Prognostic Significance of CONUT Score in Elderly NSCLC.

PURPOSE: This study evaluated the Controlling Nutritional Status (CONUT) score as a prognostic predictor in elderly non-small cell lung cancer (NSCLC) patients with surgical resection. METHODS: Overall, 114 patients over 80 years old undergoing curative resection for NSCLC were retrospectively analyzed. Receiver operating characteristic (ROC) analysis was conducted to evaluate the capacity of immune-inflammatory markers to predict overall survival (OS). Cox-proportional hazards regression analysis was implemented to investigate prognostic markers for OS. RESULTS: Based on ROC curves, the CONUT score was found to be the most valuable prognostic marker (area under the curve = 0.716). The high CONUT (≥2) group included 54 patients, and the low CONUT (0 or 1) group included 60 patients. The high CONUT group had poorer prognosis rates compared to the low CONUT group with regard to OS (5-year OS: 46.3% vs. 86.0%, p = 0.0006). In the multivariate data analysis, histology, lymphatic invasion, and CONUT score (hazard ratio: 4.23, p = 0.0003) were found to be exclusive and independent prognostic markers for OS. CONCLUSION: Preoperatively, the CONUT score can be used as a novel prognostic marker in elderly NSCLC patients. CONUT evaluations can also be used to design nutritional interventions to improve patient outcomes.

A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real- Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate Cancer.

Purpose: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer. Methods and Materials: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE. Results: Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%). Conclusions: The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies.

Mean computed tomography value to predict spread through air spaces in clinical N0 lung adenocarcinoma.

BACKGROUND: The aim of this study was to assess the ability of radiologic factors such as mean computed tomography (mCT) value, consolidation/tumor ratio (C/T ratio), solid tumor size, and the maximum standardized uptake (SUVmax) value by F-18 fluorodeoxyglucose positron emission tomography to predict the presence of spread through air spaces (STAS) of lung adenocarcinoma. METHODS: A retrospective study was conducted on 118 patients those diagnosed with clinically without lymph node metastasis and having a pathological diagnosis of adenocarcinoma after undergoing surgery. Receiver operating characteristics (ROC) analysis was used to assess the ability to use mCT value, C/T ratio, tumor size, and SUVmax value to predict STAS. Univariate and multiple logistic regression analyses were performed to determine the independent variables for the prediction of STAS. RESULTS: Forty-one lesions (34.7%) were positive for STAS and 77 lesions were negative for STAS. The STAS positive group was strongly associated with a high mCT value, high C/T ratio, large solid tumor size, large tumor size and high SUVmax value. The mCT values were - 324.9 ± 19.3 HU for STAS negative group and - 173.0 ± 26.3 HU for STAS positive group (p < 0.0001). The ROC area under the curve of the mCT value was the highest (0.738), followed by SUVmax value (0.720), C/T ratio (0.665), solid tumor size (0.649). Multiple logistic regression analyses using the preoperatively determined variables revealed that mCT value (p = 0.015) was independent predictive factors of predicting STAS. The maximum sensitivity and specificity were obtained at a cutoff value of - 251.8 HU. CONCLUSIONS: The evaluation of mCT value has a possibility to predict STAS and may potentially contribute to the selection of suitable treatment strategies.

A new predictive parameter for dose-volume metrics in intensity-modulated radiation therapy planning for prostate cancer: Initial phantom study.

BACKGROUND: Organ-at-risk (OAR) sparing is often assessed using an overlap volume-based parameter, defined as the ratio of the volume of OAR that overlaps the planning target volume (PTV) to the whole OAR volume. However, this conventional overlap-based predictive parameter (COPP) does not consider the volume relationship between the PTV and OAR. PURPOSE: We propose a new overlap-based predictive parameter that consider the PTV volume. The effectiveness of proposed overlap-based predictive parameter (POPP) is evaluated compared with COPP. METHODS: We defined as POPP = (overlap volume between OAR and PTV/OAR volume) × (PTV volume/OAR volume). We generated intensity modulated radiation therapy (IMRT) based on step and shoot technique, and volumetric modulated arc therapy (VMAT) plans with the Auto-Planning module of Pinnacle3 treatment planning system (v14.0, Philips Medical Systems, Fitchburg, WI) using the American Association of Physicists in Medicine Task Group (TG119) prostate phantom. The relationship between the position and size of the prostate phantom was systematically modified to simulate various geometric arrangements. The correlation between overlap-based predictive parameters (COPP and POPP) and dose-volume metrics (mean dose, V70Gy, V60Gy, and V37.5 Gy for rectum and bladder) was investigated using linear regression analysis. RESULTS: Our results indicated POPP was better than COPP in predicting intermediate-dose metrics. The bladder results showed a trend similar to that of the rectum. The correlation coefficient of POPP was significantly greater than that of COPP in < 62 Gy (82% of the prescribed dose) region for IMRT and in < 55 Gy (73% of the prescribed dose) region for VMAT regarding the rectum (p < 0.05). CONCLUSIONS: POPP is superior to COPP for creating predictive models at an intermediate-dose level. Because rectal bleeding and bladder toxicity can be associated with intermediate-doses as well as high-doses, it is important to predict dose-volume metrics for various dose levels. POPP is a useful parameter for predicting dose-volume metrics and assisting the generation of treatment plans.

[Indocyanine Green Fluorescence Intraoperative Imaging for Fistula Identification of Pleuroperitoneal Communication by Continuous Ambulatory Peritoneal Dialysis:Report of a Case].

A 64-year-old female with chronic renal failure had been receiving continuous ambulatory peritoneal dialysis (CAPD). She developed acute hydrothorax in the right pleural cavity 1 year after the commencement of CAPD. Scintigraphy revealed a diagnosis of pleuroperitoneal communication, and we performed video-assisted thoracoscopic surgery. We infused a dialysis solution containing indocyanine green (ICG) through CAPD catheter. Near-infrared fluorescence thoracoscopy revealed a fistula that could not be identified by white light. We sutured the fistula covered with a polyglycolic acid sheet and fibrin glue. The CAPD was able to be resumed 8 days after surgery, and there was no recurrence of pleural effusion 10 months since surgery. Identification of the diaphragmatic fistula is important in the treatment of pleuroperitoneal communication. This technique using near-infrared fluorescence thoracoscopy with ICG was useful in identifying the fistula, and it emitted sufficient fluorescence even at low concentration ICG.

Gastric and Bone Metastases Arising from Invasive Lobular Carcinoma With Ductal Carcinoma Occurring in one Breast Synchronously.

BACKGROUND/AIM: We report the case of a patient with gastric and bone metastases arising from an invasive lobular carcinoma of the breast coexisting with ductal carcinoma at the same time. CASE REPORT: A 68-year-old woman with gastric and right costal tumors was referred to our hospital. Esophagogastroduodenoscopy (EGD) revealed irregular, slightly elevated lesions extending from the gastric body to the antrum, and biopsy specimens revealed a poorly differentiated adenocarcinoma. Furthermore, abdominal contrast-enhanced computed tomography (CT) revealed extensive wall thickening with homogeneous enhancement in the stomach. 18F-2-deoxy-2-fluoro-glucose positron emission tomography (FDG-PET) showed intense FDG uptake in the right mammary gland and right third rib. Moreover, fine-needle aspiration of the third right rib lump and the right breast mass lesion was performed, and subsequent pathological investigations revealed metastatic adenocarcinoma and invasive ductal carcinoma, respectively. Immunohistochemical examination revealed that estrogen receptor was strongly positive (>95%) in breast cancer and focally positive (<5%) in gastric cancer with bone metastasis. In addition, another right breast tumor was detected by breast magnetic resonance imaging (MRI), and biopsy revealed invasive lobular carcinoma that matched the histological findings of bone and gastric lesions, including immunohistochemical examination. The patient was treated with an aromatase inhibitor, a CDK4/6 inhibitor, and a receptor activator of nuclear factor-kappa B ligand (RANKL) monoclonal antibody. She showed no symptoms or disease progression at 9-month follow-up after the initiation of systemic drug treatment. CONCLUSION: Invasive lobular carcinoma can metastasize to the gastrointestinal tract, and new treatment developments are expected as more cases will accumulate in the future.

Combined treatment with beaded EWS, Gore-tex patch and N-butyl-2-cyanoacrylate for bronchial fistula: The novel "sandwich method".

An 84-year-old man underwent right basal segmentectomy for primary lung cancer and developed empyema accompanied by a bronchopleural fistula (BPF). Emergency open-window thoracotomy was performed. Although the general and nutritional conditions improved, the fistula did not close naturally, and we planned to close it 6 months after surgery. In this report, we describe, for the first time, a novel method for closing BPF using an endobronchial Watanabe spigot (EWS), polyglycolic acid (PGA) sheet and N-butyl-2-cyanoacrylate (NBCA). We named this method the"sandwich method."

Predicting the pathological invasiveness of early lung adenocarcinoma prior to surgery using Deauville criteria: reliability and validity.

PURPOSE: This retrospective study aimed to investigate the validity and reliability of FDG-PET/CT visual assessment using Deauville criteria to predict pathological invasiveness of early lung adenocarcinoma prior to surgery. MATERIALS AND METHODS: Between April 2020 and January 2022, 51 patients who underwent surgery for pathological stage 0/I lung adenocarcinoma were enrolled. The pulmonary lesions were divided into two groups according to pathological invasiveness: less invasive (including adenocarcinoma in situ and minimally invasive adenocarcinoma and invasive adenocarcinoma. We compared CT size (total and solid size), SUVmax, and Deauville score between the two groups. Furthermore, we investigated inter-rater and intra-rater agreements regarding the Deauville score. Receiver operating characteristic (ROC) curve analysis was performed to identify the diagnostic performance of each method. RESULTS: Based on pathologic diagnoses, 51 lesions in the 51 patients were divided into 6 less invasive and 45 invasive adenocarcinoma lesions. According to quadratic-weighted Kappa statistics, inter-rater (k = 0.93) and intra-rater (k = 0.97) agreements among all five components of the Deauville score indicated high agreement. There was a statistically significant difference in CT solid size, SUVmax, and Deauville score between the two groups. There were no significant differences between CT solid size and FDG-PET/CT assessments (AUC = 0.93 for Deauville score and SUVmax, AUC = 0.84 for CT solid size). CONCLUSION: FDG-PET/CT visual assessment using the Deauville score could assist in deciding upon minimally invasive surgery for early lung adenocarcinoma.

[Surgical Treatment to Castleman's Disease after Embolization of Feeding Vessels].

A 48-year-old woman with an abnormal shadow on chest X-ray was referred to our institution. Contrast-enhanced chest computed tomography( CT) showed a large mass, 4.4 cm in diameter, in the right upper mediastinum. Castleman's disease was suspected, and several vessels flowing into the tumor were identified. Since severe intraoperative bleeding was expected, preoperative embolization of the feeding vessels was performed, followed by thoracotomy and tumor extirpation. The amount of blood loss was 50 ml. The pathological diagnosis was Castleman's disease, hyaline vascular type.

Hyperfractionated intensity-modulated proton therapy for pharyngeal cancer with variable relative biological effectiveness: A simulation study.

BACKGROUND: The relative biological effectiveness (RBE) of proton is considered to be dependent on biological parameters and fractional dose. While hyperfractionated photon therapy was effective in the treatment of patients with head and neck cancers, its effect in intensity-modulated proton therapy (IMPT) under the variable RBE has not been investigated in detail. PURPOSE: To study the effect of variable RBE on hyperfractionated IMPT for the treatment of pharyngeal cancer. We investigated the biologically effective dose (BED) to determine the theoretical effective hyperfractionated schedule. METHODS: The treatment plans of three pharyngeal cancer patients were used to define the ΔBED for the clinical target volume (CTV) and soft tissue (acute and late reaction) as the difference between the BED for the altered schedule with variable RBE and conventional schedule with constant RBE. The ΔBED with several combinations of parameters (treatment days, number of fractions, and prescribed dose) was comprehensively calculated. Of the candidate schedules, the one that commonly gave a higher ΔBED for CTV was selected as the resultant schedule. The BED volume histogram was used to compare the influence of variable RBE and fractionation. RESULTS: In the conventional schedule, compared with the constant RBE, the variable RBE resulted in a mean 2.6 and 2.7 Gy reduction of BEDmean for the CTV and soft tissue (acute reaction) of the three plans, respectively. Moreover, the BEDmean for soft tissue (late reaction) increased by 7.4 Gy, indicating a potential risk of increased RBE. Comprehensive calculation of the ΔBED resulted in the hyperfractionated schedule of 80.52 Gy (RBE = 1.1)/66 fractions in 6.5 weeks. When variable RBE was used, compared with the conventional schedule, the hyperfractionated schedule increased the BEDmean for CTV by 7.6 Gy; however, this was associated with a 7.8 Gy increase for soft tissue (acute reaction). The BEDmean for soft tissue (late reaction) decreased by 2.4 Gy. CONCLUSION: The results indicated a potential effect of the variable RBE on IMPT for pharyngeal cancer but with the possibility that hyperfractionation could outweigh this effect. Although biological uncertainties require conservative use of the resultant schedule, hyperfractionation is expected to be an effective strategy in IMPT for pharyngeal cancer.

18F FDG-PET/CT analysis of spread through air spaces (STAS) in clinical stage I lung adenocarcinoma.

OBJECTIVE: The purpose of this retrospective study was to investigate the utility of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F FDG-PET/CT) to predict spread through air spaces (STAS) in clinical stage I lung adenocarcinoma. METHODS: Between April 2020 and January 2022, 52 patients (55 lesions) who underwent surgery for clinical stage I lung adenocarcinoma were enrolled. The lesions were divided into two groups according to the presence of STAS. 18F FDG-PET/CT parameters, specifically the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were calculated. The SUVmax, MTV, and TLG were compared between the two groups upon surgical pathological examination. Receiver operating characteristic (ROC) curve analysis was performed to identify a cut-off value. RESULTS: Nineteen lesions (35%) were positive for STAS and 36 lesions were negative for STAS. According to the presence of STAS, significant differences were detected in the SUVmax (5.21 [range 1.52-16.50] vs. 2.42 [range 0.74-11.80], p = 0.0040) but not MTV (3.44 [range 0.65-24.36] vs. 2.95 [0.00-20.07], p = 0.20) and TLG (7.92 [range 0.93-47.82] vs. 5.63 [0.00-58.66], p = 0.14). SUVmax had an AUC value of 0.74 (95% CI 0.61-0.87) with a sensitivity of 89.5% and specificity of 52.8% at a cut-off of 2.48. CONCLUSIONS: SUVmax rather than MTV and TLG were shown to be valuable indices for the prediction of STAS in clinical stage I lung adenocarcinoma.

A study on predicting cases that would benefit from proton beam therapy in primary liver tumors of less than or equal to 5 cm based on the estimated incidence of hepatic toxicity.

Background: For small primary liver tumors, favorable outcomes have been reported with both of proton beam therapy (PBT) and X-ray therapy (XRT). However, no clear criteria have been proposed in the cases for which and when of PBT or XRT has to be used. The aim of this study is to investigate cases that would benefit from PBT based on the predicted rate of hepatic toxicity. Materials and methods: Eligible patients were those who underwent PBT for primary liver tumors with a maximum diameter of ≤ 5 cm and Child-Pugh grade A (n = 40). To compare the PBT-plan, the treatment plan using volumetric modulated arc therapy was generated as the XRT-plan. The rate of predicted hepatic toxicity was estimated using five normal tissue complication probability (NTCP) models with three different endpoints. The differences in NTCP values (ΔNTCP) were calculated to determine the relative advantage of PBT. Factors predicting benefits of PBT were analyzed by logistic regression analysis. Results: From the dose-volume histogram comparisons, an advantage of PBT was found in sparing of the normal liver receiving low doses. The factors predicting the benefit of PBT differed depending on the selected NTCP model. From the five models, the total tumor diameter (sum of the target tumors), location (hepatic hilum vs other), and number of tumors (1 vs 2) were significant factors. Conclusions: From the radiation-related hepatic toxicity, factors were identified to predict benefits of PBT in primary liver tumors with Child-Pugh grade A, with the maximum tumor diameter of ≤ 5 cm.

Quantitative analysis of changes in lung density by dynamic chest radiography in association with CT values: a virtual imaging study and initial clinical corroboration.

Dynamic chest radiography (DCR) identifies pulmonary impairments as decreased changes in radiographic lung density during respiration (Δpixel values), but not as scaled/standardized computed tomography (CT) values. Quantitative analysis correlated with CT values is beneficial for a better understanding of Δpixel values in DCR-based assessment of pulmonary function. The present study aimed to correlate Δpixel values from DCR with changes in CT values during respiration (ΔCT values) through a computer-based phantom study. A total of 20 four-dimensional computational phantoms during forced breathing were created to simulate both CT and projection images of the same virtual patients. The Δpixel and ΔCT values of the lung fields were correlated on a regression line, and the inclination was statistically evaluated to determine whether there were significant differences among physical types, sex, and breathing methods. The resulting conversion expression was also assessed in the DCR images of 37 patients. The resulting Δpixel values for 30/37 (81%) real patients, 6/7 (86%) normal controls, and 24/30 (80%) chronic obstructive pulmonary disorder patients were within the range of ΔCT values ± standard deviation (SD) reported in a previous study. In addition, no significant differences were detected for each condition of thoracic breathing, suggesting that the same regression line inclination values measured across the entire lung can be used for the conversion of Δpixel values, providing a quantitative analysis that can be correlated with ΔCT values. The developed conversion expression may be helpful for improving the understanding of respiratory changes using radiographic lung densities from DCR-based assessments of pulmonary function.

[Paradigm Shift in Respiratory Diagnosis: Current Status and Future Prospects of Dynamic Chest Radiography].

Dynamic chest radiography (DCR) is a flat-panel detector (FPD) -based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view of FPDs permits real-time observation of motion/kinetic findings on the entire lungs, right and left diaphragm, ribs, and chest wall; heart wall motions; respiratory changes in lung density; and diameter of the intrathoracic trachea. Since the dynamic FPDs had been developed in the early 2000s, we focused on the potential of dynamic FPDs for functional X-ray imaging and have launched a research project for the development of an imaging protocol and digital image-processing techniques for the DCR. The quantitative analysis of motion/kinetic findings is helpful for a better understanding of pulmonary function, because the interpretation of dynamic chest radiographs is challenging and time-consuming for radiologists, pulmonologists, and surgeons. Recent clinical studies have demonstrated the usefulness of DCR combined with the digital image processing techniques for the evaluation of pulmonary function and circulation. Especially, there is a major concern in color-mapping images based on dynamic changes in radiographic lung density, where pulmonary impairments can be detected as color defects, even without the use of contrast media or radioactive medicine. Dynamic chest radiography is now commercially available for the use in general X-ray room and therefore can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. This review article describes the current status and future prospects of DCR, which might bring a paradigm shift in respiratory diagnosis.

A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer.

BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated proton therapy (US-IMPT) plan with that of conventional clinical plans without urethral dose reduction. MATERIALS AND METHODS: This study included 13 patients who had undergone proton beam therapy. The prescribed dose was 63 GyE in 21 fractions for 99% of the clinical target volume. To compare the clinical impact of the US-IMPT plan with that of the conventional clinical plan, tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with a generalized equivalent uniform dose-based Lyman-Kutcher model using dose volume histograms. The endpoints of these model parameters for the rectum, bladder, and urethra were fistula, contraction, and urethral stricture, respectively. RESULTS: The mean NTCP value for the urethra in US-IMPT was significantly lower than that in the conventional clinical plan (0.6% vs. 1.2%, p < 0.05). There were no statistically significant differences between the conventional and US-IMPT plans regarding the mean minimum dose for the urethra with a 3-mm margin, TCP value, and NTCP value for the rectum and bladder. Additionally, the target dose coverage of all plans in the robustness analysis was within the clinically acceptable range. CONCLUSIONS: Compared with the conventional clinically applied plans, US-IMPT plans have potential clinical advantages and may reduce the risk of genitourinary toxicities, while maintaining the same TCP and NTCP in the rectum and bladder.

Dynamic chest radiography: clinical validation of ventilation and perfusion metrics derived from changes in radiographic lung density compared to nuclear medicine imaging.

BACKGROUND: Dynamic chest radiography (DCR) is a type of non-contrast-enhanced functional lung imaging with a dynamic flat-panel detector (FPD). This study aimed to assess the clinical significance of ventilation and perfusion metrics derived from changes in radiographic lung density on DCR in comparison to nuclear medicine imaging-derived metrics. METHODS: DCR images of 42 lung cancer patients were sequentially obtained during respiration using a dynamic FPD imaging system. For each subdivided lung region, the maximum change in the averaged pixel value (Δmax), i.e., lung density, due to respiration and cardiac function was calculated, and the percentage of Δmax relative to the total of all lung regions (Δmax%) was computed for ventilation and perfusion, respectively. The Δmax% was compared to the accumulation of radioactive agents such as Tc-99m gas and Tc-99m macro-aggregated albumin (radioactive agents%) on ventilation and perfusion scans in the subdivided lung regions, by Spearman's correlation coefficient (r) and the Dice similarity coefficients (DSC). To facilitate visual evaluation, Δmax% was visualized as a color scaling, where larger Δmax values were indicated by higher color intensities. RESULTS: We found a moderate correlation between Δmax% and radioactive agents% on ventilation and perfusion scans, with perfusion metrics (r=0.57, P<0.001) showing a higher correlation than ventilation metrics (r=0.53, P<0.001). We also found a good or strong correlation (r≥0.5) in 80.9% (34/42) of patients for perfusion metrics (r=0.60±0.16) and in 52.4% (22/42) of patients for ventilation metrics (r=0.53±0.16). DSC indicated a moderate correlation for both metrics. Decreased pulmonary function was observed in the form of reduced color intensities on color-mapping images. CONCLUSIONS: DCR-derived ventilation and perfusion metrics correlated reasonably well with nuclear medicine imaging findings in lung subdivisions, suggesting that DCR could provide useful information on pulmonary function without the use of radioactive contrast agents.

Chest Dynamic-Ventilatory Digital Radiography in Chronic Obstructive or Restrictive Lung Disease.

OBJECTIVE: The aim of this study was to identify the relationships between parameters obtained from dynamic-ventilatory digital radiography (DR) and ventilatory disorders. METHODS: This study comprised 273 participants with respiratory diseases who underwent spirometry and functional residual capacity measurements (104 with normal findings on spirometry as controls, 139 with an obstructive lung disorder, 30 with a restrictive lung disorder) were assessed by dynamic-ventilatory DR. Sequential chest radiography images of the patient's slow and maximum breathing were captured at 15 frames per second by a dynamic flat-panel imaging system. The system measured the following parameters: lung area at maximum inspiration divided by height (lung area_in/height), changes in tracheal diameter due to respiratory motions, rate of tracheal narrowing, diaphragmatic motion, and rate of change in lung area due to respiratory motion. Relationships between these parameters and ventilatory disorders were analyzed. RESULTS: Lung area_in/height in patients with restrictive disorders showed significant decreases. Tracheal diameter change and tracheal narrowing rate in patients with obstructive disorders were significantly increased compared to both the control participants and patients with restrictive disorders. Patients with obstructive disorders and patients with restrictive disorders showed decreased diaphragmatic motion and lung area change rate. With the restrictive disorders as references, the area under the curve (AUC), sensitivity and specificity of lung area_in/height were 0.88, 0.77, and 0.88, respectively. With the obstructive disorders as references, the AUC, sensitivity and specificity of tracheal narrowing rate were 0.67, 0.53 and 0.81, respectively. CONCLUSION: Dynamic-ventilatory DR shows potential as a method for the detection and evaluation of ventilatory disorders in patients with respiratory diseases.

Predicting recurrence of non-small cell lung cancer based on mean computed tomography value.

BACKGROUND: The aim of this study was to assess the ability of using mean computed tomography (mCT) values to predict non-small cell lung cancer (NSCLC) tumor recurrence. METHODS: A retrospective study was conducted on 494 patients with stage IA NSCLC. Receiver operating characteristics analysis was used to assess the ability to use mCT value, C/T ratio, tumor size, and SUV to predict tumor recurrence. Multiple logistic regression analyses were performed to determine the independent variables for the prediction of tumor recurrence. RESULTS: The m-CT values were - 213.7 ± 10.2 Hounsfield Units (HU) for the recurrence group and - 594.1 ± 11.6 HU for the non-recurrence group (p < 0.0001). Recurrence occurred in 45 patients (9.1%). The tumor recurrence group was strongly associated with a high CT attenuation value, high C/T ratio, large solid tumor size, and SUV. The diagnostic value of mCT value was more accurate than the C/T ratio, excluding the pure ground-glass opacity and pure solid (0 < C/T ratio < 100) groups. The SUV and mCT are independent predictive factors of tumor recurrence. CONCLUSIONS: The evaluation of mCT values was useful for predicting recurrence after the limited resection of small-sized NSCLC, and may potentially contribute to the selection of suitable treatment strategies.

Assessment of the confidence interval in the multivariable normal tissue complication probability model for predicting radiation-induced liver disease in primary liver cancer.

We developed a confidence interval-(CI) assessing model in multivariable normal tissue complication probability (NTCP) modeling for predicting radiation-induced liver disease (RILD) in primary liver cancer patients using clinical and dosimetric data. Both the mean NTCP and difference in the mean NTCP (ΔNTCP) between two treatment plans of different radiotherapy modalities were further evaluated and their CIs were assessed. Clinical data were retrospectively reviewed in 322 patients with hepatocellular carcinoma (n = 215) and intrahepatic cholangiocarcinoma (n = 107) treated with photon therapy. Dose-volume histograms of normal liver were reduced to mean liver dose (MLD) based on the fraction size-adjusted equivalent uniform dose. The most predictive variables were used to build the model based on multivariable logistic regression analysis with bootstrapping. Internal validation was performed using the cross-validation leave-one-out method. Both the mean NTCP and the mean ΔNTCP with 95% CIs were calculated from computationally generated multivariate random sets of NTCP model parameters using variance-covariance matrix information. RILD occurred in 108/322 patients (33.5%). The NTCP model with three clinical and one dosimetric parameter (tumor type, Child-Pugh class, hepatitis infection status and MLD) was most predictive, with an area under the receiver operative characteristics curve (AUC) of 0.79 (95% CI 0.74-0.84). In eight clinical subgroups based on the three clinical parameters, both the mean NTCP and the mean ΔNTCP with 95% CIs were able to be estimated computationally. The multivariable NTCP model with the assessment of 95% CIs has potential to improve the reliability of the NTCP model-based approach to select the appropriate radiotherapy modality for each patient.

Assessment of pleural invasion and adhesion of lung tumors with dynamic chest radiography: A virtual clinical imaging study.

PURPOSE: Accurate preoperative assessment of tumor invasion/adhesion is crucial for planning appropriate operative procedures. Recent advances in digital radiography allow a motion analysis of lung tumors with dynamic chest radiography (DCR) with total exposure dose comparable to that of conventional chest radiography. The aim of this study was to investigate the feasibility of preoperative evaluation of pleural invasion/adhesion of lung tumors with DCR through a virtual clinical imaging study, using a four-dimensional (4D) extended cardiac-torso (XCAT) computational phantom. METHODS: An XCAT phantom of an adult man (50th percentile in height and weight) with simulated respiratory and cardiac motions was generated to use as a virtual patient. To simulate lung tumors with and without pleural invasion, a 30-mm diameter tumor sphere was inserted into each lobe of the phantom. The virtual patient during respiration was virtually projected using an x-ray simulator in posteroanterior (PA) and oblique directions, and sequential bone suppression (BS) images were created. The measurement points (tumor, rib, and diaphragm) were automatically tracked on simulated images by a template matching technique. We calculated five quantitative metrics related to the movement distance and directions of the targeted tumor and evaluated whether DCR could distinguish between tumors with and without pleural invasion/adhesion. RESULTS: Precise tracking of the targeted tumor was achieved on the simulated BS images without undue influence of rib shadows. There was a significant difference in all five quantitative metrics between the lung tumors with and without pleural invasion both on the oblique and PA projection views (P < 0.05). Quantitative metrics related to the movement distance were effective for tumors in the middle and lower lobes, while, those related to the movement directions were effective for tumors close to the frontal chest wall on the oblique projection view. The oblique views were useful for the evaluation of the space between the chest wall and a moving tumor. CONCLUSION: DCR could help distinguish between tumors with and without pleural invasion/adhesion based on the two-dimensional movement distance and direction using oblique and PA projection views. With anticipated improved image: processing to evaluate the respiratory displacement of lung tumors in the upper lobe or behind the heart, DCR holds promise for clinical assessment of tumor invasion/adhesion in the parietal pleura.