The incidence of and risk factors for radiation pneumonitis in patients treated with simultaneous bevacizumab and thoracic radiotherapy

BACKGROUND

First-line chemotherapy combined with bevacizumab is one of the standard treatment modes for patients with advanced non-small cell lung cancer (NSCLC). Thoracic radiotherapy (TRT) can provide significant local control and survival benefits to patients during the treatment of advanced NSCLC. However, the safety of adding TRT has always been controversial, especially because of the occurrence of radiation pneumonia (RP) during bevacizumab treatment. Therefore, in this study, we used an expanded sample size to evaluate the incidence of RP when using bevacizumab in combination with TRT.

PATIENTS AND METHODS

Using an institutional query system, all medical records of patients with NSCLC who received TRT during first-line chemotherapy combined with bevacizumab from 2017 to 2020 at Shandong Cancer Hospital and Institute were reviewed. RP was diagnosed via computed tomography and was classified according to the RTOG toxicity scoring system. The risk factors for RP were identified using univariate and multivariate analyses. The Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS).

RESULTS

Ultimately, 119 patients were included. Thirty-eight (31.9%) patients developed Grade ≥ 2 RP, of whom 27 (68.1%) had Grade 2 RP and 11 (9.2%) had Grade 3 RP. No patients developed Grade 4 or 5 RP. The median time for RP occurrence was 2.7 months (range 1.2-5.4 months). In univariate analysis, male, age, KPS score, V20 > 16.9%, V5 > 33.6%, PTV (planning target volume)-dose > 57.2 Gy, and PTV-volume > 183.85 cm3 were correlated with the occurrence of RP. In multivariate analysis, male, V20 > 16.9%, and PTV-volume > 183.85 cm3 were identified as independent predictors of RP occurrence. The mPFS of all patients was 14.27 (95% CI, 13.1-16.1) months. The one-year and two-year PFS rates were 64.9% and 20.1%, respectively. The mOS of all patients was 37.09 (95% CI, 33.8-42.0) months. The one-year survival rate of all patients was 95%, and the two-year survival rate was 71.4%.

CONCLUSIONS

The incidence of Grade ≥ 2 RP in NSCLC patients who received both bevacizumab and TRT was 31.9%. Restricting factors such as V20 and PTV will help reduce the risk of RP in these patients. For patients who receive both bevacizumab and TRT, caution should be exercised when increasing TRT, and treatment strategies should be optimized to reduce the incidence of RP.

Associations Between Mean Lung Dose and Prevalence of Radiation Pneumonitis in Elderly Lung Cancer Patients

BACKGROUND/AIM

Pneumonitis is a serious radiotherapy complication. This study, which is a prerequisite for a prospective trial, aimed to identify the prevalence of pneumonitis and risk factors in elderly patients with lung cancer.

PATIENTS AND METHODS

Ninety-eight lung cancer patients aged ≥65 years were included. Seventeen factors were investigated regarding grade ≥2 pneumonitis at 24 weeks following radiotherapy.

RESULTS

The prevalence of grade ≥2 pneumonitis at 24 weeks was 27.3%. On univariate analysis, a significant association was observed for mean (ipsilateral) lung dose (MLD; ≤13.0 vs. 13.1-20.0 vs. >20.0 Gy; 0% vs. 24.9% vs. 48.7%). Results were significant also for ≤13.0 vs. >13.0 Gy (0% vs. 37.1%) or ≤20.0 vs. >20.0 Gy (13.4% vs. 48.7%). MLD achieved significance on multivariate analysis.

CONCLUSION

Elderly patients receiving MLDs >13.0 Gy, particularly >20.0 Gy, have a high risk of grade ≥2 pneumonitis. These results are important for designing a prospective trial.

Pneumonitis Rates Before and After Adoption of Immunotherapy Consolidation in Patients With Locally Advanced Non-Small Cell Lung Cancer Treated With Concurrent Chemoradiation

PURPOSE

We hypothesized that after adoption of immune checkpoint inhibitor (ICI) consolidation for patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving concurrent chemoradiation therapy (cCRT), rates of symptomatic pneumonitis would increase, thereby supporting efforts to reduce lung radiation dose.

METHODS AND MATERIALS

This single institution, multisite retrospective study included 783 patients with LA-NSCLC treated with definitive cCRT either before introduction of ICI consolidation (pre-ICI era cohort [January 2011-September 2017]; N = 448) or afterward (ICI era cohort [October 2017-December 2021]; N = 335). Primary endpoint was grade ≥2 pneumonitis (G2P) and secondary endpoint was grade ≥3 pneumonitis (G3P), per Common Terminology Criteria for Adverse Events v5.0. Pneumonitis was compared between pre-ICI era and ICI era cohorts using the cumulative incidence function and Gray's test. Inverse probability of treatment weighting (IPTW)-adjusted Fine-Gray models were generated. Logistic models were developed to predict the 1-year probability of G2P as a function of lung dosimetry.

RESULTS

G2P was higher in the ICI era than in the pre-ICI era (1-year cumulative incidence 31.4% vs 20.1%; P < .001; IPTW-adjusted multivariable subdistribution hazard ratio, 2.03; 95% confidence interval, 1.53-2.70; P < .001). There was no significant interaction between ICI era treatment and either lung volume receiving ≥20 Gy (V20) or mean lung dose in Fine-Gray regression for G2P; however, the predicted probability of G2P was higher in the ICI era at clinically relevant values of lung V20 (≥24%) and mean lung dose (≥14 Gy). Cut-point analysis revealed a lung V20 threshold of 28% in the ICI era (1-year G2P rate 46.0% above vs 19.8% below; P < .001). Among patients receiving ICI consolidation, lung V5 was not associated with G2P. G3P was not higher in the ICI era (1-year cumulative incidence 7.5% vs 6.0%; P = .39; IPTW-adjusted multivariable subdistribution hazard ratio, 1.12; 95% confidence interval, 0.63-2.01; P = .70).

CONCLUSIONS

In patients with LA-NSCLC treated with cCRT, the adoption of ICI consolidation was associated with an increase in G2P but not G3P. With ICI consolidation, stricter lung dose constraints may be warranted.

A comparison of the incidence of ≥ grade 2 radiation pneumonitis between intensity-modulated radiotherapy and three-dimensional conformal radiotherapy in patients with unresectable non-small cell lung cancer treated with durvalumab after concurrent chemoradiotherapy

BACKGROUND

Intensity-modulated radiation therapy (IMRT) has been increasingly used as a new radiation modality for unresectable non-small cell lung cancer (NSCLC). The risk factors for radiation pneumonitis (RP) during consolidation durvalumab following concurrent chemoradiotherapy (CCRT) using IMRT have not been thoroughly investigated.

METHODS

This retrospective study analyzed medical record data from consecutive patients diagnosed with NSCLC who underwent CCRT and consolidation durvalumab at our institution between April 2018 and September 2022. Since we adopted IMRT for the treatment of NSCLC in April 2020, these patients were categorized into two groups: those treated with IMRT after April 2020 and those treated with three-dimensional conformal radiotherapy (3D-CRT) before April 2020.

RESULTS

A total of 31 patients underwent IMRT (the IMRT group), while 25 patients underwent 3D-CRT (the 3D-CRT group). In both groups, the total dose was 60 Gy in 30 fractions. The cumulative incidence of ≥ grade 2 RP at 12 months was significantly lower in the IMRT group than in the 3D-CRT group (27.0% vs. 64.0%, hazard ratio [HR]: 0.338, 95% confidence interval [CI]: 0.144-0.793, p = 0.013). In the multivariable analysis, V20 (≥ 25.6%, HR: 2.706, 95% CI: 1.168-6.269, p = 0.020) and radiotherapy technique (IMRT, HR: 0.414, 95% CI: 0.172-0.994, p = 0.048) were identified as significant risk factors for ≥ grade 2 RP.

CONCLUSIONS

IMRT is associated with a lower rate of ≥ grade 2 RP in patients with NSCLC who received CCRT followed by durvalumab.

Dose-Volume Predictors of Radiation Pneumonitis After Thoracic Hypofractionated Radiation Therapy

PURPOSE

Hypofractionated radiation therapy (HFRT) is a common treatment for thoracic tumors, typically delivered as 60 Gy in 15 fractions. We aimed to identify dosimetric risk factors associated with radiation pneumonitis in patients receiving HFRT at 4 Gy per fraction, focusing on lung V20, mean lung dose (MLD), and lung V5 as potential predictors of grade ≥2 pneumonitis.

METHODS AND MATERIALS

All patients were treated with thoracic HFRT to 60 Gy in 15 fractions or 72 Gy in 18 fractions at a single health care system from 2013 to 2020. Tumors near critical structures (trachea, proximal tracheobronchial tree, esophagus, spinal cord, or heart) were considered central (within 2 cm), and those closer were classified as ultracentral (within 1 cm). The primary endpoint was grade ≥2 pneumonitis. Logistic regression analyses, adjusting for target size and dosimetric variables, were used to establish a dose threshold associated with <20% risk of grade ≥2 pneumonitis.

RESULTS

During a median 24.3-month follow-up, 18 patients (16.8%) developed grade ≥2 radiation pneumonitis, with no significant difference between the 2 dose regimens (17.3% vs 16.3%, P = .88). Four patients (3.7%) experienced grade ≥3 pneumonitis, including 2 grade 5 cases. Patients with grade ≥2 pneumonitis had significantly higher lung V20 (mean 23.4% vs 14.5%, P < .001), MLD (mean 13.0 Gy vs 9.5 Gy, P < .001), and lung V5 (mean 49.6% vs 40.6%, P = .01). Dose thresholds for a 20% risk of grade ≥2 pneumonitis were lung V20 <17.7%, MLD <10.6 Gy, and V5 <41.3%. Multivariable analysis revealed a significant association between lung V20 and grade ≥2 pneumonitis (adjusted odds ratio, 1.48, P = .03).

CONCLUSIONS

To minimize the risk of grade ≥2 radiation pneumonitis when delivering 4 Gy per fraction at either 60 Gy or 72 Gy, it is advisable to maintain lung V20<17.7%. MLD <10.6 Gy and V5<41.3% can also be considered as lower-priority constraints. However, additional validation is necessary before incorporating these constraints into clinical practice or trial planning guidelines.

A dynamic nomogram predicting symptomatic pneumonia in patients with lung cancer receiving thoracic radiation

PURPOSE

The most common and potentially fatal side effect of thoracic radiation therapy is radiation pneumonitis (RP). Due to the lack of effective treatments, predicting radiation pneumonitis is crucial. This study aimed to develop a dynamic nomogram to accurately predict symptomatic pneumonitis (RP ≥ 2) following thoracic radiotherapy for lung cancer patients.

METHODS

Data from patients with pathologically diagnosed lung cancer at the Zhongshan People's Hospital Department of Radiotherapy for Thoracic Cancer between January 2017 and June 2022 were retrospectively analyzed. Risk factors for radiation pneumonitis were identified through multivariate logistic regression analysis and utilized to construct a dynamic nomogram. The predictive performance of the nomogram was validated using a bootstrapped concordance index and calibration plots.

RESULTS

Age, smoking index, chemotherapy, and whole lung V5/MLD were identified as significant factors contributing to the accurate prediction of symptomatic pneumonitis. A dynamic nomogram for symptomatic pneumonitis was developed using these risk factors. The area under the curve was 0.89(95% confidence interval 0.83-0.95). The nomogram demonstrated a concordance index of 0.89(95% confidence interval 0.82-0.95) and was well calibrated. Furthermore, the threshold values for high- risk and low- risk were determined to be 154 using the receiver operating curve.

CONCLUSIONS

The developed dynamic nomogram offers an accurate and convenient tool for clinical application in predicting the risk of symptomatic pneumonitis in patients with lung cancer undergoing thoracic radiation.

Endostar acts as a pneumonitis protectant in patients with locally advanced non-small cell lung cancer receiving concurrent chemoradiotherapy

BACKGROUND

CCRT is presently the standard treatment for LA-NSCLC. RP is one of the main obstacles to the completion of thoracic radiation therapy, resulting in limited survival benefits in NSCLC patients. This research aims to explore the role of Endostar in the occurrence of grade≥2 RP and clinical curative effect in LA-NSCLC patients.

METHODS

This study retrospectively analyzed 122 patients with stage III NSCLC who received CCRT from December 2008 to December 2017, or Endostar intravenous drip concurrently with chemoradiotherapy (Endostar + CCRT group). Standard toxicity of the pneumonitis endpoint was also collected by CTCAE V5.0. We further summarized other available studies on the role of Endostar in the prognosis of NSCLC patients and the incidence of RP.

RESULTS

There were 76 cases in the CCRT group and 46 cases in the CCRT+ Endostar group. In the CCRT+ Endostar group, the occurrence of grade ≥2 RP in patients with V20Gy ≥25% was significantly higher than that in patients with V20Gy < 25% (p = 0.001). In the cohorts with V20Gy < 25%, 0 cases of 29 patients treated with Endostar developed grade ≥2 RP was lower than in the CCRT group (p = 0.026). The re-analysis of data from other available studies indicated that Endostar plus CCRT could be more efficient and safely in the occurrence of grade≥2 RP with LA-NSCLC.

CONCLUSIONS

When receiving CCRT for LA-NSCLC patients, simultaneous combination of Endostar is recommended to enhance clinical benefit and reduce pulmonary toxicity.

Radiation pneumonitis after concurrent aumolertinib and thoracic radiotherapy in EGFR-mutant non-small cell lung cancer patients

BACKGROUND

The superior efficacy of concurrent thoracic radiotherapy (TRT) and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been proven in locally advanced and advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, the high incidence of radiation pneumonitis (RP) reduced by concurrent TRT and TKIs has attracted widespread attention. Thus, this study was designed to investigate the rate and risk factors for RP in EGFR-positive NSCLC patients simultaneously treated with aumolertinib and TRT.

METHODS

We retrospectively evaluated stage IIIA-IVB NSCLC patients treated with concurrent aumolertinib and TRT between May 2020 and December 2022 at Shandong Cancer Hospital and Institute, Shandong, China. RP was diagnosed by two senior radiologists and then graded from 1 to 5 according to the Common Terminology Criteria for Adverse Events v5.0. All risk factors were evaluated by univariate and multivariate logistic regression analyses.

RESULTS

A total of 49 patients were included, the incidence of grade ≥ 2 RP was 42.9%. Grade 2 and 3 RP were observed in 28.6% and 14.3% of patients, respectively. Grade 4 to 5 RP were not observed. the gross total volume (GTV) ≥ 21 ml and ipsilateral lung V20 ≥ 25% were risk factors for RP. The median progression-free survival (PFS) in the first-line therapy group and second-line therapy group were 23.5 months and 17.2 months, respectively (p = 0.10).

CONCLUSIONS

Better local control is achieved with concurrent TRT and aumolertinib, and special attention should be given to controlling ipsilateral lung V20 and GTV to reduce the risk of RP.

The relationship of body mass index to setup errors, dosimetric parameters and incidence of radiation pneumonitis in non-small cell lung cancer patients undergoing intensity-modulated radiation therapy: a single-center observational study

BACKGROUND

The relationship among body mass index (BMI), setup error and radiation pneumonitis is not clearly illustrated.

OBJECTIVE

The present study aimed to investigate the role of BMI in non-small cell lung cancer (NSCLC) patients' radiation treatment, focusing on its relationship with setup error of patient positioning, the dosimetric parameters of intensity-modulated radiation therapy (IMRT) and the incidence of radiation pneumonitis.

METHODS

This prospective observational study included 523 cases of NSCLC patients during 2020-2022. Patients were divided into different groups by different BMI. The setup error was obtained by cone beam CT (CBCT) at three positions, lateral (LAT), longitudinal (LNG) and vertical (VRT). IMRT dosimetric parameters of V5, V20, and mean dose were collected.

RESULTS

Patients with BMI ≥28 kg/m2 showed significantly higher absolute values of LAT, LNG and VRT, higher V5, V20, mean dose, as well as higher total incidence of radiation pneumonitis and grade III radiation pneumonitis compared with patients with BMI <24 kg/m2 or 24-28 kg/m2. Spearman's analysis demonstrated that the absolute values of LAT, LNG and VRT were positively correlated with BMI, and positive correlation existed among BMI, dosimetric parameters and setup errors. ROC curves showed that LAT in setup errors and V5 in dosimetric parameters had the best diagnostic value for prediction of radiation pneumonitis. Only BMI, LAT, V5 and V20 were the independent risk factors for radiation pneumonitis.

CONCLUSIONS

Setup error caused by higher BMI might be associated with the dosimetric parameters, as well as the incidence of radiation pneumonitis in NSCLC patients.

Quantification of diffuse parenchymal lung disease in non-small cell lung cancer patients with definitive concurrent chemoradiation therapy for predicting radiation pneumonitis

BACKGROUND

We sought to quantify diffuse parenchymal lung disease (DPLD) extent using quantitative computed tomography (CT) analysis and to investigate its association with radiation pneumonitis (RP) development in non-small cell lung cancer (NSCLC) patients receiving definitive concurrent chemoradiation therapy (CCRT).

METHODS

A total of 82 NSCLC patients undergoing definitive CCRT were included in this prospective cohort study. Pretreatment CT scans were analyzed using quantitative CT analysis software. Low-attenuation area (LAA) features based on lung density and texture features reflecting interstitial lung disease (ILD) were extracted from the whole lung. Clinical and dosimetric factors were also evaluated. RP development was assessed using the Common Terminology Criteria for Adverse Events version 5.0. Univariable and multivariable logistic regression analyses were performed to identify independent risk factors for grade ≥3 (≥GR3) RP.

RESULTS

RP was identified in 68 patients (73.9%), with nine patients (10.9%) experiencing ≥GR3 RP. Univariable logistic regression analysis identified excess kurtosis and high-attenuation area (HAA)_volume (cc) as significantly associated with ≥GR3 RP. Multivariable logistic regression analysis showed that the combined use of imaging features and clinical factors (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and CHEMO regimen) demonstrated the best performance (area under the receiver operating characteristic curve = 0.924) in predicting ≥GR3 RP.

CONCLUSION

Quantified imaging features of DPLD obtained from pretreatment CT scans would predict the occurrence of RP in NSCLC patients undergoing definitive CCRT. Combining imaging features with clinical factors could improve the accuracy of the predictive model for severe RP.

Developing a Prediction Model for Radiation Pneumonitis in Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy Combined With Clinical, Dosimetric Factors, and Laboratory Biomarkers

BACKGROUND

The study aims to identify the risk factors and develop a model for predicting grade ≥2 radiation pneumonitis (RP) for lung cancer patients treated with stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

Clinical data, dosimetric data, and laboratory biomarkers from 186 patients treated with lung SBRT were collected. Univariate and multivariate logistic regression were performed to determine the predictive factors for grade ≥2 RP. Three models were developed by using the clinical, dosimetric, and combined factors, respectively.

RESULTS

With a median follow-up of 36 months, grade ≥2 RP was recorded in 13.4% of patients. On univariate logistic regression analysis, clinical factors of age and lung volume, dosimetric factors of treatment durations, fractional dose and V10, and laboratory biomarkers of neutrophil, PLT, PLR, and Hb levels were significantly associated with grade ≥2 RP. However, on multivariate analysis, only age, lung volume, fractional dose, V10, and Hb levels were independent factors. AUC values for the clinical, dosimetric, and combined models were 0.730 (95% CI, 0.660-0.793), 0.711 (95% CI, 0.641-0.775) and 0.830 (95% CI, 0.768-0.881), respectively. The combined model provided superior discriminative ability than the clinical and dosimetric models (P < .05).

CONCLUSION

Age, lung volume, fractional dose, V10, and Hb levels were demonstrated to be significant factors associated with grade ≥2 RP for lung cancer patients after SBRT. A novel model combining clinical, dosimetric factors, and laboratory biomarkers improved predictive performance compared with the clinical and dosimetric model alone.

Radiation Dermatitis and Pneumonitis in Patients Irradiated for Breast Cancer

BACKGROUND/AIM

Adjuvant radiotherapy (RT) for breast cancer can be associated with acute dermatitis (ARD) and pneumonitis (RP). Prevalence and risk factors were characterized.

PATIENTS AND METHODS

This study included 489 breast cancer patients receiving adjuvant RT with conventional fractionation (CF) ± sequential or simultaneous integrated boost, or hypo-fractionation ± sequential boost. RT-regimen and 15 characteristics were investigated for grade ≥2 ARD and RP.

RESULTS

Prevalence of grade ≥2 ARD and RP was 25.3% and 2.5%, respectively. On univariate analyses, ARD was significantly associated with CF and radiation boost (p<0.0001), age ≤60 years (p=0.008), Ki-67 ≥15% (p=0.012), and systemic treatment (p=0.002). On multivariate analysis, RT-regimen (p<0.0001) and age (p=0.009) were associated with ARD. Chronic inflammatory disease was significantly associated with RP on univariate (p=0.007) and multivariate (p=0.016) analyses.

CONCLUSION

Risk factors for grade ≥2 ARD and RP were determined that may help identify patients who require closer monitoring during and after RT.

Risk factor analysis of the development of severe radiation pneumonitis in patients with non-small cell lung cancer treated with curative radiotherapy, with focus on underlying pulmonary disease

BACKGROUND

We aim to identify the multifaceted risk factors that can affect the development of severe radiation pneumonitis (RP) in patients with non-small cell lung cancer (NSCLC) treated with curative high-dose radiotherapy with or without concurrent chemotherapy.

METHODS

We retrospectively reviewed the medical records of 175 patients with stage-I-III NSCLC treated with curative thoracic X-ray radiotherapy at the Korea University Guro Hospital between June 2019 and June 2022. Treatment-related complications were evaluated using the Common Terminology Criteria for Adverse Events (version 4.03).

RESULTS

The median follow-up duration was 15 months (range: 3-47 months). Idiopathic pulmonary fibrosis (IPF) as an underlying lung disease (P < 0.001) and clinical stage, regarded as the concurrent use of chemotherapy (P = 0.009), were associated with a high rate of severe RP. In multivariate analyses adjusting confounding variables, the presence of IPF as an underlying disease was significantly associated with severe RP (odds ratio [95% confidence interval] = 48.4 [9.09-347]; P < 0.001). In a subgroup analysis of stage-I-II NSCLC, the incidence of severe RP in the control, chronic obstructive pulmonary disease (COPD), and IPF groups was 3.2%, 4.3%, and 42.9%, respectively (P < 0.001). The incidence of severe RP was 15.2%, 10.7%, and 75.0% in the control, COPD, and IPF groups, respectively (P < 0.001) in the stage-III NSCLC group.

CONCLUSIONS

This study revealed that IPF as an underlying lung disease and the concurrent use of chemotherapy are associated with a high rate of severe RP. In contrast, COPD did not increase the risk of pulmonary toxicity after receiving curative high-dose radiotherapy.

Pneumonitis After Concurrent Chemoradiation and Immune Checkpoint Inhibition in Patients with Locally Advanced Non-small Cell Lung Cancer

AIMS

Pneumonitis is a common and potentially deadly complication of combined chemoradiation and immune checkpoint inhibition (CRT-ICI) in patients with locally advanced non-small cell lung cancer (LA-NSCLC). In this study we sought to identify the risk factors for pneumonitis with CRT-ICI therapy in LA-NSCLC cases and determine its impact on survival.

MATERIALS AND METHODS

We conducted a retrospective chart review of 140 patients with LA-NSCLC who underwent curative-intent CRT-ICI with durvalumab between 2018 and 2021. Pneumonitis was diagnosed by a multidisciplinary team of clinical experts. We used multivariable cause-specific hazard models to identify risk factors associated with grade ≥2 pneumonitis. We constructed multivariable Cox proportional hazard models to investigate the impact of pneumonitis on all-cause mortality.

RESULTS

The median age of the cohort was 67 years; most patients were current or former smokers (86%). The cumulative incidence of grade ≥2 pneumonitis was 23%. Among survivors, 25/28 patients had persistent parenchymal scarring. In multivariable analyses, the mean lung dose (hazard ratio 1.14 per Gy, 95% confidence interval 1.03-1.25) and interstitial lung disease (hazard ratio 3.8, 95% confidence interval 1.3-11.0) increased the risk for pneumonitis. In adjusted models, grade ≥2 pneumonitis (hazard ratio 2.5, 95% confidence interval 1.0-6.2, P = 0.049) and high-grade (≥3) pneumonitis (hazard ratio 8.3, 95% confidence interval 3.0-23.0, P < 0.001) were associated with higher all-cause mortality.

CONCLUSIONS

Risk factors for pneumonitis in LA-NSCLC patients undergoing CRT-ICI include the mean radiation dose to the lung and pre-treatment interstitial lung disease. Although most cases are not fatal, pneumonitis in this setting is associated with markedly increased mortality.

Analysis of the risk factors of radiation pneumonitis and the predictive ability of dosiomics in non-small-cell lung cancer

Purpose: This prospective study investigated the incidence of radiation pneumonitis (RP) after immunotherapy followed by radiotherapy in non-small-cell lung cancer, analyzed the risk factors for RP, and explored the predictive performance of dosimetry and dosiomics. Methods & materials: Risk factors for grade ≥2 RP were calculated by using a logistic regression model. Predictive performance was compared on the basis of area under the curve values. Results: Grade ≥2 RP occurred in 16 cases (26.7%). The AUC values of V5 Gy, gray-level dependence matrix-small dependence high gray-level emphasis (GLDM-SDHGLE) and combined features were 0.685, 0.724 and 0.734, respectively. Conclusion: Smoking history, bilateral lung V5 Gy and GLDM-SDHGLE were independent risk factors for RP. Dosiomics can effectively predict RP.

External validation of NTCP-models for radiation pneumonitis in lung cancer patients treated with chemoradiotherapy

PURPOSE

Normal tissue complication probability (NTCP) models can be used to estimate the risk of radiation pneumonitis (RP). The aim of this study was to externally validate the most frequently used prediction models for RP, i.e., the QUANTEC and APPELT models, in a large cohort of lung cancer patients treated with IMRT or VMAT. [1-2] METHODS AND MATERIALS: This prospective cohort study, included lung cancer patients treated between 2013 and 2018. A closed testing procedure was performed to test the need for model updating. To improve model performance, modification or removal of variables was considered. Performance measures included tests for goodness of fit, discrimination, and calibration.

RESULTS

In this cohort of 612 patients, the incidence of RP ≥ grade 2 was 14.5%. For the QUANTEC-model, recalibration was recommended which resulted in a revised intercept and adjusted regression coefficient (from 0.126 to 0.224) of the mean lung dose (MLD),. The APPELT-model needed revision including model updating with modification and elimination of variables. After revision, the New RP-model included the following predictors (and regression coefficients): MLD (B = 0.250), age (B = 0.049, and smoking status (B = 0.902). The discrimination of the updated APPELT-model was higher compared to the recalibrated QUANTEC-model (AUC: 0.79 vs. 0.73).

CONCLUSIONS

This study demonstrated that both the QUANTEC- and APPELT-model needed revision. Next to changes of the intercept and regression coefficients, the APPELT model improved further by model updating and performed better than the recalibrated QUANTEC model. This New RP-model is widely applicable containing non-tumour site specific variables, which can easily be collected.

Does shortening the duration of radiotherapy treatment in breast cancer increase the risk of radiation pneumonia: A retrospective study

Randomized studies evaluating hypofractionation and conventional fractionation radiotherapy treatments (RT) in patients with breast cancer have shown that hypofractionation achieves similar results to conventional fractionation in terms of survival and local control rates. It has also been shown that their long-term toxicities are similar. This study aimed to evaluate the effects of hypofractionated radiotherapy (H-RT) and conventional radiotherapy (C-RT) on lung toxicity and identify factors affecting this toxicity in patients with breast cancer. The study included 118 patients who underwent adjuvant RT following breast-conserving surgery (BCS). Out of these, 63 patients were assigned to receive C-RT, while the remaining 55 were assigned to receive H-RT. To clarify, we treated 63 patients with C-RT and 55 patients with H-RT. 60 patients were treated using 3-dimensional conformal radiotherapy (3DCRT) and 58 patients were treated using intensity modulated radiotherapy (IMRT). The patients were evaluated weekly for toxicity during radiotherapy (RT) treatment and were called every 3 months for routine controls after the treatment. The first control was performed 1 month after the treatment. Statistical analysis was performed using the SPSS20 program, and a P value of <.005 was considered statistically significant. The study found that the median age of the participants was 54.9 years and tomographic findings were observed in 70 patients. Radiological findings were detected at a median of 5 months after RT. The mean lung dose (MLD) on the treated breast side (referred to as ipsilateral lung or OAR) was 10.4 Gy for the entire group. Among patients who received 18 MV energy in RT, those with an area volume (V20) of the lung on the treated breast side >18.5%, those with a mean dose of the treated breast side lung (ipsilateral lung) >10.5 Gy, and those who received concurrent hormone therapy had significantly more tomographic findings. However, patients treated with YART had fewer tomographic findings. No symptomatic patients were observed during the follow-up period. Our findings show that the risk of lung toxicity is similar with H-RT and C-RT, and H-RT can be considered an effective and safe treatment option for breast cancer. The key factors affecting the development of lung toxicity were found to be the type of RT energy used, RT to the side breast, volume receiving 20 Gy in the side lung, side lung mean dose, and simultaneous hormonal therapy.

Chemoradiation-induced pneumonitis in patients with unresectable stage III non-small cell lung cancer: A systematic literature review and meta-analysis

INTRODUCTION

High-grade pneumonitis is a severe and potentially life-threatening adverse event associated with concurrent chemoradiation (cCRT) in patients with non-small cell lung cancer (NSCLC). The aim of this study was to summarize and quantify the incidence of severe (grade 3-5) cCRT-induced pneumonitis in unresectable stage III NSCLC patients.

METHODS

A systematic literature review and meta-analysis were performed in accordance with PRISMA guidelines. Published literature was searched for randomized controlled trials (RCTs), observational studies, and non-randomized trials from 2014 to April 2020. The primary outcome of interest was incidence of grade 3-5 pneumonitis.

RESULTS

Included were 17 studies for the review and 11 for the meta-analysis (1,788 participants); all studies examined radiation-related pneumonitis (RP). The pooled incidence of cCRT-induced grade 3-5 RP in unresectable stage III NSCLC patients was estimated to be 3.62% [95% confidence interval (CI): 1.65-6.21] in RCTs, 5.98% [95% CI: 2.26-12.91] in observational studies, and 7.85% [95% CI: 4.08-13.10] in observational studies using platinum-based doublet chemotherapies.

CONCLUSION

These results suggest the incidence of severe and fatal RP in patients with unresectable stage III NSCLC treated with cCRT ranges from 3.62% to 7.85%, with incidence varying by study design and chemotherapy regimen. Estimates of RP incidence were higher in the real-world setting compared to RCTs. These results can be used to contextualize the baseline risk of cCRT-induced pneumonitis in unresectable stage III NSCLC to better understand the adverse event of pneumonitis associated with novel immunotherapy treatments indicated for concomitant use with this modality.

[Radiation-induced pneumonitis : pathophysiology, risk factors and work-up in 2022]

Despite technical improvements concerning lung irradiation modalities, radiation-induced pneumonitis remains a usual complication, notably in the field of lung cancer treatment. This complication may remain asymptomatic but can also lead to respiratory distress. Thus, a low degree of suspicion and a comprehensive work-up is mandatory to evaluate the indication for specific treatment. In this article, we discuss the hypothesized pathophysiologic pathways, risk factors, clinical/radiological presentation and management.

Lung Dose Measured on Postradioembolization 90Y PET/CT and Incidence of Radiation Pneumonitis

Radiation pneumonitis is a rare but possibly fatal side effect of ⁹⁰Y radioembolization. It may occur 1-6 mo after therapy, if a significant part of the ⁹⁰Y microspheres shunts to the lungs. In current clinical practice, a predicted lung dose greater than 30 Gy is considered a criterion to exclude patients from treatment. However, contrasting findings regarding the occurrence of radiation pneumonitis and lung dose were previously reported in the literature. In this study, the relationship between the lung dose and the eventual occurrence of radiation pneumonitis after ⁹⁰Y radioembolization was investigated. Methods: We retrospectively analyzed 317 ⁹⁰Y liver radioembolization procedures performed during an 8-y period (February 2012 to September 2020). We calculated the predicted lung mean dose (LMD) using ^99mTc-MAA planar scintigraphy (LMD_MAA) acquired during the planning phase and left LMD (LMD_Y-90) using the ⁹⁰Y PET/CT acquired after the treatment. For the lung dose computation, we used the left lung as the representative lung volume, to compensate for scatter from the liver moving in the craniocaudal direction because of breathing and mainly affecting the right lung. Results: In total, 272 patients underwent ⁹⁰Y procedures, of which 63% were performed with glass microspheres and 37% with resin microspheres. The median injected activity was 1,974 MBq (range, 242-9,538 MBq). The median LMD_MAA was 3.5 Gy (range, 0.2-89.0 Gy). For 14 procedures, LMD_MAA was more than 30 Gy. Median LMD_Y-90 was 1 Gy (range, 0.0-22.1 Gy). No patients had an LMD_Y-90 of more than 30 Gy. Of the 3 patients with an LMD_Y-90 of more than 12 Gy, 2 patients (one with an LMD_Y-90 of 22.1 Gy and an LMD_MAA of 89 Gy; the other with an LMD_Y-90 of 17.7 Gy and an LMD_MAA of 34.1 Gy) developed radiation pneumonitis and consequently died. The third patient, with an LMD_Y-90 of 18.4 Gy (LMD_MAA, 29.1 Gy), died 2 mo after treatment, before the imaging evaluation, because of progressive disease. Conclusion: The occurrence of radiation pneumonitis as a consequence of a lung shunt after ⁹⁰Y radioembolization is rare (<1%). No radiation pneumonitis developed in patients with a measured LMD_Y-90 lower than 12 Gy.

Comprehensive Pneumonitis Profile of Thoracic Radiotherapy Followed by Immune Checkpoint Inhibitor and Risk Factors for Radiation Recall Pneumonitis in Lung Cancer

Purpose

Whilst survival benefits of thoracic radiotherapy (TRT) followed by immune checkpoint inhibitor (ICI) have been reported in patients with lung cancer, the potential high risk of treatment-related pneumonitis remains a concern. Asians may be more sensitive to lung toxicity than other races. This retrospective study intended to provide a comprehensive pneumonitis profile of TRT followed by ICI and investigate the risk factors from a Chinese cohort of lung cancer.

Methods and Materials

From January 2016 to July 2021, 196 patients with lung cancer who received TRT prior to ICI were retrospectively analyzed. Treatment-related pneumonitis, including checkpoint inhibitor pneumonitis (CIP), radiation pneumonitis (RP), and radiation recall pneumonitis (RRP), were recorded and graded through medical records and chest computed tomography. Characteristics predictive of pneumonitis were assessed using logistic regression models, and the receiver operating characteristic analyses were performed to identify optimal cut points for quantitative variables.

Results

With a median follow-up of 18 months, a total of 108 patients (55.1%) developed treatment-related pneumonitis during ICI therapy, with an incidence of 25.5% for grade 2 or higher (G2+) and 4.1% for G3+. The overall rates of CIP, RP and RRP were 8.2% (n=16), 46.9% (n=92) and 7.1% (n=14), respectively. With a total mortality rate of 1.5%, vast majority of the patients recovered from pneumonitis or remained stable. No patients died of RRP. Half of the patients with G2+ RP who withheld ICI therapy restarted ICI safely after resolution of RP. The history of chronic pulmonary diseases (P=0.05), mean lung dose (MLD, P=0.038), percent volume of lung receiving ≥5 Gy (V5, P=0.012) and percent volume of lung receiving ≥20 Gy (V20, P=0.030) predicted the occurrence of RRP in univariate analyses. Interval between TRT and ICI less than 3 months was an independent predictor for G2+ treatment-related pneumonitis in a multivariate model (Odds ratio OR=2.787, P=0.004).

Conclusions

Treatment-related pneumonitis, especially RRP, is acceptable and manageable in the setting of TRT followed by ICI in this Asian population. Dosimetric parameters MLD, V5 and V20 may improve the predictions of RRP in clinical practice.

Potential benefits of volumetric modulated arc therapy to reduce the incidence of ≥ grade 2 radiation pneumonitis in radiotherapy for locally advanced non-small cell lung cancer patients

BACKGROUND

The use of volumetric modulated arc therapy is gradually widespread for locally advanced non-small cell lung cancer. The purpose of this study was to identify the factors that caused ≥ grade 2 radiation pneumonitis and evaluate the impact of using volumetric modulated arc therapy on the incidence of ≥ grade 2 radiation pneumonitis by comparing three-dimensional conformal radiation therapy.

METHODS

We retrospectively evaluated 124 patients who underwent radical radiotherapy for locally advanced non-small cell lung cancer in our institution between 2008 and 2019. The following variables were analysed to detect the factors that affected ≥ grade 2 radiation pneumonitis; age, sex, the presence of interstitial lung disease, pulmonary emphysema, tumour location, stage, PTV/lung volume, lung V20Gy, total dose, concurrent chemoradiotherapy, adjuvant immune checkpoint inhibitor, radiotherapy method. Radiation pneumonitis was evaluated using the common terminology criteria for adverse events (version 5.0).

RESULTS

A total of 84 patients underwent three-dimensional conformal radiation therapy (3D-CRT group) and 40 patients underwent volumetric modulated arc therapy (VMAT group). The cumulative incidence of ≥ grade 2 radiation pneumonitis at 12 months was significantly lower in the VMAT group than in the 3D-CRT group (25% vs. 49.1%). The use of volumetric modulated arc therapy was a significant factor for ≥ grade 2 radiation pneumonitis (HR:0.32, 95% CI: 0.15-0.65, P = 0.0017) in addition to lung V20Gy (≥ 24%, HR:5.72 (95% CI: 2.87-11.4), P < 0.0001) and total dose (≥ 70 Gy, HR:2.64 (95% CI: 1.39-5.03), P = 0.0031) even after adjustment by multivariate analysis.

CONCLUSIONS

We identified factors associated with ≥ grade 2 radiation pneumonitis in radiotherapy for patients with locally advanced non-small cell lung cancer. Volumetric modulated arc therapy has potential benefits to reduce the risk of ≥ grade 2 radiation pneumonitis.

Analysis of related factors of radiation pneumonia caused by precise radiotherapy of esophageal cancer based on random forest algorithm

The precise radiotherapy of esophageal cancer may cause different degrees of radiation damage for lung tissues and cause radioactive pneumonia. However, the occurrence of radioactive pneumonia is related to many factors. To further clarify the correlation between the occurrence of radioactive pneumonia and related factors, a random forest model was used to build a risk prediction model for patients with esophageal cancer undergoing radiotherapy. In this study, we retrospectively reviewed 118 patients with esophageal cancer confirmed by pathology in our hospital. The health characteristics and related parameters of all patients were analyzed, and the predictive effect of radiation pneumonia was discussed using the random forest algorithm. After treatment, 71 patients developed radioactive pneumonia (60.17%). In univariate analyses, age, planning target volume length, Karnofsky performance score (KPS), pulmonary emphysema, with or without chemotherapy, and the ratio of planning target volume to planning gross tumor volume (PTV/PGTV) in mediastinum were significantly associated with radioactive pneumonia (P < 0.05 for each comparison). Multivariate analysis revealed that with or without pulmonary emphysema (OR = 7.491, P = 0.001), PTV/PGTV (OR = 0.205, P = 0.007), and KPS (OR = 0.251, P = 0.011) were independent predictors for radiation pneumonia. The results concluded that the analysis of radiation pneumonia-related factors based on the random forest algorithm could build a mathematical prediction model for the easily obtained data. This algorithm also could effectively analyze the risk factors of radiation pneumonia and formulate the appropriate treatment plan for esophageal cancer.

A multi-institutional analysis of fractionated versus single-fraction stereotactic body radiotherapy (SBRT) in the treatment of primary lung tumors: a comparison between two antipodal fractionations

OBJECTIVES

Stereotactic body radiotherapy (SBRT) is a consolidate treatment for inoperable early-stage lung tumors, usually delivered in single or multi-fraction regimens. We aimed to compare these two approaches in terms of local effectiveness, safety and survival.

MATERIALS AND METHODS

Patients affected by medically inoperable early-stage lung tumor were treated at two Institutions with two different schedules: 70 Gy in ten fractions (TF) (BED10: 119 Gy) or 30 Gy in single fraction (SF) (BED10: 120 Gy).

RESULTS

73 patients were treated with SBRT delivered with two biological equivalent schedules: SF (44) and TF (29). The median follow-up was 34 months (range 3-81 months). Three-year Overall survival (OS) was 57.9%, 3-year cancer-specific survival (CSS) was 77.2%, with no difference between treatment groups. Three-year progression-free survival (LPFS) was 88.9% and did not differs between SF and TF. Overall, four cases (5.4%) of acute grade ≥ 3 pneumonitis occurred. No differences in acute and late toxicity between the two groups were detected.

CONCLUSION

SF and TF seems to be equally safe and effective in the treatment of primary inoperable lung tumors especially for smaller lesion. The SF may be preferentially offered to reduce patient access to hospital with no negative impact on tumor control and survival.

Clinical and dosimetric predictors of radiation pneumonitis in early-stage lung cancer treated with Stereotactic Ablative radiotherapy (SABR) - An analysis of UK's largest cohort of lung SABR patients

BACKGROUND

Stereotactic Ablative Radiotherapy (SABR) is the standard treatment for early-stage medically inoperable lung cancer. Predictors of radiation pneumonitis (RP) in patients treated with SABR are poorly defined. In this study, we investigate clinical and dosimetric parameters, which can predict symptomatic RP in early-stage lung cancer patients treated with SABR.

MATERIALS AND METHODS

Patients treated with lung SABR between May 2009 and August 2018, in a single United Kingdom (UK) radiotherapy center were included. The patient's baseline characteristics, treatment details, and toxicity were retrieved from the electronic medical record. Dosimetric data was extracted from Xio and Monaco treatment planning systems. Patients were treated according to the UK SABR consortium guidelines. RP was graded retrospectively using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, based on available clinical and imaging information. Univariate and multivariate binary logistic regression was performed to determine predictive factors for grade ≥ 2 radiation pneumonitis, using Statistical Package for the Social Sciences (SPSS) statistics version 21 software. The goodness of fit was assessed using the Hosmer and Lemeshow test. The optimal diagnostic threshold was tested using the Receiver operating characteristics (ROC) curve. The chi-square test was carried out to test the different risk factors against the likelihood of developing grade ≥ 2 pneumonitis.

RESULTS

A total of 1266 patients included in the analysis. The median age of patients was 75 years. Six hundred sixty-six patients (52.6%) were female. Median follow up was 56 months. Sixty-five percent of patients received 55 Gy in 5 fractions. Forty-three percent of patients had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 and 16.2% had PS of 3. The Median Charlson comorbidity index was 6 (range 2-11). Median Standardized Uptake Value (SUV) max of the tumor was 6.5. Four hundred two patients (31.8%) had confirmed histological diagnosis; other patients were treated based on a radiological diagnosis. The median tumor size was 20 mm (range 4 mm-63 mm). Median Planning Target Volume (PTV) was 30.3 cc. Median values of R100, R50, and D2cm were 1.1, 5.6, 32.8 Gy. The median value of mean lung dose, V20, and V12.5 were 3.9 Gy, 5 %and 9.3% respectively. Eighty-five (6.7%) patients developed symptomatic RP (grade ≥ 2) with only 5(0.4%) developing grade 3 RP. Five percent of patients developed rib fractures but only 28% of these were symptomatic. On univariate analysis lower lobe tumor location, larger tumor size, PTV, mean lung dose, lung V20Gy, and V12.5 Gy were significantly associated with grade ≥ 2 RP. On multivariate analysis, only mean lung dose was associated with grade ≥ 2 pneumonitis. ROC curve analysis showed optimal diagnostic threshold for tumour size, PTV, mean lung dose, V20 and V12.5; are 22.5 mm ((Area Under Curve (AUC)-0.565)), 27.15 cc (AUC-0.58), 3.7 Gy (AUC-0.633), 4.6% (AUC-0.597), 9.5% (AUC-0.616). The incidence of ≥grade 2 RP was significantly high for values higher than the ROC threshold.

CONCLUSION

SABR treatment resulted in a very low rate of grade 3 pneumonitis. Lower lobe tumor location, larger tumor size, PTV, mean lung dose, V20, and V12.5 were found to be significant predictors of symptomatic radiation pneumonitis.