Precision Hypofractionated Radiation Therapy in Poor Performing Patients With Non-Small Cell Lung Cancer: Phase 1 Dose Escalation Trial

Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 2. Lung (non-small cell lung cancer)

Several recent studies have investigated the use of hypofractionated radiotherapy (HFRT) for various cancers. However, HFRT for non-small cell lung cancer (NSCLC) with or without concurrent chemotherapy is not yet widely used because of concerns about serious side effects and the lack of evidence for improved treatment results. Investigations of HFRT with concurrent chemotherapy in NSCLC have usually been performed in single-arm studies and with a small number of patients, so there are not yet sufficient data. Therefore, the Korean Society for Radiation Oncology Practice Guidelines Committee planned this review article to summarize the evidence on HFRT so far and provide it to radiation oncology clinicians. In summary, HFRT has demonstrated promising results, and the reviewed data support its feasibility and comparable efficacy for the treatment of locally advanced NSCLC. The incidence and severity of esophageal toxicity have been identified as major concerns, particularly when treating large fraction sizes. Strategies, such as esophagus-sparing techniques, image guidance, and dose constraints, may help mitigate this problem and improve treatment tolerability. Continued research and clinical trials are essential to refine treatment strategies, identify optimal patient selection criteria, and enhance therapeutic outcomes.

Accelerated Hypofractionated Magnetic Resonance Guided Adaptive Radiation Therapy for Ultracentral Lung Tumors

Radiotherapy for ultracentral lung tumors represents a treatment challenge, considering the high rates of high-grade treatment-related toxicities with stereotactic body radiation therapy (SBRT) or hypofractionated schedules. Accelerated hypofractionated magnetic resonance-guided adaptive radiation therapy (MRgART) emerged as a potential game-changer for tumors in these challenging locations, in close proximity to central organs at risk, such as the trachea, proximal bronchial tree, and esophagus. In this series, 13 consecutive patients, predominantly male (n = 9), with a median age of 71 (range (R): 46-85), underwent 195 MRgART fractions (all 60 Gy in 15 fractions) to metastatic (n = 12) or primary ultra-central lung tumors (n = 1). The median gross tumor volumes (GTVs) and planning target volumes (PTVs) were 20.72 cc (R: 0.54-121.65 cc) and 61.53 cc (R: 3.87-211.81 cc), respectively. The median beam-on time per fraction was 14 min. Adapted treatment plans were generated for all fractions, and indications included GTV/PTV undercoverage, OARs exceeding tolerance doses, or both indications in 46%, 18%, and 36% of fractions, respectively. Eight patients received concurrent systemic therapies, including immunotherapy (four), chemotherapy (two), and targeted therapy (two). The crude in-field loco-regional control rate was 92.3%. No CTCAE grade 3+ toxicities were observed. Our results offer promising insights, suggesting that MRgART has the potential to mitigate toxicities, enhance treatment precision, and improve overall patient care in the context of ultracentral lung tumors.

Hypofractionated Radiotherapy followed by Hypofractionated Boost with weekly concurrent chemotherapy for Unresectable Stage III Non-Small Cell Lung Cancer: Results of A Prospective Phase II Study (GASTO-1049)

PURPOSE

We launched a prospective phase 2 clinical trial to explore the safety and efficacy of hypofractionated radiation therapy (hypo-RT) followed by hypofractionated boost (hypo-boost) combined with concurrent weekly chemotherapy in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC).

METHODS AND MATERIALS

Patients with newly diagnosed LA-NSCLC with unresectable stage III disease were recruited between June 2018 and June 2020. Patients were treated with hypo-RT (40 Gy in 10 fractions) followed by hypo-boost (24-28 Gy in 6-7 fractions) combined with concurrent weekly chemotherapy (docetaxel 25 mg/m2 and nedaplatin 25 mg/m2). The primary endpoint of the study was progression-free survival (PFS), and the secondary endpoints included overall survival (OS), locoregional failure-free survival (LRFS), distant metastasis-free survival (DMFS), objective response rate (ORR), and toxicities.

RESULTS

From June 2018 to June 2020, 75 patients were enrolled with a median follow-up duration of 28.0 months. The ORR of the whole cohort was 94.7%. Disease progression or death was recorded in 44 (58.7%) patients, with a median PFS of 21.6 months (95% confidence interval [CI], 15.6-27.6 months). The 1- and 2-year PFS rates were 81.3% (95% CI, 72.5%-90.1%) and 43.3% (95% CI, 31.5%-55.1%), respectively. The median OS, DMFS, and LRFS had not been reached at the time of the last follow-up. The 1- and 2-year OS rates were 94.7% (95% CI, 89.6%-99.8%) and 72.4% (95% CI, 62.0%-82.8%), respectively. The most frequent acute nonhematologic toxicity was radiation esophagitis. Grade (G) 2 and G3 acute radiation esophagitis were observed in 20 (26.7%) and 4 (5.3%) patients, respectively. Thirteen patients (13/75, 17.3%) had G2 pneumonitis and no G3-G5 acute pneumonitis occurred during follow-up.

CONCLUSIONS

Hypo-RT followed by hypo-boost combined with concurrent weekly chemotherapy could yield satisfactory local control and survival outcomes with moderate radiation-induced toxicity in patients with LA-NSCLC. The new potent hypo-CCRT regimen significantly shortened treatment time and provided the potential opportunity for the combination of consolidative immunotherapy.

Accelerated hypofractionated magnetic resonance-guided adaptive radiotherapy for oligoprogressive non-small cell lung cancer

Given the positive results from recent randomized controlled trials in patients with oligometastatic, oligoprogressive, or oligoresidual disease, the role of radiotherapy has expanded in patients with metastatic non-small cell lung cancer (NSCLC). While small metastatic lesions are commonly treated with stereotactic body radiotherapy (SBRT), treatment of the primary tumor and involved regional lymph nodes may require prolonged fractionation schedules to ensure safety especially when treating larger volumes in proximity to critical organs-at-risk (OARs). We have developed an institutional MR-guided adaptive radiotherapy (MRgRT) workflow for these patients. We present a 71-year-old patient with stage IV NSCLC with oligoprogression of the primary tumor and associated regional lymph nodes in which MR-guided, online adaptive radiotherapy was performed, prescribing 60 Gy in 15 fractions. We describe our workflow, dosimetric constraints, and daily dosimetric comparisons for the critical OARs (esophagus, trachea, and proximal bronchial tree [PBT] maximum doses [D0.03cc]), in comparison to the original treatment plan recalculated on the anatomy of the day (i.e., predicted doses). During MRgRT, few fractions met the original dosimetric objectives: 6.6% for esophagus, 6.6% for PBT, and 6.6% for trachea. Online adaptive radiotherapy reduced the cumulative doses to the structures by 11.34%, 4.2%, and 5.62% when comparing predicted plan summations to the final delivered summation. Therefore, this case study presets a workflow and treatment paradigm for accelerated hypofractionated MRgRT due to the significant variations in daily dose to the central thoracic OARs to reduce treatment-related toxicity associated with radiotherapy.

STereotactic Ablative RadioTherapy in NEWly Diagnosed and Recurrent Locally Advanced Non-Small Cell Lung Cancer Patients Unfit for ConcurrEnt RAdio-Chemotherapy: Early Analysis of the START-NEW-ERA Non-Randomised Phase II Trial

PURPOSE

This is a single arm phase 2 trial (Clinical trials.gov NCT05291780) to assess local control (LC) and safety of SAbR in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC) unfit for concurrent chemo-radiation therapy (ChT-RT).

METHODS

Neoadjuvant ChT was prescribed in fit patients. The tumor volume included primary tumor and any regionally positive node/s. The coprimary study endpoints were LC and safety.

RESULTS

Between December 31, 2015, and December 31, 2020, 50 patients with LA-NSCLC were enrolled. Histology was squamous cell carcinoma and adenocarcinoma (ADC) in 52% and 48%, respectively. Forty (80%) patients had ultracentral tumor. Twenty-seven (54%) received neoadjuvant ChT and 7 (14%) adjuvant durvalumab. Median prescribed dose was 45 Gy (range, 35-55) and 40 Gy (35-45) in 5 daily fractions to tumor and node/s, respectively. After a median follow-up of 38 months (range, 12-80), 19 (38%) patients had experienced local recurrence (LR) at a median time of 13 months (range, 7-34). The median LR-free survival (FS) was not reached (95% confidence interval [CI], 28 to not reached). The 1-, 2-, and 3-year LR-FS rates were 86% ± 5%, 66% ± 7%, and 56% ± 8%, respectively. At last follow-up, 33 (66%) patients were alive. Median overall survival (OS) was 55 months (95% CI, 43-55 months). The 1-, 2-, and 3-year OS rates were 94% ± 3%, 79% ± 6%, and 72% ± 7%, respectively. No patients developed ≥ grade (G) 3 toxicity. ADC (hazard ratio [HR], 3.61; 95% CI, 1.15-11.35) was a significant predictor of better LC, while OS was significantly conditioned by smaller planning target volumes (HR, 1.004; 95% CI, 1.001-1.010) and tumor, node, and metastasis stage (HR, 4.8; 95% CI, 1.34-17).

CONCLUSIONS

Patients with LA-NSCLC treated with SABR had optimal LC and promising OS in absence of ≥G3 toxicity. Our early outcomes would suggest the feasibility of using this approach in patients with LA-NSCLC unfit for concurrent ChT-RT.

Utilization and Survival Impact of Hypofractionated Radiotherapy in Stage I Non-small Cell Lung Cancer

OBJECTIVES

The optimal fractionation schedule in unresected stage I non-small cell lung cancer (NSCLC) unsuitable for stereotactic body radiation therapy is unclear. Given the lack of comparative data regarding nonstereotactic body radiation therapy schemas, we compared overall survival (OS) with hypofractionated radiotherapy (HFRT) versus conventionally fractionated radiotherapy (CFRT) and examined the OS impact of different HFRT doses.

MATERIALS AND METHODS

This retrospective analysis included 2159 patients from the National Cancer Database diagnosed with stage I (cT1-2aN0M0) NSCLC between 2008 and 2016. Patients underwent CFRT (70≤BED10 [biologically effective dose] <100 Gy10 in ≥30 fractions), low-dose HFRT (LD-HFRT; 70≤BED10 [assuming α/β=10] <100 Gy10 in 11 to 24 fractions), or high-dose HFRT (HD-HFRT; 100≤BED10 ≤120 Gy10 in 6 to 10 fractions). Patients who received surgery, chemotherapy, or immunotherapy were excluded. We compared CFRT versus all HFRT, and separately CFRT versus LD-HFRT and CFRT versus HD-HFRT. OS was evaluated with the Kaplan-Meier estimator, log-rank test, and Cox regression.

RESULTS

A total of 63.2% of patients underwent CFRT, 23.5% LD-HFRT, and 13.3% HD-HFRT. OS was significantly longer with HFRT versus CFRT on univariable (28.2 mo [95% CI, 25.6-31.7] vs 26.4 mo [25.0-27.9]; log-rank=0.0025) but not multivariable analysis (MVA; hazard ratio [HR] 0.90; P=0.062). MVA yielded no significant difference in OS between CFRT and LD-HFRT (HR 0.96, P=0.53). OS was significantly longer with HD-HFRT versus CFRT on MVA (HR, 0.75; P=0.003). However, on sensitivity analysis using different multivariable modeling techniques, this did not retain statistical significance (HR, 0.83; P=0.12).

CONCLUSIONS

For stage I NSCLC, HFRT does not show a robust OS benefit compared with CFRT but may be preferred given the convenience and lower costs.

Persisting Gaps in Optimal Care of Stage III Non-small Cell Lung Cancer: An Australian Patterns of Care Analysis

BACKGROUND

Wide variation exists globally in the treatment and outcomes of stage III patients with non-small cell lung cancer (NSCLC). We conducted an up-to-date patterns of care analysis in the state of Victoria, Australia, with a particular focus on the proportion of patients receiving treatment with radical intent, treatment trends over time, and survival.

MATERIALS AND METHODS

Stage III patients with NSCLC were identified in the Victorian Lung Cancer Registry and categorized by treatment received and treatment intent. Logistic regression was used to explore factors predictive of receipt of radical treatment and the treatment trends over time. Cox regression was used to explore variables associated with overall survival (OS). Covariates evaluated included age, sex, ECOG performance status, smoking status, year of diagnosis, Australian born, Aboriginal or Torres Strait Islander status, socioeconomic status, rurality, public/private status of notifying institution, and multidisciplinary meeting discussion.

RESULTS

A total of 1396 patients were diagnosed between 2012 and 2019 and received treatment with radical intent 67%, palliative intent 23%, unknown intent 5% and no treatment 5%. Radical intent treatment was less likely if patients were >75 years, ECOG ≥1, had T3-4 or N3 disease or resided rurally. Surgery use decreased over time, while concurrent chemoradiotherapy and immunotherapy use increased. Median OS was 38.0, 11.1, and 4.4 months following radical treatment, palliative treatment or no treatment, respectively.

CONCLUSION

Almost a third of stage III patients with NSCLC still do not receive radical treatment. Strategies to facilitate radical treatment and better support decision making between increasing multimodality options are required.

A digital physician peer to automatically detect erroneous prescriptions in radiotherapy

Appropriate dosing of radiation is crucial to patient safety in radiotherapy. Current quality assurance depends heavily on a physician peer-review process, which includes a review of the treatment plan's dose and fractionation. Potentially, physicians may not identify errors during this manual peer review due to time constraints and caseload. A novel prescription anomaly detection algorithm is designed that utilizes historical data from the past to predict anomalous cases. Such a tool can serve as an electronic peer who will assist the peer-review process providing extra safety to the patients. In our primary model, we create two dissimilarity metrics, R and F. R defining how far a new patient's prescription is from historical prescriptions. F represents how far away a patient's feature set is from that of the group with an identical or similar prescription. We flag prescription if either metric is greater than specific optimized cut-off values. We use thoracic cancer patients (n = 2504) as an example and extracted seven features. Our testing set f1 score is between 73%-94% for different treatment technique groups. We also independently validate our results by conducting a mock peer review with three thoracic specialists. Our model has a lower type II error rate compared to the manual peer-review by physicians.

Effect of thoracic radiotherapy dose on the prognosis of advanced lung adenocarcinoma harboring EGFR mutations

Background

The aim of this study was to investigate the effects of different thoracic radiotherapy doses on OS and incidence of radiation pneumonia which may provide some basis for optimizing the comprehensive treatment scheme of these patients with advanced EGFR mutant lung adenocarcinoma.

Methods

Data from 111 patients with EGFR-mutant lung adenocarcinoma who received thoracic radiotherapy were included in this retrospective study. Overall survival (OS) was the primary endpoints of the study. Kaplan–Meier method was used for the comparison of OS. The Cox proportional-hazard model was used for the multivariate and univariate analyses to determine the prognostic factors related to the disease.

Results

The mOS rates of the patients, who received radiotherapy dose scheme of less than 50 Gy, 50–60 Gy (including 50 Gy), and 60 Gy or more were 29.1 months, 34.4 months, and 51.0 months, respectively (log-rank P = 0.011). Although trend suggested a higher levels of pneumonia cases with increasing radiation doses, these lack statistical significance (χ2 = 1.331; P = 0.514). The multivariate analysis showed that the thoracic radiotherapy dose schemes were independently associated with the improved OS of patients (adjusted hazard ratio [HR], 0.606; 95% CI, 0.382 to 0.961; P = 0.033).

Conclusions

For the patients with advanced EGFR-mutant lung adenocarcinoma, the radical thoracic radiotherapy dose scheme (≥ 60 Gy) could significantly prolong the OS of patients during the whole course management.

GOECP/SEOR radiotheraphy guidelines for non-small-cell lung cancer

Non-small cell lung cancer (NSCLC) is a heterogeneous disease accounting for approximately 85% of all lung cancers. Only 17% of patients are diagnosed at an early stage. Treatment is multidisciplinary and radiotherapy plays a key role in all stages of the disease. More than 50% of patients with NSCLC are treated with radiotherapy (curative-intent or palliative). Technological advances-including highly conformal radiotherapy techniques, new immobilization and respiratory control systems, and precision image verification systems-allow clinicians to individualize treatment to maximize tumor control while minimizing treatment-related toxicity. Novel therapeutic regimens such as moderate hypofractionation and advanced techniques such as stereotactic body radiotherapy (SBRT) have reduced the number of radiotherapy sessions. The integration of SBRT into routine clinical practice has radically altered treatment of early-stage disease. SBRT also plays an increasingly important role in oligometastatic disease. The aim of the present guidelines is to review the role of radiotherapy in the treatment of localized, locally-advanced, and metastatic NSCLC. We review the main radiotherapy techniques and clarify the role of radiotherapy in routine clinical practice. These guidelines are based on the best available evidence. The level and grade of evidence supporting each recommendation is provided.

Pooled analysis on image-guided moderately hypofractionated thoracic irradiation in inoperable node-positive/recurrent patients with non-small cell lung cancer with poor prognostic factors and severely limited pulmonary function and reserve

BACKGROUND

The objective of this study was to investigate the feasibility and efficacy of image-guided moderately hypofractionated thoracic radiotherapy (hypo-IGRT) in patients with non-small cell lung cancer (NSCLC) with poor performance status and severely limited pulmonary function and reserve.

METHODS

Consecutive inoperable patients who had node-positive, stage IIB-IIIC (TNM, 8th edition) or recurrent NSCLC, had an Eastern Cooperative Oncology Group performance status ≥1, and had a forced expiratory volume in 1 second (FEV₁ ) ≤1.0 L, had a single-breath diffusing capacity of the lung for carbon monoxide (DLCO-SB) ≤40% and/or on long-term oxygen therapy were analyzed. All patients received hypofractionated IGRT to a total dose of 42.0 to 49.0 Gy/13 to 16 fractions (2.8-3.5 Gy/fraction) (equivalent dose in 2-Gy fractions/biologically effective dose [α/β = 10] = 45.5-55.1 Gy/54.6-66.2 Gy) alone. Patients were monitored closely for nonhematological toxicity, which was classified per National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

Between 2014 and 2021, 47 consecutive patients with a median age of 72 years (range, 52.2-88 years) were treated. At baseline, the median FEV₁ , vital capacity, and DLCO-SB were 1.17 L (range, 0.69-2.84 L), 2.34 L (range, 1.23-3.74 L), and 35% predicted (range, 13.3%-69.0%), respectively. The mean and median planning target volumes were 410.8 cc (SD, 267.1 cc) and 315.4 cc (range, 83.4-1174.1 cc). With a median follow-up of 28.9 months (range, 0.5-90.6 months) after RT, the median progression-free survival (PFS)/overall survival (OS) and 6- and 12-month PFS/OS rates were 10.4 months (95% CI, 7-13.8 months)/18.3 months (95% CI, 9.2-27.4 months), 70%/89.4%, and 38.8%/66%, respectively. Treatment was well tolerated with only 1 case each of grade 3 pneumonitis and esophagitis. No toxicity greater than grade 3 was observed.

CONCLUSIONS

Patients with inoperable node-positive NSCLC, a poor performance status, and severely limited lung function can be safely and effectively treated with individualized moderately hypofractionated IGRT. The achieved survival rates for this highly multimorbid group of patients were encouraging.

Management of Stage III Non-Small-Cell Lung Cancer: ASCO Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on management of patients with stage III non-small-cell lung cancer (NSCLC).

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary oncology, community oncology, research methodology, and advocacy experts was convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2021. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 127 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address evaluation and staging workup of patients with suspected stage III NSCLC, surgical management, neoadjuvant and adjuvant approaches, and management of patients with unresectable stage III NSCLC.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

Oesophageal IGRT considerations for SBRT of LA-NSCLC: barium-enhanced CBCT and interfraction motion

Background

To determine the optimal volume of barium for oesophageal localisation on cone-beam CT (CBCT) for locally-advanced non-small cell lung cancers (NSCLC) and quantify the interfraction oesophageal movement relative to tumour.

Methods

Twenty NSCLC patients with mediastinal and/or hilar disease receiving radical radiotherapy were recruited. The first five patients received 25 ml of barium prior to their planning CT and alternate CBCTs during treatment. Subsequent five patient cohorts, received 15 ml, 10 ml and 5 ml. Six observers contoured the oesophagus on each of the 107 datasets and consensus contours were created. Overall 642 observer contours were generated and interobserver contouring reproducibility was assessed. The kappa statistic, dice coefficient and Hausdorff Distance (HD) were used to compare barium-enhanced CBCTs and non-enhanced CBCTs. Oesophageal displacement was assessed using the HD between consensus contours of barium-enhanced CBCTs and planning CTs.

Results

Interobserver contouring reproducibility was significantly improved in barium-enhanced CBCTs compared to non-contrast CBCTs with minimal difference between barium dose levels. Only 10 mL produced a significantly higher kappa (0.814, p = 0.008) and dice (0.895, p = 0.001). The poorer the reproducibility without barium, the greater the improvement barium provided. The median interfraction HD between consensus contours was 4 mm, with 95% of the oesophageal displacement within 15 mm.

Conclusions

10 mL of barium significantly improves oesophageal localisation on CBCT with minimal image artifact. The oesophagus moves substantially and unpredictably over a course of treatment, requiring close daily monitoring in the context of hypofractionation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01946-8.

American Radium Society Appropriate Use Criteria for Radiation Therapy in Oligometastatic or Oligoprogressive Non-Small Cell Lung Cancer

PURPOSE

Recent randomized studies have suggested improvements in progression-free and overall survival with the addition of stereotactic body radiation therapy (SBRT, also known as SABR) in patients with oligometastatic non-small cell lung cancer. Given the novelty and complexity of incorporating SBRT in the oligometastatic setting, the multidisciplinary American Radium Society Lung Cancer Panel was assigned to create appropriate use criteria on SBRT as part of consolidative local therapy for patients with oligometastatic and oligoprogressive non-small cell lung cancer.

METHODS AND MATERIALS

A review of the current literature was conducted from January 1, 2008, to December 25, 2020, using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to systematically search the PubMed database to retrieve a comprehensive set of relevant articles.

RESULTS

Based on representation in existing randomized trials, the panel defined the term "oligometastasis" as ≤3 metastatic deposits (not including the primary tumor) in the previously untreated setting or after first-line systemic therapy after the initial diagnosis. "Oligoprogression" also referred to ≤3 discrete areas of progression in the setting of prior or ongoing receipt of systemic therapy. In all appropriate patients, the panel strongly recommends enrollment in a clinical trial whenever available. For oligometastatic disease, administering first-line systemic therapy followed by consolidative radiation therapy (to all sites plus the primary/nodal disease) is preferred over up-front radiation therapy. Owing to a dearth of data, the panel recommended that consolidative radiation therapy be considered on a case-by-case basis for 4 to 5 sites of oligometastatic disease, driver mutation-positive oligometastatic disease without progression on up-front targeted therapy, and oligoprogressive cases.

CONCLUSIONS

Although SBRT/SABR appears to be both safe and effective in treating patients with limited metastatic sites of disease, many clinical circumstances require individualized management and strong multidisciplinary discussion on account of the limited existing data.

Treatment outcomes of passive scattering proton beam therapy for stage I non-small cell lung cancer

INTRODUCTION

To investigate the treatment outcomes of passive scattering proton beam therapy using stereotactic ablative radiotherapy (SABR) or hypofractionated radiation therapy (RT) for inoperable patients or those who refused surgery for stage I non-small cell lung cancer (NSCLC).

METHODS

From January 2016 to December 2019, we retrospectively analyzed 42 patients with stage I NSCLC treated with proton beam therapy. The initially intended dose regimen was 60 cobalt Gray equivalents (CGE) in 4 fractions; however, sequentially modified dose regimens were used when the dose-volume constraints could not be met. The median total dose was 50 CGE (range 50-70 CGE), while the corresponding median biologically effective dose using [Formula: see text]= 10 (BED₁₀) was 112.5 CGE (range 96-150 CGE).

RESULTS

The median follow-up time was 40 months (interquartile range 32-48 months). Among the 42 treated patients, 33 had pathologically proven cancers of which most were adenocarcinoma (n = 21, 64%). The 3-year overall survival rate was 71.8%. The estimated rates of local control and progression free survival at 3 years were 91.5% and 66.9%, respectively. Thirteen patients experienced disease progression consisting of three local, six regional, and nine distant failures. No grade 4 or 5 toxicities were observed.

CONCLUSION

Passive scattering proton beam therapy for stage I NSCLC using SABR or hypofractionated RT was safe and showed high LC rates.

Accelerated Hypofractionated Image-Guided vs Conventional Radiotherapy for Patients With Stage II/III Non-Small Cell Lung Cancer and Poor Performance Status: A Randomized Clinical Trial

Importance

A significant subset of patients with stage II/III non-small cell lung cancer (NSCLC) cannot receive standard concurrent chemoradiotherapy owing to the risk of toxic effects outweighing potential benefits. Without concurrent chemotherapy, however, the efficacy of conventional radiotherapy is reduced.

Objective

To determine whether hypofractionated image-guided radiotherapy (IGRT) would improve overall survival in patients with stage II/III NSCLC who could not receive concurrent chemoradiotherapy and therefore were traditionally relegated to receiving only conventionally fractionated radiotherapy (CFRT).

Design, Setting, and Participants

This nonblinded, phase 3 randomized clinical study enrolled 103 patients and analyzed 96 patients with stage II/III NSCLC and Zubrod performance status of at least 2, with greater than 10% weight loss in the previous 6 months, and/or who were ineligible for concurrent chemoradiotherapy after oncology consultation. Enrollment occurred at multiple US institutions. Patients were enrolled from November 13, 2012, to August 28, 2018, with a median follow-up of 8.7 (3.6-19.9) months. Data were analyzed from September 14, 2018, to April 11, 2021.

Interventions

Eligible patients were randomized to hypofractionated IGRT (60 Gy in 15 fractions) vs CFRT (60 Gy in 30 fractions).

Main Outcomes and Measures

The primary end point was 1-year overall survival.

Results

A total of 103 patients (96 of whom were analyzed [63 men (65.6%); mean (SD) age, 71.0 (10.2) years (range, 50-90 years)]) were randomized to hypofractionated IGRT (n = 50) or CFRT (n = 46) when a planned interim analysis suggested futility in reaching the primary end point, and the study was closed to further accrual. There was no statistically significant difference between the treatment groups for 1-year overall survival (37.7% [95% CI, 24.2%-51.0%] for hypofractionated IGRT vs 44.6% [95% CI, 29.9%-58.3%] for CFRT; P = .29). There were also no significant differences in median overall survival, progression-free survival, time to local failure, time to distant metastasis, and toxic effects of grade 3 or greater between the 2 treatment groups.

Conclusions and Relevance

This phase 3 randomized clinical trial found that hypofractionated IGRT (60 Gy in 15 fractions) was not superior to CFRT (60 Gy in 30 fractions) for patients with stage II/III NSCLC ineligible for concurrent chemoradiotherapy. Further studies are needed to verify equivalence between these radiotherapy regimens. Regardless, for well-selected patients with NSCLC (ie, peripheral primary tumors and limited mediastinal/hilar adenopathy), the convenience of hypofractionated radiotherapy regimens may offer an appropriate treatment option.

Trial Registration

ClinicalTrials.gov Identifier: NCT01459497.

Hypofractionated Volumetric-Modulated Arc Radiotherapy for Patients With Non-Small-Cell Lung Cancer Not Suitable for Surgery or Conventional Chemoradiotherapy or SBRT

Background

Hypofractionated radiotherapy (HypoRT) has been used to pursue an alternative treatment regimen for patients with non-small-cell lung cancer (NSCLC) who are not eligible for stereotactic ablative radiotherapy (SABR), surgery or concurrent chemoradiotherapy (CCRT) and has shown good local control and safety. We analyzed the feasibility of using volumetric-modulated arc radiotherapy (VMAT) with the simultaneous integrated boost (SIB) technique to achieve high local control with few treatment-related toxicities.

Patients and Methods

A total of 55 patients with stage I-IV NSCLC who were not candidates for SABR, surgery or CCRT were included in the present study. All patients received a prescribed dose of 60 to 66 Gy in 15 fractions. Local progression-free survival (LPFS), PFS, overall survival (OS), and toxicities were retrospectively analyzed.

Results

Thirty-three patients (60.0%) had stage IV or recurrent disease in this study. The median follow-up time was 8 months (interquartile range: 5.0-16.3 months). The 1-year and 2-year OS rates were 84.3% and 69.9%, and the 1-year and 2-year LPFS rates were 91.0% and 63.0%. The median OS (mOS) and median LPFS (mLPFS) were not reached, and median PFS (mPFS) was 15 months. Twenty-eight (51.9%) patients had disease progression at the time of analysis. Of these, 7 (13.0%), 7 (13.0%) and 21 (38.9%) had local recurrence, locoregional failure and distant metastasis, respectively. All cases of local recurrence were found within the SIB region. Four patients had grade 2-3 pneumonitis, and 8 patients had grade 2-3 esophagitis. Patients with grade 2-3 esophagitis had significantly higher maximum dose and dose to 5 cm³ volume to esophagus than those with grade 0-1 esophagitis. No grade 4 or higher toxicity was observed.

Conclusion

The 60 to 66 Gy in 15 fractions RT regimen provides favorable local control and survival with well-tolerated toxicities. Hypofractionated VMAT+SIB is an alternative treatment option for patients with NSCLC who cannot tolerate standard definitive therapy.

Stereotactic Radiation for Lung Cancer: A Practical Approach to Challenging Scenarios

Stereotactic body radiation therapy (SBRT) is an effective and well-tolerated treatment for medically inoperable patients with early stage NSCLC. SBRT is a noninvasive treatment involving the delivery of ablative radiation doses with high precision in the course of a few treatments. Relative to conventionally fractionated radiation, SBRT achieves superior local control and survival. SBRT use has increased dramatically in the past 15 years and is currently considered the standard of care in cases of inoperable early stage NSCLC. It is being increasingly applied to more complex patient populations at higher risk of treatment-related toxicity. In these more complex patients, there is an increasing need to balance patient and treatment factors in selecting the optimal patients for SBRT. Here, we review several challenging clinical scenarios often encountered in thoracic multidisciplinary tumor boards.

An adversarial machine learning framework and biomechanical model-guided approach for computing 3D lung tissue elasticity from end-expiration 3DCT

PURPOSE

Lung elastography aims at measuring the lung parenchymal tissue elasticity for applications ranging from diagnostic purposes to biomechanically guided deformations. Characterizing the lung tissue elasticity requires four-dimensional (4D) lung motion as an input, which is currently estimated by deformably registering 4D computed tomography (4DCT) datasets. Since 4DCT imaging is widely used only in a radiotherapy treatment setup, there is a need to predict the elasticity distribution in the absence of 4D imaging for applications within and outside of radiotherapy domain.

METHODS

In this paper, we present a machine learning-based method that predicts the three-dimensional (3D) lung tissue elasticity distribution for a given end-expiration 3DCT. The method to predict the lung tissue elasticity from an end-expiration 3DCT employed a deep neural network that predicts the tissue elasticity for the given CT dataset. For training and validation purposes, we employed five-dimensional CT (5DCT) datasets and a finite element biomechanical lung model. The 5DCT model was first used to generate end-expiration lung geometry, which was taken as the source lung geometry for biomechanical modeling. The deformation vector field pointing from end expiration to end inhalation was computed from the 5DCT model and taken as input in order to solve for the lung tissue elasticity. An inverse elasticity estimation process was employed, where we iteratively solved for the lung elasticity distribution until the model reproduced the ground-truth deformation vector field. The machine learning process uses a specific type of learning process, namely a constrained generalized adversarial neural network (cGAN) that learned the lung tissue elasticity in a supervised manner. The biomechanically estimated tissue elasticity together with the end-exhalation CT was the input for the supervised learning. The trained cGAN generated the elasticity from a given breath-hold CT image. The elasticity estimated was validated in two approaches. In the first approach, a L2-norm-based direct comparison was employed between the estimated elasticity and the ground-truth elasticity. In the second approach, we generated a synthetic four-dimensional CT (4DCT0 using a lung biomechanical model and the estimated elasticity and compared the deformations with the ground-truth 4D deformations using three image similarity metrics: mutual Information (MI), structured similarity index (SSIM), and normalized cross correlation (NCC).

RESULTS

The results show that a cGAN-based machine learning approach was effective in computing the lung tissue elasticity given the end-expiration CT datasets. For the training data set, we obtained a learning accuracy of 0.44 ± 0.2 KPa. For the validation dataset, consisting of 13 4D datasets, we were able to obtain an accuracy of 0.87 ± 0.4 KPa. These results show that the cGAN-generated elasticity correlates well with that of the underlying ground-truth elasticity. We then integrated the estimated elasticity with the biomechanical model and applied the same boundary conditions in order to generate the end inhalation CT. The cGAN-generated images were very similar to that of the original end inhalation CT. The average value of the MI is 1.77 indicating the high local symmetricity between the ground truth and the cGAN elasticity-generated end inhalation CT data. The average value of the structural similarity for the 13 patients was observed to be 0.89 indicating the high structural integrity of the cGAN elasticity-generated end inhalation CT. Finally, the average NCC value of 0.97 indicates that potential variations in the contrast and brightness of the cGAN elasticity-generated end inhalation CT and the ground-truth end inhalation CT.

CONCLUSION

The cGAN-generated lung tissue elasticity given an end-expiration CT image can be computed in near real time. Using the lung tissue elasticity along with a biomechanical model, 4D lung deformations can be generated from a given end-expiration CT image within clinically acceptable numerical accuracy.

Study protocol: a multicentre, prospective, phase II trial of isotoxic hypofractionated concurrent chemoradiotherapy for non-small cell lung cancer

INTRODUCTION

Concurrent chemoradiotherapy with conventional fractionation has been acknowledged as one of the standard treatments for locally advanced non-small cell lung cancer (NSCLC). The radiotherapy dose of 60 Gy is far from enough for local tumour control. Due to this fact, hypofractionated radiotherapy can shorten the total treatment duration, partially counteract the accelerated repopulation of tumour cells and deliver a higher biological effective dose, it has been increasingly used for NSCLC. In theory, concurrent hypofractionated chemoradiotherapy can result in an enhanced curative effect. To date, the vast majority of radiotherapy prescriptions assign a uniform radiotherapy dose to all patients. However this kind of uniform radiotherapy prescription may lead to two consequences: excess damage to normal tissues for large tumours and insufficient dose for small tumours. Our study aims to evaluate whether delivering individualised radiotherapy dose is feasible using intensity-modulated radiotherapy.

METHODS AND ANALYSIS

Our study of individualised radiotherapy is a multicenter phase II trial. From April 2019, a total of 30 patients from three Chinese centres, with a proven histological or cytological diagnosis of inoperable NSCLC, will be recruited. The dose of radiation will be increased until one or more of the organs at risk tolerance or the maximum dose of 69 Gy is reached. The primary end point is feasibility, with response rates, progression-free survival and overall survival as secondary end points. The concurrent chemotherapy regimen will be docetaxel plus lobaplatin.

ETHICS AND DISSEMINATION

The study has been approved by medical ethics committees from three research centres. The trial is conducted in accordance with the Declaration of Helsinki.The trial results will be disseminated through academic conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03606239.

Reduced Fractionation in Lung Cancer Patients Treated with Curative-intent Radiotherapy during the COVID-19 Pandemic

Patients treated with curative-intent lung radiotherapy are in the group at highest risk of severe complications and death from COVID-19. There is therefore an urgent need to reduce the risks associated with multiple hospital visits and their anti-cancer treatment. One recommendation is to consider alternative dose-fractionation schedules or radiotherapy techniques. This would also increase radiotherapy service capacity for operable patients with stage I-III lung cancer, who might be unable to have surgery during the pandemic. Here we identify reduced-fractionation for curative-intent radiotherapy regimes in lung cancer, from a literature search carried out between 20/03/2020 and 30/03/2020 as well as published and unpublished audits of hypofractionated regimes from UK centres. Evidence, practical considerations and limitations are discussed for early-stage NSCLC, stage III NSCLC, early-stage and locally advanced SCLC. We recommend discussion of this guidance document with other specialist lung MDT members to disseminate the potential changes to radiotherapy practices that could be made to reduce pressure on other departments such as thoracic surgery. It is also a crucial part of the consent process to ensure that the risks and benefits of undergoing cancer treatment during the COVID-19 pandemic and the uncertainties surrounding toxicity from reduced fractionation have been adequately discussed with patients. Furthermore, centres should document all deviations from standard protocols, and we urge all colleagues, where possible, to join national/international data collection initiatives (such as COVID-RT Lung) aimed at recording the impact of the COVID-19 pandemic on lung cancer treatment and outcomes.

Practice Recommendations for Lung Cancer Radiotherapy During the COVID-19 Pandemic: An ESTRO-ASTRO Consensus Statement

Background

The COVID-19 pandemic has caused radiotherapy resource pressures and led to increased risks for lung cancer patients and healthcare staff. An international group of experts in lung cancer radiotherapy established this practice recommendation pertaining to whether and how to adapt radiotherapy for lung cancer in the COVID-19 pandemic.

Methods

For this ESTRO & ASTRO endorsed project, 32 experts in lung cancer radiotherapy contributed to a modified Delphi consensus process. We assessed potential adaptations of radiotherapy in two pandemic scenarios. The first, an early pandemic scenario of risk mitigation, is characterized by an altered risk–benefit ratio of radiotherapy for lung cancer patients due to their increased susceptibility for severe COVID-19 infection, and minimization of patient travelling and exposure of radiotherapy staff. The second, a later pandemic scenario, is characterized by reduced radiotherapy resources requiring patient triage. Six common lung cancer cases were assessed for both scenarios: peripherally located stage I NSCLC, locally advanced NSCLC, postoperative radiotherapy after resection of pN2 NSCLC, thoracic radiotherapy and prophylactic cranial irradiation for limited stage SCLC and palliative thoracic radiotherapy for stage IV NSCLC.

Results

In a risk-mitigation pandemic scenario, efforts should be made not to compromise the prognosis of lung cancer patients by departing from guideline-recommended radiotherapy practice. In that same scenario, postponement or interruption of radiotherapy treatment of COVID-19 positive patients is generally recommended to avoid exposure of cancer patients and staff to an increased risk of COVID-19 infection. In a severe pandemic scenario characterized by reduced resources, if patients must be triaged, important factors for triage include potential for cure, relative benefit of radiation, life expectancy, and performance status. Case-specific consensus recommendations regarding multimodality treatment strategies and fractionation of radiotherapy are provided.

Conclusion

This joint ESTRO-ASTRO practice recommendation established pragmatic and balanced consensus recommendations in common clinical scenarios of radiotherapy for lung cancer in order to address the challenges of the COVID-19 pandemic.

Alternative Multidisciplinary Management Options for Locally Advanced NSCLC During the Coronavirus Disease 2019 Global Pandemic

The coronavirus disease 2019 (COVID-19) pandemic is currently accelerating. Patients with locally advanced NSCLC (LA-NSCLC) may require treatment in locations where resources are limited, and the prevalence of infection is high. Patients with LA-NSCLC frequently present with comorbidities that increase the risk of severe morbidity and mortality from COVID-19. These risks may be further increased by treatments for LA-NSCLC. Although guiding data is scarce, we present an expert thoracic oncology multidisciplinary (radiation oncology, medical oncology, surgical oncology) consensus of alternative strategies for the treatment of LA-NSCLC during a pandemic. The overarching goals of these approaches are the following: (1) reduce the number of visits to a health care facility, (2) reduce the risk of exposure to severe acute respiratory syndrome-coronavirus-2, (3) attenuate the immunocompromising effects of lung cancer therapies, and (4) provide effective oncologic therapy. Patients with resectable disease can be treated with definitive nonoperative management if surgical resources are limited or the risks of perioperative care are high. Nonoperative options include chemotherapy, chemoimmunotherapy, and radiation therapy with sequential schedules that may or may not affect long-term outcomes in an era in which immunotherapy is available. The order of treatments may be on the basis of patient factors and clinical resources. Whenever radiation therapy is delivered without concurrent chemotherapy, hypofractionated schedules are appropriate. For patients who are confirmed to have COVID-19, usually, cancer therapies may be withheld until symptoms have resolved with negative viral test results. The risk of severe treatment-related morbidity and mortality is increased for patients undergoing treatment for LA-NSCLC during the COVID-19 pandemic. Adapting alternative treatment strategies as quickly as possible may save lives and should be implemented through communication with the multidisciplinary cancer team.

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.

Survival and Toxicity of Hypofractionated Intensity Modulated Radiation Therapy in 4 Gy Fractions for Unresectable Stage III Non-Small Cell Lung Cancer

PURPOSE

To assess the survival, local and distant control, and toxicity in patients with unresectable locally advanced non-small cell lung cancer treated with radical-intent hypofractionated radiation therapy delivering approximately 60 Gy in 4-Gy fractions.

METHODS AND MATERIALS

Consecutive patients with unresectable stage III non-small cell lung cancer (n = 42) who received hypofractionated intensity modulated radiation therapy were retrospectively analyzed (2012-2016). Treatments consisted of first-line platinum-based doublet induction chemotherapy followed by an intended dose of 60 Gy in 15 fractions.

RESULTS

During a median follow-up period of 46 months (95% confidence interval, 41-59) the median overall survival was 47 months (95% confidence interval, 31 to not reached). The 1-, 2-, 3-, and 5-year overall survival rates were 81%, 69%, 64%, and 32%, respectively. The 1-, 2-, 3-, and 5-year progression-free survival rates were 58%, 35%, 25%, and 25%, respectively. An isolated locoregional recurrence was seen in 12% of the patients (n = 5). The incidence of grade (G) 3 or higher treatment-related lung toxicity was 14% (n = 6), among which G3 toxicity was 9.5% (n = 4) and G5 toxicity was 4.8% (n = 2). Twelve percent of patients (n = 5) experienced G3 radiation esophagitis, and 2% (n = 1) had G4 esophageal toxicity.

CONCLUSIONS

Patients with unresectable locally advanced non-small cell lung cancer treated with hypofractionated intensity modulated radiation therapy in doses up to 60 Gy at 4 Gy per fraction had promising survival, although high-grade esophageal and lung toxicities were seen. Our findings deserve further evaluation in prospective studies.

Practice recommendations for lung cancer radiotherapy during the COVID-19 pandemic: An ESTRO-ASTRO consensus statement

Background

The COVID-19 pandemic has caused radiotherapy resource pressures and led to increased risks for lung cancer patients and healthcare staff. An international group of experts in lung cancer radiotherapy established this practice recommendation pertaining to whether and how to adapt radiotherapy for lung cancer in the COVID-19 pandemic.

Methods

For this ESTRO & ASTRO endorsed project, 32 experts in lung cancer radiotherapy contributed to a modified Delphi consensus process. We assessed potential adaptations of radiotherapy in two pandemic scenarios. The first, an early pandemic scenario of risk mitigation, is characterized by an altered risk–benefit ratio of radiotherapy for lung cancer patients due to their increased susceptibility for severe COVID-19 infection, and minimization of patient travelling and exposure of radiotherapy staff. The second, a later pandemic scenario, is characterized by reduced radiotherapy resources requiring patient triage. Six common lung cancer cases were assessed for both scenarios: peripherally located stage I NSCLC, locally advanced NSCLC, postoperative radiotherapy after resection of pN2 NSCLC, thoracic radiotherapy and prophylactic cranial irradiation for limited stage SCLC and palliative thoracic radiotherapy for stage IV NSCLC.

Results

In a risk-mitigation pandemic scenario, efforts should be made not to compromise the prognosis of lung cancer patients by departing from guideline-recommended radiotherapy practice. In that same scenario, postponement or interruption of radiotherapy treatment of COVID-19 positive patients is generally recommended to avoid exposure of cancer patients and staff to an increased risk of COVID-19 infection. In a severe pandemic scenario characterized by reduced resources, if patients must be triaged, important factors for triage include potential for cure, relative benefit of radiation, life expectancy, and performance status. Case-specific consensus recommendations regarding multimodality treatment strategies and fractionation of radiotherapy are provided.

Conclusion

This joint ESTRO-ASTRO practice recommendation established pragmatic and balanced consensus recommendations in common clinical scenarios of radiotherapy for lung cancer in order to address the challenges of the COVID-19 pandemic.

Hypofractionated vs. conventional radiation therapy for stage III non-small cell lung cancer treated without chemotherapy

Background: Patients with unresectable locally advanced NSCLC who refuse or are not candidates for chemotherapy often receive radiation therapy (RT) alone. Hypofractionated RT (HFRT) regimens are becoming increasingly common. An analysis of the National Cancer Database (NCDB) was performed to evaluate the practice patterns and outcomes of HFRT vs. conventionally fractionated RT (CFRT) in patients with stage III NSCLC undergoing definitive RT alone.Material and methods: The NCDB was queried for all patients with stage III NSCLC diagnosed between 2004 and 2014 who received RT alone. CFRT was defined as patients treated to a total dose of 60-80 Gy in 1.8-2 Gy daily fractions. HFRT was defined as patients treated to a total dose of 50-80 Gy in 2.25-4 Gy fractions. Logistic regression, univariable and multivariable analyses (MVAs) for overall survival (OS) and propensity score matched analyses (PSMAs) were performed.Results: A total of 6490 patients were evaluated: 5378 received CFRT and 1112 received HFRT. Median CFRT dose was 66 Gy in 2 Gy fractions vs. 58.5 Gy in 2.5 Gy fractions for HFRT. HFRT was associated with older age, lower biological effective dose (BED₁₀), academic facility type, higher T-stage and lower N-stage. On initial analysis, HFRT was associated with inferior OS (median 9.9 vs. 11.1 months, p<.001), but after adjusting for the imbalance in covariates such as age, BED₁₀, T-stage and N-stage using PSMA, the difference in survival was no longer significant (p=.1).Conclusions: In the appropriate clinical context, HFRT can be an option for patients with locally advanced NSCLC who are not candidates for chemotherapy or surgical resection. HFRT needs to be further studied in prospective trials to evaluate toxicity and tumor control.

Contrast enhanced oesophageal avoidance for stereotactic body radiotherapy: Barium vs. Gastrografin

INTRODUCTION

SABR may facilitate treatment in a greater proportion of locally-advanced NSCLC patients, just as it has for early-stage disease. The oesophagus is one of the key dose-limiting organs and visualization during IGRT would better ensure toxicity is avoided. As the oesophagus is poorly seen on CBCT, we assessed the extent to which this is improved using two oral contrast agents.

MATERIALS & METHODS

Six patients receiving radiotherapy for Stage I-III NSCLC were assigned to receive 50 mL Gastrografin or 50 mL barium sulphate prior to simulation and pre-treatment CBCTs. Three additional patients who did not receive contrast were included as a control group. Oesophageal visibility was determined by assessing concordance between six experienced observers in contouring the organ. 36 datasets and 216 contours were analysed. A STAPLE contour was created and compared to each individual contour. Descriptive statistics were used and a Kappa statistic, Dice Coefficient and Hausdorff distance were calculated and compared using a t-test. Contrast-induced artefact was assessed by observer scoring.

RESULTS

Both contrast agents significantly improved the consistency of oesophagus localisation on CBCT across all comparison metrics compared to CBCTs without contrast. Barium performed significantly better than Gastrografin with improved kappa statistics (p = 0.007), dice coefficients (p < 0.001) and Hausdorff distances (p = 0.002), although at a cost of increased image artefact.

DISCUSSION

Barium produced lower delineation uncertainties but more image artefact, compared to Gastrografin and no contrast. It is feasible to use oral contrast as a tool in IGRT to help guide clinicians and therapists with online matching and monitoring of the oesophageal position.

Definitive Radiotherapy for Inoperable Stage IIB Non-small-cell Lung Cancer: Patterns of Care and Comparative Effectiveness

BACKGROUND

The purpose of this study was to analyze practice patterns and perform comparative effectiveness of definitive radiotherapy techniques for inoperable stage IIB (American Joint Committee on Cancer eighth edition) non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Adults in the National Cancer Database diagnosed with T3N0M0 or T1-2N1M0 NCSLC between 2004 and 2015 who received definitive radiotherapy were identified. Cases were divided as stereotactic body radiotherapy (SBRT), hypofractionated radiotherapy (HFRT), or conventionally fractionated radiotherapy (CFRT) and stratified by systemic therapy (ST). Cox proportional hazards models evaluated the effect of covariates on overall survival (OS). Subgroup analysis by tumor size, chest wall invasion, multifocality, and ST use was performed with Kaplan-Meier estimates of OS.

RESULTS

A total of 10,081 subjects met inclusion criteria: 4401 T3N0M0 (66.5% CFRT, 11.0% HFRT, and 22.5% SBRT) and 5680 T1-2N1M0 (92.5% CFRT and 7.5% HFRT). For T3N0M0 NSCLC, SBRT utilization increased from 3.7% in 2006% to 35.4% in 2015. Subjects treated with SBRT were more likely to have smaller tumors, multifocal tumors, or adenocarcinoma histology. SBRT resulted in similar or superior OS compared with CFRT for tumors > 5 cm, tumors invading the chest wall, or multifocal tumors. SBRT was significantly associated with improved OS on multivariate analysis (hazard ratio, 0.715; P < .001). For T1-2N1M0 NSCLC, patients treated with HFRT were significantly older and less likely to receive ST; nevertheless, there was no difference in OS between HFRT and CFRT on multivariate analysis.

CONCLUSION

CFRT + ST is utilized most frequently to treat stage IIB NSCLC in the United States when surgery is not performed, though it is decreasing. SBRT utilization for T3N0M0 NSCLC is increasing and was associated with improved OS.

Survival score to characterize prognosis in inoperable stage III NSCLC after chemoradiotherapy

Background

Stage III non-small cell lung cancer (NSCLC) represents a heterogeneous disease regarding principal patient- and tumor characteristics. A simple score may aid in personalizing multimodal therapy.

Methods

The data of 99 consecutive patients with performance status ECOG 0-1 treated until the end of 2016 with multimodal approach for inoperable NSCLC (UICC 7^th edition stage IIIA/B) were evaluated. Patient- and tumor-related factors were examined for their impact on overall survival. Factors showing a negative association with prognosis were then included in the score. Three subgroups with low, intermediate and high-risk score were defined. The results were then validated in the prospective cohort, which includes 45 patients.

Results

Most Patients were treated with concurrent (78%) or sequential (11%) chemoradiotherapy. 53% received induction chemotherapy. Median survival for the entire cohort was 20.8 (range: 15.3-26.3) months. Age (P=0.020), gender (P=0.007), pack years (P=0.015), tumor-associated atelectasis (P=0.004) and histology (P=0.004) had a significant impact on overall survival and were scored with one point each. Twelve, 59 and 28 patients were defined to have a low (0-1 points), intermediate (2-3 points) and high-risk (4-5 points) score. Median survival, 1-, 2- and 3-year survival rates were not reached, 100%, 83% and 67% in the low, 22.9 months, 80%, 47% and 24% intermediate and 13.7 months, 57%, 25% and 18% high-risk patients, respectively (P<0.001). Median survival was not reached in prospective cohort; analysis has revealed a trend for the 1-year survival rates with 100% for the low, 93% intermediate and 69% high-risk patients (P=0.100).

Conclusions

The score demonstrated remarkable survival differences in inoperable stage III NSCLC patients with good performance status receiving multimodal therapy.

Initial report on feasibility of PET/CT-based image-guided moderate hypofractionated thoracic irradiation in node-positive non-small cell lung Cancer patients with poor prognostic factors and strongly diminished lung function: a retrospective analysis

Background

To determine the feasibility of PET/CT-based image-guided moderate hypofractionated thoracic irradiation (Hypo-IGRT) in locally advanced node-positive non-small cell lung cancer patients with highly compromised pulmonary function.

Method

Eight highly-selected and closely monitored patients with highly diminished pulmonary function (FEV1 ≤ 1.0 L and/or DLCO-SB ≤ 40% and/or on long-term oxygen therapy) were treated with Hypo-IGRT. Planning was based on 18F-FDG-PET/CT and 4D-CT in the treatment position. Hypo-IGRT was delivered to a total dose of 45 Gy (ICRU) in 15 daily fractions under strict image-guidance. Vital capacity (VC), forced expiratory volume in 1 s (FEV1), and single-breath diffusing capacity of the lung for CO (DLCO-SB) were analyzed prior to, 3 and 6 months after Hypo-IGRT.

Result

Eight patients with stage IIIA-C NSCLC (8th TNM Ed.) completed Hypo-IGRT. The median follow-up was 29.4 months. The median age was 64 years. Four, three and one patient(s) presented with COPD GOLD IV, III and II, respectively and 5 patients (63%) were on long-term oxygen therapy. The median PTV was 226.9 cc (range: 100.17–379.80 cc). Median PFS and OS were 19 and 34.3 months. The 6 months and 1-year OS rates were 100, 87.5%, respectively. The 6- and 12- months PFS rates were 87.5 and 52.5%. Three patients developed local failure. Median initial VC, FEV1 and DLCO-SB was 1.69 L/64.8% predicted (range: 1.36–2.66 L/33–80%), 1 L/39.4% predicted (range:0.78–1.26 L/28–60% predicted) and 33.3% (range: 13.3–54%) predicted, respectively. Median values for VC, FEV1, DLCO-SB 3 and 6 months after Hypo-IGRT were 2.05 L/56.35% predicted (range: 1.34–2.33 L/47–81.5%), 1.08 L/47.5% predicted (range: 0.74–1.60 L/30.8–59.59%), 38.55% (range: 24–68%) and 1.64 L/66% predicted (range: 1.41–2.79/35.5–75.5%), 1.0 L/47% predicted (range: 0.65–1.28 L/24.5–54.10%), 31% (range: 27–43%), respectively. Mean lung dose was 9.4 Gy (range: 5.3–11.6 Gy) and V20 for both lungs was 15% (range: 6–19%). Mean esophageal dose was 12.76 Gy (range: 2.1–26.7 Gy). There was no case of grade 2 or higher radiation pneumonitis. Four patients developed grade 2 radiation esophagitis.

Conclusion

Hypo-IGRT can be considered for individual and closely monitored patients with locally advanced node-positive NSCLC with highly compromised pulmonary function. No severe pulmonary toxicity and significant decline of pulmonary function parameters was observed in our cohort. Currently, this protocol is being assessed in an ongoing single-centre prospective study.

Accelerated hypofractionated radiotherapy plus chemotherapy for inoperable locally advanced non-small-cell lung cancer: final results of a prospective phase-II trial with a long-term follow-up

BACKGROUND

Concurrent chemotherapy and radiation using conventional fractionation is the standard treatment for inoperable, locally advanced non-small-cell lung cancer (NSCLC). We tested accelerated hypofractionated radiotherapy (AHR) and chemotherapy for the treatment of locally advanced NSCLC.

METHODS

Eligible patients with locally advanced NSCLC were treated with induction chemotherapy (cisplatin and docetaxel), followed by AHR using tomotherapy and consolidation chemotherapy. The prescribed doses were 30 Gy/5 daily fractions at the reference isodose (60-70%) to the tumor, and 25 Gy/5 daily fractions to the clinically involved lymph nodes. The primary end-point was response rate (RR); the secondary end-points were acute and late side-effects, local progression-free survival (PFS), metastasis-free survival (MFS) and overall survival (OS). This trial closed before the first planned interim analysis due to poor accrual.

RESULTS

From January 2009 to January 2012, 17 of the 23 enrolled patients were evaluable. Treatment yielded an overall RR of 82%. Median follow-up was 87 months (range: 6-87), local PFS was 19.8 months (95% CI 9.7 - not reached), MFS was 9.7 months (95% CI 5.8-46.0) and OS was 23 months (95% CI 8.4-48.4). 70% of patients experienced acute G4 neutropenia, 24% G4 leukopenia, 24% G3 paresthesia, 4% G3 cardiac arrythmia, 4% underwent death after chemotherapy. Late toxicity was represented by 24% dyspnea G3.

CONCLUSIONS

AHR combined with chemotherapy is feasible with no severe side-effects, and it appears highly acceptable by patients.

TRIAL REGISTRATION

This study is registered with the EudractCT registration 2008-006525-14 . Registered on 9 December 2008.

Moderately Hypofractionated Radiotherapy Alone for Stage I-IIB Non-small Cell Lung Cancer

INTRODUCTION

The optimal management of patients with early non-small cell lung cancer (NSCLC) not amenable to surgical resection or stereotactic body radiotherapy (SBRT) or those with hilar nodal involvement ineligible for surgery or concurrent chemoradiotherapy is unclear. This report describes survival outcomes and toxicity profiles of patients treated with hypofractionated radiotherapy (HRT) alone.

METHODS

A total of 52 patients with Stage I-IIB NSCLC treated with HRT alone between 2010-2018 were reviewed. Patients were categorized as having ultracentral tumors if the planning target volume contacted or overlapped the proximal bronchial tree, esophagus, pulmonary vein or artery. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and the competing risk cumulative incidence of locoregional failure (LRF) and distant failure (DF) were estimated using death without failure as a competing risk. Pneumonitis and esophagitis rates were evaluated as per Acute Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.

RESULTS

Of the 52 patients analyzed, 50 patients were treated with radiotherapy alone to a dose of 70.2 Gy in 26 fractions, one patient was treated with 68 Gy in 25 fractions and one patient was treated with 65 Gy in 26 fractions. The median age was 72 (range 48-89), 42% of patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 2-3, 46% were stage I and 54% were stage II. Hilar nodal involvement was present in 21% of patients and 74% of node-negative patients had ultracentral primary tumors. Median OS was 39.6 months and the median PFS was 21.0 months. Overall three-year cumulative incidence of LRF and DF were 32% and 34%, respectively. Grade 3 pneumonitis occurred in two (4%) patients. No grade 3+ acute esophagitis or grade 4-5 toxicities were observed.

CONCLUSION

Hypofractionated thoracic radiotherapy consisting of 70.2 Gy is well-tolerated and results in favorable locoregional control for stage I-IIB patients who are not candidates for SBRT, surgery, or concurrent chemoradiotherapy.

Stereotactic Ablative Radiotherapy for Central and Ultra-Central Lung Tumors

Stereotactic ablative radiotherapy (SABR) has emerged as a standard-of-care treatment for patients with early stage non-small cell lung cancer (NSCLC) who are poor surgical candidates. Current evidence supports the consensus that lung SABR with BED ≥100 Gy leads to high local tumor control, and that the treatment is generally well-tolerated when applied to peripheral lung tumors. However, several studies present conflicting evidence for the treatment of central and ultra-central lung tumors, with some showing superb outcomes and others showing concerning rates of morbidity and mortality. Therefore, treatment of central and especially ultra-central lung tumors with SABR remains controversial. In this review, we aim to present the existing evidence for SABR treatment of central and ultra-central lung tumors and delineate the factors that could lead to significant toxicity.

Lessons Learned From Hurricane Maria in Puerto Rico: Practical Measures to Mitigate the Impact of a Catastrophic Natural Disaster on Radiation Oncology Patients

PURPOSE

Although the wind, rain, and flooding of Hurricane Maria in Puerto Rico abated shortly after its landfall on September 20, 2017, the disruption of the electrical, communications, transportation, and medical infrastructure of the island was unprecedented in scope and caused lasting harm for many months afterward. A compilation of recommendations from radiation oncologists who were in Puerto Rico during the disaster, and from a panel of American Society for Radiation Oncology (ASTRO) cancer experts was created.

METHODS AND MATERIALS

Radiation oncologists throughout Puerto Rico collaborated and improvised to continue treating patients in the immediate aftermath of the storm and as routine clinical operations were restored gradually. Empirical lessons from the experience of radiation therapy administration in this profoundly altered context of limited resources, impaired communication, and inadequate transportation were organized into a recommended template, applicable to any radiation oncology practice. ASTRO disease-site experts provided evidence-guidelines for mitigating the impact of a 2- to 3-week interruption in radiation therapy.

RESULTS

Practical measures to mitigate the medical impact of a disaster are summarized within the framework of "Prepare, Communicate, Operate, Compensate." Specific measures include the development of an emergency operations plan tailored to specific circumstances, prospective coordination with other radiation oncology clinics before a disaster, ongoing communications with emergency management organizations, and routine practice of alternate methods to disseminate information among providers and patients.

CONCLUSIONS

These recommendations serve as a starting point to assist any radiation oncology practice in becoming more resiliently prepared for a local or regional disruption from any cause. Disease-site experts provide evidence-based guidelines on how to mitigate the impact of a 2- to 3-week interruption in radiation therapy for lung, head and neck, uterine cervix, breast, and prostate cancers through altered fractionation or dose escalation.

Hypofractionated radiation therapy in the management of locally advanced NSCLC: a narrative review of the literature on behalf of the Italian Association of Radiation Oncology (AIRO)-Lung Working Group

A systematic literature was performed to assess the benefit in terms of effectiveness and feasibility of hypofractionated radiotherapy (HypoRT), with or without chemotherapy (CT), in the treatment of locally advanced non-small cell lung cancer (NSCLC). We have identified all studies, published from 2007 onwards, on patients with locally advanced NSCLC treated with HypoRT with radical intent, with a minimal dose per fraction of 2.4 Gy, with or without concurrent chemotherapy. Twenty-nine studies were identified, for a total of 2614 patients. Patients were divided in the concurrent chemo-radiation therapy group (CT-RT) and radiotherapy alone (RT). In RT group, the delivered dose ranged from 45 to 85.5 Gy, with a dose/fraction from 2.4 to 4 Gy. Actuarial 2-year PFS ranged from 13 to 57.8%, and 1, 2- and 3-year overall survival (OS) ranged from 51.3 to 95%, from 22 to 68.7%, and from 7 to 32%, respectively. Acute Grade ≥ 3 esophagitis occurred in 0-15%, while late esophageal toxicity was 0-16%. Acute pneumonitis occured in 0-44%, whereas late pneumonitis occured in 0-47%, most commonly grade ≤ G3. In CT-RT group, the delivered dose ranged from 52.5 to 75 Gy, with a dose/fraction ranging from 2.4 to 3.5 Gy. Actuarial 2-year PFS ranged from 19 to 57.8%, and OS at 1, 2 and 3 years ranged from 28 to 95%, 38.6 to 68.7%, and 31 to 44%, respectively. Acute Grade 2 and 3 esophagitis occurred in 3-41.7%, while late esophageal toxicity occurred in 0-8.3%. Acute pneumonitis ranged from 0 to 23%, whereas late pneumonitis occured 0-47%. HypoRT seems to be safe in patients with locally advanced NSCLC. The encouraging survival results of several studies analyzed suggest that hypofractionated radiation schemes should be further investigated in the future.

Optimizing radiation dose and fractionation for the definitive treatment of locally advanced non-small cell lung cancer

Radiation therapy is the foundation for treatment of locally advanced non-small cell lung cancer (NSCLC), a disease that is often inoperable and has limited long term survival. Local control of disease is strongly linked to patient survival and continues to be problematic despite continued attempts at changing the dose and fractionation of radiation delivered. Technological advancements such as 4-dimensional computed tomography (CT) based planning, positron emission tomography (PET) based target delineation, and daily image guidance have allowed for ever more accurate and conformal treatments. A limit to dose escalation with conventional fractions of 2 Gy once per day appears to have been reached at 60 Gy in the randomized trial Radiation Therapy Oncology Group (RTOG) 0617. Higher doses were surprisingly associated with worse overall survival. Approaches other than conventional dose escalation have been explored to better control disease including accelerating treatment to limit tumor repopulation both with hyperfractionation and its multiple small (<2 Gy) fractions each day and with hypofractionation and its single larger (>2 Gy) fraction each day. These accelerated regimens are increasingly being used with concurrent chemotherapy, and multiple institutions have reported it as tolerable. Tailoring treatment to individual patient disease and normal anatomic characteristics has been explored with isotoxic dose escalation up to the tolerance of organs at risk, with both hyperfractionation and hypofractionation. Metabolic imaging during and after treatment is increasingly being used to boost doses to residual disease. Boost doses have included moderate hypofractionation of 2-4 Gy, and more recently extreme hypofractionation with stereotactic body radiation therapy (SBRT). In spite of all these changes in dose and fractionation, lung and cardiovascular toxicity remain obstacles that limit disease control and patient survival.

SUNSET: Stereotactic Radiation for Ultracentral Non-Small-Cell Lung Cancer-A Safety and Efficacy Trial

BACKGROUND

Lung stereotactic body radiotherapy (SBRT) is considered a standard curative treatment for medically inoperable early stage non-small-cell lung cancer (NSCLC). Patients with ultracentral tumors (signifying tumors whose planning target volume touches or overlaps the central bronchial tree, esophagus, or pulmonary artery) may be at higher risk of serious toxicities such as bronchial stricture and collapse, esophageal strictures, tracheal-esophageal fistula, and hemorrhage. The primary objective of the study is to determine the maximum tolerated dose of radiotherapy for ultracentral NSCLC.

METHODS

This multicenter phase 1 dose-escalation study will use a time-to-event continual reassessment method (TITE-CRM). Accrual will start at level 1 (60 Gy in 8 fractions delivered daily). The model will use all available information from previously accrued patients to assign the highest dose with a predicted risk of grade 3-5 toxicity of 30% or less. All patients with newly diagnosed stage T1-3 N0M0 NSCLC (International Union Against Cancer, 8th edition) with tumor size ≤ 6 cm and meeting the criteria for ultracentral location (ie, tumors whose planning target volume touches or overlaps the central bronchial tree, esophagus, pulmonary vein, or pulmonary artery) will be eligible for this study.

DISCUSSION

It is important to identify a safe dose-fractionation regimen for treating ultracentral tumors with SBRT. In addition, the data from this study may be informative in guiding future studies on the use of SBRT in treating malignancies within the mediastinum-for example, for salvage treatment of mediastinal lymph nodes for recurrent NSCLC or mediastinal oligometastases.

Feasibility of stereotactic body radiotherapy for locally-advanced non-small cell lung cancer

SBRT was feasible for approximately half of the locally-advanced NSCLC patients we assessed and for these patients has the potential to reduce a 30 fraction course to 12 fractions. Using SBRT in this setting requires compromises in techniques and further compromises may allow SBRT in a greater proportion of patients.

Comparison of photon volumetric modulated arc therapy, intensity-modulated proton therapy, and intensity-modulated carbon ion therapy for delivery of hypo-fractionated thoracic radiotherapy

Purpose

The aim of the present study was to compare the dose distribution generated from photon volumetric modulated arc therapy (VMAT), intensity modulated proton therapy (IMPT), and intensity modulated carbon ion therapy (IMCIT) in the delivery of hypo-fractionated thoracic radiotherapy.

Methods and materials

Ten selected patients who underwent thoracic particle therapy between 2015 and 2016 were re-planned to receive a relative biological effectiveness (RBE) weighted dose of 60 Gy (i.e., GyE) in 15 fractions delivered with VMAT, IMPT, or IMCIT with the same optimization criteria. Treatment plans were then compared.

Results

There were no significant differences in target volume dose coverage or dose conformity, except improved D₉₅ was found with IMCIT compared with VMAT (p = 0.01), and IMCIT was significantly better than IMPT in all target volume dose parameters. Particle therapy led to more prominent lung sparing at low doses, and this result was most prominent with IMCIT (p < 0.05). Improved sparing of other thoracic organs at risk (OARs) was observed with particle therapy, and IMCIT further lowered the D_1cc and D_5cc for major blood vessels, as compared with IMPT (p = 0.01).

Conclusion

Although it was comparable to VMAT, IMCIT led to significantly better tumor target dose coverage and conformity than did IMPT. Particle therapy, compared with VMAT, improved thoracic OAR sparing. IMCIT, compared with IMPT, may further improve normal lung and major blood vessel sparing under limited respiratory motion.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-017-0866-0) contains supplementary material, which is available to authorized users.

Outcomes and toxicity following high-dose radiation therapy in 15 fractions for non-small cell lung cancer

PURPOSE

Accelerated hypofractionated radiation therapy (AHRT) is increasingly used for select lung cancer patients. We evaluated clinical outcomes and predictors of pulmonary/esophageal toxicity in patients treated with ≥52.5 Gy in 15 fractions.

METHODS AND MATERIALS

We evaluated 229 patients treated with radiation therapy doses ≥52.5 Gy in 15 fractions for non-small cell lung cancer from January 2009 through January 2016. Toxicity was scored using Common Terminology Criteria for Adverse Events, v4.0. Univariate and multivariate logistic regression was used to identify predictors of toxicity. Overall survival, progression-free survival, and local control were estimated using the Kaplan-Meier method. Predictors of clinical outcome were modeled using Cox proportional hazards regression.

RESULTS

Median follow-up was 7 months. Forty-two patients (19%) developed grade ≥2 pneumonitis, and 9 (4%) developed grade ≥3 esophagitis. In multivariate analysis, age >75 years (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.24-5.25; P = .01) and percentage of lung volume receiving doses of >10 Gy higher than 32% were associated with grade ≥2 pneumonitis (OR, 2.79; 95% CI, 1.39-5.79; P = .005). On univariate analysis, esophagus mean dose ≥17 Gy (OR, 10.14; 95% CI, 1.82-189.8; P = .006), gross tumor volume size ≥71 cm³ (P = .002), and planning target volume size ≥409 cm³ (P = .02) were associated with development of grade ≥3 esophagitis. In patients with stage II/III disease (n = 73), median local control was not reached, median overall survival was 14 months, and median progression-free survival was 6 months.

CONCLUSIONS

AHRT in 15 fractions can be safe and effective. Consideration for using AHRT with immunotherapy and sequential chemotherapy for improved out-of-radiation field and distant control is warranted.

Integration of Stereotactic Body Radiation Therapy With Tyrosine Kinase Inhibitors in Stage IV Oncogene-Driven Lung Cancer

: Genotype-based selection of patients for targeted therapies has had a substantial impact on the treatment of non-small cell lung cancers (NSCLCs). Tyrosine kinase inhibitors (TKIs) directed at cancers driven by oncogenes, such as epidermal growth factor receptor mutations or anaplastic lymphoma kinase rearrangements, often achieve dramatic responses and result in prolonged survival compared with chemotherapy. However, TKI resistance invariably develops. Disease progression can be limited to only one or a few sites and might not be symptomatic, raising the important question of whether this type of oligoprogression warrants a change in systemic therapy or consideration of local treatment. Recent clinical observations suggest a growing role for stereotactic body radiation therapy (SBRT) in the treatment of oligoprogressive and perhaps even oligopersistent disease (primary and/or metastases) in oncogene-driven NSCLC. SBRT might allow patients to continue with existing TKI treatments longer and delay the need to switch to other systemic options. We review the current data with regard to the use of SBRT for metastatic NSCLC and particularly oncogene-driven disease. Although there is great promise in the marriage of targeted therapies with SBRT, prospective data are urgently needed. In the meantime, such strategies are being used in carefully selected patients, with risk-adapted SBRT dose-fractionation regimens used to optimize the therapeutic index.

IMPLICATIONS FOR PRACTICE

Stereotactic body radiation therapy (SBRT) or SBRT-like treatments are increasingly being used for oligoprogression in patients with oncogene-driven non-small cell lung cancer. This approach allows patients to extend the duration of tyrosine kinase inhibitor therapy and has the potential to prolong survival times. Careful patient selection and risk-adapted radiation dosing is of critical importance to minimize toxicity and preserve patient quality of life.

Hypofractionated Intensity-Modulated Radiotherapy for Patients With Non-Small-Cell Lung Cancer

BACKGROUND

Alternative treatment regimens are needed for patients with non-small cell lung cancer (NSCLC) who cannot receive definitive treatment with concurrent chemoradiotherapy, surgery, or stereotactic ablative radiotherapy (SABR).

PATIENTS AND METHODS

We report survival, patterns of failure and toxicity outcomes for patients with NSCLC who were not eligible for surgical resection, concurrent chemoradiotherapy, or SABR and underwent hypofractionated intensity-modulated radiotherapy (IMRT). Kaplan-Meier survival analysis was used to evaluate the progression-free and overall survival. Competing risk analysis was used to evaluate in-field, locoregional, and distant failure.

RESULTS

A total of 42 patients treated to 52.5 to 60 Gy in 15 fractions were included. Most of the patients had metastatic or recurrent disease (64%) and a relatively large, centrally located tumor burden (74%). The median follow-up period was 13 months (interquartile range, 6-18 months). All patients received the total prescribed dose. The median survival was 15.1 months. The overall and progression-free survival rates at 1 year were 63% and 22.5%, respectively. The pattern of failure was predominantly distant, with only 2% of patients experiencing isolated in-field recurrence. The cumulative incidence of in-field failure at 6 and 12 months was 2.5% (95% confidence interval, 0.4%-15.6%) and 16.1% (95% confidence interval, 7.5%-34.7%), respectively. The risk of esophageal toxicity was associated with the esophageal mean dose, maximal point dose, and dose to the 5 cm³ volume. The risk of pneumonitis was associated with the lung mean dose and volume receiving 18 Gy.

CONCLUSION

Hypofractionated IMRT without concurrent chemotherapy provides favorable rates of local control and survival for well-selected patients with NSCLC who cannot tolerate standard definitive therapy.