Predicting severe acute radiation pneumonitis in patients with non-small cell lung cancer receiving postoperative radiotherapy: Development and internal validation of a nomogram based on the clinical and dose–volume histogram parameters

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.

Analysis of clinical and physical dosimetric factors that determine the outcome of severe acute radiation pneumonitis in lung cancer patients

OBJECTIVE

We conducted a retrospective statistical analysis of clinical and physical dosimetric factors of lung cancer patients who had previously undergone lung and/or mediastinal radiotherapy and died of or survived severe acute radiation pneumonitis (SARP). Our study was the first to reveal the heterogeneity in clinical factors, physical dosimetric factors, and SARP onset time that determined the clinical outcomes of lung cancer patients who developed SARP.

MATERIALS AND METHODS

The clinical characteristics, physical dosimetry factors, and SARP onset time of deceased and surviving patients were retrospectively analyzed. SPSS 20.0 was used for data analysis. Student's t-test was used for intergroup comparison, and a Mann-Whitney U test was used for data with skewed distribution. Qualitative data were represented using frequencies (%), and Fisher's exact test or χ2 test was used for intergroup comparison of nonparametric data. Binary logistic analysis was used for univariate and multivariate analyses. Differences with a P < 0.05 were considered statistically significant.

RESULTS

Univariate analysis revealed that the potential predictors of SARP death were as follows: ipsilateral lung V5 and V30, contralateral lung V5, V10, and V30, total lung V5, V10, and V30, mean lung dose, mean heart dose, and maximum spinal cord dose. Multivariate analysis showed that ipsilateral lung V5 and total lung V5 were predictors that determined the final outcome of SARP patients. In addition, we analyzed the time from the completion of radiotherapy to SARP onset, and found significant difference between the two groups.

CONCLUSIONS

There was no decisive correlation between clinical characteristics and SARP outcome (i.e., death or survival) in lung radiotherapy patients. Ipsilateral lung V5 and total lung V5 were independent predictors of death in SARP patients.

Association of T Cell Senescence with Radiation Pneumonitis in Patients with Non-small Cell Lung Cancer

PURPOSE

Associations between immunosenescence and radiation pneumonitis (RP) are largely unknown. We aimed to identify a peripheral blood T cell senescence biomarker to predict RP in patients with non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Patients with locally advanced NSCLC who received definitive concurrent chemoradiotherapy (dCRT) were prospectively registered (cohort 1, n=23; cohort 2, n=31). Peripheral blood was collected at baseline, during dCRT, and at 1 month post-dCRT. Patients were dichotomized to grade ≥2 (G2+) RP and grade 0-1 (G0-1) RP. Flow cytometry was performed to assess phenotypes and functional properties of T cell subsets. RP incidence was estimated via competing risk analysis.

RESULTS

Five and six patients exhibited G2+ RP following dCRT in cohorts 1 and 2, respectively. Patients with G2+ RP exhibited a more aged T cell pool and higher frequencies of senescent CD57⁺CD28^-CD8⁺ T cells than patients with G0-1 RP at baseline, during dCRT, and at 1 month post-dCRT. These senescent cells exhibited increased granzyme B, IFN-γ, and TNF-α production. Higher baseline frequency of CD57⁺CD28^-CD8⁺ T cells was an independent predictor of G2+ RP (hazard ratio, 8.42; 95% confidence interval, 2.58-27.45; P<0.001). Recursive partitioning analysis revealed three distinct risk groups stratified by baseline CD57⁺CD28^-CD8⁺ T cell frequency and lung V_{20 Gy}, with 1-year cumulative G2+ RP incidences of 50.0%, 16.7%, and 0% for high-, intermediate-, and low-risk groups, respectively (P=0.002).

CONCLUSIONS

Higher baseline frequencies of CD57⁺CD28^-CD8⁺ T cells correlated with increased G2+ RP risks. Our results suggest the need for further investigation of the role of T cell senescence on radiation-induced organ damage.

Uncertain resection of highest mediastinal lymph node positive among pN2 non-small cell lung cancer patients: survival analysis of postoperative radiotherapy and driver gene mutations

BACKGROUND AND PURPOSE

The role of postoperative radiotherapy (PORT) in uncertain resection of pN2 non-small cell lung cancer (NSCLC) with highest mediastinal lymph node positive has not been determined. We aim to evaluate the effect of PORT and driver gene mutation status (DGMS) on survival in such patients.

METHODS

140 selected patients were grouped according to whether they received PORT and their DGMS. Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) of each group were evaluated by Kaplan-Meier analyses. COX regression was used to evaluate the effects of various factors on DFS and OS.

RESULTS

Of 140 patients, thirty-four patients (24.3%) received PORT, and forty (28.6%) had positive driver gene mutation status (DGp). PORT significantly prolonged LRFS (p = 0.002), DFS (p = 0.019) and OS (p = 0.02), but not DMFS (p = 0.062). By subgroup analysis, in patients with negative driver gene mutation status (DGn), those receiving PORT had notably longer LRFS (p = 0.022) and DFS (p = 0.033), but not DMFS (p = 0.060) or OS (p = 0.215), compared to those not receiving PORT. Cox analysis showed that the number of positive lymph nodes (PLNs) and administration of PORT were independent prognostic factors of DFS, and pathology, PLNs, and DGMS may be prognostic factors of OS (all p < 0.05).

CONCLUSION

Postoperative radiotherapy may improve locoregional recurrence-free and disease-free survival in patients with pN2 NSCLC with positive highest mediastinal lymph nodes, while driver gene mutation status impacted OS significantly. Only patients with positive driver gene mutations experienced significant overall survival benefits from postoperative radiotherapy.

Tumor-suppressive E3 ubiquitin ligase CHIP inhibits the PBK/ERK axis to repress stem cell properties and radioresistance in non-small cell lung cancer

Recently, radioresistant cancer cells surviving radiotherapy have been suggested to show more aggressive phenotypes than parental cells, and the underlying mechanisms may be associated with cancer stem cells. This study provided novel mechanistic insights for E3 ubiquitin ligase CHIP in stem cell properties and radioresistance of non-small cell lung cancer (NSCLC). After bioinformatic prediction for key genes involved, NSCLC tissues and cells were collected to measure the expression of CHIP and PBK. E3 ubiquitin ligase CHIP was poorly expressed, while PBK was highly expressed in NSCLC tissues and cells. CHIP reduced the protein stability of PBK through the ubiquitin-protease pathway to repress the activation of ERK pathway. Based on the gain- or loss-of-function experiments, it was noted that restoration of CHIP curtailed stem cell properties and radioresistance in NSCLC, as manifested by inhibited sphere formation and cell proliferation, decreased number of CD133⁺CD44⁺ cells and expression of OCT4, SOX2, and NANOG, as well as facilitated apoptosis of NSCLC cells. Besides, in vivo animal experiments further confirmed that CHIP restrained tumorigenic ability and improved radiosensitivity of NSCLC cells by inhibiting PBK/ERK axis. Collectively, CHIP suppressed stem cell properties and radioresistance of NSCLC cells by inhibiting PBK/ERK axis, therefore offering a potential therapeutic target for enhancing efficacy of radiotherapy.

Risk analysis of grade ≥ 2 radiation pneumonitis based on radiotherapy timeline in stage III/IV non-small cell lung cancer treated with volumetric modulated arc therapy: a retrospective study

Background

Radiotherapy is an important treatment for patients with stage III/IV non-small cell lung cancer (NSCLC), and due to its high incidence of radiation pneumonitis, it is essential to identify high-risk people as early as possible. The present work investigates the value of the application of different phase data throughout the radiotherapy process in analyzing risk of grade ≥ 2 radiation pneumonitis in stage III/IV NSCLC. Furthermore, the phase data fusion was gradually performed with the radiotherapy timeline to develop a risk assessment model.

Methods

This study retrospectively collected data from 91 stage III/IV NSCLC cases treated with Volumetric modulated arc therapy (VMAT). Patient data were collected according to the radiotherapy timeline for four phases: clinical characteristics, radiomics features, radiation dosimetry parameters, and hematological indexes during treatment. Risk assessment models for single-phase and stepwise fusion phases were established according to logistic regression. In addition, a nomogram of the final fusion phase model and risk classification system was generated. Receiver operating characteristic (ROC), decision curve, and calibration curve analysis were conducted to internally validate the nomogram to analyze its discrimination.

Results

Smoking status, PTV and lung radiomics feature, lung and esophageal dosimetry parameters, and platelets at the third week of radiotherapy were independent risk factors for the four single-phase models. The ROC result analysis of the risk assessment models created by stepwise phase fusion were: (area under curve [AUC]: 0.67,95% confidence interval [CI]: 0.52–0.81), (AUC: 0.82,95%CI: 0.70–0.94), (AUC: 0.90,95%CI: 0.80–1.00), and (AUC:0.90,95%CI: 0.80–1.00), respectively. The nomogram based on the final fusion phase model was validated using calibration curve analysis and decision curve analysis, demonstrating good consistency and clinical utility. The nomogram-based risk classification system could correctly classify cases into three diverse risk groups: low-(ratio:3.6%; 0 < score < 135), intermediate-(ratio:30.7%, 135 < score < 160) and high-risk group (ratio:80.0%, score > 160).

Conclusions

In our study, the risk assessment model makes it easy for physicians to assess the risk of grade ≥ 2 radiation pneumonitis at various phases in the radiotherapy process, and the risk classification system and nomogram identify the patient’s risk level after completion of radiation therapy.

Systematic quantitative evaluation of Plan-IQ for intensity-modulated radiation therapy after modified radical mastectomy

Radiotherapy (RT) is one of the main treatment strategies of breast cancer. It is challenging to design RT plans that can completely cover the target area while protecting organs at risk (OAR). The Plan-IQ feasibility tool can estimate the best sparing dose of OAR before optimizing the Plan. A systematic quantitative evaluation of the quality change of intensity-modulated radiation therapy (IMRT) using the Plan-IQ feasibility tool was performed for modified radical mastectomy in this study. We selected 50 patients with breast cancer treated with IMRT. All patients received the same dose in the planning target volume (PTV). The plans are categorized into two groups, with each patient having one plan in each group: the clinically accepted normal plan group (NP group) and the repeat plan group (RP group). An automated planning strategy was generated using a Plan-IQ feasibility dose volume histogram (FDVH) in RP group. These plans were assessed according to the dosimetry parameters. A detailed scoring strategy was based on the RTOG9804 report and 2018 National Comprehensive Cancer Network guidelines, combined with clinical experience. PTV coverage in both groups was achieved at 100% of the prescribed dose. Except for the thyroid coverage, the dose limit of organs at risk (OAR) in RP group was significantly better than that in NP group. In the scoring analysis, the total scores of RP group decreased compared to that of NP group (P < 0.05), and the individual scores of PTV and OAR significantly changed. PTV scores in RP group decreased (P < 0.01); however, OAR scores improved (P < 0.01). The Plan-IQ FDVH was useful for evaluating a class solution for IMRT planning. Plan-IQ can automatically help physicians design the best OAR protection plan, which sacrifices part of PTV, but still meets clinical requirements.

Postoperative radiotherapy in resected non-small cell lung cancer: The never-ending story

This manuscript collects in a joint and orderly manner the existing evidence at the present time about postoperative treatment with radiotherapy in non-small cell lung cancer. It also systematically reviews the current evidence, the international recommendations in the most relevant guidelines, the most controversial aspects in clinical and pathological staging, the specific technical aspects of radiotherapy treatment, and also collects all the potential risk factors that have been postulated as significant in the prognosis of these patients, evaluating the possibility of segmenting a particularly sensitive subpopulation with a high risk of relapse on which an adjuvant treatment with radiotherapy could have an impact on their clinical evolution. Finally, currently active trials that aspire to provide more evidence on this topic are reviewed.

Survival impact of concurrent chemoradiotherapy for elderly patients with synchronous oligometastatic esophageal squamous cell carcinoma: A propensity score matching and landmark analyses

PURPOSE

To evaluate the potential benefits of concurrent chemoradiotherapy (CCRT), and to establish a nomogram for predicting survival outcomes of elderly patients with synchronous oligometastatic esophageal squamous cell carcinoma (SOEC).

MATERIALS AND METHODS

This study eventually enrolled 314 elderly patients who initially diagnosed with SOEC from two centers. Treatment responses and outcomes of 151 patients receiving CCRT and 163 patients undergoing chemotherapy alone (CT) were compared. Propensity score matching and landmark analyses were performed to control potential confounding factors. A nomogram was established on the basis of the Cox regression model.

RESULTS

After a median follow-up of 42.3 months, CCRT was superior to CT alone in objective response rate (ORR, 59.6% vs. 39.9%, P < 0.001), median progression-free survival (PFS, 10.0 vs. 7.2 months, P < 0.001), and median overall survival (OS, 18.5 vs. 15.6 months, P < 0.001). The propensity score matching (PSM) and landmark analyses redemonstrated the same trend (P < 0.01). On hierarchical analysis, patients with 1-3 metastatic lesions involving one organ displayed longer median PFS (9.0 vs. 7.8 months, P = 0.008) and OS (17.8 vs. 15.2 months, P < 0.001) than those with 4-5 metastatic lesions involving 2-3 organs. The major toxicities of grade III or higher for CCRT included leukocytopenia (23.2%), radiation esophagitis (7.3%), and radiation pneumonitis (8.6%). Cox multivariate analysis showed that the number of metastatic lesions (P = 0.012) and tumor response (P < 0.001) were independent prognostic factors associated with OS. A nomogram was established by incorporating the number of metastatic lesions and tumor response, with a concordance index of 0.743 after internal cross-validation. Calibration curves and decision curve analysis confirmed that nomogram had a favorable predictive value for individualized survival.

CONCLUSIONS

Compared with CT alone, CCRT exhibited superior efficacy and acceptable toxicity in the first-line treatment for elderly patients with SOEC. The current study supports the oligometastatic definition of ≤3 metastatic lesions involving one organ for esophageal cancer patients. The constructed nomogram can effectively predict the individualized survival.

Post-operative radiation therapy for non-small cell lung cancer: A comparison of radiation therapy techniques

OBJECTIVES

Post-operative radiation therapy (PORT) in locally advanced non-small cell lung cancer (LA-NSCLC) has historically been associated with toxicity. Conformal techniques like intensity modulated radiation therapy (IMRT) have the potential to reduce acute and long-term toxicity from radiation therapy. Among patients receiving PORT for LA-NSCLC, we identified factors associated with receipt of IMRT and evaluated the association between IMRT and toxicity.

METHODS

We queried the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between January 1, 2006 to December 31, 2014 to identify patients diagnosed with Stage II or III NSCLC and who received upfront surgery and subsequent PORT. Baseline differences between patients receiving 3-dimentional conformal radiation therapy (3D-CRT) and IMRT were assessed using the chi-squared test for proportions and the t-test for means. Multivariable logistic regression was used to identify predictors of receipt of IMRT and pulmonary, esophageal, and cardiac toxicity. Propensity-score matching was employed to reduce the effect of known confounders.

RESULTS

A total of 620 patients met the inclusion criteria, among whom 441 (71.2%) received 3D-CRT and 179 (28.8%) received IMRT. The mean age of the cohort was 73.9 years and 54.7% were male. The proportion of patients receiving IMRT increased from 6.2% in 2006 to 41.4% in 2014 (P < 0.001). IMRT was not associated with decreased pulmonary (OR 0.89; 95% CI, 0.62-1.29), esophageal (OR 1.09; 95% CI, 0.0.75-1.58), or cardiac toxicity (OR 1.02; 95% CI, 0.69-1.51). These findings held on propensity-score matching. Clinical risk factors including comorbidity and prior treatment history were associated with treatment toxicity.

CONCLUSION

In a cohort of elderly patients, the use of IMRT in the setting of PORT for LA-NSCLC was not associated with a difference in toxicity compared to 3D-CRT. This finding suggests that outcomes from PORT may be independent of radiotherapy treatment technique.

A 2D-3D hybrid convolutional neural network for lung lobe auto-segmentation on standard slice thickness computed tomography of patients receiving radiotherapy

Background

Accurate segmentation of lung lobe on routine computed tomography (CT) images of locally advanced stage lung cancer patients undergoing radiotherapy can help radiation oncologists to implement lobar-level treatment planning, dose assessment and efficacy prediction. We aim to establish a novel 2D–3D hybrid convolutional neural network (CNN) to provide reliable lung lobe auto-segmentation results in the clinical setting.

Methods

We retrospectively collected and evaluated thorax CT scans of 105 locally advanced non-small-cell lung cancer (NSCLC) patients treated at our institution from June 2019 to August 2020. The CT images were acquired with 5 mm slice thickness. Two CNNs were used for lung lobe segmentation, a 3D CNN for extracting 3D contextual information and a 2D CNN for extracting texture information. Contouring quality was evaluated using six quantitative metrics and visual evaluation was performed to assess the clinical acceptability.

Results

For the 35 cases in the test group, Dice Similarity Coefficient (DSC) of all lung lobes contours exceeded 0.75, which met the pass criteria of the segmentation result. Our model achieved high performances with DSC as high as 0.9579, 0.9479, 0.9507, 0.9484, and 0.9003 for left upper lobe (LUL), left lower lobe (LLL), right upper lobe (RUL), right lower lobe (RLL), and right middle lobe (RML), respectively. The proposed model resulted in accuracy, sensitivity, and specificity of 99.57, 98.23, 99.65 for LUL; 99.6, 96.14, 99.76 for LLL; 99.67, 96.13, 99.81 for RUL; 99.72, 92.38, 99.83 for RML; 99.58, 96.03, 99.78 for RLL, respectively. Clinician's visual assessment showed that 164/175 lobe contours met the requirements for clinical use, only 11 contours need manual correction.

Conclusions

Our 2D–3D hybrid CNN model achieved accurate automatic segmentation of lung lobes on conventional slice-thickness CT of locally advanced lung cancer patients, and has good clinical practicability.

Secondary Infections After Diagnosis of Severe Radiation Pneumonitis (SRP) Among Patients With Non-small Cell Lung Cancer: Pathogen Distributions, Choice of Empirical Antibiotics, and the Value of Empirical Antifungal Treatment

PURPOSE

This study aimed to assess pathogen distributions and antimicrobial sensitivity characteristics in patients with non-small cell lung cancer (NSCLC) with severe radiation pneumonitis (SRP) and secondary infections.

METHODS AND MATERIALS

Data from 1746 patients with NSCLC and SRP after thoracic radiation therapy from January 2009 to December 2020 were retrospectively analyzed. Pneumonia incidence, causative pathogens, and antibiotic resistance characteristics in patients with secondary lung infections were analyzed. Risk factors associated with mortality were identified through univariate and multivariate analyses. Antifungal drug efficacy and duration-related effects were assessed with Forest plots and receiver operating characteristic curves.

RESULTS

Overall, 44.5% of patients with NSCLC and SRP (777 of 1746 patients) were diagnosed with secondary lung infections. In total, 899 bacterial strains were isolated from these patients, with Acinetobacter baumannii (n = 206; 27%), Klebsiella pneumonia (n = 200; 26.2%), and Pseudomonas aeruginosa (n = 104; 13.6%) being the most common. Carbapenems and cefoperazone-sulbactam resistance rates of 52.7% and 32.2%, 28.8% and 26.4%, and 23.7% and 20.2% were observed for these isolates, respectively. Infection-related deaths occurred in 22.4% of patients with SRP. Independent risk factors for infection-related death included poor performance status scores, inappropriate empirical antimicrobial treatment, bacteria/fungal coinfection, and lack of empirical antifungal treatment. Receiver operating characteristic curves showed that the cutoff value of empirical antifungal treatment duration was 9 (area under the curve: 0.819).

CONCLUSIONS

For patients with SRP and secondary lung infections, appropriate empirical antimicrobial treatment could decrease infection-related mortality, and cefoperazone-sulbactam may be an appropriate antibacterial drug. Empirical antifungal treatment for a minimum of 9 days might contribute to better outcomes. Although this represents a promising treatment approach for patients with SRP and secondary lung infections before antibacterial susceptibility testing, further prospective validation is essential.

A nomogram for predicting late radiation-induced xerostomia among locoregionally advanced nasopharyngeal carcinoma in intensity modulated radiation therapy era

Background: Dry mouth sensation cannot be improved completely even though parotids are spared correctly. Our purpose is to develop a nomogram to predict the moderate-to-severe late radiation xerostomia for patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) in intensity modulated radiation therapy (IMRT) / volumetric modulated arc radiotherapy (VMAT) era.

Methods: A dataset of 311 patients was retrospectively collected between January 2010 and February 2013. The binary logistic regression was to estimate each factor’s prognostic value for development of moderate-to-severe patient-reported xerostomia at least 2 years (Xer2y) after completion of radiotherapy. Therefore, we can develop a nomogram according to binary logistic regression coefficients. This novel model was validated by bootstrapping analyses.

Results: Contralateral Parotid mean dose (coMD<24.4Gy), VMAT (yes), and platinum-based concurrent chemoradiotherapy (no) were significantly related to patient-reported xerostomia at least 2 years (Xer2y) (all p < 0.001), and were included in the nomogram. Receiver operating characteristic (ROC) analysis revealed AUC (area under the ROC curve) with the value of 0.811 (0.710-0.912) of the nomogram, which was significantly higher than coMD 0.698 (0.560-0.840) from QUANTEC2010 (p<0.001). Calibration plots illustrated that the predicted Xer2y was close to the actual observation, and decision curve analyses (DCA) indicated valid positive net benefits.

Conclusion: We developed a feasible nomogram to predict patient-rated Xer2y based on comprehensive individual data in patients with LA-NPC in the real world. The proposed model is able to facilitate the development of treatment plan and quality of life improvement.

A novel nomogram based on prognostic factors for predicting venous thrombosis risk in lymphoma patients

Lymphoma-associated venous thromboembolism (VTE) can be a serious complication in lymphoma patients. We designed a nomogram as a guide to estimate the VTE risk in lymphoma patients. We retrospectively analyzed 555 Chinese lymphoma patients who were newly diagnosed at West China Hospital. The nomogram was generated based on multivariate regression coefficients. The multivariate analysis indicated that advanced clinical stage (p < .001*), Hodgkin lymphoma (p = .045*), and prechemotherapy Hb level <115 g/L (p = .01*) were independent risk factors for VTE in lymphoma patients. A calibration plot and the area under the receiver operating characteristic curve were used to validate the novel nomogram. The nomogram displayed a good C-index (0.73), and the calibration plot showed excellent agreement between the predicted and actual probabilities. The AUROC of the nomogram was 0.731, demonstrating a strong discriminatory ability. Notably, the predictive value of the nomogram was better than the Khorana risk score.

Early differential diagnosis model for acute radiation pneumonitis based on multiple parameters

Objective: The present study aimed to construct a diagnosis model for the early differentiation of acute radiation pneumonitis (ARP) and infectious pneumonitis based on multiple parameters.

Methods: The present study included data of 152 patients admitted to the Department of Radiochemotherapy, Tangshan People’s Hospital, who developed ARP (91 patients) or infectious pneumonia (IP; 61 patients) after radiotherapy. The radiophysical parameters, imaging characteristics, serological indicators, and other data were collected as independent variables, and ARP was considered as a dependent variable. Logistics univariate analysis and Spearman correlation analysis were used for selecting independent variables. Logistics multivariate analysis was used to fit the variables into the regression model to predict ARP.

Results: The univariate analysis showed that the positional relation between lesions and V20 area (PRLV), procalcitonin (PCT), C-reactive protein (CRP), mean lung dose (MLD), and lung volume receiving ≥20 Gy (V20) correlated with ARP while the planning target volume (PTV) dose marginally correlated with ARP. The multivariate analysis showed that the PRLV, PCT, white blood cell (WBC), and MLD were independent diagnostic factors. The nomogram was drawn on the basis of the logistics regression model. The area under the curve (AUC) of the model was 0.849, which was significantly better than that of a single indicator and the sensitivity and specificity of the model were high (82.4 and 82.0%, respectively). These results predicted by the model were highly consistent with the actual diagnostic results. The decision curve analysis (DCA) demonstrated a satisfactory positive net benefit of the model.

Conclusion: The diagnosis model constructed in the present study is of certain value for the differential diagnosis of ARP and IP.

Study of the predictors for radiation pneumonitis in patient with non-small cell lung cancer received radiotherapy after pneumonectomy

PURPOSE

To identify the valuable predictors of grade≥2 radiation pneumonitis (RP) in patient treated with radiotherapy after pneumonectomy for non-small cell lung cancer (NSCLC); and to construct a nomogram predicting the incidence of grade≥2 RP in such patients.

PATIENTS AND METHODS

We reviewed 82 patients with NSCLC received radiotherapy after pneumonectomy from 2008 to 2018. The endpoint was grade≥2 RP. Univariate and multivariate regression analysis were conducted to evaluate significant factors of grade≥2 RP. Receiver operating characteristic (ROC) curve was used to establish optimal cutoff values and the nomogram was built to make the predictive model visualized. Descriptive analysis was performed on 5 patients with grade 3 RP.

RESULTS

A total of 22(26.8%) patients developed grade 2 RP and 5(6.1%) patients were grade 3 RP. V5, V10, V20, V30, MLD, PTV, and PTV/TLV were associated with the occurrence of grade≥2 RP in univariate analysis, while none of the clinical factors was significant; V5(OR,1.213;95%CI,1.099-1.339; P<0.001) and V20(OR,1.435;95%CI,1.166-1.765; P=0.001) were the independent significant predictors by multivariate analysis and were included in the nomogram. The ROC analysis for the cutoff values for predicting grade≥2 RP were V5>23% (AUC=0.819, sensitivity:0.701, specificity:0.832) and V20>8% (AUC=0.812, sensitivity:0.683, specificity:0.811). Additionally, grade≥3 RP did not occur when V5<30%, V20<13% and MLD<751.2cGy, respectively.

CONCLUSIONS

Our study showed that V5 and V20 were independent predictors for grade≥2 RP in NSCLC patients receiving radiotherapy after pneumonectomy. Grade 3 RP did not occur whenV5<30%, V20<13% and MLD<751.2cGy, respectively. In addition, patient underwent right pneumonectomy may have a lower tolerance to radiation compared to left pneumonectomy.

A prognostic model for elderly patients with squamous non-small cell lung cancer: a population-based study

Background

Squamous cell carcinoma (SCC) is a main pathological type of non-small cell lung cancer. It is common among elderly patients with poor prognosis. We aimed to establish an accurate nomogram to predict survival for elderly patients (≥ 60 years old) with SCC based on the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

The gerontal patients diagnosed with SCC from 2010 to 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. The independent prognostic factors were identified using multivariate Cox proportional hazards regression analysis, which were utilized to conduct a nomogram for predicting survival. The novel nomogram was evaluated by Concordance index (C-index), calibration curves, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).

Results

32,474 elderly SCC patients were included in the analysis, who were randomly assigned to training cohort (n = 22,732) and validation cohort (n = 9742). The following factors were contained in the final prognostic model: age, sex, race, marital status, tumor site, AJCC stage, surgery, radiation and chemotherapy. Compared to AJCC stage, the novel nomogram exhibited better performance: C-index (training group: 0.789 vs. 0.730, validation group: 0.791 vs. 0.733), the areas under the receiver operating characteristic curve of the training set (1-year AUC: 0.846 vs. 0.791, 3-year AUC: 0.860 vs. 0.801, 5-year AUC: 0.859 vs. 0.794) and the validation set (1-year AUC: 0.846 vs. 0.793, 3-year AUC: 0.863 vs. 0.806, 5-year AUC: 0.866 vs. 0.801), and the 1-, 3- and 5-year calibration plots. Additionally, the NRI and IDI and 1-, 3- and 5-year DCA curves all confirmed that the nomogram was a great prognosis tool.

Conclusions

We constructed a novel nomogram that could be practical and helpful for precise evaluation of elderly SCC patient prognosis, thus helping clinicians in determining the appropriate therapy strategies for individual SCC patients.

A clinical nomogram and heat map for assessing survival in patients with stage I non-small cell lung cancer after complete resection

Background:

Assessing the prognosis of patients with early-stage non-small cell lung cancer (NSCLC) has become a major clinical issue. This study aimed to devise an effective clinical nomogram and heat map for assessing the survival of patients with stage I NSCLC receiving complete resection.

Methods:

Nomograms were established based on a retrospective study of 654 patients with stage I NSCLC who underwent radical resection at Sun Yat-Sen University Cancer Center between January 2009 and December 2014. The concordance index (C-index) and calibration curve were used to measure the accuracy and discriminative ability of the final nomogram. Heat maps were constructed with prognostic factors and survival probabilities. Survival curves were depicted using the Kaplan–Meier method, and the log-rank test was used to determine significance. Patients were classified into low- and high-risk subgroups using recursive partitioning analysis based on nomogram scores.

Results:

In univariate and multivariate analyses, the independent factors for overall survival (OS) and disease-free survival (DFS) were age, sex, tumor size, and visceral pleural invasion, which were all selected in the nomogram. The C-indices of the nomogram for predicting OS and DFS were 0.694 [95% confidence interval (CI) 0.651–0.737] and 0.653 (95% CI 0.61–0.696), respectively. The calibration curves for OS and DFS probabilities showed a good agreement between the nomogram prediction and actual observation. A heat map was generated using the above independent factors for OS and DFS. High-risk patients had shorter OS [hazard ratio (HR) = 3.535, 95% CI 2.444–5.113, p < 0.001] and DFS (HR = 2.607, 95% CI 1.922–3.537, p < 0.001) than low-risk patients.

Conclusion:

We established a prognostic nomogram and heat map that can be useful for evaluating survival in patients with stage I NSCLC after complete resection. The tools resulted in more accurate prediction and may guide clinicians in making treatment decisions.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Analysis of early respiratory-related mortality after radiation therapy of non-small-cell lung cancer: feasibility of automatic data extraction for dose-response studies

Purpose: To examine the feasibility of automatic data extraction from clinical radiation therapy (RT) databases at four hospitals to investigate the impact of mean lung dose (MLD) and age on the risk of early respiratory-related death and early overall death for patients treated with RT for non-small-cell lung cancer (NSCLC).Material and methods: We included adult patients with NSCLC receiving curatively intended RT between 2002 and 2017 at four hospitals. A script was developed to automatically extract RT-related data. The cause of death for patients deceased within 180 days of the start of RT was retrospectively assessed. Using logistic regression, the risks of respiratory-related death and of overall death within 90 and 180 days were investigated using MLD and age as variables.Results: Altogether, 1785 patients were included in the analysis of early overall mortality and 1655 of early respiratory-related mortality. The respiratory-related mortalities within 90 and 180 days were 0.9% (15/1655) and 3.6% (60/1655). The overall mortalities within 90 and 180 days were 2.5% (45/1785) and 10.6% (190/1785). Higher MLD and older age were associated with an increased risk of respiratory-related death within 180 days and overall death within 90 and 180 days (all p<.05). For example, the risk of respiratory-related death within 180 days and their 95% confidence interval for patients aged 65 and 75 years with MLDs of 20 Gy was according to our logistic model 3.8% (2.6-5.0%) and 7.7% (5.5-10%), respectively.Conclusions: Automatic data extraction was successfully used to pool data from four hospitals. MLD and age were associated with the risk of respiratory-related death within 180 days of the start of RT and with overall death within 90 and 180 days. A model quantifying the risk of respiratory-related death within 180 days was formulated.

The role of procalcitonin in differential diagnosis between acute radiation pneumonitis and bacterial pneumonia in lung cancer patients receiving thoracic radiotherapy

Acute Radiation Pneumonitis (ARP) is one of the most common dose-limiting toxicities of thoracic radiotherapy. The accurate diagnosis of ARP remains a challenge because of the lack of a rapid biomarker capable of differentiating ARP from bacterial pneumo (BP). The aim of this study was to investigate the potential usefulness of procalcitonin (PCT) in the differential diagnosis of ARP and BP. Lung cancer patients who had undergone thoracic radiotherapy within 6 months and were admitted to hospital for ARP or BP were retrospectively analyzed. The serum levels of PCT, C-reactive protein (CRP) and white blood cells (WBC) were compared between the two groups. Receiver operating characteristic (ROC) curve was used to assess the diagnostic value of PCT, CRP and WBC in the differential diagnosis of ARP and BP and determine the best cut-off values. One hundred eighteen patients were included. Among them, seventy-seven patients were diagnosed with ARP, and 41 patients were diagnosed with BP. The PCT concentrations for patients diagnosed with ARP group were significantly lower than those in the BP group (P < 0.001). There were no differences in CRP and WBC between the two groups. The areas under the ROC curves (AUC) for PCT, CRP and WBC were 0.745, 0.589 and 0.578, respectively. The best cutoff values of PCT, CRP and WBC were 0.47 μg/L, 54.5 mg/L and 9.9 × 10⁹/L, respectively. Low serum PCT levels are associated with ARP. PCT is a useful biomarker to distinguish ARP from BP.

Validation study of the association between genetic variant of IL4 and severe radiation pneumonitis in lung cancer patients treated with radiation therapy

BACKGROUND AND PURPOSE

Recent researches demonstrated that single nucleotide polymorphisms (SNPs) of genes involving inflammation, DNA repair, etc. were associated with risk of radiation pneumonitis (RP). However, these studies were single-centered, from single ethnic origin, without validation from independent cohort studies from other populations. In order to identify clinical valuable SNPs for RP, in this study we selected 19 RP-related SNPs candidates previously published before 2016 for validation in our cohort.

MATERIAL AND METHODS

359 lung cancer patients with radiotherapy were included in our prospective study (NCT02490319). Peripheral blood samples from these patients were genotyped by MassArray and Sanger Sequence method. Multivariate Cox hazard and other analyses were applied to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) of all factors possibly related to the risk of RP.

RESULTS

Patients with elder age, MLD ≥15 Gy, V₂₀ ≥24% had higher risk of RP ≥grade 3 compared with their counterparts (HR = 2.020, 95% CI: 1.045-3.906, P = 0.037; HR = 2.502, 95% CI: 1.346-4.652, P = 0.004; HR = 2.256, 95% CI: 1.191-4.272, P = 0.013, respectively). Moreover, patients receiving IMRT were associated with decreased incidence of RP (HR = 0.520, 95% CI: 0.280-0.963, P = 0.037). Importantly, CT + TT genotype of IL4: rs2243250 was strongly related to decreased risk of RP ≥grade 3 (HR = 0.195, 95% CI: 0.090-0.424, P = 0.000037, P_c = 0.0006).

CONCLUSION

IL4: rs2243250 was validated to be significantly related to RP of grade ≥3 in our cohort. Our results further emphasized the prevalence and clinical value of IL4: rs2243250 on RP, and may thus be one of the important predictors of severe RP before radiotherapy.

Dosimetric and Radiobiological Comparison of External Beam Radiotherapy Using Simultaneous Integrated Boost Technique for Esophageal Cancer in Different Location

Objectives: To compare treatment plans of intensity modulated radiotherapy (IMRT), volumetric modulated arc radiotherapy (VMAT), and helical tomotherapy (HT) with simultaneous integrated boost (SIB) technique for esophageal cancer (EC) of different locations using dosimetry and radiobiology. Methods: Forty EC patients were planned for IMRT, VMAT, and HT plans, including 10 cases located in the cervix, upper, middle, and lower thorax, respectively. Dose-volume metrics, conformity index (CI), homogeneity index (HI), tumor control probability (TCP), and normal tissue complication probability (NTCP) were analyzed to evaluate treatment plans. Results: HT showed significant improvement over IMRT and VMAT in terms of CI (p = 0.007), HI (p < 0.001), and TCP (p < 0.001) in cervical EC. IMRT yielded more superior CI, HI and TCP compared with VMAT and HT in upper and middle thoracic EC (all p < 0.05). Additionally, V30 (27.72 ± 8.67%), mean dose (1801.47 ± 989.58cGy), and NTCP (Niemierko model: 0.44 ± 0.55%; Lyman-Kutcher-Burman model: 0.61 ± 0.59%) of heart in IMRT were sharply reduced than VMAT and HT in middle thoracic EC. For lower thoracic EC, the three techniques offered similar CI and HI (all p > 0.05). But VMAT dramatically lowered liver V30 (9.97 ± 2.84%), and reduced NTCP of lungs (Niemierko model: 0.47 ± 0.48%; Lyman-Kutcher-Burman model: 1.41 ± 1.07%) and liver (Niemierko model: 0.10 ± 0.08%; Lyman-Kutcher-Burman model: 0.17 ± 0.17%). Conclusions: HT was a good option for cervical EC with complex target coverage but little lungs and heart involvement as it achieved superior dose conformity and uniformity. Due to potentially improving tumor control and reducing heart dose with acceptable lungs sparing, IMRT was a preferred choice for upper and middle thoracic EC with large lungs involvement. VMAT could ameliorate therapeutic ratio and lower lungs and liver toxicity, which was beneficial for lower thoracic EC with little thoracic involvement but being closer to heart and liver. Individually choosing optimal technique for EC in different location will be warranted.