Phase 2 Trial of Consolidation Pembrolizumab After Proton Reirradiation for Thoracic Recurrences of Non-Small Cell Lung Cancer

PURPOSE

Reirradiation (reRT) with proton beam therapy (PBT) may offer a chance of cure while minimizing toxicity for patients with isolated intrathoracic recurrences of non-small cell lung cancer (NSCLC). However, distant failure remains common, necessitating strategies to integrate more effective systemic therapy.

METHODS AND MATERIALS

This was a phase 2, single-arm trial (NCT03087760) of consolidation pembrolizumab after PBT reRT for locoregional recurrences of NSCLC. Four to 12 weeks after completion of 60 to 70 Gy PBT reRT, patients without progressive disease received pembrolizumab for up to 12 months. Primary endpoint was progression-free survival (PFS), measured from the start of reRT. Secondary endpoints were overall survival (OS) and National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0 toxicity.

RESULTS

Between 2017 and 2021, 22 patients received PBT reRT. Median interval from prior radiation end to reRT start was 20 months. Most recurrences (91%) were centrally located. Most patients received concurrent chemotherapy (95%) and pencil beam scanning PBT (77%), and 36% had received prior durvalumab. Fifteen patients (68%) initiated consolidation pembrolizumab on trial and received a median of 3 cycles (range, 2-17). Pembrolizumab was discontinued most commonly due to toxicity (n = 5; 2 were pembrolizumab-related), disease progression (n = 4), and completion of 1 year (n = 3). Median follow-up was 38.7 months. Median PFS and OS were 8.8 months (95% CI, 4.2-23.7) and 22.8 months (95% CI, 6.9-not reached), respectively. There was only one isolated in-field failure after reRT. Grade ≥3 toxicities occurred in 10 patients (45%); 2 were pembrolizumab-related. There were 2 grade 5 toxicities, an aorto-esophageal fistula at 6.9 months and hemoptysis at 46.8 months, both probably from reRT. The trial closed early due to widespread adoption of immunotherapy off-protocol.

CONCLUSIONS

In the first-ever prospective trial combining PBT reRT with consolidation immunotherapy, PFS was acceptable and OS favorable. Late grade 5 toxicity occurred in 2 of 22 patients. This approach may be considered in selected patients with isolated thoracic recurrences of NSCLC.

Differences in Radiotherapy-Treated Members with Cancer during COVID-19 Pandemic Using Nationwide Claim Data

PURPOSE/OBJECTIVE(S)

This study aimed to identify the impact of the pandemic on radiotherapy activity among members with cancer.

MATERIALS/METHODS

This retrospective study included fully-insured commercial members of a large national payor with cancer aged ≥18 years undergoing radiotherapy from March 1, 2018 to February 28, 2022. Radiotherapy activity was defined as the mean weekly number of treatment courses and attendances (fractions) per month pre-COVID (March 2018 to February 2020); during COVID (March 2020 to February 2021); and post-COVID (March 2021 to February 2022). T-tests assessed differences between pre-COVID and post-COVID on radiotherapy activity by age, gender, and cancer type. Interrupted time series analysis (ITS) assessed change in activity overtime, controlling for pre-COVID trends and other potential confounders. A p-value of <0.05 was considered significant.

RESULTS

The study included 9,275 members, 10,121 courses, and 169,257 fractions; most members were female (57%), the mean age was 57 years (SD = 12). Overall, there was a decline in mean weekly number of courses from the pre-COVID to post-COVID (-18%, p<0.05) timeframe. Females < 70 years experienced the largest decline in mean weekly number of courses (-23%, p<0.05) followed by males aged 70+ (-16%, p<0.05) and males < 70 years (-16%, p<0.05). All cancer types saw a significant decline (p<0.05); breast cancer reported the largest decline (-21%, p<0.05). Fraction numbers significantly declined overall by 27% (p<0.05) from the pre-COVID to post-COVID timeframe. The largest decline in fraction numbers was observed in females < 70 (-28%, p<0.05) followed by males < 70 years (-24%, p<0.05) and males aged 70+ (-22%, p<0.05). No difference between COVID and pre-COVID weeks for courses was observed once pre-COVID trends were accounted for using ITS. Females aged 70+ received 25% (p<0.05) fewer fractions during COVID compared to pre-COVID; a decline which continued to grow even as the pandemic eased (March 2021 to February 2022). Males aged 70+ also experienced a decreased level of fractions during the pandemic (-30%, p<0.05), but increased in the recovery period (+24%, p<0.05). Males < 70 years had an increased level of fractions during the pandemic (+14%, p<0.05).

CONCLUSION

Radiation mean weekly number of courses and fractions between pre-COVID and post-COVID declined with the effect more pronounced in females < 70 years. A decrease in fraction number was observed in all cancer types; specifically, breast cancer had the largest decline. ITS analysis revealed no difference between COVID and pre-COVID weeks for courses as the downward trend was already present prior to the pandemic. These findings suggest while radiotherapy courses and fractions were significantly impacted, fractionation was decreased to a greater extent, indicating an increased adoption of hypofractionation during the pandemic.

Utilization and factors precluding receipt of checkpoint inhibitor consolidation for stage III NSCLC in a large U.S. academic health system

OBJECTIVES

We sought to determine the proportion of patients with stage III non-small cell lung cancer (NSCLC) who initiate consolidation durvalumab or other immune checkpoint inhibitors (ICIs) after concurrent chemoradiotherapy (cCRT), as well as reasons for nonreceipt and prognostic implications.

MATERIALS AND METHODS

We retrospectively identified consecutive patients with unresectable stage III NSCLC treated with definitive cCRT between October 2017 and December 2021 within a large US academic health system. Patients either received consolidation ICIs (ICI group) or did not (no-ICI group). Baseline characteristics and overall survival (OS) of the groups were assessed. Factors predictive of ICI nonreceipt were evaluated using logistic regression.

RESULTS

Of 333 patients who completed cCRT, 229 (69%) initiated consolidation ICIs; 104 (31%) did not. Reasons for ICI nonreceipt included progressive disease post-cCRT (N = 31, 9%), comorbidity or intercurrent illness (N = 25, 8%), cCRT toxicity (N = 23, 7%; 19/23 pneumonitis), and EGFR/ALK alteration (N = 14, 4%). The no-ICI group had worse performance status and a higher rate of baseline pulmonary comorbidity. Larger planning target volume was associated with post-cCRT progressive disease, and higher lung radiation dose with cCRT toxicity. Median OS was 16 months in the no-ICI group and 34.4 months in the ICI group. In the no-ICI group, OS was superior among those with EGFR/ALK alterations (median 44.5 months) and worst among those with progressive disease (median 5.9 months, P < 0.001).

CONCLUSION

31% of patients who completed cCRT for stage III NSCLC did not receive consolidation ICIs. Survival amongst these patients is poor, especially for those with progressive disease post-cCRT.

Death without progression as an endpoint to describe cardiac radiation effects in locally advanced non-small cell lung cancer

Background and purpose

Prior studies have examined associations of cardiovascular substructure dose with overall survival (OS) or cardiac events after chemoradiotherapy (CRT) for non-small cell lung cancer (NSCLC). Herein, we investigate an alternative endpoint, death without cancer progression (DWP), which is potentially more specific than OS and more sensitive than cardiac events for understanding CRT toxicity.

Materials and methods

We retrospectively reviewed records of 187 patients with locally advanced or oligometastatic NSCLC treated with definitive CRT from 2008 to 2016 at a single institution. Dosimetric parameters to the heart, lung, and ten cardiovascular substructures were extracted. Charlson Comorbidity Index (CCI), excluding NSCLC diagnosis, was used to stratify patients into CCI low (0-2; n = 66), CCI intermediate (3-4; n = 78), and CCI high (≥5; n = 43) groups. Primary endpoint was DWP, modeled with competing risk regression. Secondary endpoints included OS. An external cohort consisted of 140 patients from another institution.

Results

Median follow-up was 7.3 years for survivors. Death occurred in 143 patients (76.5 %), including death after progression in 118 (63.1 %) and DWP in 25 (13.4 %). On multivariable analysis, increasing CCI stratum and mean heart dose were associated with DWP. For mean heart dose ≥ 10 Gy vs < 10 Gy, DWP was higher (5-year rate, 16.9 % vs 6.7 %, p = 0.04) and OS worse (median, 22.9 vs 34.1 months, p < 0.001). Ventricle (left, right, and bilateral) and pericardial but not atrial substructure dose were associated with DWP, whereas all three were inversely associated with OS. Cutpoint analysis identified right ventricle mean dose ≥ 5.5 Gy as a predictor of DWP. In the external cohort, we confirmed an association of ventricle, but not atrial, dose with DWP.

Conclusion

Cardiovascular substructure dose showed distinct associations with DWP. Future cardiotoxicity studies in NSCLC could consider DWP as an endpoint.

Combining natural and artificial intelligence for robust automatic anatomy segmentation: Application in neck and thorax auto-contouring

BACKGROUND

Automatic segmentation of 3D objects in computed tomography (CT) is challenging. Current methods, based mainly on artificial intelligence (AI) and end-to-end deep learning (DL) networks, are weak in garnering high-level anatomic information, which leads to compromised efficiency and robustness. This can be overcome by incorporating natural intelligence (NI) into AI methods via computational models of human anatomic knowledge.

PURPOSE

We formulate a hybrid intelligence (HI) approach that integrates the complementary strengths of NI and AI for organ segmentation in CT images and illustrate performance in the application of radiation therapy (RT) planning via multisite clinical evaluation.

METHODS

The system employs five modules: (i) body region recognition, which automatically trims a given image to a precisely defined target body region; (ii) NI-based automatic anatomy recognition object recognition (AAR-R), which performs object recognition in the trimmed image without DL and outputs a localized fuzzy model for each object; (iii) DL-based recognition (DL-R), which refines the coarse recognition results of AAR-R and outputs a stack of 2D bounding boxes (BBs) for each object; (iv) model morphing (MM), which deforms the AAR-R fuzzy model of each object guided by the BBs output by DL-R; and (v) DL-based delineation (DL-D), which employs the object containment information provided by MM to delineate each object. NI from (ii), AI from (i), (iii), and (v), and their combination from (iv) facilitate the HI system.

RESULTS

The HI system was tested on 26 organs in neck and thorax body regions on CT images obtained prospectively from 464 patients in a study involving four RT centers. Data sets from one separate independent institution involving 125 patients were employed in training/model building for each of the two body regions, whereas 104 and 110 data sets from the 4 RT centers were utilized for testing on neck and thorax, respectively. In the testing data sets, 83% of the images had limitations such as streak artifacts, poor contrast, shape distortion, pathology, or implants. The contours output by the HI system were compared to contours drawn in clinical practice at the four RT centers by utilizing an independently established ground-truth set of contours as reference. Three sets of measures were employed: accuracy via Dice coefficient (DC) and Hausdorff boundary distance (HD), subjective clinical acceptability via a blinded reader study, and efficiency by measuring human time saved in contouring by the HI system. Overall, the HI system achieved a mean DC of 0.78 and 0.87 and a mean HD of 2.22 and 4.53 mm for neck and thorax, respectively. It significantly outperformed clinical contouring in accuracy and saved overall 70% of human time over clinical contouring time, whereas acceptability scores varied significantly from site to site for both auto-contours and clinically drawn contours.

CONCLUSIONS

The HI system is observed to behave like an expert human in robustness in the contouring task but vastly more efficiently. It seems to use NI help where image information alone will not suffice to decide, first for the correct localization of the object and then for the precise delineation of the boundary.

Checkpoint inhibitor consolidation after definitive chemoradiation for stage III non–small cell lung cancer: Real-world experience in a large academic health system

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Background: The PACIFIC trial demonstrated a 10% improvement in 5-year survival with the addition of consolidation durvalumab versus placebo after chemoradiation (CRT) in good performance status patients (pts) with stage III non-small cell lung cancer (NSCLC). However, not all patients who complete CRT go on to receive consolidation durvalumab. We sought to describe real-world use of consolidation durvalumab or other immune checkpoint inhibitors (ICI) in this setting within a single academic health system. Methods: We retrospectively identified pts with unresectable stage III NSCLC treated with definitive CRT between October 2017 and October 2020 within the University of Pennsylvania Health System, including two urban hospitals and two satellite centers. Pts either received consolidation ICI (ICI group) or did not (no ICI group). Baseline characteristics of the groups were compared with the Chi-squared, Fisher exact, or Wilcoxon rank-sum test as appropriate. Overall survival (OS), measured from the last day of CRT, was compared using the Kaplan-Meier method and log-rank test. Results: Of the 148 consecutively treated pts who completed CRT, 108 (73%) received consolidation ICI; 40 (27%) did not. Within the ICI group, 42% completed 1 year (yr) of treatment. Within the no ICI group, reasons for non-receipt included disease progression (n = 14, 35%), CRT toxicity (n = 7, 18%), comorbidity or decline unrelated to CRT (n = 7, 18%), provider choice (n = 6, 15%) due to EGFR mutation (n = 5) or atypical histology (n = 1), pt refusal (n = 3, 8%), and death without progression (n = 3, 8%). The ICI group had better performance status (ECOG 0/1/2, 46%/49%/5% ICI vs 25%/48%/28% no ICI, p < 0.001) lower Charlson Comorbidity Index (median, 5 [IQR 4-6] ICI vs 6 [IQR 5-8] no ICI, p = 0.02), and lower rates of active autoimmune disease or immunosuppression (5% ICI vs 15% no ICI, p = 0.03). There were no differences between groups in age (median, 68 yrs [IQR 63-73] ICI vs 71 yrs [IQR 65-73] no ICI, p = 0.25), sex (female, 60% ICI vs 50% no ICI, p = 0.27), race (Black, 19% ICI vs 20% no ICI, p = 0.82), stage (IIIA/B/C, 42%/48%/11% ICI vs 40%/50%/10% no ICI, p = 0.96), and PD-L1 expression ( < 1%/1-50%/ > 50%/unknown, 36%/25%/29%/10% ICI vs 40%/25%/28%/8% no ICI, p = 0.97). 1- and 2-yr OS were 83% and 61% in the ICI group versus 52% and 34% in the no ICI group, respectively (p < 0.001). Within the no ICI group, OS was worse among those with versus those without disease progression (PD) post-CRT (1-yr OS 24% vs 74%, p = 0.03). Conclusions: In this retrospective study within a large academic health system, we found that over one-quarter of pts who completed chemoradiation for stage III NSCLC did not receive consolidation ICI, most commonly due to disease progression, CRT toxicity, or comorbidity. Survival amongst these pts is particularly poor, especially for those who experience PD shortly after CRT.

Activity Monitoring for Toxicity Detection and Management in Patients Undergoing Chemoradiation for Gastrointestinal Malignancies

PURPOSE

Physical activity is associated with decreased hospitalization during cancer treatment. We hypothesize that activity data can help identify and triage high-risk patients with GI cancer undergoing concurrent chemoradiation.

MATERIALS AND METHODS

This prospective study randomly assigned patients to activity monitoring versus observation. In the intervention arm, a 20% decrease in daily steps or 20% increase in heart rate triggered triage visits to provide supportive care, medication changes, and escalation of care. In the observation group, activity data were recorded but not monitored. The primary objective was to show a 20% increase in triage visits in the intervention group. Secondary objectives were estimating the rates of emergency department (ED) visits and hospitalizations. Crude and adjusted odds ratios were computed using logistic regression modeling.

RESULTS

There were 22 patients in the intervention and 18 in the observation group. Baseline patient and treatment characteristics were similar. The primary objective was met, with 3.4 more triage visits in the intervention group than in the observation group (95% CI, 2.10 to 5.50; P < .0001). Twenty-six (65.0%) patients required at least one triage visit, with a higher rate in the intervention arm compared with that in the observation arm (86.4% v 38.9%; odds ratio, 9.95; 95% CI, 2.13 to 46.56; P = .004). There was no statistically significant difference in ED visit (9.1% v 22.2%; P = .38) or hospitalization (4.5% v 16.7%; P = .31).

CONCLUSION

It is feasible to use activity data to trigger triage visits for symptom management. Further studies are investigating whether automated activity monitoring can assist with early outpatient management to decrease ED visits and hospitalizations.

Impact of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic

Background

To ensure safe delivery of oncologic care during the COVID-19 pandemic, telemedicine has been rapidly adopted. However, little data exist on the impact of telemedicine on quality and accessibility of oncologic care. This study assessed whether conducting an office visit for thoracic oncology patients via telemedicine affected time to treatment initiation and accessibility.

Methods

This was a retrospective cohort study of patients with thoracic malignancies seen by a multidisciplinary team during the first surge of COVID-19 cases in Philadelphia (March 1 to June 30, 2020). Patients with an index visit for a new phase of care, defined as a new diagnosis, local recurrence, or newly discovered metastatic disease, were included.

Results

240 distinct patients with thoracic malignancies were seen: 132 patients (55.0%) were seen initially in-person vs 108 (45.0%) via telemedicine. The majority of visits were for a diagnosis of a new thoracic cancer (87.5%). Among newly diagnosed patients referred to the thoracic oncology team, the median time from referral to initial visit was significantly shorter amongst the patients seen via telemedicine vs. in-person (median 5.0 vs. 6.5 days, p < 0.001). Patients received surgery (32.5%), radiation (24.2%), or systemic therapy (30.4%). Time from initial visit to treatment initiation by modality did not differ by telemedicine vs in-person: surgery (22 vs 16 days, p = 0.47), radiation (27.5 vs 27.5 days, p = 0.86, systemic therapy (15 vs 13 days, p = 0.45).

Conclusions

Rapid adoption of telemedicine allowed timely delivery of oncologic care during the initial surge of the COVID19 pandemic by a thoracic oncology multi-disciplinary clinic.

Incorporation of plasma-based next-generation sequencing to improve guideline-concordant molecular testing in patients with newly diagnosed metastatic nonsquamous non-small cell lung cancer

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Background: Current NCCN guidelines recommend comprehensive molecular profiling for all newly diagnosed patients with metastatic non-squamous NSCLC to enable the delivery of personalized medicine. We have previously demonstrated that incorporation of plasma based next-generation gene sequencing (NGS) improves detection of clinically actionable mutations in patients with advanced NSCLC (Aggarwal et al, JAMA Oncology, 2018). To increase rates of comprehensive molecular testing at our institution, we adapted our clinical practice to include concurrent use of plasma (P) and tissue (T) based NGS upon initial diagnosis. P NGS testing was performed using a commercial 74 gene assay. We analyzed the impact of this practice change on guideline concordant molecular testing at our institution. Methods: A retrospective cohort study of patients with newly diagnosed metastatic non-squamous NSCLC following the implementation of this practice change in 12/2018 was performed. Tiers of NCCN guideline concordant testing were defined, Tier 1: complete EGFR, ALK, BRAF, ROS1, MET, RET, NTRK testing, Tier 2: included above, but with incomplete NTRK testing, Tier 3: > 2 genes tested, Tier 4: single gene testing, Tier 5: no testing. Proportion of patients with comprehensive molecular testing by modality (T NGS vs. T+P NGS) were compared using one-sided Fisher’s exact test. Results: Between 01/2019, and 12/2019, 170 patients with newly diagnosed metastatic non-Sq NSCLC were treated at our institution. Overall, 98.2% (167/170) patients underwent molecular testing, Tier 1: n = 100 (59%), Tier 2: n = 39 (23%), Tier 3/4: n = 28 (16.5%), Tier 5: n = 3 (2%). Amongst these patients, 43.1% (72/167) were tested with T NGS alone, 8% (15/167) with P NGS alone, and 47.9% (80/167) with T+P NGS. A higher proportion of patients underwent comprehensive molecular testing (Tiers 1+2) using T+P NGS: 95.7% (79/80) compared to T alone: 62.5% (45/72), p < 0.0005. Prior to the initiation of first line treatment, 72.4% (123/170) patients underwent molecular testing, Tier 1: n = 73 (59%), Tier 2: n = 27 (22%) and Tier 3/4: n = 23 (18%). Amongst these, 39% (48/123) were tested with T NGS alone, 7% (9/123) with P NGS alone and 53.6% (66/123) with T+P NGS. A higher proportion of patients underwent comprehensive molecular testing (Tiers 1+2) using T+P NGS, 100% (66/66) compared to 52% (25/48) with T NGS alone (p < 0.0005). Conclusions: Incorporation of concurrent T+P NGS testing in treatment naïve metastatic non-Sq NSCLC significantly increased the proportion of patients undergoing guideline concordant molecular testing, including prior to initiation of first-line therapy at our institution. Concurrent T+P NGS should be adopted into institutional pathways and routine clinical practice.

Multiblock Discriminant Analysis of Integrative 18F-FDG-PET/CT Radiomics for Predicting Circulating Tumor Cells in Early-Stage Non-small Cell Lung Cancer Treated With Stereotactic Body Radiation Therapy

PURPOSE

The main objective of the present study was to integrate 18F-FDG-PET/CT radiomics with multiblock discriminant analysis for predicting circulating tumor cells (CTCs) in early-stage non-small cell lung cancer (ES-NSCLC) treated with stereotactic body radiation therapy (SBRT).

METHODS

Fifty-six patients with stage I NSCLC treated with SBRT underwent 18F-FDG-PET/CT imaging pre-SBRT and post-SBRT (median, 5 months; range, 3-10 months). CTCs were assessed via a telomerase-based assay before and within 3 months after SBRT and dichotomized at 5 and 1.3 CTCs/mL. Pre-SBRT, post-SBRT, and delta PET/CT radiomics features (n = 1548 × 3/1562 × 3) were extracted from gross tumor volume. Seven feature blocks were constructed including clinical parameters (n = 12). Multiblock data integration was performed using block sparse partial least squares-discriminant analysis (sPLS-DA) referred to as Data Integration Analysis for Biomarker Discovery Using Latent Components (DIABLO) for identifying key signatures by maximizing common information between different feature blocks while discriminating CTC levels. Optimal input blocks were identified using a pairwise combination method. DIABLO performance for predicting pre-SBRT and post-SBRT CTCs was evaluated using combined AUC (area under the curve, averaged across different blocks) analysis with 20 × 5-fold cross-validation (CV) and compared with that of concatenation-based sPLS-DA that consisted of combining all features into 1 block. CV prediction scores between 1 class versus the other were compared using the Wilcoxon rank sum test.

RESULTS

For predicting pre-SBRT CTCs, DIABLO achieved the best performance with combined pre-SBRT PET radiomics and clinical feature blocks, showing CV AUC of 0.875 (P = .009). For predicting post-SBRT CTCs, DIABLO achieved the best performance with combined post-SBRT CT and delta CT radiomics feature blocks, showing CV AUCs of 0.883 (P = .001). In contrast, all single-block sPLS-DA models could not attain CV AUCs higher than 0.7.

CONCLUSIONS

Multiblock integration with discriminant analysis of 18F-FDG-PET/CT radiomics has the potential for predicting pre-SBRT and post-SBRT CTCs. Radiomics and CTC analysis may complement and together help guide the subsequent management of patients with ES-NSCLC.

Phase II Trial of Flaxseed to Prevent Acute Complications After Chemoradiation for Lung Cancer

Background: Thoracic radiotherapy is complicated by acute radiation-induced adverse events such as radiation pneumonitis (RP) and radiation esophagitis (RE). Based on preclinical work and a randomized pilot trial from our laboratory, this single-arm phase II trial investigated administering flaxseed as a radioprotector in patients receiving definitive chemoradiation for nonsmall cell lung cancer (NSCLC). Methods: Between June 2015 and February 2018, 33 patients with locally advanced or metastatic NSCLC with planned definitive chemoradiation were enrolled. Finely-ground Linum usitatissimum L. (Linaceae; flaxseed or linseed) in 40-g packets were provided for daily consumption in any patient-desired formulation 1 week before radiotherapy and throughout radiotherapy as tolerated. The primary outcomes were overall adverse events, with particular focus on Grade ≥3 RP, and flaxseed tolerability. Adverse events were graded according to CTCAE v4.0. Results: Of the 33 patients enrolled, 5 patients (15%) did not receive chemoradiation, 4 (12%) withdrew promptly after enrollment, 4 (12%) did not return a flaxseed consumption log, and 1 patient had irritable bowel syndrome (3%). The remaining 19 patients (57%) had chemoradiation and flaxseed ingestion with a mean completion and standard deviation of the intended flaxseed course of 62% ± 8.3%. Nine (50%) of these 19 patients reported difficulties with flaxseed consumption, citing nausea, constipation, odynophagia, or poor taste or texture. One patient (5%), with unverifiable flaxseed consumption, developed Grade 3 RP. There were no cases of Grade 2 RP. Six patients (32%) developed Grade 2 RE, but no patients developed Grade ≥3 RE. Median overall and progression-free survival were 31 and 12 months, respectively. Conclusions: Despite the low incidence of acute radiation-induced complications reported, significant treatment-related gastrointestinal toxicities and subsequently low flaxseed tolerability inhibit accurate determination of flaxseed effect in patients receiving concurrent thoracic chemoradiation. Thus, further investigations should focus on optimizing flaxseed formulation for improved tolerability and evaluation. CTR #: NCT02475330, https://clinicaltrials.gov/ct2/show/study/NCT02475330.

Final results of a phase I “RadVax” trial of hypofractionated radiation combined with pembrolizumab in patients with metastatic solid tumors

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Background: Many patients treated with anti-PD-1 therapy do not show a clinical response. Preclinical studies suggest that adding hypofractionated radiotherapy (HFRT) to anti-PD1 can increase the efficacy of immunotherapy through several mechanisms including increased antigen presentation. We conducted a prospective trial testing the combination of pembrolizumab and HFRT in patients with metastatic solid tumors. Methods: This prospective single-institution phase I trial tested pembrolizumab in combination with HFRT in patients with metastatic cancers (NSCLC, melanoma, pancreas, breast, others) and an ECOG performance status of 0-1. Melanoma and NSCLC patients were required to have progression of disease on anti-PD1, having received ≥ 2 doses of anti-PD1 and progression documented by RECIST v1.1. Patients were required to have an index lesion ≥1 cm that was amenable to HFRT and at least one other lesion that was not irradiated and could be followed for response using RECIST criteria. Pembrolizumab 200 mg IV every 3 weeks was administered beginning 1 week prior to the first fraction of radiation. The HFRT dose was 8 Gy x 3 fractions or 17 Gy x 1 fraction, determined by randomization during the Expansion phase. The primary objective was the safety of HFRT combined with pembrolizumab, with dose-limiting toxicity (DLT) defined as Grade ≥ 3 non-hematological toxicity related to the combination of Pembrolizumab and HFRT. The secondary objective was the radiographic response of metastatic lesions outside the radiation field as measured by RECIST. Results: 59 patients aged 27-90 years (median 60) were enrolled from March 2015 to December 2018 (24 in the Safety Phase and 35 in Expansion Phase). 40 patients (67.7%) had treatment-related AEs, of which 4 were grade 3 and none were grade 4. One patient experienced hepatitis, classified as DLT. While most patients did not have a radiologic response, in patients with metastatic melanoma, 7 of 16 (43.8%, exact 95% CI 19.8-70.1%) had an objective response to HFRT + pembrolizumab, including 3 complete and 4 partial responses. Responses are durable with 3/3 complete responders alive with no progression, and 3/4 partial responders alive with 2 having no evidence of progression. Among melanoma patients, only 2 of 7 (29%) responders received ipilimumab prior to enrollment, compared to 8 of 9 (89%) non-responders (p = 0.035). An increase in Ki67+ PD-1+ non-naïve CD8 T-cells was observed in the blood 2 weeks after HFRT, but the magnitude did not correlate with likelihood of response. Responses were observed after either 17 Gy x 1 fraction or 8 Gy x 3 fractions, with no difference in response rate by fractionation. Conclusions: This study suggests that HFRT administered with concurrent pembrolizumab is associated with acceptable toxicity and that in patients with metastatic melanoma progressing on anti-PD-1 therapy, this approach yields an ORR of 44%. Clinical trial information: NCT02303990.

Abstract P17: Effect of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic

Introduction: To ensure safe delivery of oncologic care in the COVID-19 pandemic, telemedicine has been rapidly adopted. We assessed accessibility and time to treatment initiation for thoracic oncology patients seen via telemedicine or in-person during the initial phase of the COVID-19 pandemic. Methods: We conducted a retrospective cohort study of patients with thoracic malignancies seen within a multidisciplinary team at the University of Pennsylvania Health System (UPHS) during the first surge of COVID-19 cases in Philadelphia (March 1 to June 30, 2020). Patients with an index visit for a new phase of care, defined as a new diagnosis, local recurrence, or newly discovered metastatic disease were included. Patients who did not receive subsequent oncologic care within the UPHS were excluded. Dates of referral, index visit, and treatment initiation were abstracted from the electronic medical record (EMR). Patients were divided into groups based on index visit type (in-person vs. telemedicine). Comparisons of time to care between groups were evaluated using the Wilcoxon rank-sum test. Results: Between March 1 and June 30, 2020, 241 distinct thoracic oncology patients were seen for a new phase of care and managed with surgery (n=78, 32.4%), radiation (including concurrent chemoradiation) (n=59, 24.5%), or systemic therapy (n=73, 30.3%). The majority of visits were for a diagnosis of a new thoracic cancer (87.1%). 133 patients (55.2%) were seen in-person and 108 (44.8%) were seen via telemedicine. Baseline characteristics of patients seen via telemedicine vs in-person were well balanced. As expected, the proportion of telemedicine to in-person visit types changed with the local phase of the pandemic with an initial increase of telemedicine during the lockdown period and a decrease during the re-opening phase. A higher proportion of visits were conducted via telemedicine when receiving systemic therapy or radiation as compared to surgery. Among patients with new diagnoses (n=210), the median time from referral to initial visit was significantly shorter amongst the patients seen via telemedicine vs. in-person (4.5 vs. 6.0 days, p=0.006), though only 67.1% had referral dates reported in the EMR. Time-to-treatment stratified by treatment modality received did not differ by type of initial visit (median values in-person vs. telemedicine: surgery 16 vs. 22 days, p= 0.48; radiation 26.5 vs. 28 days, p=0.90; systemic therapy 13.5 vs. 14 days, p=0.49). A sensitivity analysis limited to new diagnoses only (210/241) confirmed the same results. Conclusions: Rapid adoption of telemedicine sustained timely delivery of oncologic care during the initial surge of the COVID19 pandemic across a thoracic oncology multi-disciplinary clinic. While the full impact of telemedicine on long term clinical outcomes remains to be determined, faster times from referral to initial visit in the telemedicine group provide preliminary evidence that telemedicine could sustain or improve accessibility to oncologic care, especially during current and future pandemics.

Citation Format: Vivek U. Nimgaonkar, Abigail T. Berman, Peter Gabriel, John Kucharczuk, Lawrence N. Shulman, Charu Aggarwal, Melina E. Marmarelis. Effect of telemedicine adoption on accessibility and time to treatment in patients with thoracic malignancies during the COVID-19 pandemic [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P17.

Early Changes in Physical Activity and Quality of Life With Thoracic Radiation Therapy in Breast Cancer, Lung Cancer, and Lymphoma

PURPOSE

The effects of thoracic radiation therapy (RT) on physical functioning and quality of life (QoL) are incompletely defined. We determined the associations between thoracic RT dose volume metrics, physical activity, and QoL in patients with cancer.

METHODS AND MATERIALS

Participants with breast cancer, lung cancer, or mediastinal lymphoma treated with radiation with or without chemotherapy were enrolled in a prospective, longitudinal cohort study. Data were collected pre-RT, immediately post-RT, and 5 to 9 months post-RT. At each timepoint, self-reported physical activity was assessed via the Godin-Shephard Leisure-Time Physical Activity Questionnaire, and QoL metrics were assessed via Functional Assessment of Chronic Illness Therapy Fatigue and Dyspnea Scales. Multivariable adjusted linear regression models were stratified by breast cancer alone and lung cancer and lymphoma combined.

RESULTS

One hundred thirty participants were included in the study. In breast cancer (n = 80), each 1-Gy increase in mean heart dose was associated with worse Functional Assessment of Chronic Illness Therapy Fatigue scores (-1.0; 95% confidence interval [CI], -1.9 to -0.2; P = .021); similar associations were observed between V5 and fatigue (-2.5; 95% CI, -4.4 to -0.6; P = .010 for each 10% increase in V5). In lung cancer and lymphoma (n = 50), each 10% increase in V5 was associated with decreased physical activity (Godin-Shephard Leisure-Time Physical Activity Questionnaire score -2.3; 95% CI, -4.3 to -0.4; P = .017). Although the associations between baseline levels of physical activity and fatigue and dyspnea were of borderline significance in breast cancer alone (P < .10), increased physical activity over time was associated with improvements in fatigue and dyspnea across all cancer types (P < .05 for all).

CONCLUSIONS

Higher cardiac RT dose was associated with worse fatigue and physical activity across breast cancer, lung cancer, and mediastinal lymphoma. Longitudinal increases in physical activity were associated with concurrent improvements in QoL measures. Strategies to increase physical activity and decrease cardiac RT dose may improve physical functioning and QoL for patients with cancer.

Phase 1 Trial of Pembrolizumab Administered Concurrently With Chemoradiotherapy for Locally Advanced Non-Small Cell Lung Cancer: A Nonrandomized Controlled Trial

Importance

Consolidative programmed death ligand-1 (PD-L) inhibition after chemoradiotherapy improves overall survival and progression-free survival (PFS) for stage III non-small cell lung cancer (NSCLC) and requires safety evaluation for incorporation of programmed cell death 1 (PD-1) inhibition at the onset of chemoradiotherapy.

Objective

To determine the safety and tolerability of PD-1 inhibition concurrently with definitive chemoradiotherapy for NSCLC.

Design, Setting, and Participants

This phase 1 prospective multicenter nonrandomized controlled trial using a 3 plus 3 design was performed from August 30, 2016, to October 24, 2018, with a median follow-up of 16.0 (95% CI, 12.0-22.6) months and data locked on July 25, 2019. Twenty-one participants had locally advanced, unresectable, stage III NSCLC as determined by multidisciplinary review, Eastern Cooperative Oncology Group performance status 0 or 1, and adequate hematologic, renal, and hepatic function. Data were analyzed from October 17, 2016, to July 19, 2019.

Interventions

Pembrolizumab was combined with concurrent chemoradiotherapy (weekly carboplatin and paclitaxel with 60 Gy of radiation in 2 Gy per d). Dose cohorts evaluated included full-dose pembrolizumab (200 mg intravenously every 3 weeks) 2 to 6 weeks after chemoradiotherapy (cohort 1); reduced-dose pembrolizumab (100 mg intravenously every 3 weeks) starting day 29 of chemoradiotherapy (cohort 2); full-dose pembrolizumab starting day 29 of chemoradiotherapy (cohort 3); reduced-dose pembrolizumab starting day 1 of chemoradiotherapy (cohort 4); and full-dose pembrolizumab starting day 1 of chemoradiotherapy (cohort 5). A safety expansion cohort of 6 patients was planned based on the maximum tolerated dose of pembrolizumab. Dose-limiting toxic effects were defined as pneumonitis of at least grade 4 within cycle 1 of pembrolizumab treatment.

Main Outcomes and Measures

Safety and tolerability of PD-1 inhibition with chemoradiotherapy for NSCLC. Secondary outcomes included PFS and pneumonitis rates.

Results

Among the 21 patients included in the analysis (11 female [52%]; median age, 69.5 [range, 53.0-85.0] years), no dose-limiting toxic effects in any cohort were observed. One case of grade 5 pneumonitis occurred in the safety expansion cohort with the cohort 5 regimen. Immune-related adverse events of at least grade 3 occurred in 4 patients (18%). Median PFS for patients who received at least 1 dose of pembrolizumab (n = 21) was 18.7 (95% CI, 11.8-29.4) months, and 6- and 12-month PFS were 81.0% (95% CI, 64.1%-97.7%) and 69.7% (95% CI, 49.3%-90.2%), respectively. Median PFS for patients who received at least 2 doses of pembrolizumab (n = 19) was 21.0 (95% CI, 15.3 to infinity) months.

Conclusions and Relevance

These findings suggest that combined treatment with PD-1 inhibitors and chemoradiotherapy for stage III NSCLC is tolerable, with promising PFS of 69.7% at 12 months, and requires further study.

Trial Registration

ClinicalTrials.gov Identifier: NCT02621398.

Initial Clinical Experience Treating Patients With Lung Cancer on a 6MV-Flattening-Filter-Free O-Ring Linear Accelerator

Introduction Modern technologies, like intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT), have improved the therapeutic ratio of thoracic radiotherapy (TRT) for lung cancer (LC). Halcyon™ (Varian Medical Systems, Palo Alto, CA, USA), a novel 6MV-flattening-filter-free O-ring linear accelerator (6X-FFF ORL), was designed to deliver IMRT and VMAT with greater speed than a C-arm linac. Herein, we report our initial clinical experience treating patients with LC on this linac. Methods All patients who received TRT for LC on the 6X-FFF ORL at our institution were retrospectively identified. Patients' clinicopathologic data, radiotherapy details, early disease-control and toxicity outcomes, dosimetric data, couch corrections, and treatment times are reported. Results Between 10/2018-12/2019, 30 consecutive patients (median age 66 years, range 54-94 years) received definitive or post-operative TRT for LC (median 66 Gy/33 fractions; range 5-70 Gy/2-37 fractions) following four-dimensional computed tomography (CT) simulation (97%) using daily kilovoltage KV cone-beam CT (CBCT) (100%) on a 6X-FFF ORL for non-small cell LC (84%) or small cell LC (16%), with 53% receiving VMAT, 43% receiving static-field IMRT, and 77% receiving concurrent systemic therapy. All plans were approved through institutional peer review. The average three-dimensional vector couch correction based on CBCT guidance was 0.90 ± 0.50 cm. The average beam-on and beam on plus CBCT times were 1.7 ± 1.1 min, and 5.0 ± 3.2 min, respectively. Grade 3 dyspnea and fatigue occurred in 3% and 3% of patients, respectively. There were no grade ≥4 toxicities. Conclusion In this first clinical report of TRT for LC on a 6X-FFF ORL, daily CBCT-guided treatment was fast and safe with respect to dosimetry and clinical outcomes. Thus, use of this linac for TRT may increase LC patient throughput without a detriment in radiotherapy quality.

Multi-institutional analysis of stereotactic body radiotherapy for sarcoma pulmonary metastases: High rates of local control with favorable toxicity

BACKGROUND/OBJECTIVES

Oligometastatic sarcoma pulmonary metastases (PM's) are traditionally treated with resection and/or chemotherapy. We hypothesize that stereotactic body radiotherapy (SBRT) is an effective, safe alternative to surgery that can achieve excellent local control (LC) with a favorable toxicity profile.

METHODS

Patients treated with SBRT for sarcoma PM's from 2011 to 2016 at Massachusetts General Hospital and the University of Pennsylvania were included. Median dose was 50 Gy. Patients underwent computed tomography (CT) or positron emission tomography/CT Q3 months post-SBRT.

RESULTS

44 patients with 56 separate PM's were treated with SBRT. Median age was 59 (range 19-82). 82% received prior chemotherapy, 66% had prior pulmonary resections (range, 1-5 resections), and 32% received prior thoracic radiotherapy. Median lesion size was 2.0 cm (range, 0.5-8.1 cm). Median follow-up was 16 months and 25 months for patients alive at last follow-up. Overall survival at 12 and 24 months was 74% (95% confidence interval [CI], 67%-81%) and 46% (95% CI, 38%-55%). LC at 12 and 24 months was 96% (95% CI, 93%-98%) and 90% (95% CI, 84%-96%). LC and overall survival did not differ based on age, gender, histology, fractionation, lesion location, or size (P > .05). Three developed Common Terminology Criteria for Adverse Events version 4 grade-2 chest-wall toxicities; one had grade-2 pneumonitis.

CONCLUSIONS

In the first multi-institutional series on SBRT for sarcoma PM's, SBRT has excellent LC and is well-tolerated. SBRT should be considered as an alternative/complement to resection.

Patient-Centered Outcomes in Radiation Oncology

Patient-reported outcome and health-related quality of life scales have the potential to engage patients and providers, allowing for better communication and shared decision-making in oncology care. When monitored longitudinally, they facilitate earlier interventions that may help with symptom management and improve traditional outcome metrics, including survival. Their use in clinical trials has allowed for changes in guidelines in the management of various cancers. The voice and experience of the patient, captured by these scales, enable providers to better detail the journey patients can expect to experience during and after treatment.

Management of Lung Cancer During the COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) has had a devastating impact around the world. With high rates of transmission and no curative therapies or vaccine yet available, the current cornerstone of management focuses on prevention by social distancing. This includes decreased health care contact for patients. Patients with lung cancer are a particularly vulnerable population, where the risk of mortality from cancer must now be balanced by the potential risk of a life-threatening infection. In these unprecedented times, a collaborative and multidisciplinary approach is required to streamline but not compromise care. We have developed guidelines at our academic cancer center to standardize management of patients with lung cancer across our health care system and provide guidance to the larger oncology community. We recommend that general principles of lung cancer treatment continue to be followed in most cases where delays could result in rapid cancer progression. We recognize that our recommendations may change over time based on clinical resources and the evolving nature of the COVID-19 pandemic. In principle, however, treatment paradigms must continue to be individualized, with careful consideration of risks and benefits of continuing or altering lung cancer-directed therapy.

Outcomes in patients with metastatic non-small cell lung cancer (mNSCLC) with brain metastases treated with pembrolizumab-based therapy

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Background: Patients (pts) with mNSCLC with active brain metastases (BM) are often excluded from clinical trials; data on efficacy and safety of immunotherapy in this population are limited. We compared outcomes of pts with mNSCLC with and without BM who received pembrolizumab-based therapy. Methods: We conducted a retrospective single-center study of pts with mNSCLC treated with pembrolizumab (P) with or without chemotherapy. Progression-free survival (PFS) and overall survival (OS) were determined by Kaplan-Meier methodology and compared using multivariable Cox regression and log rank testing. Results: We identified 587 consecutive pts with mNSCLC who began P-based therapy between 8/2013 and 12/2018: 306 (52%) female, median age 67 years (range 32-98), 437 (74%) adenocarcinoma, and 508 (87%) former/current smokers. 388 (66%) patients received P in first line therapy, and 334 (57%) received single-agent P. 131 pts (22%) had detectable BM at baseline (start of P-based therapy). Pts with BM were younger (median 65 y vs 68 y, p < 0.01) and more likely to have adenocarcinoma (86% vs. 71%, p < 0.01) and baseline steroid use (22% vs 1%, p < 0.01). Presence of BM did not differ by race, sex, line of therapy, treatment regimen, or PD-L1 status. Of the 131 patients with detectable BM on pre-treatment brain MRI, 55 (42%) had stable BM as a result of prior local therapy, while 76 (58%) had active (new or growing) BM on pre-treatment imaging. Most patients with active BM underwent radiation therapy (RT) in either the 30 days before (n = 46) or 30 days after (n = 17) P start; of the remaining 13 treated with P-based therapy alone, intracranial responses included 2 CR, 2 PR, 3 SD, and 4 PD. As of 1/1/2020, with 15-month median follow up, there was no difference in mPFS (9.2 vs 7.3 months, p = 0.41) or mOS (18.3 vs 18.0 mo, p = 0.67) between pts with and without BM in our P-treated cohort. On multivariable analysis, female sex, ECOG 0-1, adenocarcinoma histology, and P as first line therapy were associated with improved PFS and OS. Presence of BM, baseline steroid use, and timing of local RT (before vs. after P) were not associated with inferior survival. Conclusions: In our single-center experience of pts with mNSCLC treated with P, pts with and without BM had similar PFS and OS. We observed several intracranial responses to P-based therapy alone, but most pts with active BM underwent local RT. mNSCLC pts with BM should be considered for P-based therapy; BM may be treated with RT immediately before or even after P with similar survival outcomes.

Updating Photon-Based Normal Tissue Complication Probability Models for Pneumonitis in Patients With Lung Cancer Treated With Proton Beam Therapy

PURPOSE

No validated models for predicting the risk of radiation pneumonitis (RP) with proton beam therapy (PBT) currently exist. Our goal was to externally validate and recalibrate multiple established photon-based normal tissue complication probability models for RP in a cohort with locally advanced nonsmall cell lung cancer treated with contemporary doses of chemoradiation using PBT.

METHODS AND MATERIALS

The external validation cohort consisted of 99 consecutive patients with locally advanced nonsmall cell lung cancer treated with chemoradiation using PBT. RP was retrospectively scored at 3 and 6 months posttreatment. We evaluated the performance of the photon Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) pneumonitis model, the QUANTEC model adjusted for clinical risk factors, and the newer Netherlands updated QUANTEC model. A closed testing procedure was performed to test the need for model updating, either by recalibration-in-the-large (re-estimation of intercept), recalibration (re-estimation of intercept/slope), or model revision (re-estimation of all coefficients).

RESULTS

There were 21 events (21%) of ≥grade 2 RP. The closed testing procedure on the PBT data set did not detect major deviations between the models and the data and recommended adjustment of the intercept only for the photon-based Netherlands updated QUANTEC model (intercept update: -1.2). However, an update of the slope and revision of the model coefficients were not recommended by the closed testing procedure, as the deviations were not significant within the power of the data.

CONCLUSIONS

The similarity between the dose-response relationship for PBT and photons for normal tissue complications has been an assumption until now. We demonstrate that the preexisting, widely used photon based models fit our PBT data well with minor modifications. These now-validated and updated normal tissue complication probability models can aid in individualizing selection of the most optimal treatment technique for a particular patient.

Circulating Tumor Cells Are Associated with Recurrent Disease in Patients with Early-Stage Non-Small Cell Lung Cancer Treated with Stereotactic Body Radiotherapy

PURPOSE

Although stereotactic body radiotherapy (SBRT) is effective in early-stage non-small cell lung cancer (NSCLC), approximately 10%-15% of patients will fail regionally and 20%-25% distantly. We evaluate a novel circulating tumor cell (CTC) assay as a prognostic marker for increased risk of recurrence following SBRT.

EXPERIMENTAL DESIGN

Ninety-two subjects (median age, 71 years) with T1a (64%), T1b (23%), or T2a (13%) stage I NSCLC treated with SBRT were prospectively enrolled. CTCs were enumerated by utilizing a GFP-expressing adenoviral probe that detects elevated telomerase activity in cancer cells. Samples were obtained before, during, and serially up to 24 months after treatment. SBRT was delivered to a median dose of 50 Gy (range, 40-60 Gy), mostly commonly in four to five fractions (92%).

RESULTS

Thirty-eight of 92 subjects (41%) had a positive CTC test prior to SBRT. A cutoff of ≥5 CTCs/mL before treatment defined favorable (n = 78) and unfavorable (n = 14) prognostic groups. Increased risk of nodal (P = 0.04) and distant (P = 0.03) failure was observed in the unfavorable group. Within 3 months following SBRT, CTCs continued to be detected in 10 of 35 (29%) subjects. Persistent detection of CTCs was associated with increased risk of distant failure (P = 0.04) and trended toward increased regional (P = 0.08) and local failure (P = 0.16).

CONCLUSIONS

Higher pretreatment CTCs and persistence of CTCs posttreatment is significantly associated with increased risk of recurrence outside the targeted treatment site. This suggests that CTC analysis may potentially identify patients at higher risk for regional or distant recurrences and who may benefit from either systemic therapy and/or timely locoregional salvage treatment.

Introducing Multidisciplinary Oncology Management to the Medical Student

Despite the fact that a large portion of medical students pursue training in a cancer-related discipline, oncology is emphasized to a disproportionately lesser extent than are other disciplines in medical school. Medical students have wide gaps in their oncology-specific knowledge, and undergraduate medical education fails to address the multidisciplinary nature of oncology. To address these shortcomings and improve medical students’ understanding of the multidisciplinary nature of oncology, we have instituted a clinical oncology elective for medical students: an optional, 2-day session held after classes and promoted by student interest groups. Day 1 comprised a series of short faculty lectures beginning with the concepts of and rationale for staging, an approach to breaking bad news, guideline-based management, and multidisciplinary tumor board discussion. Three multidisciplinary tumor boards were simulated on the second day, run by attending surgeons, medical oncologists, and radiation oncologists with expertise in the cancer of interest, using real patient examples. Ultimately, the clinical oncology elective shows medical students how the oncology care team works together to care for cancer patients.

Emerging role of immunotherapy in locally advanced non-small cell lung cancer

Non-small cell lung cancer (NSCLC) accounts for 85% of the cases of lung cancer in the United States, and 70% of patients with NSCLC have locally advanced or metastatic disease at the time of diagnosis. The 5-year overall survival rate for patients with locally advanced NSCLC is 15% to 20%. The traditional treatment paradigm for unresectable locally advanced NSCLC consists of platinum-based chemotherapy with concurrent radiation. Evidence from phase 3 clinical trials has established a role for immunotherapy after chemoradiation, and emerging data continue to elucidate the expanding role of immunotherapy.

Machine learning highlights the deficiency of conventional dosimetric constraints for prevention of high-grade radiation esophagitis in non-small cell lung cancer treated with chemoradiation

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A large cohort to predict radiation esophagitis in lung cancer patients was used.

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Modern machine learning models were implemented to predict radiation esophagitis.

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Previously published predictors of grade ≥ 3 radiation esophagitis may be unreliable.

Background and Purpose

Radiation esophagitis is a clinically important toxicity seen with treatment for locally-advanced non-small cell lung cancer. There is considerable disagreement among prior studies in identifying predictors of radiation esophagitis. We apply machine learning algorithms to identify factors contributing to the development of radiation esophagitis to uncover previously unidentified criteria and more robust dosimetric factors.

Materials and Methods

We used machine learning approaches to identify predictors of grade ≥ 3 radiation esophagitis in a cohort of 202 consecutive locally-advanced non-small cell lung cancer patients treated with definitive chemoradiation from 2008 to 2016. We evaluated 35 clinical features per patient grouped into risk factors, comorbidities, imaging, stage, histology, radiotherapy, chemotherapy and dosimetry. Univariate and multivariate analyses were performed using a panel of 11 machine learning algorithms combined with predictive power assessments.

Results

All patients were treated to a median dose of 66.6 Gy at 1.8 Gy per fraction using photon (89.6%) and proton (10.4%) beam therapy, most often with concurrent chemotherapy (86.6%). 11.4% of patients developed grade ≥ 3 radiation esophagitis. On univariate analysis, no individual feature was found to predict radiation esophagitis (AUC range 0.45–0.55, p ≥ 0.07). In multivariate analysis, all machine learning algorithms exhibited poor predictive performance (AUC range 0.46–0.56, p ≥ 0.07).

Conclusions

Contemporary machine learning algorithms applied to our modern, relatively large institutional cohort could not identify any reliable predictors of grade ≥ 3 radiation esophagitis. Additional patients are needed, and novel patient-specific and treatment characteristics should be investigated to develop clinically meaningful methods to mitigate this survival altering toxicity.

Baseline Plasma Tumor Mutation Burden Predicts Response to Pembrolizumab-based Therapy in Patients with Metastatic Non-Small Cell Lung Cancer

PURPOSE

The role of plasma-based tumor mutation burden (pTMB) in predicting response to pembrolizumab-based first-line standard-of-care therapy for metastatic non-small cell lung cancer (mNSCLC) has not been explored.

EXPERIMENTAL DESIGN

A 500-gene next-generation sequencing panel was used to assess pTMB. Sixty-six patients with newly diagnosed mNSCLC starting first-line pembrolizumab-based therapy, either alone or in combination with chemotherapy, were enrolled (Clinicaltrial.gov identifier: NCT03047616). Response was assessed using RECIST 1.1. Associations were made for patient characteristics, 6-month durable clinical benefit (DCB), progression-free survival (PFS), and overall survival (OS).

RESULTS

Of 66 patients, 52 (78.8%) were pTMB-evaluable. Median pTMB was 16.8 mutations per megabase (mut/Mb; range, 1.9-52.5) and was significantly higher for patients achieving DCB compared with no durable benefit (21.3 mut/Mb vs. 12.4 mut/Mb, P = 0.003). For patients with pTMB ≥ 16 mut/Mb, median PFS was 14.1 versus 4.7 months for patients with pTMB < 16 mut/Mb [HR, 0.30 (0.16-0.60); P < 0.001]. Median OS for patients with pTMB ≥ 16 was not reached versus 8.8 months for patients with pTMB < 16 mut/Mb [HR, 0.48 (0.22-1.03); P = 0.061]. Mutations in ERBB2 exon 20, STK11, KEAP1, or PTEN were more common in patients with no DCB. A combination of pTMB ≥ 16 and absence of negative predictor mutations was associated with PFS [HR, 0.24 (0.11-0.49); P < 0.001] and OS [HR, 0.31 (0.13-0.74); P = 0.009].

CONCLUSIONS

pTMB ≥ 16 mut/Mb is associated with improved PFS after first-line standard-of-care pembrolizumab-based therapy in mNSCLC. STK11/KEAP1/PTEN and ERBB2 mutations may help identify pTMB-high patients unlikely to respond. These results should be validated in larger prospective studies.

Early Tumor and Nodal Response in Patients with Locally Advanced Non-Small Cell Lung Carcinoma Predict for Oncologic Outcomes in Patients Treated with Concurrent Proton Therapy and Chemotherapy

PURPOSE

There are no established imaging biomarkers that predict response during chemoradiation for patients with locally advanced non-small cell lung carcinoma. At our institution, proton therapy (PT) patients undergo repeat computed tomography (CT) simulations twice during radiation. We hypothesized that tumor regression measured on these scans would separate early and late responders and that early response would translate into better outcomes.

METHODS AND MATERIALS

Patients underwent CT simulations before starting PT (CT0) and between weeks 1 to 3 (CT1) and weeks 4 to 7 (CT2) of PT. Primary tumor volume (TVR) and nodal volume (NVR) reduction were calculated at CT1 and CT2. Based on recursive partitioning analysis, early response at CT1 and CT2 was defined as ≥20% and ≥40%, respectively. Locoregional and overall progression-free survival (PFS), distant metastasis-free survival, and overall survival by response status were measured using Kaplan-Meier analysis.

RESULTS

Ninety-seven patients with locally advanced non-small cell lung carcinoma underwent definitive PT to a median dose of 66.6 Gy with concurrent chemotherapy. Median TVR and NVR at CT1 were 19% (0-79%) and 19% (0-75%), respectively. At CT2, they were 33% (2-98%) and 35% (0-89%), respectively. With a median follow-up of 25 months, the median overall survival and PFS for the entire cohort was 24.9 and 13.2 months, respectively. Compared with patients with TVR and NVR <20% at T1 and <40% at T2, patients with TVR and NVR ≥20% at CT1 and ≥40% at CT2 had improved median locoregional PFS (27.15 vs 12.97 months for TVR ≥40% vs <40%, P < .01, and 25.67 vs 12.09 months for NVR ≥40% vs <40%, P < .01) and median PFS (22.7 vs 9.2 months, P < .01, and 20.3 vs 7.9 months, P < .01), confirmed on multivariate Cox regression analysis.

CONCLUSIONS

Significantly improved outcomes in patients with early responses to therapy, as measured by TVR and NVR, were seen. Further study is warranted to determine whether treatment intensification will improve outcomes in slow-responding patients.

Early Detection of Recurrence in Patients With Locally Advanced Non-Small-Cell Lung Cancer via Circulating Tumor Cell Analysis

BACKGROUND

Assays to identify circulating tumor cells (CTCs) might allow for noninvasive and sequential monitoring of lung cancer. We investigated whether serial CTC analysis could complement conventional imaging for detecting recurrences after treatment in patients with locally advanced non-small-cell lung cancer (LA-NSCLC).

PATIENTS AND METHODS

Patients with LA-NSCLC (stage II-III) who definitively received concurrent chemoradiation were prospectively enrolled, with CTCs from peripheral blood samples identified using an adenoviral probe that detects elevated telomerase activity present in nearly all lung cancer cells. A "detectable" CTC level was defined as 1.3 green flourescent protein-positive cells per milliliter of collected blood. Samples were obtained before, during (at weeks 2, 4, and 6), and after treatment (post-radiation therapy [RT]; at months 1, 3, 6, 12, 18, and 24).

RESULTS

Forty-eight patients were enrolled. At a median follow-up of 10.9 months, 22 (46%) patients had disease recurrence at a median time of 7.6 months post-RT (range, 1.3-32.0 months). Of the 20 of 22 patients for whom post-RT samples were obtained, 15 (75%) had an increase in CTC counts post-RT. In 10 of these 15 patients, CTCs were undetectable on initial post-RT draw but were then detected again before radiographic detection of recurrence, with a median lead time of 6.2 months and mean lead time of 6.1 months (range, 0.1-12.0 months) between CTC count increase and radiographic evidence of recurrence. One patient with an early recurrence (4.7 months) had persistently elevated detectable CTC levels during and after treatment.

CONCLUSION

These results indicate that longitudinal CTC monitoring in patients with LA-NSCLC treated with chemoradiation is feasible, and that detectable CTC levels in many patients meaningfully precede radiologic evidence of disease recurrence.

Design and implementation of outpatient-based rapid MRI protocols to rule out metastatic spinal cord compression and brain metastases

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Background: Metastatic spinal cord compression (MSCC) and symptomatic brain metastases (mets) are potential emergencies that demand coordinated multidisciplinary management. Patients (pts) with concerning symptoms are often referred to the Emergency Department (ED) for expedited imaging, but most do not require subsequent ED or inpatient management. Unnecessary ED visits incur substantial cost to the health system and patients, and cause psychosocial stress for patients often near the end-of-life. To improve access to expedited outpatient imaging for high-risk pts and reduce unnecessary ED visits, we developed outpatient rapid MRI protocols and pathways to rule out MSCC and brain mets. Methods: Tailored abbreviated MRI protocols were developed to allow rapid acquisition of brain ( < 13 minutes) and full spine ( < 25 minutes) exams. Dedicated appointments were reserved on the daily MRI schedule. Exams were immediately interpreted and reported by Radiology to the ordering clinician. This pathway was piloted within the Thoracic Oncology group beginning in 10/2018. Results: Referring specialties included Radiation Oncology (50%), Medical Oncology (36%), Pulmonology (7%), and Surgery (7%). For 6 pts who had outpatient rapid brain imaging, median time from order to exam start was 4.3 h (1.8-31) and order to final report 6.8 h (3.2-34.1). Brain mets were found in 4/6 patients. Only 1/4 positive studies required subsequent ED management. For 8 pts referred for rapid spine imaging, median time from order to exam start was 14.4 h (2.2-72.5) and order to final report 16.7 h (4.0-74.4). Only 1 patient was found to have cord compression and required ED/inpatient management. Overall, 86% of patients did not require ED or inpatient admission. 3 pts (all with negative imaging) died a median 13.4 d (1.4-28.3) after order placement. Conclusions: Outpatient rapid MRI protocols facilitate same-day imaging, interpretation, and management, improving care for thoracic oncology pts with new concerning neurologic symptoms and reducing unnecessary ED visits. Future work will expand access beyond Thoracic Oncology and further quantify improvements in cost savings and patient quality of life.

Prospective phase I multi-institutional trial of PD-1 blockade with pembrolizumab during concurrent chemoradiation for locally advanced, unresectable non-small cell lung cancer

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Background: The PACIFIC study showed that consolidative Programmed Death Ligand 1 inhibition (PD-L1i) after chemoradiation therapy (CRT) improves PFS and OS in patients with Stage IIII NSCLC (Antonia et al. NEJM 2017, 2018). Limited data, however, exist regarding the incorporation of PD-L1i concurrently during CRT. We sought to assess the safety and toxicity of PD-1i using pembrolizumab (pembro) during definitive CRT for Stage III NSCLC. Methods: In this multi-center prospective Phase I clinical trial using a 3+3 design, we evaluated the timing and dosing of pembro combined with chemotherapy (carboplatin + paclitaxel weekly) and definitive RT (60 Gy in 2 Gy/day x 30 fractions) for unresectable, locally advanced Stage III NSCLC (AJCC 7thEd). Dose Cohorts (C) evaluated were--C1: full dose (FD) pembro (200 mg IV Q3 weeks) 2-6 weeks after CRT; C2: reduced dose (RD) pembro (100 mg IV Q3 weeks) starting Day 29 of CRT; C3: FD pembro starting Day 29 of CRT; C4: RD pembro starting on Day 1 of CRT; C5: FD pembro starting on Day 1 of CRT. For each cohort, pembro was continued Q3 weeks for up to 18 cycles (as monotherapy after CRT in either RD or FD based on initial dose assignment). Dose Limiting Toxicity (DLT) was defined as Grade ≥4 pneumonitis within 21 days of cycle 1 of pembro. Results: We enrolled 23 subjects from 8/2016-11/2018; median follow up (f/u) was 11.4 mo (range, 3.1 mo- 25.2 mo). Median age was 69 yrs (range 53-85); 52% were women. No DLTs were observed in any of the cohorts (C1 to C5). Grade ≥3 immune-related adverse events (irAE) occurred in 4 patients (18%). irAE’s included: Grade 5 (bilateral), 3, 2 pneumonitis (n=1, 1, 4, respectively (6 total)); Grade 3 hyperglycemia (n=1); Grade 3 interstitial nephritis (n=1); Grade 2 thyroiditis (n=4); Grade 2 myositis (n=1); Grade 1-2 transaminitis (n=3). Median PFS for patients who received ≥2 doses (n=18) of pembro was 20.3 mo. Conclusions: Combined treatment with PD-Li and CRT for stage III NSCLC was well tolerated with promising PFS to date but showed an increased risk for irAEs, particularly pneumonitis. Based on these encouraging results, further prospective study of PD-1i and CRT for Stage III NSCLC is warranted. Clinical trial information: NCT02621398.

Clinical Implications of Plasma-Based Genotyping With the Delivery of Personalized Therapy in Metastatic Non-Small Cell Lung Cancer

Importance

The clinical implications of adding plasma-based circulating tumor DNA next-generation sequencing (NGS) to tissue NGS for targetable mutation detection in non-small cell lung cancer (NSCLC) have not been formally assessed.

Objective

To determine whether plasma NGS testing was associated with improved mutation detection and enhanced delivery of personalized therapy in a real-world clinical setting.

Design, Setting, and Participants

This prospective cohort study enrolled 323 patients with metastatic NSCLC who had plasma testing ordered as part of routine clinical management. Plasma NGS was performed using a 73-gene commercial platform. Patients were enrolled at the Hospital of the University of Pennsylvania from April 1, 2016, through January 2, 2018. The database was locked for follow-up and analyses on January 2, 2018, with a median follow-up of 7 months (range, 1-21 months).

Main Outcomes and Measures

The number of patients with targetable alterations detected with plasma and tissue NGS; the association between the allele fractions (AFs) of mutations detected in tissue and plasma; and the association of response rate with the plasma AF of the targeted mutations.

Results

Among the 323 patients with NSCLC (60.1% female; median age, 65 years [range, 33-93 years]), therapeutically targetable mutations were detected in EGFR, ALK, MET, BRCA1, ROS1, RET, ERBB2, or BRAF for 113 (35.0%) overall. Ninety-four patients (29.1%) had plasma testing only at the discretion of the treating physician or patient preference. Among the 94 patients with plasma testing alone, 31 (33.0%) had a therapeutically targetable mutation detected, thus obviating the need for an invasive biopsy. Among the remaining 229 patients who had concurrent plasma and tissue NGS or were unable to have tissue NGS, a therapeutically targetable mutation was detected in tissue alone for 47 patients (20.5%), whereas the addition of plasma testing increased this number to 82 (35.8%). Thirty-six of 42 patients (85.7%) who received a targeted therapy based on the plasma result achieved a complete or a partial response or stable disease. The plasma-based targeted mutation AF had no correlation with depth of Response Evaluation Criteria in Solid Tumors response (r = -0.121; P = .45).

Conclusions and Relevance

Integration of plasma NGS testing into the routine management of stage IV NSCLC demonstrates a marked increase of the detection of therapeutically targetable mutations and improved delivery of molecularly guided therapy.

Empiric Radiotherapy for Lung Cancer Collaborative Group multi-institutional evidence-based guidelines for the use of empiric stereotactic body radiation therapy for non-small cell lung cancer without pathologic confirmation

The standard of care for managing early stage non-small cell lung cancer (NSCLC) is definitive surgical resection. Stereotactic body radiation therapy (SBRT) has become the standard treatment for patient who are medically inoperable, and it is increasingly being considered as an option in operable patients. With the growing use of screening thoracic CT scans for patients with a history of heavy smoking, as well as improved imaging capabilities, the discovery of small lung nodes has become a common dilemma. As a result, clinicians are increasingly faced with managing lung nodules in patients in whom diagnostic biopsy is not safe or feasible. Herein, we describe the scope of the problem, tools available for predicting the probability that a lung nodule is a malignancy, staging procedures, benefits of pathology-proven and empiric SBRT, considerations of safety based on location of the lesion of concern, and overall efficacy of SBRT.

Predicting radiation pneumonitis in locally advanced stage II-III non-small cell lung cancer using machine learning

BACKGROUND AND PURPOSE

Radiation pneumonitis (RP) is a radiotherapy dose-limiting toxicity for locally advanced non-small cell lung cancer (LA-NSCLC). Prior studies have proposed relevant dosimetric constraints to limit this toxicity. Using machine learning algorithms, we performed analyses of contributing factors in the development of RP to uncover previously unidentified criteria and elucidate the relative importance of individual factors.

MATERIALS AND METHODS

We evaluated 32 clinical features per patient in a cohort of 203 stage II-III LA-NSCLC patients treated with definitive chemoradiation to a median dose of 66.6 Gy in 1.8 Gy daily fractions at our institution from 2008 to 2016. Of this cohort, 17.7% of patients developed grade ≥2 RP. Univariate analysis was performed using trained decision stumps to individually analyze statistically significant predictors of RP and perform feature selection. Applying Random Forest, we performed multivariate analysis to assess the combined performance of important predictors of RP.

RESULTS

On univariate analysis, lung V20, lung mean, lung V10 and lung V5 were found to be significant RP predictors with the greatest balance of specificity and sensitivity. On multivariate analysis, Random Forest (AUC = 0.66, p = 0.0005) identified esophagus max (20.5%), lung V20 (16.4%), lung mean (15.7%) and pack-year (14.9%) as the most common primary differentiators of RP.

CONCLUSIONS

We highlight Random Forest as an accurate machine learning method to identify known and new predictors of symptomatic RP. Furthermore, this analysis confirms the importance of lung V20, lung mean and pack-year as predictors of RP while also introducing esophagus max as an important RP predictor.

LGM2605 Reduces Space Radiation-Induced NLRP3 Inflammasome Activation and Damage in In Vitro Lung Vascular Networks

Updated measurements of charged particle fluxes during the transit from Earth to Mars as well as on site measurements by Curiosity of Martian surface radiation fluxes identified potential health hazards associated with radiation exposure for human space missions. Designing mitigation strategies of radiation risks to astronauts is critical. We investigated radiation-induced endothelial cell damage and its mitigation by LGM2605, a radioprotector with antioxidant and free radical scavenging properties. We used an in vitro model of lung vascular networks (flow-adapted endothelial cells; FAECs), exposed to gamma rays, low/higher linear energy transfer (LET) protons (3⁻4 or 8⁻10 keV/µm, respectively), and mixed field radiation sources (gamma and protons), given at mission-relevant doses (0.25 gray (Gy)⁻1 Gy). We evaluated endothelial inflammatory phenotype, NLRP3 inflammasome activation, and oxidative cell injury. LGM2605 (100 µM) was added 30 min post radiation exposure and gene expression changes evaluated 24 h later. Radiation induced a robust increase in mRNA levels of antioxidant enzymes post 0.25 Gy and 0.5 Gy gamma radiation, which was significantly decreased by LGM2605. Intercellular cell adhesion molecule-1 (ICAM-1) and NOD-like receptor protein 3 (NLRP3) induction by individual or mixed-field exposures were also significantly blunted by LGM2605. We conclude that LGM2605 is a likely candidate to reduce tissue damage from space-relevant radiation exposure.

Impact of Enlarged Nonhypermetabolic Lymph Nodes on Outcomes After Stereotactic Body Radiotherapy for Early-Stage Non-Small-Cell Lung Cancer

BACKGROUND

Up to 15% of patients undergoing positron emission tomography (PET)/computed tomography (CT) before stereotactic body radiotherapy (SBRT) harbor occult nodal disease. In the absence of invasive mediastinal staging, the clinical significance of enlarged nonhypermetabolic lymph nodes (LNs) remains unclear. We performed what is to our knowledge the first study to address whether enlarged nonhypermetabolic LNs were associated with higher post-SBRT failure rates.

PATIENTS AND METHODS

Two academic centers assessed 157 consecutive patients treated with SBRT for cT1-2aN0M0 non-small-cell lung cancer who underwent PET/CT without pathologic nodal staging. The cutoff of an enlarged node was ≥ 1.0 cm, although a 7 mm threshold was also evaluated. Local recurrence-free survival (RFS), regional RFS, distant metastasis-free survival, RFS, and overall survival (OS) were calculated by Kaplan-Meier methodology. Multivariate Cox modeling addressed factors associated with RFS and OS.

RESULTS

There were 120 patients (76%) with LNs < 1 cm and 37 (24%) with nodes ≥ 1 cm. Most patients had peripheral and/or T1 tumors. Median follow-up was 25.5 months. There were no differences between cohorts in actuarial local RFS, regional RFS, distant metastasis-free survival, RFS, or OS (P > .05 for all). Thirteen percent of patients experienced any nodal relapse, 15% of which occurred in the same station as that of the largest pre-SBRT LN. Stratification by largest LN location in an N1 versus N2 station showed no differences in RFS or OS (P > .05 for both). A 7 mm cutoff also showed no differences in outcomes (P > .05 for all). LN size was not correlated with RFS/OS on multivariable analysis (P > .05 for both).

CONCLUSION

The presence of enlarged nonhypermetabolic LNs on PET/CT is not associated with increased post-SBRT failure rates.

Exploratory analysis using machine learning to predict for chest wall pain in patients with stage I non-small-cell lung cancer treated with stereotactic body radiation therapy

Background and purpose

Chest wall toxicity is observed after stereotactic body radiation therapy (SBRT) for peripherally located lung tumors. We utilize machine learning algorithms to identify toxicity predictors to develop dose–volume constraints.

Materials and methods

Twenty‐five patient, tumor, and dosimetric features were recorded for 197 consecutive patients with Stage I NSCLC treated with SBRT, 11 of whom (5.6%) developed CTCAEv4 grade ≥2 chest wall pain. Decision tree modeling was used to determine chest wall syndrome (CWS) thresholds for individual features. Significant features were determined using independent multivariate methods. These methods incorporate out‐of‐bag estimation using Random forests (RF) and bootstrapping (100 iterations) using decision trees.

Results

Univariate analysis identified rib dose to 1 cc < 4000 cGy (P = 0.01), chest wall dose to 30 cc < 1900 cGy (P = 0.035), rib Dmax < 5100 cGy (P = 0.05) and lung dose to 1000 cc < 70 cGy (P = 0.039) to be statistically significant thresholds for avoiding CWS. Subsequent multivariate analysis confirmed the importance of rib dose to 1 cc, chest wall dose to 30 cc, and rib Dmax. Using learning‐curve experiments, the dataset proved to be self‐consistent and provides a realistic model for CWS analysis.

Conclusions

Using machine learning algorithms in this first of its kind study, we identify robust features and cutoffs predictive for the rare clinical event of CWS. Additional data in planned subsequent multicenter studies will help increase the accuracy of multivariate analysis.

Radiation Pneumonitis: Old Problem, New Tricks

Radiation therapy is a major treatment modality for management of non-small cell lung cancer. Radiation pneumonitis is a dose limiting toxicity of radiotherapy, affecting its therapeutic ratio. This review presents patient and treatment related factors associated with the development of radiation pneumonitis. Research focusing on reducing the incidence of radiation pneumonitis by using information about lung ventilation, imaging-based biomarkers as well as normal tissue complication models is discussed. Recent advances in our understanding of molecular mechanisms underlying lung injury has led to the development of several targeted interventions, which are also explored in this review.

The state of survivorship care in radiation oncology: Results from a nationally distributed survey

BACKGROUND

Survivorship care has become an increasingly critical component of oncologic care as well as a quality practice and reimbursement metric. To the authors' knowledge, the current climate of survivorship medicine in radiation oncology has not been investigated fully.

METHODS

An institutional review board-approved, Internet-based survey examining practices and preparedness in survivorship care was distributed to radiation oncology practices participating in the American College of Radiology Radiation Oncology Practice Accreditation program between November 2016 and January 2017. A total of 78 surveys were completed. Among these, 2 were nonphysicians, resulting in 76 evaluable responses.

RESULTS

Radiation oncologists (ROs) frequently reported that they are the primary provider in the evaluation of late toxicities and the recurrence of primary cancer. Although approximately 68% of ROs frequently discuss plans for future care with survivors, few provide a written survivorship care plan to their patients (18%) or the patients' primary care providers (24%). Patient prognosis, disease site, and reimbursement factors often influence the provision of survivorship care. Although ROs report that several platforms offer training in survivorship medicine, the quality of these resources is variable and extensive instruction is rare. Fewer than one-half of ROs believe they are expertly trained in survivorship care.

CONCLUSIONS

ROs play an active role within the multidisciplinary team in the cancer-related follow-up care of survivors. Investigation of barriers to the provision of survivorship care and optimization of service delivery should be pursued further. The development of high-quality, easily accessible educational programming is needed so that ROs can participate more effectively in the care of cancer survivors. Cancer 2018;124:2653-60. © 2018 American Cancer Society.

Introductory Radiation Oncology Curriculum: Report of a National Needs Assessment and Multi-institutional Pilot Implementation

PURPOSE

To assess the optimal structure of an introductory curriculum (IC) for radiation oncology residents, including the perceived utility of a 2-day off-site "boot camp," and evaluate the success of a pilot introductory radiation oncology curriculum (IROC) based on these initial data.

METHODS AND MATERIALS

In the first phase, anonymous, web-based surveys were sent to US radiation oncology program directors and residents. Likert-type scores (1, not at all; 5, extremely) are reported as the median and interquartile range. Using the phase 1 results, IROC was developed, piloted, and evaluated.

RESULTS

Of the 89 program directors and 697 residents, 47 (53%) and 165 (24%) responded, respectively. Of the 89 program directors, 37 (79%) reported offering a formal IC. However, only 83 residents (50%) reported having a formal IC. Program directors reported resident preparation for clinical training as "moderate" (median 3, interquartile range 2-3) on entering residency and "moderate" (median 3, interquartile range 3-4) after IC completion (P = .03). However, residents only believed they were "slightly" prepared (median 2, interquartile range 1-2) on entering residency and "moderately" (median 3, interquartile range 2-3) prepared after IC completion (P < .01). Program directors believed an off-site boot camp would be of "moderate" utility (median 3, interquartile range 3-4) with participation limited by funding (57%). Residents without an IC reported that having an IC would be "quite" beneficial (median 4, interquartile range 3-5). Residents preferred instruction before the clinical training (49%) and over 1 week (40%). Both program directors and residents rated lectures on radiation emergencies and simulation highly. Using these data, IROC was developed and piloted with incoming residents at 4 institutions. After IROC, residents reported improvement in overall preparedness for clinical training (before: median 1, interquartile range 1-2; vs after: median 3, interquartile range 2-3; P < .01) and among specific practice domains.

CONCLUSIONS

Beginning radiation oncology residents frequently lack structured introductory curricula but desire instruction before the clinical training with a focus on practical aspects (emergency management, contouring). Program directors recognize the value of both off-site and on-site boot camps. An on-site IC could mitigate funding barriers. A standardized IC, IROC, piloted at 4 programs, showed promising outcomes.

Proton therapy for thoracic reirradiation of non-small cell lung cancer

Lung cancer is a leading cause of cancer death with frequent local failures after initial curative-intent treatment. Locally recurrent non-small cell lung cancer represents a challenging clinical scenario as patients have often received prior radiation as part of a definitive treatment regimen. Proton beam therapy, through its characteristic Bragg peak and lack of exit dose is a potential means of minimizing the toxicity to previously irradiated organs and improving the therapeutic ratio. This article aims to review the rationale for the use of proton beam therapy for treatment of locally recurrent non-small cell lung cancer, highlight the current published experience on the feasibility, efficacy, and limitations of proton beam reirradiation, and discuss future avenues for improved patient selection and treatment delivery.

Focusing on the "Person" in Personalized Medicine: The Future of Patient-Centered Care in Radiation Oncology

Numerous efforts in radiation oncology aim to improve the value of clinical care. To evaluate the success of these efforts, outcome measures must be well defined and incorporate the beliefs of the patients they affect. These outcomes have historically centered on rates of tumor control, overall survival, and adverse events as perceived and reported by providers. However, the future of patient-centered care in radiation oncology is increasingly focusing on the "person" in the population and the individual in the studies to more closely reflect the ideals of personalized medicine. Formally known as patient-centered outcomes, this metric encompasses parameters of patient satisfaction, engagement, and treatment compliance. Evaluations that investigate the safety and efficacy of treatments are increasingly soliciting participation from patients within a model of shared decision making that improves patients' knowledge, satisfaction, physical and emotional well-being, and trust in providers. Modern clinical trials that embrace this approach may even focus on patient-reported outcomes as the primary end point, as opposed to time-honored physician-reported events. The authors explore the growing role of patient-centered care, the incorporation of shared decision making, and the relevant body of existing and developing literature on this topic in radiation oncology. The authors report recent discoveries from this area of study and describe how they can not only support high-quality, high-value patient care but also enhance recruitment to clinical oncology trials, both of which are challenging to achieve in today's relatively resource-strapped environment.

Proton beam reirradiation for locally recurrent pancreatic adenocarcinoma

BACKGROUND

Local recurrence following definitive treatment for pancreatic adenocarcinoma is common and can be associated with significant morbidity and mortality. Retreatment options for these patients are limited. Proton beam reirradiation (PRT) may limit dose and toxicity to previously irradiated normal tissues in patients without evidence of metastatic disease.

METHODS

Between 8/2010-2/2015, 15 patients with isolated, locally-recurrent pancreatic cancer were treated with PRT. Acute toxicity was graded using CTC v 4.0 and defined as occurring within 90 days. Kaplan-Meier survival analysis was performed from the start of PRT. A log-rank test was used to compare survival with or without concurrent chemotherapy.

RESULTS

Median follow-up was 15.7 months [2-48] from the start of PRT. The median clinical target volume (CTV) was 71 cc [15-200]. Ten (67%) patients received concurrent chemotherapy. Median PRT dose was 59.4 Gy (37.5-59.4 Gy). The median time interval from the prior treatment course was 26.7 months (7-461.3). There was a rate of 13% acute ≥ grade 3 toxicities attributed to PRT. The median overall survival (OS) was 16.7 months (95% CI, 4.7-36) and OS at 1 year was 67%. The "in-field" failure free survival at one year was 87%. The locoregional progression free survival (LPFS) and distant metastasis free survival (DMFS) at 1 year was 72% and 64% respectively. Concurrent chemotherapy was associated with a higher median survival.

CONCLUSIONS

PRT was well tolerated, resulted in prolonged clinical outcomes compared to historical controls, and should be considered as a treatment option with concurrent chemotherapy in selected patients with locally-recurrent pancreatic cancer.