Association of computed tomography-detected pulmonary interstitial changes with severe radiation pneumonitis for patients treated with thoracic radiotherapy

Early Detection of Radiation Pneumonitis on Cone-Beam CT Images During a Course of Radiotherapy: A Case Series Report

Background and aim Radiation pneumonitis (RP) is a critical pulmonary toxicity following dose delivery to the lung, and it is usually diagnosed after radiotherapy courses are completed. Because RP may result in a lethal complication, a practical method for detecting early-phase RP is awaited. In this article, we describe our experience through a variety of clinical cases and discuss treatment decisions and lessons we have made and learned. Materials and methods A daily cone-beam computed tomography (CBCT) scan was employed with a lung window setting to detect the early-phase RP during treatment courses. For the past five years, thirty patients were diagnosed with RP, and eight patients were detected during radiotherapy courses on the CBCT images. Our best efforts were made in detecting early ground-glass opacity and early RP on CBCT images prior to symptoms. The eight cases were described in more detail with CBCT or CT images. Results and discussion Initially, RP was detected at 50 Gy or greater. However, more careful CBCT observation resulted in earlier detection at around 40 Gy. Then, a new problem arose whether the treatment should be terminated. It was reported that early RP development was associated with higher-grade complications, and therefore it is preferable to terminate radiotherapy once we detect even early-phase RP. However, termination in the middle of the treatment course may significantly reduce the therapeutic effect. In our experience, patients with favorable clinical status may continue to receive radiotherapy with careful observation of lung parenchyma on CBCT images and clinical data, such as Krebs Von den Lungen-6 (KL-6) and C-reactive protein (CRP). Conclusion We have shown that early detection of RP may be feasible during radiotherapy courses by daily monitoring of CBCT lung images. Further studies are awaited to proceed.

Impact of interstitial lung abnormality on survival after adjuvant durvalumab with chemoradiotherapy for locally advanced non-small cell lung cancer

INTRODUCTION

Concurrent chemoradiotherapy (CCRT) has been the standard of care for patients with locally advanced non-small cell lung cancer (LA-NSCLC).

BACKGROUND AND PURPOSE

The results of the PACIFIC trial established the use of consolidative durvalumab after concurrent chemoradiotherapy (CCRT) as the standard of care for patients with locally advanced non-small cell lung cancer (LA-NSCLC). A subgroup analysis of the PACIFIC trial reported a better progression-free survival (PFS) in Asians. Although real-world data on LA-NSCLC patients who received CCRT plus durvalumab have been reported, there have been few large-scale reports on Asians. In this study, we investigated prognostic factors in the largest real-world data set in Asia of only Japanese LA-NSCLC patients treated with CCRT plus durvalumab.

MATERIALS AND METHODS

One hundred and thirteen LA-NSCLC patients who received definitive CCRT and consolidative durvalumab at our institution between May 2018 and April 2021 were analyzed. Overall survival (OS), cause-specific survival (CSS), PFS, distant metastasis-free survival (DMFS), and in-field progression-free survival (IFPFS) were investigated as treatment outcomes using competing risk analyses.

RESULTS

During a median follow-up of 24 months (range, 5-47) after the initiation of durvalumab therapy, 31 patients died, of whom 23 died of lung cancer. In the multivariate analysis, the pretreatment factors that correlated with OS were ILA scores, adenocarcinoma, and performance status at the initiation of durvalumab. Furthermore, ILA score and programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) ≥ 1 % were significantly correlated with CSS, and PD-L1 TPS ≥ 1 % was significantly correlated with PFS and IFPFS.

CONCLUSION

Pretreatment ILA, adenocarcinoma, and performance status may have an impact on OS of LA-NSCLC patients receiving CCRT plus durvalumab.

Radiomic and Dosiomic Features for the Prediction of Radiation Pneumonitis Across Esophageal Cancer and Lung Cancer

PURPOSE

The aim was to investigate the advantages of dosiomic and radiomic features over traditional dose-volume histogram (DVH) features for predicting the development of radiation pneumonitis (RP), to validate the generalizability of dosiomic and radiomic features by using features selected from an esophageal cancer dataset and to use these features with a lung cancer dataset.

MATERIALS AND METHODS

A dataset containing 101 patients with esophageal cancer and 93 patients with lung cancer was included in this study. DVH and dosiomic features were extracted from 3D dose distributions. Radiomic features were extracted from pretreatment CT images. Feature selection was performed using only the esophageal cancer dataset. Four predictive models for RP (DVH, dosiomic, radiomic and dosiomic + radiomic models) were compared on the esophageal cancer dataset. We further used a lung cancer dataset for the external validation of the selected dosiomic and radiomic features from the esophageal cancer dataset. The performance of the predictive models was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve (ROCAUC) and the AUC of the precision recall curve (PRAUC) metrics.

RESULT

The ROCAUCs and PRAUCs of the DVH, dosiomic, radiomic and dosiomic + radiomic models on esophageal cancer dataset were 0.67 ± 0.11 and 0.75 ± 0.10, 0.71 ± 0.10 and 0.77 ± 0.09, 0.71 ± 0.11 and 0.79 ± 0.09, and 0.75 ± 0.10 and 0.81 ± 0.09, respectively. The predictive performance of the dosiomic- and radiomic-based models was significantly higher than that of the DVH-based model with respect to esophageal cancer. The ROCAUCs and PRAUCs of the DVH, dosiomic, radiomic and dosiomic + radiomic models on the lung cancer dataset were 0.64 ± 0.18 and 0.37 ± 0.20, 0.67 ± 0.17 and 0.37 ± 0.20, 0.67 ± 0.16 and 0.45 ± 0.23, and 0.68 ± 0.16 and 0.44 ± 0.22, respectively. On the lung cancer dataset, the predictive performance of the radiomic and dosiomic + radiomic models was significantly higher than that of the DVH-based model. However, the PRAUC of the dosiomic-based model showed no significant difference relative to the corresponding RP prediction performance on the lung cancer dataset.

CONCLUSION

The results suggested that dosiomic and CT radiomic features could improve RP prediction in thoracic radiotherapy. Dosiomic and radiomic feature knowledge might be transferrable from esophageal cancer to lung cancer.

Radiation pneumonitis after palliative radiotherapy in cancer patients with interstitial lung disease

PURPOSE

The risk of radiation pneumonitis (RP) after palliative radiotherapy (RT) in cancer patients with interstitial lung disease (ILD) remains unclear. This study aimed to investigate the incidence, severity, and predictive factors of RP among patients with ILD who received palliative RT.

METHODS AND MATERIALS

The medical records of cancer patients with ILD who received palliative RT involving a lung field between January 2008 and December 2019 were retrospectively reviewed. Screening for ILD was performed by using the ICD-10 diagnosis code, and the ILD was evaluated on the basis of pretreatment computed tomography (CT). RP was scored using Common Terminology Criteria for Adverse Events, version 5.0. Associations between both clinical and dosimetric factors and RP were assessed by univariate and multivariate analyses.

RESULTS

Sixty-two patients were included in the analysis. The median prescribed physical dose of RT was 25 Gy (range, 6-40 Gy). The RP was graded 1, 2, 3, 4, and 5 in 6 (10%), 3 (5%), 1 (2%), 2 (3%), and 6 (10%) patients, respectively. The median time to onset of grade 3 or more RP (≥Gr3 RP) was 39 days (range, 10-155). The results of the multivariate analysis indicated that ILD pattern was a significant predictive factor for ≥Gr3 RP (odds ratio, 12.0; 95% confidence interval, 1.02-1664; P < 0.05).

CONCLUSIONS

RT involving a lung field, even when prescribed with palliative intent, should be administered carefully to ILD patients. Evaluation of the ILD pattern on pretreatment CT images may be of help in determining whether to perform RT.

Establishment and Verification of a Prediction Model for Symptomatic Radiation Pneumonitis in Patients with Esophageal Cancer Receiving Radiotherapy

BACKGROUND This study aimed to determine the value of the significant index in predicting symptomatic radiation pneumonitis (RP) in esophageal cancer patients, establish a nomogram prediction model, and verify the model. MATERIAL AND METHODS The patients enrolled were divided into 2 groups: a model group and a validation group. According to the logistic regression analysis, the independent predictors for symptomatic RP were obtained, and the nomogram prediction model was established according to these independent predictors. The consistency index (C-index) and calibration curve were used to evaluate the accuracy of the model, and the prediction ability of the model was verified in the validation group. Recursive partitioning analysis (RPA) was used for the risk stratification analysis. RESULTS The ratio of change regarding the pre-albumin at the end of treatment (P=0.001), platelet-to-lymphocyte ratio during treatment (P=0.027), and neutrophil-to-lymphocyte ratio at the end of treatment (P=0.001) were the independent predictors for symptomatic RP. The C-index of the nomogram model was 0.811. According to the risk stratification of RPA, the whole group was divided into 3 groups: a low-risk group, a medium-risk group, and a high-risk group. The incidence of symptomatic RP was 0%, 16.9%, and 57.6%, respectively. The receiver operating characteristic curve also revealed that the nomogram model has good accuracy in the validation group. CONCLUSIONS The developed nomogram and corresponding risk classification system have superior prediction ability for symptomatic RP and can predict the occurrence of RP in the early stage.

Risk factors for radiation pneumonitis in lung cancer patients with subclinical interstitial lung disease after thoracic radiation therapy

Background

Previous studies have found that patients with subclinical interstitial lung disease (ILD) are highly susceptible to developing radiation pneumonitis (RP) after thoracic radiation therapy. In the present study we aimed to evaluate the incidence of and risk factors for RP after thoracic intensity-modulated radiation therapy in lung cancer patients with subclinical ILD.

Methods

We retrospectively analyzed data from lung cancer patients with subclinical ILD who were treated with thoracic intensity-modulated radiation therapy with a prescribed dose of ≥ 50 Gy in our institution between January 2016 and December 2017.

Results

Eighty-seven consecutive lung cancer patients with subclinical ILD were selected for the study. The median follow-up period was 14.0 months. The cumulative incidence of grades ≥ 2 and ≥ 3 RP at one year was 51.0% and 20.9%, respectively. In the multivariate analysis, a mean lung dose ≥ 12 Gy was a significant risk factor for grade ≥ 2 RP (p = 0.049). Chemotherapy with gemcitabine in the past, V5 ≥ 50%, and subclinical ILD involving ≥ 25% of the lung volume were significantly associated with grade ≥ 3 RP (p = 0.046, p = 0.040, and p = 0.024, respectively).

Conclusion

Mean lung dose is a significant risk factor for grade ≥ 2 RP. Lung cancer patients who have received chemotherapy with gemcitabine in the past, V5 ≥ 50%, and those with subclinical ILD involving ≥ 25% of lung volume have an increased risk of grade ≥ 3 RP in lung cancer patients with subclinical ILD.

Stereotactic radiotherapy for early stage non-small cell lung cancer: current standards and ongoing research

Stereotactic body radiation therapy (SBRT) allows for the non-invasive and precise delivery of ablative radiation dose. The use and availability of SBRT has increased rapidly over the past decades. SBRT has been proven to be a safe, effective and efficient treatment for early stage non-small cell lung cancer (NSCLC) and is presently considered the standard of care in the treatment of medically or functionally inoperable patients. Evidence from prospective randomized trials on the optimal treatment of patients deemed medically operable remains owing, as three trials comparing SBRT to surgery in this cohort were terminated prematurely due to poor accrual. Yet, SBRT in early stage NSCLC is associated with favorable toxicity profiles and excellent rates of local control, prompting discussion in regard of the treatment of medically operable patients, where the standard of care currently remains surgical resection. Although local control in early stage NSCLC after SBRT is high, distant failure remains an issue, prompting research interest to the combination of SBRT and systemic treatment. Evolving advances in SBRT technology further facilitate the safe treatment of patients with medically or anatomically challenging situations. In this review article, we discuss international guidelines and the current standard of care, ongoing clinical challenges and future directions from the clinical and technical point of view.

Usefulness of Simple Original Interstitial Lung Abnormality Scores for Predicting Radiation Pneumonitis Requiring Steroidal Treatment After Definitive Radiation Therapy for Patients With Locally Advanced Non-Small Cell Lung Cancer

Purpose

Adjuvant durvalumab has become a standard treatment after chemoradiation therapy for patients with locally advanced non-small cell lung cancer (LA-NSCLC). Accordingly, predicting radiation pneumonitis (RP) requiring steroidal treatment (steroid-RP) is of utmost importance because steroidal administration is reported to weaken the effectiveness of immunotherapy. However, grade 2 RP was used as an index of RP in previous studies, but it is an ambiguous definition because it includes not only steroid-RP but also a mild cough requiring only a cough medicine. Therefore, in this study, steroid-RP was used for evaluating RP, and the purpose of this study was to investigate predictive factors of steroid-RP, including original simple interstitial lung abnormality scores (ILASs).

Methods and Materials

A total of 145 patients with LA-NSCLC who received definitive radiation therapy (DRT) in our institution from January 2014 to May 2017 were identified. Original ILASs, performance status, age, respiratory function, Brinkman index, concurrent administration of chemotherapy, and dose-volume histogram metrics of the lung were analyzed to evaluate their association with steroid-RP. Additionally, 3 diagnostic radiologists evaluated the patients' pre-DRT chest computed tomography images and determined the simple ILASs. ILASs were rated as follows: 0: none; 1: abnormality without honeycombing (ground-glass attenuation, fine reticular opacity, and microcysts); and 2: honeycombing.

Results

The median follow-up period was 729 days. Thirty-one patients (21.4%) experienced steroid-RP. In the univariate analysis, lung V5/V10/VS5, Brinkman index, and ILASs were significant predictive factors of steroid-RP. Additionally, multivariate analysis including Brinkman index ≥840, lung V5 ≥37%, and an ILAS ≥1 revealed that only an ILAS (P = .001) was an independent predictive factor of steroid-RP.

Conclusions

The original simple ILAS was an easy-to-use tool and a significant predictive factor of steroid-RP in DRT in patients with LA-NSCLC.

Radiation-induced lung injury: current evidence

Chemo-radiotherapy and systemic therapies have proven satisfactory outcomes as standard treatments for various thoracic malignancies; however, adverse pulmonary effects, like pneumonitis, can be life-threatening. Pneumonitis is caused by direct cytotoxic effect, oxidative stress, and immune-mediated injury. Radiotherapy Induced Lung Injury (RILI) encompasses two phases: an early phase known as Radiation Pneumonitis (RP), characterized by acute lung tissue inflammation as a result of exposure to radiation; and a late phase called Radiation Fibrosis (RF), a clinical syndrome that results from chronic pulmonary tissue damage. Currently, diagnoses are made by exclusion using clinical assessment and radiological findings. Pulmonary function tests have constituted a significant step in evaluating lung function status during radiotherapy and useful predictive tools to avoid complications or limit toxicity. Systemic corticosteroids are widely used to treat pneumonitis complications, but its use must be standardized, and consider in the prophylaxis setting given the fatal outcome of this adverse event. This review aims to discuss the clinicopathological features of pneumonitis and provide practical clinical recommendations for prevention, diagnosis, and management.

Prediction of radiation pneumonitis using dose-volume histogram parameters with high attenuation in two types of cancer: A retrospective study

The constraint values of dose-volume histogram (DVH) parameters for radiation pneumonitis (RP) prediction have not been uniform in previous studies. We compared the differences between conventional DVH parameters and DVH parameters with high attenuation volume (HAV) in CT imaging in both esophageal cancer and lung cancer patients to determine the most suitable DVH parameters in predicting RP onset. Seventy-seven and 72 patients who underwent radiation therapy for lung cancer and esophageal cancer, respectively, were retrospectively assessed. RP was valued according to the Common Terminology Criteria for Adverse Events. We quantified HAV with quantitative computed tomography analysis. We compared conventional DVH parameters and DVH parameters with HAV in both groups of patients. Then, the thresholds of DVH parameters that predicted symptomatic RP and the differences in threshold of DVH parameters between lung cancer and esophageal cancer patient groups were compared. The predictive performance of DVH parameters for symptomatic RP was compared using the area under the receiver operating characteristic curve. Mean lung dose, HAV30% (the proportion of the lung with HAV receiving ≥30 Gy), and HAV20% were the top three parameters in lung cancer, while HAV10%, HAV5%, and V10 (the percentage of lung volume receiving 10 Gy or more) were the top three in esophageal cancer. By comparing the differences in the threshold for parameters predicting RP between the two cancers, we saw that HAV30% retained the same value in both cancers. DVH parameters with HAV showed narrow differences in the threshold between the two cancer patient groups compared to conventional DVH parameters. DVH parameters with HAV may have higher commonality than conventional DVH parameters in both patient groups tested.

Clinicopathological characteristics of lung cancer in patients with systemic sclerosis

Background and objectives

Systemic sclerosis (SSc) is a connective tissue disorder (CTD) associated with an increased risk of malignancy including lung cancer (LC). Our objective was to provide a description of demographics and clinicopathological characteristics of LC patients with SSc.

Methods

Lung cancer patients with SSc admitted to Peking Union Medical College Hospital from January 2000 to August 2017 were reviewed. Demographic and clinicopathologic data were collected.

Results

Of the 12 cases included in our study, all were female. No patients had a history of smoking. The most common histological type was adenocarcinoma, followed by squamous cell carcinoma and small‐cell carcinoma. No driver mutation was identified in the five patients undergoing genetic testing. Eight patients had interstitial lung disease (ILD). Six were manifested as nonspecific interstitial pneumonia (NSIP) and two as usual interstitial pneumonia (UIP). Four (33.3%) patients underwent surgical resection. Among them, two had ILD with a normal preoperative pulmonary function tests (PFT). Eight (66.7%) patients received chemotherapy. Radiotherapy was administered in only one (8.3%) patient. No grade 3/4 adverse events were documented.

Conclusion

The predominance of female patients in our study is different from that reported in general lung cancer patients. A high proportion of patients has SSc‐ILD, including NSIP and UIP. Surgery or radiotherapy could still be considered in carefully selected patients with ILD.

Nationwide survey of radiation therapy in Japan for lung cancer complicated with interstitial lung disease

The purpose of this study was to clarify the opinions of radiation oncologists in Japan regarding treatment for lung cancer complicated with interstitial lung disease (ILD) by a questionnaire survey, and the risk of acute exacerbation (AE) after radiotherapy. Questionnaires were sent to all of the facilities in which radiation therapy is performed for lung cancer in Japan by using the mailing list of the Japanese Society for Radiation Oncology (JASTRO). The questionnaire survey was conducted to clarify who judges the existence of ILD, the indications for radiation therapy in cases of ILD-combined lung cancer, and the ratio of ILD-combined lung cancer in lung cancer patients treated with radiation therapy. Patients with ILD-combined lung cancer who received radiotherapy during the period from April 2014 to March 2015 were retrospectively analysed. Any cases of AE without any other obvious cause were included. ILD confirmation was performed by central radiologists using computed tomography images. A total of 47 facilities responded to the questionnaire. Radiation therapy was an option in cases of ILD-combined lung cancer in 39 (83%) of the facilities. The indication for radiation therapy was based on image findings in 35 (90%) of the 39 facilities in which radiation therapy was acceptable or was a choice in some cases of ILD. The final indication was based on the opinion of the pulmonologist in 29 (74%) of those 39 facilities. In fiscal year 2014, a total of 2128 patients in 38 facilities received chest irradiation. Seventy-eight (3.7%) of those 2128 patients had ILD-combined lung cancer. Sixty-seven patients were included in patient analysis. AE occurred in 5 patients (7.5%), and one of those 5 patients (20.0%) died from radiation-induced AE. The median period from radiotherapy to AE was 4 months (range, 2-7 months). The following four independent risk factors for AE were identified in univariate analysis: non-advanced age (<75 years), increased C-reactive protein level (≥0.3 mg/dl), adjuvant chemotherapy and ≥ Grade 2 radiation pneumonitis. Radiotherapy was an option for lung cancer even in cases with ILD in 83% (39/47) of the facilities in Japan. Seventy-eight (3.7%) of 2128 patients who received radiation therapy for lung cancer had ILD. Radiotherapy for ILD-combined lung cancer may induce AE at a substantial rate and AE can be life-threatening. Minimizing the risk of radiation pneumonitis might enable the risk of AE to be reduced.

Perioperative pirfenidone treatment as prophylaxis against acute exacerbation of idiopathic pulmonary fibrosis: a single-center analysis

PURPOSE

Lung cancer in patients with idiopathic pulmonary fibrosis (IPF) is associated with a poor prognosis and postoperative acute exacerbation (AE) of IPF is a fatal complication. Studies have shown that perioperative pirfenidone treatment (PPT) may reduce the incidence of AE-IPF. We evaluated the efficacy of PPT in preventing AE-IPF and improving overall survival.

METHODS

The subjects of this study were 56 patients with IPF who underwent resection of lung cancer in our hospital between January, 2011 and September, 2016. Pirfenidone was administered to patients from 4 weeks before the operation and continued for longer periods. Thirty-six patients received PPT and their outcome was compared with that of the other 20 patients who did not.

RESULTS

There were no differences in age, gender, smoking history, respiratory function, or surgical procedures between the groups. AE-IPF developed in three patients (8%) in the PPT group and four (20%) patients in the non-PPT group, without a significant difference between the groups. The interval was significantly longer in the PPT group (p = 0.03). PPT reduced postoperative mortality significantly (p = 0.04).

CONCLUSIONS

Although perioperative pirfenidone treatment did not obviously prevent postoperative AE-IPF, it may reduce the mortality of lung cancer patients with IPF.

Clinical Management of Risk of Radiation Pneumonia with Serum Markers During the Radiotherapy for Patients with Thoracic Malignant Tumors

PURPOSE

Risk of radiation pneumonia (RP) could not be effectively detected due to non-specific clinical symptoms in the early stage. The purpose of this investigation was to evaluate serum biomarkers of cytokines interleukin-6 (IL-6), C-reactive protein (CRP) and procalcitonin (PCT) for its early detection in patients with thoracic malignant tumors receiving radiotherapy.

PATIENTS AND METHODS

The clinical data of 105 patients with thoracic malignant tumors (lung cancer, esophageal carcinoma and mediastinal tumors) treated by radiotherapy were retrospectively analyzed. The patients were divided into RP group and non-RP group according to the Common Terminology Criteria for Adverse Events (CTCAE 5.0). The serum level of IL-6 was detected by chemiluminescence, and the level of CRP was measured by nephelometry during radiotherapy. The level of PCT, one of the specific indicators to distinguish infection and non-infectious etiologies, was also detected by chemiluminescence.

RESULTS

Among 105 patients treated by radiotherapy, 28 developed RP, and the other 77 had no RP. There was no significant difference in the risk of RP between patients' factors (age, sex, PS score, smoking, tumor type) and treatment factors (chemotherapy, V5, GTV dose). However, chronic obstructive pulmonary disease (COPD), V20 and mean lung dose (MLD) were significantly different between the two groups (χ2 = 4.131, 3.986, 7.830, P < 0.05). Furthermore, PCT levels were also found to have insignificant differences between RP group and non-RP group (P > 0.05). However, there were significant differences between the groups in the levels of IL-6 and CRP (P < 0.05). The IL-6 levels significantly increased earlier than that of conventional CT imaging when patients suffering from RP and peaked at 6 weeks during radiotherapy. CRP had a similar change as IL-6. Single cytokine and combination of IL-6 and CRP possessed a good ability to predict RP with the AUC of IL-6 of 0.89±0.04 (95% CI, 0.80-0.95, P<0.001), CRP of 0.87±0.05 (95% CI, 0.78-0.94, P<0.001), IL-6 + CRP of 0.92 ± 0.03 (95% CI, 0.83-0.97, P < 0.001), respectively.

CONCLUSION

The combined detection of serum IL-6, CRP and PCT may be an effectual method for early detection and clinical practice management of risk of RP.

Dynamic changes in T-cell subsets and C-reactive protein after radiation therapy in lung cancer patients and correlation with symptomatic radiation pneumonitis treated with steroid therapy

Objectives

To investigate relationships among serum T-cell subsets, CRP, levels and radiation pneumonitis (RP) in lung cancer patients receiving radiotherapy.

Methods

A case-control study with frequency matching was carried out. The case group comprised 36 lung cancer patients who had developed grade ≥2 RP after thoracic radiotherapy. The control group was 36 patients with lung cancer without RP. Patients in the case group received steroid therapy for 1 month after diagnosis of RP and were followed up for 3 months. T-cell subsets, CRP, and pulmonary function were detected at three time points (onset of RP and 1 and 3 months after diagnosis). Data for the control group were collected 3 months after radiotherapy. Treatment effectiveness was evaluated at 1 and 3 months after diagnosis of RP.

Results

Of the 36 patients in the case group, three with grade5 RP died from respiratory failure. The other 33 cases had all improved with steroid therapy at 3 months after RP diagnosis. In these 33, CD3⁺T-cell quantity, CD4⁺T-cell quantity, and of CD4⁺:CD8⁺ ratio in T-cell subsets decreased significantly and CRP increased (P<0.05) at the onset of RP compared with the control group. After steroid therapy, CD4⁺T-cell quantity increased significantly compared to before treatment. The same change was seen in CD4⁺:CD8⁺ ratio, whereas CRP levels decreased obviously, with treatment effectiveness improved. In addition, with the damage level of RP increased, CD4⁺ T -cell quantity decreased obviously and CRP levels increased accordingly at the onset of RP (P<0.05).

Conclusion

T-cell subsets and CRP may become effective immunological biomarkers for predicting damage from RP and evaluating treatment effectivesness of steroid therapy.

Stereotactic body radiotherapy in patients with chronic obstructive pulmonary disease and interstitial pneumonia: a review

Stereotactic body radiation therapy (SBRT) can yield excellent local tumor control, as well as survival benefit comparable to that of surgery for early-stage lung cancer. However, in terms of toxicity, SBRT might lead to fatal radiation pneumonitis. Lung diseases, such as chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), are major risk factors for lung cancer. However, these patients are typically not candidates for the gold-standard treatment option, lobectomy, because of the perioperative risks. In addition, patients with poor respiratory function can be excluded in prospective clinical trials. Thus, SBRT for patients with pulmonary diseases is still challenging, but there appears to be a clinical role for this modality as an alternative treatment. However, there are few well-documented review articles on SBRT for patients with pulmonary diseases. Therefore, we aimed to review SBRT in the context of important patient-related factors, including COPD and ILD. SBRT is an acceptable alternative treatment option for patients with lung cancer who also have COPD with an equivalent risk of radiation pneumonitis to normal lung. However, latent ILD should be detected prior to treatment. The indication for SBRT should be decided by carefully considering the risks and benefit for patients with ILD.

Radiation Pneumonitis after Intensity-Modulated Radiotherapy for Esophageal Cancer: Institutional Data and a Systematic Review

Radiation pneumonitis (RP) is a serious complication that can occur after thoracic radiotherapy. The goal of this study is to investigate the incidence of RP after radiochemotherapy with intensity modulated radiotherapy (IMRT) in patients with esophageal cancer and correlate this with dose volume histogram (DVH) related parameters. For this purpose, the clinical course of 73 patients was evaluated and irradiation doses to the lungs were extracted from radiotherapy treatment plans. Furthermore, a systematic review on this topic was conducted across PubMed. In our institutional cohort, Common Terminology Criteria for Adverse Events (CTCAE) grade II or higher RP occurred in four patients (5.5%). The systematic review identified 493 titles of which 19 studies reporting 874 patients qualified for the final analysis. No grade IV or V RP after radiochemotherapy with IMRT for esophageal cancer was reported in the screened literature. Grade II or higher RP is reported in 6.6% of the patients. A higher incidence can be seen with increasing values for lung V20. In conclusion, our institutional data and the literature consistently show a low incidence of symptomatic RP after radiochemotherapy in patients with esophageal cancer treated with IMRT. However, efforts should be made to keep the lung V20 below 23% and specific caution is warranted in patients with pre-existing lung conditions.

Long-term survival after complete resection of non-small-cell lung cancer in patients with interstitial lung disease

OBJECTIVES

Patients with lung cancer and interstitial lung disease (ILD), usual interstitial pneumonia in particular, are known to have a poor outcome. The aim of this study was to evaluate the prognostic impact of ILD in patients with non-small-cell lung cancer.

METHODS

A total of 2054 consecutive patients underwent complete resection of Stage IA-IIIA non-small-cell lung cancer in our institution between January 2002 and March 2013. The presence of ILD was diagnosed and categorized based on high-resolution computed tomography images. Multivariate analysis was performed to identify the prognostic factors.

RESULTS

There were 106 (5%) patients with ILD. There were significantly more patients who developed severe complications (P < 0.01) in the ILD group, with 4 (4%) patients developing acute exacerbation. Although the difference in postoperative mortality rate was marginal between the groups (P = 0.07), the 5-year overall survival and cancer-specific survival rates of the ILD patients were significantly worse than those of the non-ILD group (overall survival: 40.4% vs 72.0%, P < 0.01; cancer-specific survival 55.4% vs 78.6%, P < 0.01). The results of multivariate analysis showed that coexistence of ILD (hazard ratio 1.45; P = 0.01) was an independent, unfavourable prognostic factor.

CONCLUSIONS

The presence of ILD led to a much poorer survival after complete resection of non-small-cell lung cancer.

Radiation pneumonitis in lung cancer treated with volumetric modulated arc therapy

Background

Few studies to date have assessed the incidence of radiation pneumonitis (RP) in lung cancer patients who have been treated with volumetric modulated arc therapy (VMAT). This study is aimed at reporting the RP incidence rate and the risk factors associated with a symptomatic RP in patients with lung cancer treated with VMAT.

Methods

A total of 77 consecutive lung cancer patients treated with VMAT from 2013 through 2015 were reviewed. RP severity was graded according to the Common Terminology Criteria for Adverse Events (CTCEA) v.4. Univariate and multivariate analyses were performed to identify the significant factors associated with RP.

Results

VMAT allowed us to achieve most planning objectives on the target volumes and organs at risk, for PTV V_95% =96.8%±3.1%, for lung V₅ =41.3%±8.7%, V₁₀ =30.0%±7.1%, V₂₀ =20.9%±5.7%, for heart V₅ =43.2%±29.9%, for esophagus V₆₀ =8.1%±12.9%. The maximum dose of spinal cord was 34.4±9.5 Gy. The overall incidence of symptomatic RP (grade ≥2 by CTCAE) was 28.6% in the entire cohort, and the rate of grade ≥3 RP was 11.7%. Based on the multivariate analysis, factors predictive of symptomatic RP included lung volume receiving ≥10 Gy (V₁₀) (P=0.019) and C-reactive protein changing level (P=0.013).

Conclusions

Our data showed that the incidence rate of RP was acceptable in lung cancer patients treated with VMAT. Additionally, we found that V₁₀ might be an important factor for predicting the development of RP when VMAT was used; but this observation needs to be validated in future studies.

The utility of quantitative CT radiomics features for improved prediction of radiation pneumonitis

PURPOSE

The purpose of this study was to explore gains in predictive model performance for radiation pneumonitis (RP) using pretreatment CT radiomics features extracted from the normal lung volume.

METHODS

A total of 192 patients treated for nonsmall cell lung cancer with definitive radiotherapy were considered in the current study. In addition to clinical and dosimetric data, CT radiomics features were extracted from the total lung volume defined using the treatment planning scan. A total of 6851 features (15 clinical, 298 total lung and heart dosimetric, and 6538 image features) were gathered and considered candidate predictors for modeling of RP grade ≥3. Models were built with the least absolute shrinkage and selection operator (LASSO) logistic regression and applied to the set of candidate predictors with 50 iterations of tenfold nested cross-validation.

RESULTS

In the current cohort, 30 of 192 patients (15.6%) presented with RP grade ≥3. Average cross-validated AUC (CV-AUC) using only the clinical and dosimetric parameters was 0.51. CV-AUC was 0.68 when total lung CT radiomics features were added. Analysis with the entire set of available predictors revealed seven different image features selected in at least 40% of the model fits.

CONCLUSIONS

We have successfully incorporated CT radiomics features into a framework for building predictive RP models via LASSO logistic regression. Addition of normal lung image features produced superior model performance relative to traditional dosimetric and clinical predictors of RP, suggesting that pretreatment CT radiomics features should be considered in the context of RP prediction.

The Safety and Efficacy of Treatment with Nab-paclitaxel and Carboplatin for Patients with Advanced Squamous Non-small Cell Lung Cancer Concurrent with Idiopathic Interstitial Pneumonias

Objective Although lung squamous cell carcinoma (SCC) accounts for 20-30% of lung cancer cases, new treatment options are limited. The CA031 study showed that nanoparticle albumin-bound-paclitaxel (nab-PTX) plus carboplatin produced a significantly higher overall response rate (41%) than solvent-based paclitaxel plus carboplatin in patients with lung SCC. However, the safety and efficacy of combination chemotherapy of nab-PTX and carboplatin has not yet been established for patients with concurrent lung SCC and idiopathic interstitial pneumonias (IIPs). The aim of this study was to assess the safety and efficacy profiles of nab-PTX and carboplatin in patients with lung SCC and concurrent IIPs. Methods Eight patients with inoperable-stage lung SCC and IIPs were treated with nab-PTX plus carboplatin in a first-line setting between June 2013 and December 2016. One of the eight was a woman, and the median age was 77 (range=72-80) years. Their clinical outcomes, including chemotherapy-associated acute exacerbation of IIPs, were retrospectively investigated. Results The overall response rate was 50%, the median progression-free survival time was 5.6 months, and the median overall survival time was 8.1 months. No patients experienced chemotherapy-related exacerbation of IIPs in the first-line treatment with nab-PTX plus carboplatin. However, IIPs worsened in two of four patients who received second-line chemotherapy. Conclusion Combination chemotherapy of nab-PTX and carboplatin may be an effective and safe treatment option for patients with inoperable lung SCC with IIPs. To confirm this, a large-scale prospective study is needed.

Impact of Interstitial Lung Disease Classification on the Development of Acute Exacerbation of Interstitial Lung Disease and Prognosis in Patients with Stage III Non-Small-Cell Lung Cancer and Interstitial Lung Disease Treated With Chemoradiotherapy

Introduction: Data on the efficacy and risk of curative-intent chemoradiotherapy in patients with inoperable stage III non-small-cell lung cancer (NSCLC) and interstitial lung disease (ILD) are limited. The aim of this study was to explore the impact of ILD classification on acute exacerbation (AE) of ILD and prognosis in patients with stage III NSCLC and ILD treated with chemoradiotherapy.

Materials and methods: We retrospectively reviewed the medical records of patients with stage III NSCLC and ILD treated with curative-intent chemoradiotherapy as the first-line treatment at the Shizuoka Cancer Center between June 2009 and May 2014.

Results: Of 37 patients, 17 (46%) developed AE of ILD worse than grade 3 within 1 year after the last irradiation. In univariate analysis, the incidence rate of AE of ILD was lower in patients with a non-usual interstitial pneumonia (UIP) pattern than in those with a UIP pattern. Multivariate analysis showed that ILD classification was significantly associated with the incidence of AE of ILD. The median overall survival (OS) durations in patients with a non-UIP pattern and a UIP pattern were 16.5 and 9.3 months, respectively. In univariate analysis, patients with a non-UIP pattern showed better survival. Multivariate analysis showed that ILD classification was a significant independent prognostic factor.

Conclusion: The incidence of AE of ILD was high in patients with stage III NSCLC and ILD treated with chemoradiotherapy as the first-line treatment. However, diagnosis of a non-UIP pattern could predict lower risk of AE of ILD and longer OS durations.

ILD-NSCLC-GAP index scoring and staging system for patients with non-small cell lung cancer and interstitial lung disease

BACKGROUND AND OBJECTIVE

Patients with advanced non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) are commonly excluded from most clinical trials because of acute exacerbation (AE) of ILD triggered by chemotherapy. Data on the efficacy and feasibility of chemotherapy are limited in this patient population. Recently, the ILD-GAP index and staging system was reported as a clinical prognostic factor associated with mortality in patients with ILD. Therefore, we evaluated the incidence of ILD-AE during the surveillance term in this study and the prognosis in patients with NSCLC and ILD using a modified ILD-GAP (ILD-NSCLC-GAP) index scoring system.

MATERIALS AND METHODS

The medical records of patients with NSCLC and ILD who underwent a pulmonary function test before initiation of platinum-based chemotherapy as first-line treatment at the Shizuoka Cancer Center between September 2002 and December 2014 were reviewed retrospectively. Among these patients, we compared the incidence of ILD-AE, one-year survival rate, and overall survival (OS) between the ILD-NSCLC-GAP index scores and stages.

RESULTS

Of the 78 patients included, 21 (27%; 95% confidence interval [CI], 18%-38%) had ILD-AE during the surveillance term in this study. The one-year survival and median OS rates were 49% and 11.3 months, respectively. The incidence of ILD-AE increased gradually and the one-year survival and median OS rates decreased gradually with increasing ILD-NSCLC-GAP index scores and stages.

CONCLUSION

The ILD-NSCLC-GAP index scoring and staging system may be a useful tool to calculate a prediction of the incidence of ILD-AE and its prognosis for patients with NSCLC and ILD.

Clarithromycin mitigates radiation pneumonitis in patients with lung cancer treated with stereotactic body radiotherapy

Background

Radiation pneumonitis is a critical pulmonary toxicity after irradiation of the lung. Macrolides including clarithromycin (CAM) are antibiotics. They also have immunomodulatory properties and are used to treat respiratory inflammatory diseases. Radiation pneumonitis has similar pathology to them. Adverse reactions to macrolides are few and self-limited. We thus administered CAM to patients with high-risk factors for radiation pneumonitis, and retrospectively investigated whether CAM mitigated radiation pneumonitis following stereotactic body radiotherapy (SBRT).

Methods

Among consecutive patients treated with SBRT, we retrospectively examined lung cancer patients treated with a total dose of 40-60 Gy in 5-10 fractions and followed ≥6 months. Since January 2014, CAM has been administered in patients with pretreatment predictable radiation pneumonitis high-risk factors, including idiopathic interstitial pneumonias (IIPs), and elevated Krebs von den Lungen-6 (KL-6) and/or surfactant protein D (SP-D), and in patients developing early onset radiation pneumonitis.

Results

Five hundred and eighty eligible patients were identified and divided into 445 patients during the non-CAM-administration era (non-CAM-era) (before December 2013) and 136 patients during the CAM-administration era (CAM-era) (after January 2014). Median follow-up durations were 38.0 and 13.9 months, respectively. The rates of radiation pneumonitis ≥ grade 2 and ≥ grade 3 were significantly lower in CAM-era (grade ≥2, 16% vs. 9.6%, P=0.047; grade ≥3, 3.8% vs. 0.73%, P=0.037). For patients with the pretreatment predictable high-risk factors, the rate of radiation pneumonitis ≥ grade 3 was significantly lower, and that of grade ≥2 had a lower tendency (grade ≥3, 7.2% vs. 0%, P=0.011; grade ≥2, 21% vs. 9.6%, P=0.061). For patients developing early onset radiation pneumonitis, the rate of radiation pneumonitis ≥ grade 3 was also significantly lower (23% vs. 0%, P<0.05). Multivariate analysis revealed that dose-volumetric factor, the pretreatment predictable high-risk factors and non-CAM-administration era were significantly associated with or trended toward radiation pneumonitis ≥ grade 2 and ≥ grade 3.

Conclusions

CAM mitigated radiation pneumonitis following SBRT. The efficacy of CAM should be confirmed in prospective studies.

Exclusion of emphysematous lung from dose-volume estimates of risk improves prediction of radiation pneumonitis

BACKGROUND

The risk factors for radiation pneumonitis (RP) in patients with chronic obstructive pulmonary disease (COPD) are unclear. Mean lung dose (MLD) and percentage of irradiated lung volume are common predictors of RP, but the most accurate dosimetric parameter has not been established. We hypothesized that the total lung volume irradiated without emphysema would influence the onset of RP.

METHODS

We retrospectively evaluated 100 patients who received radiotherapy for lung cancer. RP was graded according to the Common Terminology Criteria for Adverse Events (version 4.03). We quantified low attenuation volume (LAV) using quantitative computed tomography analysis. The association between RP and traditional dosimetric parameters including MLD, volume of the lung receiving a dose of ≥2 Gy, ≥ 5 Gy, ≥ 10 Gy, ≥ 20 Gy, and ≥30 Gy, and counterpart measurements of the lung without LAV, were analyzed by logistic regression. We compared each dosimetric parameter for RP using multiple predictive performance measures including area under the receiver operating characteristic curve (AUC) and integrated discrimination improvement (IDI).

RESULTS

Of 100 patients, RP of Grades 1, 2, 3, 4, and 5 was diagnosed in 24, 12, 13, 1, and 1 patients, respectively. Compared with traditional dosimetric parameters, counterpart measurements without LAV improved risk prediction of symptomatic RP. The ratio of the lung without LAV receiving ≥30 Gy to the total lung volume without LAV most accurately predicted symptomatic RP (AUC, 0.894; IDI, 0.064).

CONCLUSION

Irradiated lung volume without LAV predicted RP more accurately than traditional dosimetric parameters.

Stereotactic body radiotherapy for lung cancer patients with idiopathic interstitial pneumonias

PURPOSE

To compare toxicity and survival after stereotactic body radiotherapy (SBRT) between lung cancer patients with or without idiopathic interstitial pneumonias (IIPs), and to investigate the potential value of SBRT for the patients.

METHODS

Among lung cancer patients receiving SBRT between 2005 and 2016, we evaluated those treated with a total dose of 40-60Gy in five fractions with curative intent who either were staged as cT1-4N0M0 or experienced postoperative isolated local recurrence. We analyzed the incidence of radiation pneumonitis (RP) in all patients and local recurrence and overall survival (OS) in T1a-2a patients.

RESULTS

A total of 508 patients were eligible, including 42 with IIPs. The median follow-up was 32.3 (6.0-120.9) months. Significantly more patients with IIPs had grade ≥3RP than did those without IIPs (12% vs. 3%, p=0.009). The 2-year local recurrence rate was low in both groups (3.4% vs. 5.6%, p=0.38). The 2-year OS rate was significantly lower in the patients with IIPs (42.2% vs. 80.9%, p<0.001), although death from lung cancer was comparable (p=0.74).

CONCLUSION

SBRT achieved excellent local control with acceptable pulmonary toxicity in lung cancer patients with IIPs. SBRT can be a reasonable option for early lung cancer patients with IIPs.

The feasibility of a heart block with an electron compensation as an alternative whole breast radiotherapy technique in patients with underlying cardiac or pulmonary disease

PURPOSE

We aimed to evaluate the feasibility of the heart block with electron compensation (HBE) technique, based on three-dimensional conformal radiotherapy (3D-CRT) in left-sided breast cancer patients with underlying cardiac or pulmonary disease.

METHODS

Twenty patients with left-sided breast cancer who were treated with whole breast radiotherapy (WBRT) were included in this study. Intensity-modulated radiotherapy (IMRT), 3D-CRT, and HBE treatment plans were generated for each patient. Based on the 3D-CRT plan, the HBE plan included a heart block from the medial tangential field to shield the heart and added an electron beam to compensate for the loss in target volume coverage. The dosimetric parameters for the heart and lung and the target volume between the three treatment types were compared.

RESULTS

Of the three plans, the HBE plan yielded the most significant reduction in the doses received by the heart and lung (heart Dmean: 5.1 Gy vs. 12.9 Gy vs. 4.0 Gy and lung Dmean: 11.4 Gy vs. 13.2 Gy vs. 10.5 Gy, for 3D-CRT, IMRT, and HBE, respectively). Target coverage with all three techniques was within the acceptable range (Dmean 51.0 Gy vs. 51.2 Gy vs. 50.6 Gy, for 3D-CRT, IMRT, and HBE, respectively).

CONCLUSIONS

The HBE plan effectively reduced the amount of radiation exposure to the heart and lung. It could be beneficial for patients who are vulnerable to radiation-related cardiac or pulmonary toxicities.

Neutrophil-lymphocyte ratio and a dosimetric factor for predicting symptomatic radiation pneumonitis in non-small-cell lung cancer patients treated with concurrent chemoradiotherapy

OBJECTIVES

To identify the factors that predict the progression of radiological radiation pneumonitis (RP) to symptomatic RP, and to evaluate the usefulness of the neutrophil-lymphocyte ratio (NLR) as a marker of RP severity and prognosis in stage III non-small cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (CCRT).

MATERIALS AND METHODS

We retrospectively reviewed 61 patients treated between January 2010 and December 2015. Patients' demographic characteristics, clinical data, laboratory findings and treatment parameters were analyzed to determine the predictive factors associated with progression from radiological RP to symptomatic RP.

RESULTS

Forty-seven patients (77%) exhibited radiological RP at a median of 78 days after radiation therapy (RT) completion, and 15 (32%) of these patients developed symptomatic RP. The interval between RT completion and radiological RP presentation was shorter in patients who progressed to symptomatic RP (P = .001); progression was highly probable if this latency period was ≤2 months (P = .002). Stage and RT technique correlated with symptomatic RP development (P = .046 and P = .046, respectively). Among dosimetric factors, a V₂₀ (defined as the lung volume receiving ≥20 Gy) of >30% was the most significant predictor of symptomatic RP (P = .001). The NLR and C-reactive protein level at radiological RP were higher in patients who developed symptomatic RP (P = .067 and P = .012, respectively). On multivariate analysis, a V₂₀ >30% and an NLR at radiological RP >6 were associated with symptomatic RP development.

CONCLUSION

The NLR at radiological RP is a useful biomarker for predicting symptomatic RP development after CCRT in stage III NSCLC patients.

An analysis of the clinical features of lung cancer in patients with connective tissue diseases

BACKGROUND

Patients with connective tissue diseases (CTDs) are at increased risk for lung cancer (LC); interstitial lung disease (ILD) is a common form of organ dysfunction in cases of CTD. However, the influence of ILD on the treatment and prognosis in LC patients with CTD is unclear.

METHODS

Between January 2010 and December 2014, 27 patients among all patients with CTD at our institution were diagnosed with primary LC. We retrospectively analyzed the clinical features, treatment modalities, and outcomes of these patients, and evaluated the potential prognostic factors. Forty-four LC patients without CTD were also analyzed as a control cohort.

RESULTS

LC patients with CTD had a significantly higher incidence of ILD as a complication compared with those without CTD (52% and 14%, respectively). CTD-associated ILD (CTD-ILD) at diagnosis was associated with significantly worse survival in LC patients with CTD. Multivariate analysis demonstrated that the complication of CTD-ILD was an independent poor prognostic factor in LC patients with CTD. The incidence of acute exacerbation (AE) of CTD-ILD was 21% among LC patients with CTD, and all of these patients died despite intensive treatment including high-dose corticosteroids. The restrictions in curative therapy for LC due to the presence of ILD and AE of CTD-ILD were thought to be the major reasons for the poor outcome.

CONCLUSIONS

LC patients with CTD had a high prevalence of ILD, and the presence of CTD-ILD was significantly associated with poor prognosis.

Impact of Preexisting Interstitial Lung Disease on Acute, Extensive Radiation Pneumonitis: Retrospective Analysis of Patients with Lung Cancer

INTRODUCTION

This study investigated the clinical characteristics and predictive factors for developing acute extended radiation pneumonitis with a focus on the presence and radiological characteristics of preexisting interstitial lung disease.

METHODS

Of 1429 irradiations for lung cancer from May 2006 to August 2013, we reviewed 651 irradiations involving the lung field. The presence, compatibility with usual interstitial pneumonia, and occupying area of preexisting interstitial lung disease were retrospectively evaluated by pretreatment computed tomography. Cases of non-infectious, non-cardiogenic, acute respiratory failure with an extended bilateral shadow developing within 30 days after the last irradiation were defined as acute extended radiation pneumonitis.

RESULTS

Nine (1.4%) patients developed acute extended radiation pneumonitis a mean of 6.7 days after the last irradiation. Although preexisting interstitial lung disease was found in 13% of patients (84 patients), 78% of patients (7 patients) with acute extended radiation pneumonitis cases had preexisting interstitial lung disease, which resulted in incidences of acute extended radiation pneumonitis of 0.35 and 8.3% in patients without and with preexisting interstitial lung disease, respectively. Multivariate logistic analysis indicated that the presence of preexisting interstitial lung disease (odds ratio = 22.6; 95% confidence interval = 5.29-155; p < 0.001) and performance status (≥2; odds ratio = 4.22; 95% confidence interval = 1.06-20.8; p = 0.049) were significant predictive factors. Further analysis of the 84 patients with preexisting interstitial lung disease revealed that involvement of more than 10% of the lung field was the only independent predictive factor associated with the risk of acute extended radiation pneumonitis (odds ratio = 6.14; 95% confidence interval = 1.0-37.4); p = 0.038).

CONCLUSIONS

Pretreatment computed tomography evaluations of the presence of and area size occupied by preexisting interstitial lung disease should be assessed for safer irradiation of areas involving the lung field.

Interstitial Lung Change in Pre-radiation Therapy Computed Tomography Is a Risk Factor for Severe Radiation Pneumonitis

PURPOSE

We examined clinical and dosimetric factors as predictors of symptomatic radiation pneumonitis (RP) in lung cancer patients and evaluated the relationship between interstitial lung changes in the pre-radiotherapy (RT) computed tomography (CT) and symptomatic RP.

MATERIALS AND METHODS

Medical records and dose volume histogram data of 60 lung cancer patients from August 2005 to July 2006 were analyzed. All patients were treated with three dimensional (3D) conformal RT of median 56.9 Gy. We assessed the association of symptomatic RP with clinical and dosimetric factors.

RESULTS

With a median follow-up of 15.5 months (range, 6.1 to 40.9 months), Radiation Therapy Oncology Group grade ≥ 2 RP was observed in 14 patients (23.3%). Five patients (8.3%) died from RP. The interstitial changes in the pre-RT chest CT, mean lung dose (MLD), and V30 significantly predicted RP in multivariable analysis (p=0.009, p < 0.001, and p < 0.001, respectively). MLD, V20, V30, and normal tissue complication probability normal tissue complication probability (NTCP) were associated with the RP grade but less so for grade 5 RP. The risk of RP grade ≥ 2, ≥ 3, or ≥ 4 was higher in the patients with interstitial lung change (grade 2, 15.6% to 46.7%, p=0.03; grade 3, 4.4% to 40%, p=0.002; grade 4, 4.4% to 33.3%, p=0.008). Four of the grade 5 RP patients had diffuse interstitial change in pre-RT CT and received chemoradiotherapy.

CONCLUSION

Our study identified diffuse interstitial disease as a significant clinical risk for RP, particularly fatal RP. We showed the usefulness of MLD, V20, V30, and NTCP in predicting the incidence and severity of RP.

Combined analysis of V20, VS5, pulmonary fibrosis score on baseline computed tomography, and patient age improves prediction of severe radiation pneumonitis after concurrent chemoradiotherapy for locally advanced non-small-cell lung cancer

INTRODUCTION

We aimed to develop a more accurate model for predicting severe radiation pneumonitis (RP) after concurrent chemoradiotherapy for non-small-cell lung cancer.

METHODS

We retrospectively analyzed data from 122 patients with locally advanced non-small-cell lung cancer treated with concurrent chemoradiotherapy. Several dose-volume histogram metrics including absolute lung volume spared from a 5 Gy dose (VS5) were analyzed for an association with RP above NCI-CTC grade 3 (RP ≥ G3). Clinical factors including pulmonary fibrosis score (PFS) and pulmonary emphysema score on baseline chest computed tomography (CT) were also analyzed.

RESULTS

Fourteen patients (11.4%) developed RP greater than or equal to G3. On univariate analysis, all dose-volume histogram metrics, sex, and PFS on baseline CT were significantly (p < 0.05) associated with occurrence of RP greater than or equal to G3. Multivariate analysis revealed that V20 greater than or equal to 26%, VS5 less than 1500 cc, age greater than or equal to 68 years, and PFS on baseline CT greater than or equal to 2 were significant risk factors. Thus, we defined a new predictive risk score (PRS) that combines these factors. The cumulative incidence of RP greater than or equal to G3 at 12 months were 0%, 7.8%, 26.6%, and 71.4% when the PRS was 0, 3-5, 6-8, and 9-14, respectively (p < 0.001). This PRS was superior at predicting RP than both V20 and VS5 combined, or V20 alone by receiver operating characteristic analysis (area under the curve, 0.888 versus 0.779 versus 0.678).

CONCLUSIONS

V20, VS5, age, and PFS on baseline CT are independent and significant risk factors for occurrence of severe RP. Combining these factors may improve the predictability of severe RP.

Pre-Radiation Therapy Fluorine 18 Fluorodeoxyglucose PET Helps Identify Patients with Esophageal Cancer at High Risk for Radiation Pneumonitis

PURPOSE

To examine the association between pre-radiation therapy (RT) fluorine 18 fluorodeoxyglucose (FDG) uptake and post-RT symptomatic radiation pneumonitis (RP).

MATERIALS AND METHODS

In accordance with the retrospective study protocol approved by the institutional review board, 228 esophageal cancer patients who underwent FDG PET/CT before chemotherapy and RT were examined. RP symptoms were evaluated by using the Common Terminology Criteria for Adverse Events, version 4.0, from the consensus of five clinicians. By using the cumulative distribution of standardized uptake values (SUVs) within the lungs, those values greater than 80%-95% of the total lung voxels were determined for each patient. The effect of pre-chemotherapy and RT FDG uptake, dose, and patient or treatment characteristics on RP toxicity was studied by using logistic regression.

RESULTS

The study subjects were treated with three-dimensional conformal RT (n = 36), intensity-modulated RT (n = 135), or proton therapy (n = 57). Logistic regression analysis demonstrated elevated FDG uptake at pre-chemotherapy and RT was related to expression of RP symptoms. Study subjects with elevated 95% percentile of the SUV (SUV95) were more likely to develop symptomatic RP (P < .000012); each 0.1 unit increase in SUV95 was associated with a 1.36-fold increase in the odds of symptomatic RP. Receiver operating characteristic (ROC) curve analysis resulted in area under the ROC curve of 0.676 (95% confidence interval: 0.58, 0.77), sensitivity of 60%, and specificity of 71% at the 1.17 SUV95 threshold. CT imaging and dosimetric parameters were found to be poor predictors of RP symptoms.

CONCLUSION

The SUV95, a biomarker of pretreatment pulmonary metabolic activity, was shown to be prognostic of symptomatic RP. Elevation in this pretreatment biomarker identifies patients at high risk for posttreatment symptomatic RP.

Nondosimetric risk factors for radiation-induced lung toxicity

The decision to administer a radical course of radiotherapy (RT) is largely influenced by the dose-volume metrics of the treatment plan, but what are the patient-related and other factors that may independently increase the risk of radiation lung toxicity? Poor pulmonary function has been regarded as a risk factor and a relative contraindication for patients undergoing radical RT, but recent evidence suggests that patients with poor spirometry results may tolerate conventional or high-dose RT as well as, if not better than, patients with normal function. However, caution may need to be exercised in patients with underlying interstitial pulmonary fibrosis. Furthermore, there is emerging evidence of molecular markers of increased risk of toxicity. This review discusses patient-related risk factors other than dosimetry for radiation lung toxicity.

Pre-radiotherapy FDG PET predicts radiation pneumonitis in lung cancer

BACKGROUND

A retrospective analysis is performed to determine if pre-treatment [18 F]-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) image derived parameters can predict radiation pneumonitis (RP) clinical symptoms in lung cancer patients.

METHODS AND MATERIALS

We retrospectively studied 100 non-small cell lung cancer (NSCLC) patients who underwent FDG PET/CT imaging before initiation of radiotherapy (RT). Pneumonitis symptoms were evaluated using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) from the consensus of 5 clinicians. Using the cumulative distribution of pre-treatment standard uptake values (SUV) within the lungs, the 80th to 95th percentile SUV values (SUV(80) to SUV(95) were determined. The effect of pre-RT FDG uptake, dose, patient and treatment characteristics on pulmonary toxicity was studied using multiple logistic regression.

RESULTS

The study subjects were treated with 3D conformal RT (n=23), intensity modulated RT (n=64), and proton therapy (n=13). Multiple logistic regression analysis demonstrated that elevated pre-RT lung FDG uptake on staging FDG PET was related to development of RP symptoms after RT. A patient of average age and V(30) with SUV(95)=1.5 was an estimated 6.9 times more likely to develop grade ≥ 2 radiation pneumonitis when compared to a patient with SUV(95)=0.5 of the same age and identical V(30). Receiver operating characteristic curve analysis showed the area under the curve was 0.78 (95% CI=0.69 - 0.87). The CT imaging and dosimetry parameters were found to be poor predictors of RP symptoms.

CONCLUSIONS

The pretreatment pulmonary FDG uptake, as quantified by the SUV(95), predicted symptoms of RP in this study. Elevation in this pre-treatment biomarker identifies a patient group at high risk for post-treatment symptomatic RP.

Development of radiation pneumopathy and generalised radiological changes after radiotherapy are independent negative prognostic factors for survival in non-small cell lung cancer patients

BACKGROUND AND PURPOSE

To investigate the risk factors for radiation pneumopathy (RP) and survival rate of non-small cell lung cancer patients with RP and generalised interstitial lung changes (gen-ILC).

MATERIAL AND METHODS

A total of 147 consecutive patients receiving curative radiotherapy were analysed. RP was graded according to Common Terminology Criteria for Adverse Events v. 3. Computed tomography images were assessed for the presence of gen-ILC after radiotherapy. Univariate and multivariate analyses were performed to identify significant factors.

RESULTS

Median follow-up was 16.2 months (range 1.4-58.6). Radiological changes after radiotherapy were confined to high dose irradiation volume in 111 patients, while 31 patients developed gen-ILC. Dosimetric parameters and level of C-reactive protein before radiotherapy were significantly associated with severe RP. Development of gen-ILC (p=0.008), as well as severe RP (p=0.03) had significant negative impact on patients' survival. These two factors remained significant in the multivariate analysis.

CONCLUSIONS

Severe radiation pneumopathy and generalised radiographic changes were significant independent prognostic factors for survival. More studies on pathophysiology of radiation induced damage are necessary to fully understand the mechanisms behind it.