/or the generation of "RPEarly sparing" treatment plans to improve overall treatment outcomes.

Disparities in Stage at Presentation among Hispanic and Latinx Patients with Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Hispanic and Latinx people in the United States comprise 19% of the population and are the fastest-growing ethnic group. However, prior studies in non-small cell lung cancer (NSCLC) often analyze these diverse communities in aggregate. We aimed to identify differences in NSCLC stage at diagnosis in the US population, with a particular focus on disaggregated Hispanic populations.

MATERIALS/METHODS

Data from the National Cancer Database (NCDB) from 2004 to 2018 were used to identify patients with primary NSCLC. Individuals were disaggregated by racial and ethnic subgroup and Hispanic country of origin. Ordinal logistic regression adjusting for age, facility type, income, educational attainment, comorbidity index, insurance, and year of diagnosis was used to create adjusted odds ratios (aORs), with higher odds representing diagnosis at later-stage NSCLC.

RESULTS

Out of 1,773,177 patients with NSCLC, 50,512 were Hispanic/Latinx (2.8%). Hispanic patients were less likely to be insured (χ2 P<0.001) and were more likely to live in lower-income ZIP codes (χ2 P<0.001). Hispanic patients were more likely to be diagnosed with metastatic disease compared to non-Hispanic White (NHW) patients: 47% for Hispanic Black (HB), 46% Hispanic White (HW), and 44.3% of Hispanic other (HO) patients vs. 39.1% of NHW patients (aORs for later-stage disease with NHW as reference: HW 1.23, HB 1.26, HO 1.14, P<0.001 for all). Upon disaggregation by country of origin, 51.4% of Mexican, 41.7% of Puerto Rican, 44.6% of Cuban, 50.8% of South or Central American, 48.4% of Dominican, and 45.6% of Other Hispanic patients were diagnosed with metastatic disease, compared with 39.1% of NHW patients. Conversely, 20.2% of Mexican, 26.9% of Puerto Rican, 24.2% of Cuban, 22.5% of South or Central American, 23.7% of Dominican, and 24.5% of Other Hispanic patients were diagnosed with stage I disease, compared with 30.0% of NHW patients. On multivariable analysis, all Hispanic groups were more likely to present with later-stage NSCLC than NHW patients, with the greatest odds for Mexican patients (aOR 1.45, P<0.001).

CONCLUSION

Hispanic/Latinx patients with non-small cell lung cancer were more likely to be diagnosed with more advanced disease compared with non-Hispanic White patients. Disparities persisted upon disaggregation by both race and country of origin, with over half of Mexican patients with metastatic disease at diagnosis. Disparities amongst Hispanic groups by race and by country of origin highlight the shortcomings of treating these groups as a monolith and underscore the need for disaggregated research and targeted interventions. Further work should explore differences in exposures, behaviors, and access to care that may underlie these disparities.