Risk Of Symptomatic Radiation Pneumonitis Research Articles

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.

Factors affecting post-treatment radiation-induced lung disease in patients receiving stereotactic body radiotherapy to lung.

The aim of the study is to investigate factors that may cause radiation-induced lung disease (RILD) in patients undergoing stereotactic body radiotherapy (SBRT) for lung tumors. Medical records of patients treated between May 2018 and June 2019 with SBRT were retrospectively evaluated. All patients should have a diagnosis of either primary non-small cell lung cancer (NSCLC) or less than three metastases to lung from another primary. The median treatment dose was 50Gy in 4-5 fractions. Tumor response and RILD were evaluated in thoracic computer tomography (CT) using RECIST criteria. 82 patients with 97 lung lesions were treated. The median age was 68years (IQR = 62-76). With a median follow-up of 7.2months (3-18months), three patients had grade 3 radiation pneumonitis (RP). RILD was observed in 52% of cases. Patients who had RILD had a higher risk of symptomatic RP (p = 0.007). In multivariate analyses older age, previous lung radiotherapy history, and median planning treatment volume (PTV) D95 value of ≥ 48Gy were associated with RILD. Local recurrence (LR) was observed in 5.1% of cases. There was no difference in overall survival and LR with the presence of RILD. Older age, previous lung radiotherapy history, and median PTV D95 value of ≥ 48Gy seems to be associated with post-SBRT RILD.

Adoption of Biologically Effective Dose of the Non-Target Lung Volume to Predict Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy With Variable Fractionations for Lung Cancer.

Background: This study aims to establish lung biologically effective dose (BED)–based uniform dosimetric constraints for minimizing the risk of symptomatic radiation pneumonitis (SRP) from stereotactic body radiation therapy (SBRT) using variable fractionations in patients with lung tumors.Materials and Methods: A total of 102 patients with primary or oligometastatic lung tumors treated with SBRT in our institution were enrolled into this study. The associations between the clinical and dosimetric parameters and the incidences of SRP were analyzed using univariate and multivariate Cox regression hazard models. The receiver operating characteristic (ROC) curve was generated to evaluate the predictive performance of lung BED on the SRP risk compared with the physical dose.Results: SRP occurred in 11 patients (10.8%). In univariate analysis, the mean lung dose (p = 0.002), V5 (p = 0.005), V20 (p < 0.001), and the percentage of non-target normal lung volume receiving more than a BED of 5–170 Gy (VBED5−170, p < 0.05) were associated with SRP. Multivariate logistic regression analysis showed that there existed a significant statistical correlation between SRP and VBED70 (p < 0.001), which performed better than V5 or V20 on the ROC curves, resulting in an optimal cut-off value of lung VBED70 of 2.22%.Conclusions: This retrospective study indicated that non-target lung BED may better predict SRP from patients with SBRT-treated lung cancer. Limiting the lung VBED70 below 2.22% may be favorable to reduce the incidence of SRP, which warranted further prospective validation.

Influence of respiratory motion management technique on radiation pneumonitis risk with robotic stereotactic body radiation therapy.

Purpose/ObjectivesFor lung stereotactic body radiation therapy (SBRT), real‐time tumor tracking (RTT) allows for less radiation to normal lung compared to the internal target volume (ITV) method of respiratory motion management. To quantify the advantage of RTT, we examined the difference in radiation pneumonitis risk between these two techniques using a normal tissue complication probability (NTCP) model.Materials/Method20 lung SBRT treatment plans using RTT were replanned with the ITV method using respiratory motion information from a 4D‐CT image acquired at the original simulation. Risk of symptomatic radiation pneumonitis was calculated for both plans using a previously derived NTCP model. Features available before treatment planning that identified significant increase in NTCP with ITV versus RTT plans were identified.ResultsPrescription dose to the planning target volume (PTV) ranged from 22 to 60 Gy in 1–5 fractions. The median tumor diameter was 3.5 cm (range 2.1–5.5 cm) with a median volume of 14.5 mL (range 3.6–59.9 mL). The median increase in PTV volume from RTT to ITV plans was 17.1 mL (range 3.5–72.4 mL), and the median increase in PTV/lung volume ratio was 0.46% (range 0.13–1.98%). Mean lung dose and percentage dose–volumes were significantly higher in ITV plans at all levels tested. The median NTCP was 5.1% for RTT plans and 8.9% for ITV plans, with a median difference of 1.9% (range 0.4–25.5%, pairwise P < 0.001). Increases in NTCP between plans were best predicted by increases in PTV volume and PTV/lung volume ratio.ConclusionsThe use of RTT decreased the risk of radiation pneumonitis in all plans. However, for most patients the risk reduction was minimal. Differences in plan PTV volume and PTV/lung volume ratio may identify patients who would benefit from RTT technique before completing treatment planning.

Risk Factors Associated With Symptomatic Radiation Pneumonitis After Stereotactic Body Radiation Therapy for Stage I Non-Small Cell Lung Cancer.

Radiation pneumonitis is the most frequent acute pulmonary toxicity following stereotactic body radiation therapy for lung cancer. Here, we investigate clinical and dosimetric factors associated with symptomatic radiation pneumonitis in patients with stage I non-small cell lung cancer treated with stereotactic body radiation therapy. A total of 67 patients with stage I non-small cell lung cancer who received stereotactic body radiation therapy at our institution were enrolled, and their clinicopathological parameters and dosimetric parameters were recorded and analyzed. The median follow-up period was 26.4 months (range: 7-48 months). In univariate analysis, tumor size ( P = .041), mean lung dose ( P = .028), V2.5 ( P = .024), V5 ( P = .014), V10 ( P = .004), V20 ( P = .024), V30 ( P = .020), V40 ( P = .040), and V50 ( P = 0.040) were associated with symptomatic radiation pneumonitis. In multivariable logistic regression analysis, V10 ( P = .049) was significantly associated with symptomatic radiation pneumonitis. In conclusion, this study found that tumor size, mean lung dose, and V2.5 to V50 were risk factors markedly associated with symptomatic radiation pneumonitis. Our data suggested that lung V10 was the most significant factor, and optimizing lung V10 may reduce the risk of symptomatic radiation pneumonitis. For both central and peripheral stage I lung cancer, rate of radiation pneumonitis ≥grade 2 was low after stereotactic body radiation therapy with appropriate fraction dose.

Risk of Symptomatic Radiation Pneumonitis After Thoracic Radiation Therapy in Patients With a Reticular Shadow

Risk of Symptomatic Radiation Pneumonitis After Thoracic Radiation Therapy in Patients With a Reticular Shadow

Loss of lung function after chemo-radiotherapy for NSCLC measured by perfusion SPECT/CT: Correlation with radiation dose and clinical morbidity

ABSTRACTBackground. The purpose of the study was to assess dose and time dependence of radiotherapy (RT)-induced changes in regional lung function measured with single photon emission computed tomography (SPECT) of the lung and relate these changes to the symptomatic endpoint of radiation pneumonitis (RP) in patients treated for non-small cell lung cancer (NSCLC).Material and methods. NSCLC patients scheduled to receive curative RT of minimum 60 Gy were included prospectively in the study. Lung perfusion SPECT/CT was performed before and three months after RT. Reconstructed SPECT/CT data were registered to treatment planning CT. Dose to the lung was segmented into regions corresponding to 0–5, 6–20, 21–40, 41–60 and > 60 Gy. Changes (%) in regional lung perfusion before and after RT were correlated with regional dose and symptomatic RP (CTC grade 2–5) outcome.Results. A total of 58 patients were included, of which 45 had three-month follow-up SPECT/CT scans. Analysis showed a statistically significant dose-dependent reduction in regional perfusion at three-month follow-up. The largest population composite perfusion loss was in 41–60 Gy (42.2%) and > 60 Gy (41.7%) dose bins. Lung regions receiving low dose of 0–5 Gy and 6–20 Gy had corresponding perfusion increase (-7.2% and -6.1%, respectively). Regional perfusion reduction was different in patients with and without RP with the largest difference in 21–40 Gy bin (p = 0.02), while for other bins the difference did not reach statistical significance. The risk of symptomatic RP was higher for the patients with perfusion reduction after RT (p = 0.02), with the relative risk estimate of 3.6 (95% CI 1.1–12).Conclusion. Perfusion lung function changes in a dose-dependent manner after RT. The severity of radiation-induced lung symptoms is significantly correlated with SPECT perfusion changes. Perfusion reduction early after RT is associated with a high risk of later development of symptomatic RP.

Do Angiotensin-Converting Enzyme Inhibitors Reduce the Risk of Symptomatic Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer After Definitive Radiation Therapy? Analysis of a Single-Institution Database

Preclinical studies have suggested that angiotensin-converting enzyme inhibitors (ACEIs) can mitigate radiation-induced lung injury. We sought here to investigate possible associations between ACEI use and the risk of symptomatic radiation pneumonitis (RP) among patients undergoing radiation therapy (RT) for non-small cell lung cancer (NSCLC). We retrospectively identified patients who received definitive radiation therapy for stages I to III NSCLC between 2004 and 2010 at a single tertiary cancer center. Patients must have received a radiation dose of at least 60 Gy for a single primary lung tumor and have had imaging and dosimetric data available for analysis. RP was quantified according to Common Terminology Criteria for Adverse Events, version 3.0. A Cox proportional hazard model was used to assess potential associations between ACEI use and risk of symptomatic RP. Of 413 patients analyzed, 65 were using ACEIs during RT. In univariate analysis, the rate of RP grade ≥2 seemed lower in ACEI users than in nonusers (34% vs 46%), but this apparent difference was not statistically significant (P=.06). In multivariate analysis of all patients, ACEI use was not associated with the risk of symptomatic RP (hazard ratio [HR] = 0.66; P=.07) after adjustment for sex, smoking status, mean lung dose (MLD), and concurrent carboplatin and paclitaxel chemotherapy. Subgroup analysis showed that ACEI use did have a protective effect from RP grade ≥2 among patients who received a low (≤20-Gy) MLD (P<.01) or were male (P=.04). A trend toward reduction in symptomatic RP among patients taking ACEIs during RT for NSCLC was not statistically significant on univariate or multivariate analyses, although certain subgroups may benefit from use (ie, male patients and those receiving low MLD). The evidence at this point is insufficient to establish whether the use of ACEIs does or does not reduce the risk of RP.

PD-111 Predicting the risk of symptomatic radiation pneumonitis by clinical and dosimetric parameter in lung cancer patients treated with 3-D conformal radiation therapy

PD-111 Predicting the risk of symptomatic radiation pneumonitis by clinical and dosimetric parameter in lung cancer patients treated with 3-D conformal radiation therapy

Dose-volume histogram analysis as predictor of radiation pneumonitis in primary lung cancer patients treated with radiotherapy

To determine the relationship between various parameters derived from lung dose-volume histogram analysis and the risk of symptomatic radiation pneumonitis (RP) in patients undergoing radical radiotherapy for primary lung cancer. The records of 156 patients with lung cancer who had been treated with radical radiotherapy (>/=45 Gy) and for whom dose-volume histogram data were available were reviewed. The incidence of symptomatic RP was correlated with a variety of parameters derived from the dose-volume histogram data, including the volume of lung receiving 10 Gy (V(10)) through 50 Gy (V(50)) and the mean lung dose (MLD). The rate of RP at 6 months was 15% (95% confidence interval 9-22%). On univariate analysis, only V(30) (p = 0.036) and MLD (p = 0.043) were statistically significantly related to RP. V(30) correlated highly positively with MLD (r = 0.96, p < 0.001). V(30) and MLD can be used to predict the risk of RP in lung cancer patients undergoing radical radiotherapy.

Characteristics of patients who developed radiation pneumonitis requiring steroid therapy after stereotactic irradiation

Stereotactic irradiation (STI) for primary non-small cell lung cancers was shown to be effective, with a low risk of symptomatic radiation pneumonitis (RP). However, small portion of the patients were reported to have received steroid for their symptomatic radiation pneumonitis (RP). The risk of radiation pneumonitis was shown to be related to the percent by which total lung volume exceeded 20 Gy (V20) in conventional radiotherapy. To find the possible risk factors for symptomatic RP, the characteristics of patients who developed radiation pneumonitis requiring steroid therapy (SWOG grade 2) after STI, as well as their treatment parameters, were investigated retrospectively.

Characteristics of patients who developed radiation pneumonitis requiring steroid therapy after stereotactic irradiation

Purpose/Objective: Stereotactic irradiation (STI) for primary non-small cell lung cancers was shown to be effective, with a low risk of symptomatic radiation pneumonitis (RP). However, small portion of the patients were reported to have received steroid for their symptomatic radiation pneumonitis (RP). The risk of radiation pneumonitis was shown to be related to the percent by which total lung volume exceeded 20 Gy (V20) in conventional radiotherapy. To find the possible risk factors for symptomatic RP, the characteristics of patients who developed radiation pneumonitis requiring steroid therapy (SWOG grade 2) after STI, as well as their treatment parameters, were investigated retrospectively.

Prospective assessment of dosimetric/physiologic models to predict radiation pneumonitis

7280 Background: A variety of clinical and dosimetric parameters extracted from the 3D dose distribution have been associated with the risk of symptomatic radiation pneumonitis in retrospective studies. Such parameters include the mean lung dose (MLD), the radiation dose distribution relative to functioning perfused lung (assessed by single photon emission computed tomography-SPECT), and the pre-RT lung function (i.e. PFT's). Based on our work and others, we defined pre-RT criteria that we hypothesized would be predictive for the later development of pneumonitis. We herein prospectively test the predictive abilities of these dosimetric/functional parameters. This study was performed on a new cohort of patients, who were not included in our analyses that defined the predictive models. Methods: Between 1999–2003, 63 patients receiving thoracic RT for lung cancer were enrolled onto a prospective IRB-approved study to monitor RT-induced lung injury. 37 patients without evidence of recurrent intra-thoracic tumor after >6 months post-RT were included in this analysis. Patients at high and low risk for pneumonitis were defined based on: a) the mean lung dose, b) the 3D dose distribution relative to the pre-RT SPECT lung perfusion scan, and c) the pre-RT DLCO. The rates of pneumonitis in the high and low risk groups were compared using Fisher's exact test. The areas under receiver operating characteristic (ROC) curves were used to compare alternative predictive models. Results: Pneumonitis rates in the patients predicted to be at high vs. low risk were similar. For the overall patient population, the ROC areas provided by the different models were similar and suboptimal (<0.6). No model provided a statistically significant segregation of the patients. Conclusions: Segregating patients into high and low risk groups for pneumonitis is challenging. While the models do have some predictive value, their ROC areas are far from ideal. Additional work is needed to better identify predictors of RT-induced lung injury. Supported by NIH R01 Grant CA69579. Thanks to UNC for PLUNC software. No significant financial relationships to disclose.

The benefit and risk of postmastectomy radiation therapy in patients with high-risk breast cancer.

To evaluate the efficacy of postmastectomy radiation therapy (PMRT) for prophylaxis against locoregional recurrence in high-risk breast cancer patients, and the rate of complication associated with such treatment, we retrospectively reviewed 79 breast cancers in 78 patients, who were given therapy (PMRT) between April 1990 and March 1995. Radiation doses were 46-50 Gy in 2-Gy fractions. High-risk factors included primary tumor (> or = 5 cm) in 19 (24.1%) patients, positive axillary lymph nodes (> or = 4) in 56 (70.9%) patients, positive or close (< or = 2 mm) surgical margins in 14 (17.7%) patients, and central or inner quadrant tumor with positive axillary nodes and lymphovascular invasion in seven (8.9%) patients. Adjuvant chemotherapy was also given to 69 of 78 (88.5%), patients and hormonal therapy to 41 of 78 (53.7%) patients. The median follow-up time was 25 months (range, 7-66 months) after mastectomy. Our study revealed that locoregional failure as the first site of failure occurred in only one of 78 (1.3%) patients. Relapse-free survival at 3 years was 67.7% [95% confidence interval (CI), 52.0-81.3], and overall survival was 76.9% (95% CI, 63.3-90.6). The incidence of radiological evidence of lung fibrosis increased significantly in patients whose internal mammary chain was included in the radiation field. The occurrence of lung fibrosis can be reduced by changing radiation treatment technique and keeping central lung distance (CLD) of tangential field to < or = 2.8 cm in tangential field technique or < or = 1.4 cm in tangential with a separate internal mammary field technique. We concluded that the risk of locoregional recurrence in high-risk breast cancer patients can be much reduced by PMRT. With careful selection of radiation treatment fields, radiotherapy technique, and limitation of CLD to < or = 2.8 cm in tangential technique or < or = 1.4 cm in separate technique, the risk of symptomatic radiation pneumonitis is minimal. PMRT should be recommended for breast cancer patients who are at high risk for locoregional recurrence.