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

Dosimetric Predictors of Acute Radiation Pneumonitis and Esophagitis in Hypofractionated Thoracic Irradiation of Non-Small Cell Lung Cancer Patients With Poor Prognostic Factors

PURPOSE

The proliferation rates of non-small cell lung cancer (NSCLC) and associated radiation resistance highlight the potential of hypofractionated radiation therapy (hypoRT). However, radiation pneumonitis and esophagitis remain dose-limiting adverse events. This study investigates dosimetric factors influencing the risk of pneumonitis and esophagitis in highly multimorbid patients undergoing moderately hypoRT.

METHODS AND MATERIALS

Forty-seven NSCLC patients with poor performance status treated between January 2014 and July 2021 were included. Dosimetric parameters including mean lung dose (MLD), percentage of normal (ipsi-/contralateral) lung volume (Vx) receiving ≥x Gy (x = 20, 18, 10, and 5 Gy); mean heart dose (MHD), percentage of the heart volume (HVx) receiving ≥x Gy (x = 20, 10, and 5 Gy); and mean esophageal dose (MED), percentage of esophagus volume (EVx) receiving ≥x Gy (x = 40, 30, 20, 18, 10, and 5 Gy) were analyzed retrospectively. Acute radiation pneumonitis/esophagitis events were assessed within 6/3 months posttreatment. Statistical analyses included random forests, binary logistic regression, and linear regression.

RESULTS

Among the 47 patients with compromised lung function and poor prognostic factors, 8 (17%) and 26 (55%) patients developed all-grade pneumonitis or esophagitis, while 4 (9%) and 10 (21%) patients developed CTCAE grade ≥2 pneumonitis and esophagitis, respectively. Exploratory analyses suggest that V10, V18, and MLD values are associated with an increased risk of pneumonitis. Linear regressions confirmed this for MLD values greater than 9.2 Gy (P = .050). Additionally, higher V5 and V10 values in the contralateral lung were associated with a greater risk of pneumonitis (P = .013/P = .032). Dmax proved to be a significant predictor of esophagitis (P = .020). Moreover, evidence suggests that EV5 and EV40 may portend esophagitis onset.

CONCLUSIONS

This study provides insights into dosimetric factors influencing pneumonitis/esophagitis development in NSCLC patients undergoing hypoRT. While MLD and Dmax emerged as significant predictors of pneumonitis and esophagitis, the small sample size limited the depth of conclusions. Further research with larger cohorts is warranted to validate these observations, potentially optimizing treatment planning and outcomes in this challenging patient population.

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.

Research Progress on Radiotherapy Combined with Immunotherapy for Associated Pneumonitis During Treatment of Non-Small Cell Lung Cancer

Radiation pneumonitis is a common and serious complication of radiotherapy for thoracic tumours. Although radiotherapy technology is constantly improving, the incidence of radiation pneumonitis is still not low, and severe cases can be life-threatening. Once radiation pneumonitis develops into radiation fibrosis (RF), it will have irreversible consequences, so it is particularly important to prevent the occurrence and development of radiation pneumonitis. Immune checkpoint inhibitors (ICIs) have rapidly altered the treatment landscape for multiple tumour types, providing unprecedented survival in some patients, especially for the treatment of non-small cell lung cancer (NSCLC). However, in addition to its remarkable curative effect, ICls may cause immune-related adverse events. The incidence of checkpoint inhibitor pneumonitis (CIP) is 3% to 5%, and its mortality rate is 10% to 17%. In addition, the incidence of CIP in NSCLC is higher than in other tumour types, reaching 7%–13%. With the increasing use of immune checkpoint inhibitors (ICls) and thoracic radiotherapy in the treatment of patients with NSCLC, ICIs may induce delayed radiation pneumonitis in patients previously treated with radiation therapy, or radiation activation of the systemic immune system increases the toxicity of adverse reactions, which may lead to increased pulmonary toxicity and the incidence of pneumonitis. In this paper, the data about the occurrence of radiation pneumonitis, immune pneumonitis, and combined treatment and the latest related research results will be reviewed.

Risk factors for radiation pneumonitis after rotating gantry intensity-modulated radiation therapy for lung cancer

The risk factors for severe radiation pneumonitis (RP) in patients with lung cancer who undergo rotating gantry intensity-modulated radiation therapy (IMRT) using volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT) are poorly understood. Fifty-two patients who received rotating gantry IMRT for locally advanced lung cancer were included in this retrospective study. In total, 31 and 21 patients received VMAT and HT, respectively. The median follow-up duration was 14 months (range, 5.2-33.6). Twenty (38%) and eight (15%) patients developed grade ≥ 2 and ≥ 3 RP, respectively. In multivariate analysis, lung V5 ≥ 40% was associated with grade ≥ 2 RP (P = 0.02), and past medical history of pneumonectomy and total lung volume ≤ 3260 cc were independently associated with grade ≥ 3 RP (P = 0.02 and P = 0.03, respectively). Rotating gantry IMRT was feasible and safe in patients with lung cancer undergoing definitive radiotherapy. Reducing lung V5 may decrease the risk of symptomatic RP, and care should be taken to avoid severe RP after radiotherapy in patients with a past medical history of pneumonectomy and small total lung volume.

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.

Serum MMP-9 and SAA in the Diagnosis of Severe Pneumonia Caused by Radiotherapy of Esophageal Cancer

OBJECTIVE

To explore the relationship and diagnostic value of serum MMP-9 and SAA in severe pneumonia (sCAP) caused by radiotherapy of esophageal cancer.

METHODS

A total of 144 esophageal cancer patients who underwent radiotherapy in our hospital from April 2016 to February 2018 were collected. Among them, 58 patients without radiation pneumonitis (RP) were in the control group, 49 patients with grade 1∼2 RP were in the radiation group, and 37 patients with sCAP were in the severe group. The levels of serum MMP-9 and SAA in every group of patients were detected. The ROC curve was used to determine the diagnostic value of serum MMP-9 and SAA in the diagnosis of RP and sCAP. The correlation between serum MMP-9 and SAA and the patient's lung function indexes was analyzed, and the logistic single-factor and multivariate analyses were performed to analyze the factors of sCAP in esophageal cancer radiotherapy.

RESULTS

PaO2, FVC, and FEV1 decreased in RP and sCAP, and PaCO2, white blood cells, serum MMP-9, and SAA levels increased (P < 0.05); serum MMP-9 and SAA were negatively correlated with lung function (P < 0.05); the AUC of serum MMP-9 and SAA in RP was 0.833 and 0.823, respectively, and the AUC of the two combined diagnosis of RP was 0.919. The AUC of serum MMP-9 and SAA in sCAP was 0.809 and 0.797, respectively, and the AUC of both combined diagnosis of sCAP was 0.873; logistics multivariate analysis found that serum MMP-9, serum SAA, double lung V5, and V20 were independent risk factors for sCAP caused by radiotherapy for esophageal cancer (P < 0.05).

CONCLUSION

Serum MMP-9 and SAA increase in RP and sCAP and are negatively correlated with lung function in patients with pneumonia. They are independent risk factors for severe pneumonia caused by radiotherapy of esophageal cancer and have good diagnostic value.