Potential clinical predictors of outcome after postoperative radiotherapy of non-small cell lung cancer

Noninvasive Quantification of Radiation-Induced Lung Injury Using a Targeted Molecular Imaging Probe

PURPOSE

Radiation-induced lung injury (RILI) is a progressive inflammatory process seen after irradiation for lung cancer. The disease can be insidious, often characterized by acute pneumonitis followed by chronic fibrosis with significant associated morbidity. No therapies are approved for RILI, and accurate disease quantification is a major barrier to improved management. Here, we sought to noninvasively quantify RILI using a molecular imaging probe that specifically targets type 1 collagen in mouse models and patients with confirmed RILI.

METHODS AND MATERIALS

Using a murine model of lung radiation, mice were imaged with EP-3533, a type 1 collagen probe, to characterize the development of RILI and to assess disease mitigation after losartan treatment. The human analog probe 68Ga-CBP8, targeting type 1 collagen, was tested on excised human lung tissue containing RILI and was quantified via autoradiography. 68Ga-CBP8 positron emission tomography was used to assess RILI in vivo in 6 human subjects.

RESULTS

Murine models demonstrated that probe signal correlated with progressive RILI severity over 6 months. The probe was sensitive to mitigation of RILI by losartan. Excised human lung tissue with RILI had increased binding versus unirradiated control tissue, and 68Ga-CBP8 uptake correlated with collagen proportional area. Human imaging revealed significant 68Ga-CBP8 uptake in areas of RILI and minimal background uptake.

CONCLUSIONS

These findings support the ability of a molecular imaging probe targeted at type 1 collagen to detect RILI in preclinical models and human disease, suggesting a role for targeted molecular imaging of collagen in the assessment of RILI.

Symptomatic Pneumonitis With Durvalumab After Concurrent Chemoradiotherapy in Unresectable Stage III NSCLC

Introduction

In the placebo-controlled, phase 3 PACIFIC trial, durvalumab significantly prolonged progression-free survival (PFS) (p < 0.0001) and overall survival (OS) (p = 0.00251) in patients with unresectable stage III NSCLC and no progression after platinum-based concurrent chemoradiotherapy (cCRT). Pneumonitis or radiation pneumonitis (PRP) was common in both arms. We report exploratory analyses evaluating the association of symptomatic (grade ≥2) PRP (G2+PRP) with baseline factors and clinical outcomes.

Methods

Patients with WHO performance status of 0 or 1 were randomized (2:1) to 12 months of durvalumab or placebo, 1 to 42 days after cCRT. Associations between baseline factors and on-study G2+PRP in durvalumab-treated patients were investigated using univariate and multivariate logistic regression. PFS and OS were analyzed using Cox proportional hazards models adjusted for time-dependent G2+PRP plus covariates for randomization stratification factors without and with additional baseline factors.

Results

On-study G2+PRP occurred in 94 of 475 (19.8%) and 33 of 234 patients (14.1%) on durvalumab and placebo, respectively (median follow-up, 25.2 mo); grade greater than or equal to 3 PRP was uncommon (4.6% and 4.7%, respectively). Time to onset and resolution of G2+PRP was similar with durvalumab and placebo. Univariate and multivariate analyses identified patients treated in Asia, those with stage IIIA disease, those with performance status of 1, and those who had not received induction chemotherapy as having a higher risk of G2+PRP. PFS and OS benefit favoring durvalumab versus placebo was maintained regardless of time-dependent G2+PRP.

Conclusions

Factors associated with higher risk of G2+PRP with durvalumab after cCRT were identified. Clinical benefit was maintained regardless of on-study G2+PRP, suggesting the risk of this event should not deter the use of durvalumab in eligible patients with unresectable stage III NSCLC.

Noninvasive Quantification of Radiation-Induced Lung Injury using a Targeted Molecular Imaging Probe

Rationale

Radiation-induced lung injury (RILI) is a progressive inflammatory process commonly seen following irradiation for lung cancer. The disease can be insidious, often characterized by acute pneumonitis followed by chronic fibrosis with significant associated morbidity. No therapies are approved for RILI, and accurate disease quantification is a major barrier to improved management.

Objective

To noninvasively quantify RILI, utilizing a molecular imaging probe that specifically targets type 1 collagen in mouse models and patients with confirmed RILI.

Methods

Using a murine model of lung radiation, mice were imaged with EP-3533, a type 1 collagen probe to characterize the development of RILI and to assess disease mitigation following losartan treatment. The human analog probe targeted against type 1 collagen, 68Ga-CBP8, was tested on excised human lung tissue containing RILI and quantified via autoradiography. Finally, 68Ga-CBP8 PET was used to assess RILI in vivo in six human subjects.

Results

Murine models demonstrated that probe signal correlated with progressive RILI severity over six-months. The probe was sensitive to mitigation of RILI by losartan. Excised human lung tissue with RILI had increased binding vs unirradiated control tissue and 68Ga-CBP8 uptake correlated with collagen proportional area. Human imaging revealed significant 68Ga-CBP8 uptake in areas of RILI and minimal background uptake.

Conclusions

These findings support the ability of a molecular imaging probe targeted at type 1 collagen to detect RILI in preclinical models and human disease, suggesting a role for targeted molecular imaging of collagen in the assessment of RILI.Clinical trial registered with www.clinicaltrials.gov (NCT04485286, NCT03535545).

European Respiratory Society guideline on various aspects of quality in lung cancer care

This European Respiratory Society guideline is dedicated to the provision of good quality recommendations in lung cancer care. All the clinical recommendations contained were based on a comprehensive systematic review and evidence syntheses based on eight PICO (Patients, Intervention, Comparison, Outcomes) questions. The evidence was appraised in compliance with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Evidence profiles and the GRADE Evidence to Decision frameworks were used to summarise results and to make the decision-making process transparent. A multidisciplinary Task Force panel of lung cancer experts formulated and consented the clinical recommendations following thorough discussions of the systematic review results. In particular, we have made recommendations relating to the following quality improvement measures deemed applicable to routine lung cancer care: 1) avoidance of delay in the diagnostic and therapeutic period, 2) integration of multidisciplinary teams and multidisciplinary consultations, 3) implementation of and adherence to lung cancer guidelines, 4) benefit of higher institutional/individual volume and advanced specialisation in lung cancer surgery and other procedures, 5) need for pathological confirmation of lesions in patients with pulmonary lesions and suspected lung cancer, and histological subtyping and molecular characterisation for actionable targets or response to treatment of confirmed lung cancers, 6) added value of early integration of palliative care teams or specialists, 7) advantage of integrating specific quality improvement measures, and 8) benefit of using patient decision tools. These recommendations should be reconsidered and updated, as appropriate, as new evidence becomes available.

Radiation-Induced Lung Injury-Current Perspectives and Management

Radiotherapy plays an important role in the treatment of localized primary malignancies involving the chest wall or intrathoracic malignancies. Secondary effects of radiotherapy on the lung result in radiation-induced lung disease. The phases of lung injury from radiation range from acute pneumonitis to chronic pulmonary fibrosis. Radiation pneumonitis is a clinical diagnosis based on the history of radiation, imaging findings, and the presence of classic symptoms after exclusion of infection, pulmonary embolism, heart failure, drug-induced pneumonitis, and progression of the primary tumor. Computed tomography (CT) is the preferred imaging modality as it provides a better picture of parenchymal changes. Lung biopsy is rarely required for the diagnosis. Treatment is necessary only for symptomatic patients. Mild symptoms can be treated with inhaled steroids while subacute to moderate symptoms with impaired lung function require oral corticosteroids. Patients who do not tolerate or are refractory to steroids can be considered for treatment with immunosuppressive agents such as azathioprine and cyclosporine. Improvements in radiation technique, as well as early diagnosis and appropriate treatment with high-dose steroids, will lead to lower rates of pneumonitis and an overall good prognosis.

Clinical and Dosimetric Predictors of Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer Undergoing Postoperative Radiation Therapy

PURPOSE

Radiation pneumonitis (RP) is a common and potentially life-threatening toxicity from lung cancer radiation therapy. Data sets reporting RP rates after postoperative radiation therapy (PORT) have historically been small and with predominantly outdated field designs and radiation techniques. We examined a large cohort of patients in this context to assess the incidence and causes of RP in the modern era.

METHODS AND MATERIALS

We reviewed 285 patients with non-small cell lung cancer treated with PORT at our institution from May 2004 to January 2017. Complete dosimetric data and clinical records were reviewed and analyzed with grade 2 or higher RP as the endpoint (RP2+) (Common Terminology Criteria for Adverse Events v4.0). Patients were a median of 67 years old (range, 28-87), and most had pathologic stage III non-small cell lung cancer (91%) and received trimodality therapy (90%). Systematic dosimetric analyses using Dx increments of 5% and Vx increments of 2 Gy were performed to robustly evaluate dosimetric variables. Lung V₅ was also evaluated.

RESULTS

The incidence of RP2+ after PORT was 12.6%. Dosimetric factors most associated with RP2+ were total lungV₄ (hazard ratio [HR] 1.04, P < .001) and heart V₁₆ (HR 1.03, P = .001). On univariate analysis, the clinical factors of age (HR 1.05, P = .006) and carboplatin chemotherapy (HR 2.32, P = .012) were correlated with RP2+. On step-up multivariate analysis, only bivariate models remained significant, including lungV₅ (HR 1.037, P < .001) and age (HR 1.052, P = .011).

CONCLUSIONS

The incidence of RP after PORT is consistent with the literature. Factors correlated with RP include lung and heart doses, age, and carboplatin chemotherapy. These data also suggest that elderly patients may be more susceptible to lower doses of radiation to the lung. Based on these data, dose constraints to limit the risk of RP2+ to <5% in the setting of PORT include lungV₅ ≤65% in patients <65 years old and lungV₅ ≤36% in patients 65 years or older.

Adoption of Biologically Effective Dose of the Non-Target Lung Volume to Predict Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy With Variable Fractionations for Lung Cancer

Background: This study aims to establish lung biologically effective dose (BED)–based uniform dosimetric constraints for minimizing the risk of symptomatic radiation pneumonitis (SRP) from stereotactic body radiation therapy (SBRT) using variable fractionations in patients with lung tumors.

Materials and Methods: A total of 102 patients with primary or oligometastatic lung tumors treated with SBRT in our institution were enrolled into this study. The associations between the clinical and dosimetric parameters and the incidences of SRP were analyzed using univariate and multivariate Cox regression hazard models. The receiver operating characteristic (ROC) curve was generated to evaluate the predictive performance of lung BED on the SRP risk compared with the physical dose.

Results: SRP occurred in 11 patients (10.8%). In univariate analysis, the mean lung dose (p = 0.002), V₅ (p = 0.005), V₂₀ (p < 0.001), and the percentage of non-target normal lung volume receiving more than a BED of 5–170 Gy (V_BED5−170, p < 0.05) were associated with SRP. Multivariate logistic regression analysis showed that there existed a significant statistical correlation between SRP and V_BED70 (p < 0.001), which performed better than V₅ or V₂₀ on the ROC curves, resulting in an optimal cut-off value of lung V_BED70 of 2.22%.

Conclusions: This retrospective study indicated that non-target lung BED may better predict SRP from patients with SBRT-treated lung cancer. Limiting the lung V_BED70 below 2.22% may be favorable to reduce the incidence of SRP, which warranted further prospective validation.

High incidence of radiation pneumonitis in lung cancer patients with chronic silicosis treated with radiotherapy

Silica is an independent risk factor for lung cancer in addition to smoking. Chronic silicosis is one of the most common and serious occupational diseases associated with poor prognosis. However, the role of radiotherapy is unclear in patients with chronic silicosis. We conducted a retrospective study to evaluate efficacy and safety in lung cancer patients with chronic silicosis, especially focusing on the incidence of radiation pneumonitis (RP). Lung cancer patients with chronic silicosis who had been treated with radiotherapy from 2005 to 2018 in our hospital were enrolled in this retrospective study. RP was graded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Of the 22 patients, ten (45.5%) developed RP ≥2. Two RP-related deaths (9.1%) occurred within 3 months after radiotherapy. Dosimetric factors V5, V10, V15, V20 and mean lung dose (MLD) were significantly higher in patients who had RP >2 (P < 0.05). The median overall survival times in patients with RP ≤2 and RP>2 were 11.5 months and 7.1 months, respectively. Radiotherapy is associated with excessive and fatal pulmonary toxicity in lung cancer patients with chronic silicosis.

Risk factors of grade ≥ 2 radiation pneumonitis after gemcitabine induction chemotherapy for patients with non-small cell lung cancer

Objectives

To observe the risk factors affecting the occurrence of RP after gemcitabine-based induction chemotherapy.

Methods

Between January 2010 and December 2017, patients with NSCLC received gemcitabine or docetaxel chemotherapy, followed by radiotherapy at Zhejiang cancer hospital were enrolled in this study. Patients were treated with gemcitabine or docetaxel induction chemotherapy, followed by radiotherapy or concurrent chemoradiotherapy. Acute radiation pneumonitis was scored post chemoradiotherapy.

Results

One hundred and eighty-four patients with NSCLC were included in the gemcitabine group and 144 in the docetaxel group. The gemcitabine group experienced a higher incidence of grade ≥ 2 RP, compared with docetaxel group (25.5% Vs. 13.2%, P = 0.005). The optimal cutoff values of lung V₅, V₂₀, V₃₀ and MLD were set at 44% (AUC [area under the curve] = 0.593), 24% (AUC = 0.607), 14.2% (AUC = 0.622) and 1226 cGy (AUC = 0.626). On multivariate analysis, only lung V₃₀ was identified as a predictor for grade ≥ 2 RP (P = 0.03). The grade ≥ 2 RP rate was only 9.4% for the low-risk group (Lung V₅ ≤ 44%, V₂₀ ≤ 24%, V₃₀ ≤ 14.2%, and MLD ≤ 1226 cGy) in patients received gemcitabine induction chemotherapy.

Conclusions

Gemcitabine chemotherapy before thoracic radiotherapy in NSCLC patients was related to a higher incidence of grade ≥ 2 RP, compared with docetaxel chemotherapy. The Lung dose-volume variable V₃₀ was the best predictor of grade ≥ 2 RP.

PORTAF - postoperative radiotherapy of non-small cell lung cancer: accelerated versus conventional fractionation - study protocol for a randomized controlled trial

BACKGROUND

In early-stage non-small cell lung cancer (NSCLC) without affected lymph nodes detected at staging, surgical resection is still the mainstay of treatment. However, in patients with metastatic mediastinal lymph nodes (pN2) or non-radically resected primary tumors (R1/R2), postoperative radiotherapy (possibly combined with chemotherapy) is indicated. So far, investigations about time factors affecting postoperative radiotherapy have only examined the waiting time defined as interval between surgery and start of radiotherapy, but not the overall treatment time (OTT) itself. Conversely, results from trials on primary radio(chemo)therapy in NSCLC show that longer OTT correlates with significantly worse local tumor control and overall survival rates. This time factor of primary radio(chemo)therapy is thought to mainly be based on repopulation of surviving tumor cells between irradiation fractions. It remains to be elucidated if such an effect also occurs when patients with NSCLC are treated with postoperative radiotherapy after surgery (and chemotherapy). Our own retrospective data suggest an advantage of shorter OTT also for postoperative radiotherapy in this patient group.

METHODS/DESIGN

This is a multicenter, prospective randomized trial investigating whether an accelerated course of postoperative radiotherapy with photons or protons (7 fractions per week, 2 Gy fractions) improves locoregional tumor control in NSCLC patients in comparison to conventional fractionation (5 fractions per week, 2 Gy fractions). Target volumes and total radiation doses will be stratified in both treatment arms based on individual risk factors.

DISCUSSION

For the primary endpoint of the study we postulate an increase in local tumor control from 70% to 85% after 36 months. Secondary endpoints are overall survival of patients; local recurrence-free and distant metastases-free survival after 36 months; acute and late toxicity and quality of life for both treatment methods.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02189967 . Registered on 22 May 2014.

Postoperative radiotherapy is associated with better survival in non-small cell lung cancer with involved N2 lymph nodes: results of an analysis of the National Cancer Data Base

INTRODUCTION

Use of postoperative radiotherapy (PORT) in non-small-cell lung cancer remains controversial. Limited data indicate that PORT may benefit patients with involved N2 nodes. This study evaluates this hypothesis in a large retrospective cohort treated with chemotherapy and contemporary radiation techniques.

METHODS

The National Cancer Data Base was queried for patients diagnosed 2004-2006 with resected non-small-cell lung cancer and pathologically involved N2 (pN2) nodes also treated with chemotherapy. Multivariable Cox proportional hazards model was used to assess factors associated with overall survival (OS). Inverse probability of treatment weighting (IPTW) using the propensity score was used to reduce selection bias. OS was compared between patients treated with versus without PORT using the adjusted Kaplan-Meier estimator and weighted log-rank test based on IPTW.

RESULTS

Two thousand and one hundred and fifteen patients were eligible for analysis. 918 (43.4%) received PORT, 1197 (56.6%) did not. PORT was associated with better OS (median survival time 42 months with PORT versus 38 months without, p = 0.048). This effect was significant in multivariable and IPTW Cox models (hazard ratio: 0.87, 95% confidence interval: 0.78-0.98, p = 0.026, and hazard ratio: 0.89, 95% confidence interval: 0.79-1.00, p = 0.046, respectively). No interaction was seen between the effects of PORT and number of involved lymph nodes (p = 0.615).

CONCLUSIONS

PORT was associated with better survival for patients with pN2 nodes also treated with chemotherapy. No interaction was seen between benefit of PORT and number of involved nodes. These findings reinforce the benefit of PORT for N2 disease in modern practice using the largest, most recent cohort of chemotherapy-treated pN2 patients to date.

Outcome and prognostic factors of postoperative radiation therapy (PORT) after incomplete resection of non-small cell lung cancer (NSCLC)

PURPOSE

Current guidelines recommend postoperative radiation therapy (PORT) for incompletely resected non-small cell lung cancer (NSCLC). However, there is still a paucity of evidence for this approach. Hence, we analyzed survival in 78 patients following radiotherapy for incompletely resected NSCLC (R1) and investigated prognostic factors.

PATIENTS AND METHODS

All 78 patients with incompletely resected NSCLC (R1) received PORT between December 2001 and September 2014. The median total dose for PORT was 60 Gy (range 44-68 Gy). The majority of patients had locally advanced tumor stages (stage IIA (2.6%), stage IIB (19.2%), stage IIIA (57.7%) and stage IIIB (20.5%)). 21 patients (25%) received postoperative chemotherapy.

RESULTS

Median follow-up after radiotherapy was 17.7 months. Three-year overall (OS), progression-free (PFS), local (LPFS) and distant progression-free survival (DPFS) rates were 34.1, 29.1, 44.9 and 51.9%, respectively. OS was significantly prolonged at lower nodal status (pN0/1) and following dose-escalated PORT with total radiation doses >54 Gy (p=0.012, p=0.013). Furthermore, radiation doses >54 Gy significantly improved PFS, LPFS and DPFS (p=0.005; p=0.050, p=0.022). Interestingly, survival was neither significantly influenced by R1 localization nor by extent (localized vs. diffuse). Multivariate analyses revealed lower nodal status and radiation doses >54.0 Gy as the only independent prognostic factors for OS (p=0.021, p=0.036).

CONCLUSION

For incompletely resected NSCLC, PORT is used for improving local tumor control. Local progression is still the major pattern of failure. Radiation doses >54 Gy seem to support improved local control and were associated with better OS in this retrospective study.