In Vitro Comparison of Sex-Specific Splicing Efficiencies of fem Pre-mRNA under Monoallelic and Heteroallelic Conditions of csd, a Master Sex-Determining Gene in the Honeybee.

The sexual fate of honeybees is determined by the complementary sex determination (CSD) model: heterozygosity at a single locus (the CSD locus) determines femaleness, while hemizygosity or homozygosity at the CSD locus determines maleness. The csd gene encodes a splicing factor that regulates sex-specific splicing of the downstream target gene feminizer (fem), which is required for femaleness. The female mode of fem splicing occurs only when csd is present in the heteroallelic condition. To gain insights into how Csd proteins are only activated under the heterozygous allelic composition, we developed an in vitro assay system to evaluate the activity of Csd proteins. Consistent with the CSD model, the co-expression of two csd alleles, both of which lack splicing activity under the single-allele condition, restored the splicing activity that governs the female mode of fem splicing. RNA immunoprecipitation quantitative PCR analyses demonstrated that the CSD protein was specifically enriched in several exonic regions in the fem pre-mRNA, and enrichment in exons 3a and 5 was significantly greater under the heterozygous allelic composition than the single-allelic condition. However, in most cases csd expression under the monoallelic condition was capable of inducing the female mode of fem splicing contrary to the conventional CSD model. In contrast, repression of the male mode of fem splicing was predominant under heteroallelic conditions. These results were reproduced by real-time PCR of endogenous fem expression in female and male pupae. These findings strongly suggest that the heteroallelic composition of csd may be more important for the repression of the male splicing mode than for the induction of the female splicing mode of the fem gene.

Clinical utility of psoas muscle volume in assessment of sarcopenia in patients with early-stage non-small cell lung cancer.

PURPOSE: Sarcopenia influences postoperative outcomes of patients with non-small cell lung cancer (NSCLC). Imaging tools for evaluating and diagnosing sarcopenia have developed, and a novel method of psoas volume index (PVI) obtained by measuring bilateral psoas major muscle volume has been reported. However, the relationship between sarcopenia based on PVI and clinical outcomes has not been fully investigated for patients with early-stage NSCLC. This study aimed to clarify the utility of PVI values in assessing the relationshipe between sarcopenia and clinical outcomes. METHODS: This study included 645 patients with stage I-II NSCLC who underwent curative lung resection between 2012 and 2017. Bilateral psoas major muscle volumes were calculated semi-automatically using a three-dimensional workstation. The cutoff value of PVI for defining sarcopenia was < 60.5 cm3/m3 for men and < 43.6 cm3/m3 for women. RESULTS: The avrage time to obtaine PVI was only 25 s with the 3D system, and interobserver agreements for evauating sarcopenia on PVI was 1. A total of 159 patients (24.7%) were preoperatively diagnosed with sarcopenia. On multivariate analysis, sarcopenia was an independent prognostic factor for overall survival (OS, p < 0.001), recurrence-free survival (RFS, p < 0.001), and lung cancer-specific survival (LCS, p < 0.001). The 5-year OS, RFS, and LCS were significantly worse in sarcopenic patients than non-sarcopenic patients (88.8 vs. 72.4%, p < 0.001; 80.1 vs. 65.0%, p < 0.001; 92.4 vs. 78.9%, p < 0.001, respectively). CONCLUSION: Sarcopenia diagnosed using PVI is an independent prognostic predictor of OS, RFS, and LCS in early-stage NSCLC.

A giant left atrial myxoma causing left-sided heart failure.

This report presents a case study on giant left atrial myxoma. Transthoracic echocardiography showed a giant mass in the left atrium of a 53-year-old female patient causing functional mitral stenosis. Tumor resection was performed, and the pathological diagnosis confirmed the atrial myxoma. Postoperative echocardiography showed no evidence of any remaining mass and mitral stenosis.

Clinical Impact of Sarcopenia 1 Year After Surgery for Patients with Early-Stage Non-small Cell Lung Cancer.

BACKGROUND: Sarcopenia is associated with prognostic outcomes for patients with various solid tumors, whereas the clinical significance of sarcopenia 1 year after surgery (post-sarcopenia) for non-small cell lung cancer (NSCLC) has not been investigated. This study aimed to clarify the clinical impact of post-sarcopenia and factors associated with post-sarcopenia in NSCLC patients without preoperative sarcopenia. METHODS: This study enrolled 443 patients with clinical stage 1 or 2 NSCLC (234 patients without preoperative sarcopenia [NS group] and 209 patients with preoperative sarcopenia [S group]) who underwent computed tomography (CT) at two time points (before surgery and a year afterward) or more. The study assessed CT images at the L3 level to calculate the psoas muscle area index (PAI). The PAI cutoff value for sarcopenia was defined as 6.36 cm2/m2 for the men and 3.92 cm2/m2 for the women. RESULTS: In the NS group, the diagnosis for 40.1% of the women and 52.6% of the men was post-sarcopenia (NS-S group). The overall survival (OS) for the S and NS-S cohorts was worse than for the non-sarcopenic patients before and after surgery (p < 0.001 and p = 0.017, respectively). In the multivariable analysis, sarcopenia, either before or after surgery (hazard ratio, 3.272; p = 0.002), in the NS group was independently associated with OS, whereas the factors associated with post-sarcopenia were male sex (p = 0.002), aging (p < 0.001), and low body mass index (p < 0.001). CONCLUSIONS: Sarcopenia, either before or after surgery, is prognostic in early-stage NSCLC. Male sex, aging, and low body mass index (BMI) are associated with post-sarcopenia.

Prognostic impact of artificial intelligence-based volumetric quantification of the solid part of the tumor in clinical stage 0-I adenocarcinoma.

INTRODUCTION: The size of the solid part of a tumor, as measured using thin-section computed tomography, can help predict disease prognosis in patients with early-stage lung cancer. Although three-dimensional volumetric analysis may be more useful than two-dimensional evaluation, measuring the solid part of some lesions is difficult using this methods. We developed an artificial intelligence-based analysis software that can distinguish the solid and non-solid parts (ground-grass opacity). This software calculates the solid part volume in a totally automated and reproducible manner. The predictive performance of the artificial intelligence software was evaluated in terms of survival or recurrence-free survival. METHODS: We analyzed the high-resolution computed tomography images of the primary lesion in 772 consecutive patients with clinical stage 0-I adenocarcinoma. We performed automated measurement of the solid part volume using an artificial intelligence-based algorithm in collaboration with FUJIFILM Corporation. The solid part size, the solid part volume based on traditional three-dimensional volumetric analysis, and the solid part volume based on artificial intelligence were compared. RESULTS: Higher areas under the curve related to the solid part volume were provided by the artificial intelligence-based method (0.752) than by the solid part size (0.722) and traditional three-dimensional volumetric analysis-based method (0.723). Multivariate analysis demonstrated that the solid part volume based on artificial intelligence was independently correlated with overall survival (P = 0.019) and recurrence-free survival (P < 0.001). CONCLUSION: The solid part volume measured by artificial intelligence was superior to conventional methods in predicting the prognosis of clinical stage 0-I adenocarcinoma.

Comparison of Liver Fibrosis and Function Indices with Extracellular Volume Using Dual-energy CT: A Retrospective Study.

BACKGROUND: Dual-Energy Computed Tomography (DECT) enables the direct measurement of iodine accumulation in the extracellular space. OBJECTIVE: To compare measures of liver fibrosis and function with Extracellular Volume (ECV) from iodine/water images using DECT. METHODS: Data was obtained from 119 consecutive patients who underwent abdominal DECT. A region of interest was set in the right lobe of the liver, pancreas, spleen, and aorta on iodine density images. ECV was calculated using the following formula: ECV = (1 - hematocrit) × [iodine concentration in the liver (or pancreas, spleen) / iodine concentration in the aorta]. The severity of liver fibrosis was estimated using the aminotransferase/platelet ratio index (APRI) and the Fibrosis-4 (FIB-4) index. Liver function was assessed by the Child-Pugh classification and albumin-bilirubin (ALBI) grade. Data were analyzed by the Spearman rank correlation coefficient, one-way analysis of variance, and post hoc analysis. RESULTS: The correlation between ECV and fibrosis indices (APRI and FIB-4) was only significant, with a weak magnitude for liver ECV quantification at the equilibrium phase (r=0.25 and r=0.20, respectively). The correlations between liver function index and ECV quantification were more robust than with fibrosis index. The highest correlations (r=0.50) were found between ALBI grade and liver ECV at the equilibrium phase. Liver ECV values at the equilibrium phase had a significant difference between ALBI grade 1 vs. 2 and grade 1 vs. 3. CONCLUSION: Liver ECV quantification by DECT is more suitable for evaluating liver function than liver fibrosis severity.

Management of Arteriovenous Graft Infection.

Objective: Arteriovenous graft (AVG) infection influences the survival and quality of life of patients, causing life-threatening sepsis reducing dialysis access. This study aimed to evaluate an appropriate treatment strategy for AVG infection. Methods: We analyzed 61 cases involving AVG infections identified at a single center. The cases were divided into two groups based on the type of AVG and surgical methods, namely, currently used AVG (cAVG) (n=29) or abandoned AVG (aAVG) (n=32) and total graft excision (TGE) (n=10) or partial graft excision (PGE) (n=46). Results: There was a significant difference in lower procedure frequency (p<0.001) and longer procedure time (p=0.014) in the cAVG group. A significant difference in lower reinfection rate (p=0.009) was found in the TGE group. Multivariable analysis confirmed that aAVG significantly independently affected the reinfection rate (hazard ratio, 2.208; 95% confidence interval, 1.069-4.561; p=0.032). Staphylococcus aureus was the most frequent cause of AVG infection (61.5%); 77.5% of Staphylococcus aureus were methicillin-resistant Staphylococcus aureus. Conclusion: We found a higher risk of reinfection after PGE than TGE, and aAVG infection was associated with approximately two times higher likelihood of reinfection. These findings suggest that TGE should be considered for patients with AVG infections, particularly aAVG infections.

Artificial intelligence analysis of three-dimensional imaging data derives factors associated with postoperative recurrence in patients with radiologically solid-predominant small-sized lung cancers.

OBJECTIVES: Indications of limited resection, such as segmentectomy, have recently been reported for patients with solid-predominant lung cancers ≤2 cm. This study aims to identify unfavourable prognostic factors using three-dimensional imaging analysis with artificial intelligence (AI) technology. METHODS: A total of 157 patients who had clinical N0 non-small cell lung cancer with a radiological size ≤2 cm, and a consolidation tumour ratio > 0.5, who underwent anatomical lung resection between 2011 and 2017 were enrolled. To evaluate the three-dimensional structure, the ground-glass nodule/Solid Automatic Identification AI software Beta Version (AI software; Fujifilm Corporation, Japan) was used. RESULTS: Maximum standardized uptake value (SUVmax) and solid-part volume measured by AI software (AI-SV) showed significant differences between the 139 patients with adenocarcinoma and the 18 patients with non-adenocarcinoma. Among the adenocarcinoma patients, 42 patients (30.2%) were found to be pathological upstaging. Multivariable analysis demonstrated that high SUVmax, high carcinoembryonic antigen level and high AI-SV were significant prognostic factors for recurrence-free survival (RFS; P < 0.05). The 5-year RFS was compared between patients with tumours showing high SUVmax and those showing low SUVmax (67.7% vs 95.4%, respectively, P < 0.001). The 5-year RFS was 91.0% in patients with small AI-SV and 68.1% in those with high AI-SV (P = 0.001). CONCLUSIONS: High AI-SV, high SUVmax and abnormal carcinoembryonic antigen level were unfavourable prognostic factors of patients with solid-predominant lung adenocarcinoma with a radiological size ≤2 cm. Our results suggest that lobectomy should be preferred to segmentectomy for patients with these prognostic factors.

Perilesional Lymph Node Swelling Might be a Radiologic Clue for Appendiceal Schwannoma: A Case Report.

BACKGROUND: Gastrointestinal schwannoma is not a common type of tumor, and lesions originating from the appendix are extremely rare. Herein, we report a patient with appendiceal schwannoma characterized by lymph node swelling. CASE REPORT: A 67-year-old male patient who had diabetes complained of weight loss. A computed tomography scan revealed a mass in the right side of the pelvic cavity. Moreover, a contrast-enhanced computed tomography scan showed perilesional lymph node swelling measuring up to 28 mm. A low-intensity mass was observed on T1-weighted imaging, heterogeneous high-intensity mass on T2-weighted imaging, and restricted diffusion on diffusion-weighted imaging. There were no abnormal findings on colonoscopy. Based on a preoperative examination, a differential diagnosis of either appendiceal schwannoma, carcinoid, or gastrointestinal stromal tumor was considered. During surgery, a large appendiceal mass and multiple swollen perilesional lymph nodes were observed. Therefore, ileocecal resection and D3 lymph node dissection were performed. Pathological and immunohistochemical analyses confirmed the diagnosis of appendiceal schwannoma. There were numerous swollen lymph nodes in the mesenteric region. The lymph nodes revealed reactive lymphoid hyperplasia, with enlarged follicles of various sizes and shapes with an irregular distribution. Almost all lymphocytes, except those at the germinal centers, were small. CONCLUSION: Gastrointestinal schwannoma is characterized by lymph node swelling. Appendiceal schwannoma may have characteristics, including peritumoral lymph node swelling, similar to other types of gastrointestinal schwannoma such as that in the stomach. Thus, this characteristic can be a diagnostic clue for appendiceal schwannoma.

Transcirculation microballoon-assisted coil embolization for dorsal pancreatic artery aneurysm due to celiac artery dissection: A case report.

The dorsal pancreatic artery is a part of peripancreatic arcade connecting celiac artery to transpancreatic artery. A dorsal pancreatic artery aneurysm derived from dissection of celiac artery is a rare pathology, and it sometimes requires ingenious strategy in an endovascular surgery. Hereby, we report a case of a patient who underwent coil embolization for dorsal pancreatic artery aneurysm due to celiac artery dissection by applying transcirculation approach of a balloon catheter through the peripancreatic arcade, which was successfully achieved.

Evaluation of the relationship between the range of radiation-induced lung injury on CT images after IMRT for stage I lung cancer and dosimetric parameters.

BACKGROUND: This study evaluated the correlation between radiation-induced lung injury (RILI) and dosimetric parameters on computed tomography (CT) images of stage I non-small cell lung cancer (NSCLC) patients undergoing intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Sixty-three stage I NSLC patients who underwent IMRT were enrolled in the study. The patients underwent CT within 6 months (acute phase) and 1.5 years (late phase) after radiotherapy. These were fused with the planned irradiation CT. The range of RILI was measured from 10% to 100%, with an IC in 10% increments. RESULTS: The median interval from completion of radiotherapy to acute and late phase CT was 92 and 440 days, respectively. The median RILI ranges of the acute and late phases were in the 80% (20-100%) and 70% dose regions (20-100%), respectively. The significantly narrower range of RILI when lung V20 in the acute phase was less than 19.2% and that of V5 in the late phase was less than 27.6% at the time of treatment planning. CONCLUSIONS: This study showed that RILI occurred in a localized range in stage I NSCLC patients who underwent IMRT. The range of RILI was correlated with V20 in the acute phase and V5 in the late phase. KEY MESSAGES RILI correlated with V20 in acute and V5 in late phase. The shadow of RILI occurred in 80% dose region in acute and 70% in late phase. No relationship exists between radiographic changes in RILI and PTV volume.

Impact of Glucose Uptake of Noncancerous Lung Area in Respiratory Events for Lung Cancer Patients.

BACKGROUND: Postoperative severe respiratory adverse events (SRAEs) are the major cause of perioperative morbidity in patients after thoracic surgery. In particular, SRAEs often occur in lung cancer patients concomitant with chronic inflammatory lung diseases (CILDs) such as interstitial lung disease, emphysema, infectious disease, and asthma. We aimed to clarify whether the measurement of the maximum of standardized uptake value in the noncancerous lung area (NCA-SUVmax) and CILDs on high-resolution computed tomography were useful for predicting the risk of SRAEs. METHODS: A total of 984 patients with lung cancer undergoing preoperative computed tomography, F-18 fluorodeoxyglucose-positron emission tomography/computed tomography followed by surgery between July 2012 and March 2019 were assessed. NCA-SUVmax was measured using a 3-dimensional workstation. We extracted the records of patients with CILDs and their disease history. Predictive factors associated with SRAEs were identified. RESULTS: SRAEs were observed in 75 patients (7.6%), and 7 patients (9.3%) died of SRAEs within 90 days after surgery. NCA-SUVmax in patients with CILDs (n = 325; emphysema = 161, interstitial lung disease = 134, infectious disease = 17, asthma = 13) were higher than that in patients without CILDs (n = 659; 1.3 ± 0.7 vs 1.1 ± 0.4, respectively; P < .001). On multivariate analysis, CILDs, percent vital capacity, and NCA-SUVmax were independently associated with SRAEs (P < .001). Rate of SRAEs in patients with CILDs, NCA-SUVmax ≥1.3, and percent vital capacity ≤ 110 was 31.8%. CONCLUSIONS: NCA-SUVmax was independently associated with the incidence of SRAEs in patients with resected lung cancer and was significantly increased in patients with CILDs.

A case of a patient who underwent transcatheter arterial embolization for unruptured splenic aneurysm during pregnancy.

Here, we report the case of a 30-year-old female patient who underwent coil embolization for unruptured splenic artery aneurysm without any complication at 26 weeks of pregnancy with reduction in fetal radiation exposure. The patient did not suffer from rupture of splenic artery aneurysm during or after procedure. Pregnancy is a risk factor of splenic artery aneurysm rupture with a high mortality rate. Transcatheter arterial embolization at 26 weeks of pregnancy might be a better treatment alternative for a pregnant patient with splenic artery aneurysm with respect to the endurance of fetal radiation exposure to prevent aneurysm rupture.

Profiles of Lung Adenocarcinoma With Multiple Ground-Glass Opacities and the Fate of Residual Lesions.

BACKGROUND: We aimed to clarify clinical profiles of patients with adenocarcinoma presenting as multifocal ground-glass opacities (MGGOs) to assess their prognosis and the optimal management method for residual satellite lesions. METHODS: We identified 190 patients with cN0 MGGOs (MGGO cohort) and 1426 patients with solitary lung adenocarcinoma (control cohort) who underwent complete resection between 2004 and 2016. Propensity score matching was performed to adjust for differences in baseline characteristics of both cohorts for survival analyses. MGGOs consist of a main tumor and satellite lesions and were subdivided into 3 groups: the PG group, with multifocal pure GGOs; the GD group, in which the main tumor presented as GGO dominant; and the SD group, where the main tumor presented as solid dominant. RESULTS: No significant differences in recurrence-free survival were observed between the 2 cohorts before and after the propensity score matching. For patients with MGGOs, 22 were in the PG group, 47 in the GD group, and 121 in the SD group. Type of MGGOs was a significant factor for recurrence-free survival recurrence-free survival both in the entire population (SD vs PG-GD, P = .008) and in p-stage I cohorts (P = .004) on multivariable analysis. Among 116 patients (61.1%) with residual satellite lesions, 38 patients had progressed lesions and 69 stable lesions. Although the emergence of new lesions during the follow-up period was an independent predictor for satellite lesion progression, neither progressed lesions nor the emergence of new lesions influenced survival. CONCLUSIONS: Patients with MGGOs and solitary adenocarcinoma had a similar prognosis. The biologic behavior of main tumors dominates clinical outcomes in patients with MGGOs.

Prognostic impact of solid-part tumour volume doubling time in patients with radiological part-solid or solid lung cancer.

OBJECTIVES: The measurement of part-solid and whole tumour sizes in patients with non-small-cell lung cancer (NSCLC) using computed tomography (CT) has been widely accepted for assessing clinical outcomes. Although the volume doubling time (VDT) of a tumour is useful for distinguishing high-risk nodules from low-risk ones, it remains to be clarified whether separate calculation of whole-tumour VDT and solid-part tumour VDT (SVDT) greatly affects the survival rate of patients with radiologically node-negative part-solid or solid NSCLC. METHODS: The study included 258 patients with NSCLC who had radiologically node-negative, part-solid or solid tumours and who had at least 2 preoperative CT scans taken more than 30 days apart followed by radical lobectomy and systemic lymph node dissection between January 2012 and December 2015. Univariable and multivariable analyses of recurrence-free survival were performed using the Cox proportional hazards regression model. RESULTS: The mean whole-tumour VDT and SVDT were 375 and 458 days, respectively. Multivariable analyses demonstrated that whole-tumour VDT (P = 0.003), SVDT (P < 0.001), solid-part tumour size, whole-tumour size and comorbidities significantly affected the recurrence-free survival. Using the receiver operating characteristic curve, the cut-off value of the SVDT for recurrence was 215 days, and the 5-year recurrence-free survival rates for patients with SVDT >215 days and those with SVDT <215 days were 85.7% and 43.0%, respectively (P < 0.001). CONCLUSION: The calculation of SVDT in patients with node-negative, part-solid or solid NSCLC is highly useful for predicting postoperative survival outcomes.

Preparation of a Series of Photoresponsive Polymersomes Bearing Photocleavable a 2-nitrobenzyl Group at the Hydrophobic/Hydrophilic Interfaces and Their Payload Releasing Behaviors.

In this study, the structure-function relationships of a series of polymersomes composed of well-defined amphiphilic diblock copolymers were investigated. The building blocks were synthesized by clicking hydrophobic polymers, synthesized beforehand, and commercially available poly(ethylene glycol) with photocleavable 2-nitrobenzyl compounds bearing alkyne and maleimide functionalities. All of the tested polymersomes preserved their hollow structures even after sufficient photoirradiation. Nevertheless, the release rate of an entrapped anionic fluorophore was highly dependent on the molecular weight and the type of hydrophobic polymer, as well as on the presence or absence of the charged end groups. Moreover, the polymersomes with a 2-nitrosobenzyl photolysis residue within the hydrophobic shells exhibited photo-induced payload release after complete photolysis. It was concluded that the payload release was mediated by photo-induced permeability changes of the hydrophobic shells rather than the decomposition of their overall structures.

Computed Tomography Histogram Approach to Predict Lymph Node Metastasis in Patients With Clinical Stage IA Lung Cancer.

BACKGROUND: Quantitative computed tomography (CT) histogram analysis of tumors is reported to help distinguish between invasive and less invasive lung cancers. This study aimed to clarify whether CT histogram analysis of tumors can be used to classify patients with clinical stage 0 to IA non-small cell lung cancer according to pathologic lymph node (pN) status. METHODS: Predictive factors associated with pN metastasis were identified from the derivation dataset including 629 patients with clinical stage 0 to IA non-small cell lung cancer who underwent complete resection with lymph node dissection (surgeries between 2008 and 2013). The validation dataset including 238 patients (surgeries between 2014 and 2015) were subsequently reevaluated. Clinicosurgical factors, including CT histogram analysis of tumors (CT value percentiles 2.5, 25, 50, 75, and 97.5, skewness, and kurtosis) were assessed. RESULTS: Seventy-three patients (12%) in the derivation cohort and 35 patients (15%) in the validation cohort had positive nodes. The pN status significantly affected survival in the entire population: 5-year overall survival of 93.1% vs 71.1% and 5-year disease-free survival of 85.9% vs 43.1% for negative vs positive (both P < .001). On multivariate analysis in the derivation cohort, the 75th percentile CT value (P < .001), age (P = .003), and comorbidities (P = .006) were significantly associated with pN metastasis. The area under the curve and the cutoff level of the 75th percentile CT value relevant to pN metastasis were 0.729 and 1.5 HU, respectively, and the threshold value provided accuracy of 71% for the validation cohort. CONCLUSIONS: Histogram analysis of CT imaging metrics of tumors contributes to noninvasive prediction of pN metastasis in patients with clinical stage 0 to IA non-small cell lung cancer.

Is severe emphysema, as defined by quantitative CT measurement, a negative risk factor of radiation fibrosis?

OBJECTIVE: To investigate whether patients with emphysema, as evaluated by quantitative CT image measurement, are at risk of developing radiation pneumonitis (RP) after radiotherapy (RT) for non-small cell lung cancer (NSCLC). METHODS: Between March 2011 and June 2015, 68 consecutive patients with Stage I NSCLC treated with a RT dose of 75 Gy given in 30 fractions were enrolled. The median age was 79 years and there were 45 males and 23 females. The number of patients with T1 and T2 were 49 and 19, respectively. The severity of emphysema was evaluated by the percentages of the low attenuation area (LAA) of ≤-860 or -950 Hounsfield unit (HU) and average HU in the whole lung. RESULTS: The mean difference percentages of LAA of ≤-860 (p = 0.0004) or -950 HU (p = 0.005) and average HU (p = 0.001) in patients with RP were significantly lower than those in patients without RP. The area under curve (AUC) of average HU was significantly higher than AUC of LAA of ≤-860 (p < 0.0001) or -950 HU (p < 0.0001). The RP rate after RT was significantly lower when the average HU values were ≤-850 HU (p = 0.0003). CONCLUSION: Patients with emphysema evaluated by average HU (≤-850 HU) in the whole lung were found to be at low risk of RP after RT. Advances in Knowledge: Quantitative measurement of average HU from CT images was predicted of RP after RT.