Changes in pulmonary function and their correlation with dose-volume parameters in patients undergoing stereotactic body radiotherapy for lung cancer

Management of Oligometastatic Colorectal Cancer

The management of oligometastatic colorectal cancer differs from the treatment of metastatic colorectal cancer, and it is essential that those who treat oligometastatic disease be familiar with the treatment options for these patients. Although definitive treatment is often surgical, there are situations where local therapies such as SBRT or ablative techniques may better serve the patient. Adjuvant therapy should be provided to all patients, and neoadjuvant chemotherapy should be considered as well. The role of immunotherapy is currently limited due to the lack of clinical trials in this area.

Optimizing lung cancer radiation therapy: A systematic review of multifactorial risk assessment for radiation-induced lung toxicity

BACKGROUND

Radiation therapy (RT) is essential in treating advanced lung cancer, but may lead to radiation pneumonitis (RP). This systematic review investigates the use of pulmonary function tests (PFT) and other parameters to predict and mitigate RP, thereby improving RT planning.

METHODS

A systematic review sifted through PubMed and on BioMed Central, targeting articles from September 2005 to December 2022 containing the keywords: Lung Cancer, Radiotherapy, and pulmonary function test.

RESULTS

From 1153 articles, 80 were included. RP was assessed using CTCAEv.4 in 30 % of these. Six studies evaluated post-RT quality of life in lung cancer patients, reporting no decline. Patients with RP and chronic obstructive pulmonary disease (COPD) generally exhibited poorer overall survival. Notably, forced expiratory volume in one second (FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) declined 24 months post-RT, while forced vital capacity (FVC) stayed stable. In the majority of studies, age over 60, tumors located in the lower part of the lung, and low FEV1 before RT were associated with a higher risk of RP. Dosimetric factors (V5, V20, MLD) and metabolic imaging emerged as significant predictors of RP risk. A clinical checklist blending patient and tumor characteristics, PFT results, and dosimetric criteria was proposed for assessing RP risk before RT.

CONCLUSION

The review reveals the multifactorial nature of RP development following RT in lung cancer. This approach should guide individualized management and calls for a prospective study to validate these findings and enhance RP prevention strategies.

Factors that Influence the Need to Start Adaptive Radiotherapy

Introduction

Adaptive radiotherapy (ART) is an essential approach to account for anatomical and biological uncertainties. Adaptive radiotherapy is, however, time-consuming, and it is unclear which patients are eligible or when is the best time to start ART.

Methods

This prospective study was conducted at Kasr El-Aini Center of Clinical Oncology and Nuclear Medicine, Cairo, Egypt from January 2019 to December 2020. Thirty patients with pathologically proven, limited-stage small cell or stage I-II non-small cell lung cancer who were either not fit for or refused surgery or had stage III disease were recruited and underwent treatment planning to receive 60 Gy on a conventional 3D conformal radiation schedule with platinum-based chemotherapy. All patients underwent computed tomography (CT) planning within 2 and 4 weeks of starting radiation therapy to assess the need for adaptation. Pulmonary function test and echocardiography findings were assessed at the end of treatment and at 3 and 6 months after treatment, and were compared to the baseline.

Results

We found a significant reduction in mean value of the planning target volume (PTV) in the CT scans at the second (331 cm3) and fourth (257 cm3) weeks of treatment as compared to baseline (342 cm3) (p-value < 0.0001). Adaptation decreased the dose to the organ at risk with statistical significance and with improvement of the target coverage. At week 2 of radiotherapy, the need for adaptation was correlated to the conformity index (p = 0.0473), esophageal V35 (p = 0.0488), esophageal V50 (p = 0.0295), and its mean dose (p = 0.0087). At week 4 it was correlated to forced expiratory volume in 1 second (FEV1) (p = 0.0303), ratio between the forced expiratory volume in 1 second and the forced vital capacity (FEV1/FVC) (p = 0.0024), and echocardiography (p = 0.0183).

Conclusions

Conformity index and esophageal dose constraints can predict the need for adaptation at week 2, whereas baseline pulmonary function parameters and echocardiography can predict the need for adaptation at week 4 of radiotherapy.

SABR for Early Non-Small Cell Lung Cancer: Changes in Pulmonary Function, Dyspnea, and Quality of Life

PURPOSE

The aim of this study was to report pulmonary function tests (PFTs) and clinician-reported and patient-reported quality-of-life (QoL) outcomes on a cohort of patients with non-small cell lung cancer (NSCLC) treated with SABR.

METHODS AND MATERIALS

A total of 119 patients with NSCLC were treated with SABR in the prospective cohort SSBROC study of patients with T1-T2N0M0 NSCLC. PFTs and QoL measures were obtained at baseline pretreatment and at 6-month intervals. Here we report on the 6- to 18-month time points. Analysis of covariance (ANCOVA) methods adjusting for baseline analyzed potential predictors on outcomes of PFTs and patient-reported dyspnea at 18 months.

RESULTS

The only statistically significant decline in PFTs was seen in forced expiratory volume in 1 second (FEV1) at 18 months post-SABR, with a decline of -0.11 L (P = .0087; 95% CI, -0.18 to -0.02). Of potential predictors of decline, only a 1-unit increase in smoking pack-years resulted in a -0.12 change in diffusing capacity for carbon monoxide (P = .026; 95% CI, -0.02 to -0.23) and a 0.003 decrease in FEV1 (P = .026; 95% CI, -0.006 to -0.0004). For patient-reported outcomes, statistically significant worsening in both the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (QLQ-C30 Version 3) and the lung module (QLQ-LC13) dyspnea scores occurred at the 18-month time point, but not earlier. No potential predictors of worsening dyspnea were statistically significant. There was no statistically significant decline in clinician-reported outcomes or global QoL scores.

CONCLUSIONS

We found a statistically significant decline in FEV1 at 18 months posttreatment. Smoking pack-years was a predictor for decline in diffusing capacity for carbon monoxide and FEV1 at 18 months. Worsening of patient-reported dyspnea scores was observed, consistent with the expected progression of lung comorbid disease.

Comparison of Changes in Pulmonary Function After Stereotactic Body Radiation Therapy Versus Conventional 3-Dimensional Conformal Radiation Therapy for Stage I and IIA Non-Small Cell Lung Cancer: An Analysis of the TROG 09.02 (CHISEL) Phase 3 Trial

PURPOSE

The TROG 09.02 CHISEL trial compared conventional radiation therapy (CRT) with stereotactic body radiation therapy (SBRT) in patients with inoperable early-stage non-small cell lung cancer. Patients randomized to SBRT had less local failure and improved overall survival. This analysis reports differences in pulmonary function tests (PFTs) and the 6-minute walk test (SMWT) between patients who received SBRT and those who received CRT.

METHODS AND MATERIALS

We analyzed the PFTs and SMWTs of all patients recruited to the CHISEL [trial. During this trial, patients underwent serial PFTs. Linear regression models were used to compare parameters between SBRT and CRT at 3 and 12 months after treatment.

RESULTS

One hundred and one patients were enrolled; 33 patients were treated with CRT, 61 were treated with SBRT, and 7 did not receive treatment. Primary tumor size was similar between arms: SBRT 25 mm (standard deviation [SD], 9) and CRT 28 mm (SD, 9). On regression analysis, at 3 and 12 months, there was no evidence of a difference between arms in PFT decline or distance walked in the SMWT. Planning target volume size was significantly larger in the CRT arm, 142.79 cc (SD, 61.14), compared with the SBRT group, 46.15 cc (SD, 23.39). The mean biologically effective dose received by the target was significantly larger in the SBRT group, 125.92 Gy (SD, 21.58), compared with CRT, 65.49 Gy (SD, 6.32). Mean dose to the lungs minus the gross target volume incorporating motion was 8.9 Gy (SD, 2.34) in the CRT group and 4.37 Gy (SD, 1.42) in the SBRT group.

CONCLUSIONS

Despite the considerably higher biologically effective doses delivered to the tumor in SBRT, there was no difference in decline in respiratory function observed between the 2 groups.

Clinical outcomes and lung toxicities after lung SABR using dynamic conformal arc therapy: a single-institution cohort study

BACKGROUND

Stereotactic ablative radiotherapy (SABR) is a validated treatment for early stage lung cancer and pulmonary metastases. It provides a high local control rate with low symptomatic toxicities. Recently, Dynamic Conformal Arc Therapy (DCAT), a delivery option that differs from conventional DCA, has been implemented in the Monaco Treatment Planning System for SABR. The aim of the study was to report clinical outcomes and toxicities for patients treated for lung SABR with this new technique.

METHODS

We retrospectively identified adult patients treated for primary or secondary lung tumors with DCAT-SABR and reported their clinical, radiological, histological characteristics and dosimetric parameters. Total dose was delivered in 3 or 5 fractions for 95% of patients and prescribed on the 80% isodose line to the PTV periphery.

RESULTS

145 patients met inclusion criteria for a total of 152 lesions with a median follow up of 12 months. Local control for the irradiated site was 96.7% at 1 year. Overall survival was 93.1% at 1 year. Mean prescription dose in BED₁₀ was 110 Gy. 92% of patients had a prescribed dose superior to 100 Gy BED₁₀. Mean PTV coverage was 95.1%. There were 66 cases of grade 1 radiation pneumonitis (RP) (43%) and only 7 cases of symptomatic grade 2 RP (4.6%).

CONCLUSION

Lung SABR for primary or metastatic lung tumors using dynamic conformal arc therapy provides efficient results of local control and low lung toxicities, similar to other SABR techniques.

ADVANCES IN KNOWLEDGE

SABR using DCAT is a safe technique to treat lung lesions, allowing intra-fraction motion limitation, potentially higher OARs protection and a shortened beam delivery.

Statistical evaluation of the effectiveness of dual amplitude-gated stereotactic body radiotherapy using fiducial markers and lung volume

•

Approximately 30% of the fiducial markers demonstrated a low correlation on comparing lung volumes.

•

Monitoring of lung volume can achieve stable tracking of lung tumors.

•

Dual monitoring by employing the marker and lung volume may possibly avoid the deterioration of monitoring accuracy.

Background and purpose

The low tracking accuracy of lung stereotactic body radiotherapy (SBRT) risks reduced treatment efficacy. We used four-dimensional computed tomography (4DCT) images to determine the correlation between changes in fiducial marker positions and lung volume for lung tumors, and we evaluated the effectiveness of the combined use of these images in lung SBRT.

Materials and methods

Data of 30 patients who underwent fiducial marker placement were retrospectively analyzed. We calculated the motion amplitudes of the center of gravity coordinates of the lung tumor and fiducial markers in each phase and the ipsilateral, contralateral, and bilateral lung volumes using 4DCT. Moreover, we calculated the cross-correlation coefficient between the fiducial marker position and the lung volume changes waveform for the motion amplitude waveform of the lung tumor over three gating windows (all phases, ≤2 mm³, and ≤3 mm³).

Results

Compared with the lung volume, approximately 30 % of the fiducial markers demonstrated a low correlation with the lung tumor. In the ≤2 mm³ and ≤3 mm³ gating windows, the cross-correlation coefficients between the lung tumor and the optimal marker (r > 0.9: 83 % and 86 %) were significantly different for all fiducial markers (r > 0.9: 39 %, 53 %) and the ipsilateral (r > 0.9: 35 % and 40 %), contralateral (r > 0.9: 44 % and 41 %), and bilateral (r > 0.9: 39 % and 45 %) lung volumes.

Conclusions

Some of the fiducial markers showed a low correlation with the lung tumor. This study indicated that the combined use of lung volume monitoring can improve tracking accuracy.