Chest Tumors Research Articles

The possibilities of wide-range MSCT in assessing the invasion of mediastinal structures in giant neoplasms of the thoracic organs

Despite the constant increase in the level of equipment of medical institutions with modern high-tech equipment (CT, MRI, endoscopes, etc.), in the last decade there has been a clear trend towards an increase in the number of patients with tumors of intra-thoracic localization, including giant sizes. Oncologists consider neoplasms that occupy more than half of the hemithorax or simultaneously spread to the anterior and posterior mediastinum to be giant tumors of the chest. According to leading oncologists, giant tumors should include chest tumors whose diameter is equal to or exceeds 20 cm, have different initial localization, more than 80% of cases have different histological affiliation. There is no unity of views of leading oncologists and thoracic surgeons on the classification of giant intra-thoracic formations, diagnosis, determination of their initial localization and, accordingly, determination of the possibility of their surgical treatment and selection of optimal access. It is not uncommon when issues related to the initial localization, histological affiliation, as well as invasion of surrounding structures are resolved during surgical intervention. Unfortunately, there is little information in the Russian scientific literature about the high-tech diagnosis of this group of neoplasms, then malignant formations are twice as common as benign ones. Given the prevalence of malignant neoplasms in the category of giant tumors of intra-thoracic localization, a very relevant diagnostic issue is the identification of invasion of mediastinal structures, which largely determines both the feasibility of surgical intervention and its possible variants.

Bilan tomodensitométrique thoracique et abdomino-pelvien chez les patients insuffisants rénaux candidats à une transplantation rénale : intérêts et indications

IntroductionScreening for neoplasms and vascular calcifications is a key step before kidney transplantation. American, European and French recommendations diverge on the imaging assessment to be carried out in this context. MethodWe carried out a retrospective single-center study including patients who underwent imaging for kidney transplantation between the 01/01/2011 and the 12/31/2018. The neoplastic pathologies and vascular calcifications discovered on this assessment were noted. ResultsWe included 579 patients: 293 performed a thoracic CT scan, 579 an abdominopelvic CT scan. The imaging work-up revealed 5 malignant thoracic tumors, 14 malignant abdominal tumors and 140 significant calcifications of the external iliac axes. All malignant chest tumors were found in patients with estimated smoking greater than or equal to 30 PY. DiscussionLike the American recommendations, our results are in favor of performing a chest computed tomography in patients with smoking greater than or equal to 30 PY. Contrary to American and European recommendations, our results are in favor of performing an abdominopelvic tomodensitometry in all patients. ConclusionScreening for vascular calcifications and neoplasms in kidney transplant candidates should include routine abdominopelvic CT and chest CT for smoking greater than or equal to 30 PY.

A Study on the Radiosensitivity of Radiation-Induced Lung Injury at the Acute Phase Based on Single-Cell Transcriptomics.

Background and AimsRadiation-induced lung injury (RILI) is the most common complication associated with chest tumors, such as lung and breast cancers, after radiotherapy; however, the pathogenic mechanisms are unclear. Single-cell RNA sequencing has laid the foundation for studying RILI at the cellular microenvironmental level. This study focused on changes during the acute pneumonitis stage of RILI at the cellular microenvironmental level and investigated the interactions between different cell types.MethodsAn acute RILI model in mice and a single-cell transcriptional library were established. Intercellular communication networks were constructed to study the heterogeneity and intercellular interactions among different cell types.ResultsA single-cell transcriptome map was established in a mouse model of acute lung injury. In total, 18,500 single-cell transcripts were generated, and 10 major cell types were identified. The heterogeneity and radiosensitivity of each cell type or subtype in the lung tissues during the acute stage were revealed. It was found that immune cells had higher radiosensitivity than stromal cells. Immune cells were highly heterogeneous in terms of radiosensitivity, while some immune cells had the characteristics of radiation resistance. Two groups of radiation-induced Cd8+Mki67+ T cells and Cd4+Cxcr6+ helper T cells were identified. The presence of these cells was verified using immunofluorescence. The ligand-receptor interactions were analyzed by constructing intercellular communication networks. These explained the origins of the cells and revealed that they had been recruited from endothelial cells to the inflammatory site.ConclusionsThis study revealed the heterogeneity of in vivo radiosensitivity of different cell types in the lung at the initial stage post irradiation

Rubidium Uptake in Chest Tumors on PET/CT.

Background Chest tumors are often found incidentally on cardiac scans; we aimed to describe the findings of rubidium (Rb) in incidentally discovered extracardiac tumors. Materials and Methods We reviewed a database of cardiac Rb scans performed over a period of 11 years and identified those with a previously unsuspected malignancy seen on the plane of section. We then measured maximum standard uptake value for each of the tumors, as well as background lung, liver, mediastinum, and body wall. In cases where fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) was available, we compared Rb results with FDG PET/CT. Results We identified 63 patients meeting criteria including full visualization of a tumor of at least 1.0 cm with no prior treatment. Of these patients, 17 had breast, 36 had lung, and 10 had miscellaneous other tumors. We selected patients with either breast or lung tumors for further analysis. Overall uptake was relatively stable between rest and stress but lower than FDG PET/CT; it was generally low and similar to blood pool. There was a small but statistically significant correlation between estrogen receptor positivity and Rb uptake in breast tumors. There was a stable pattern of uptake in background tissues, with liver being greater than mediastinal blood pool, which in turn was more avid than lung, which was more avid than subcutaneous body wall tissues. Lung showed a noticeable tendency toward increased uptake in dependent regions, likely reflecting low-level atelectasis. Conclusion Uptake was stable between rest and stress but low relative to FDG PET/CT; some correlations with receptors suggest it may be useful in molecular imaging.

Higher frequency of new chest tumor diagnoses in emergency department due to the COVID-19 pandemic

• Performing chest CTs in the ED identified previously undiagnosed tumors • More frequent HR CTs in the ED resulted in more frequent diagnosis of chest tumors • HR CT should be used more frequently in ED patients with pulmonary symptoms

Rubidium uptake in chest tumors on positron emission tomography/computed tomography

Chest tumors are often found incidentally on cardiac scans; we aimed to describe the findings of rubidium in incidentally discovered extracardiac tumors. We reviewed a database of cardiac rubidium scans performed over a period of 11 years and identified those with a previously unsuspected malignancy seen on the plane of section. We then measured maximum standardized uptake value for each of the tumors, as well as background lung, liver, mediastinum, and body wall. In cases where fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) was available, we compared rubidium results to FDG-PET/CT. We identified 63 patients meeting criteria including full visualization of a tumor of at least 1.0 cm with no prior treatment. Of these patients, 17 had breast, 36 had lung, and 10 had miscellaneous other tumors. We selected patients with either breast or lung tumors for further analysis. Overall uptake was relatively stable between rest and stress but lower than FDG-PET/CT; it was generally low and similar to blood pool. There was a small but statistically significant correlation between estrogen receptor positivity and rubidium uptake in breast tumors. There was a stable pattern of uptake in background tissues, with liver being greater than mediastinal blood pool, which in turn was more avid than lung, which was more avid than subcutaneous body wall tissues. The lung showed a noticeable tendency toward increased uptake in dependent regions, likely reflecting low-level atelectasis. Uptake was stable between rest and stress but low relative to FDG-PET/CT; some correlations with receptors suggest it may be useful in molecular imaging.

Recombinant Human Endostatin Combined With Radiation Promotes Myocardial Fibrosis in Rat via TGF-β1/Smads/CTGF Signaling Pathway

Recombinant human endostatin (rh-ES) has been found to cause heart damage in clinical use. The heart tissue can be irradiated inevitably while radiation therapy for chest tumors and may result in radiation damage. The regulation of myocardial fibrosis may be related to TGF-β1, Smad2/3, and CTGF signaling pathways. At present, whether targeted drug therapy combined with radiotherapy will increase the damage of the heart is a subject worth studying.The experimental animals were randomly divided into 25 Gy irradiation group (5 Gy/ time × 5 days), rh-ES 6mg/kg group, rh-ES 12mg/kg group, 25 Gy irradiation + rh-ES 6mg/kg group, 25 Gy irradiation + rh-ES 12mg/kg group and blank control group, with 15 in each group. rh-ES was injected intraperitoneally for 14 consecutive days. Five rats in each group were sacrificed and the cardiac tissues were extracted for HE staining, Masson staining and transmission electron microscopy at 1, 3 and 6 months after irradiation and rh-ES rejection. MTT was used to detect the value of the IC50 rh-ES to cardiomyocytes with different concentrations of rh-ES. The cardiomyocytes with stable knockdown of TGF-β1 is grouped, the irradiation dose is 10 Gy. According to cardiomyocytes trial were divided into four group, the blank control group (without any treatment), the irradiation group (irradiation + TGF-β1 gene knockdown), the rh-ES group (rh-ES + TGF-β1 gene knockdown), the combined group (irradiation, rh-ES and TGF-β1 gene knockdown), flow cytometry was used to detect cardiomyocytes apoptosis, qPCR and Western Blot were used to detect the expression of TGF-β1/Smad2. Smad3/CTGF gene and protein.In vivo experiments on the heart of rats showed that a little inflammatory cell infiltration was observed under light microscope at 1 month after radiation and rh-ES treatment, and the inflammatory cell infiltration was obvious with fibrosis changes at 3 months, and the fibrosis changes were aggravated 6 months later. rh-ES alone caused slight injury to rats (no change under light microscope, but some mitochondria swelling and cristae missing under electron microscope). rh-ES and radiation treatment increased the damage of myocardial tissues in rats to some extent, and the process of radiation-induced myocardial fibrosis lasted at least 6 months after radiotherapy. rh-ES can aggravate the process of myocardial fibrosis after radiation injury, but has no toxic effect on normal myocardial tissue. The IC50 value of rh-ES on rat cardiomyocytes was 529μg/ mL in vitro experiment. qPCR and Western Blot results showed that TGF-β1, Smad2/Smad3, CTGF gene and protein expressions were up-regulated in rat cardiomyocytes after rh-ES and irradiation treatment.The TGF-β1, Smad2/Smad3 and CTGF signaling pathways may be the common signaling pathways of myocardial fibrosis injury induced by rh-ES combined with radiation, which may be the target for the treatment of myocardial fibrosis by radiation.

P36.02 A Case of Recurrent Giant Malignant Solitary Fibrous Tumour of the Pleura: An Elephant in the Room?

Solitary fibrous tumor of the pleura (SFTP) is a rare soft tissue neoplasm, accounting for 4% of chest tumors. The biological behavior of SFTP is generally benign, with 10-15% of SFTP that show malignant features with unpredictable long-term behavior. A 59-year-old Caucasian woman with no history of previous malignancies or comorbidities arrived at our institution with cough, increasing dyspnoea, and chest pain. A chest CT scan showed a giant intra-thoracic mass (25x16x16 cm) partially occupying the right hemithorax (fig.1A). Total body 18F-FDG/PET-CT showed a very inhomogeneous mass pattern, with necrotic areas and areas with various patterns of enhancement. A transthoracic FNAB revealed pulmonary SFTP. After cardio-respiratory complete assessment and tumor board evaluation, the patient underwent surgical excision of the mass en-bloc with right upper lobe by thoracotomy. Microscopically, the tumor showed solid spindle cells with high mitotic activity (5 mitoses/10 HPF), high Ki67 expression, and CD34, bcl2, and STAT6 positive. According to England’s criteria, the diagnosis was indicative of a giant malignant SFTP, and the tumor had a Tapias score of 5, which indicated a high risk of recurrence. The postoperative course was uneventful, and the patient was discharged on 8th postoperative day. Due to R0 resection, no adjuvant radiotherapy or chemotherapy was administered, and a strict follow-up was conducted. After 72 months of follow-up, the patient experimented local pleural recurrences (fig.1B) traded with surgical excision in re-thoracotomy. The histopathological analysis showed eight lesions with a median diameter of 1.5 cm, microscopically composed by spindle cells with 10 mitoses/10 HPF, STAT6+, CD34+. Although R0 resection was achieved, adjuvant chemotherapy was administered. A genome sequencing with the next generation approach was performed on the primary lesion and the recurrent disease. SFTP is a rare neoplasm with unpredictable biological behavior. The surgical resection represents the gold standard if complete resection can be reached. The recently introduced Tapias score can be helpful to assess the risk of recurrence: a strict and long-term follow-up should be conducted in case of a high score (>3). In case of local relapse, surgical excision remains the best therapeutic option.

The role of ultrasound-guided transthoracic Tru-Cut core biopsy in the diagnosis peripheral thorax lesion

BackgroundThe nature of opaque lesions such as effusions, atelectasis, masses, and consolidations can be clarified by sonography. This study investigated the sensitivity and accuracy of ultrasound-guided percutaneous core needle biopsy in different thoracic tumors (lung, pleural, chest wall, and mediastinal).ResultsSixty patients underwent ultrasound-guided percutaneous transthoracic core biopsy of peripheral thoracic masses with a Tru-Cut needle with a big bore. Twenty masses were in the lung, seventeen lesions were in the pleura, ten masses were in the mediastinum, eleven were enlarged palpable lymph nodes, and two masses were in chest wall. The sensitivity, PPV, and accuracy for detection of chest tumors in the chest wall, mediastinum, lung, and pleura were 100% for all, and in LN 88.9, 100, and 90.9%, respectively. The overall diagnostic performance of sonar-guided Tru-Cut needle biopsy in diagnosis was 97.78% sensitivity, 98.18% accuracy, and 100% PPV.ConclusionTru-Cut needle percutaneous transthoracic core biopsy is a convenient and sensitive process in obtaining samples under ultrasound guidance for exact histological diagnosis of thoracic tumors. The diagnostic efficiency is high, and the technique can also be used in outpatients, which is relatively simple.Trial registrationNCT, NCT04741958 Registered 5 February 2021, retrospectively registered,

Penpulimab plus anlotinib as second-line treatment for the small cell lung cancer after failure of platinum-based systemic chemotherapy.

8568 Background: Combined therapy of an immune checkpoint inhibitor with a targeted anti-angiogenic agent had been proved to be effective for lung cancer. Penpulimab (AK105) was engineered to eliminate FcγR binding and antibody-dependent cell-mediated cytotoxicity (ADCC)/ antibody-dependent celluar phagocytosis (ADCP) completely, where ADCC/ADCP effects could induce T-cell apoptosis and clearance and therefore compromise anti-tumor activity. Penpulimab demonstrated a slower programmed death-1(PD-1) antigen binding off-rate, which resulted in better cellular activity and higher receptor occupancy. Penpulimab also showed numerous contacts with N58 glycosylation on the BC loop of PD-1. These structural differentiations enhance the anti-tumor activity of penpulimab and improve its safety. Anlotinib is a multi-targeted tyrosine kinase inhibitor selective for VEGF receptors 1/2/3, FGF receptors 1-4, PDGF receptors α and β, and c-kit. Anlotinib has been approved by National Medical Products Administration as the treatment for small cell lung cancer (SCLC) patients, who had progressed/relapsed on or after at least two regimens of chemotherapy. Here we report the results of one cohort which received penpulimab plus anlotinib in a Phase II study. Methods: In Cohort 4 of an open-label, multi-center, multi-cohort Phase II study evaluating the efficacy and safety of penpulimab plus anlotinib in pts with advanced head, neck or chest tumors(NCT04203719), the SCLC patients, who failed to platinum-based systemic chemotherapy treatment, received penpulimab (200 mg IV Q3W) and anlotinib (12/10 mg PO 2 weeks on/1 week off). Primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints were disease control rate (DCR), duration of response, progression-free survival (PFS) and overall survival. Results: 20 patients (median age was 61 [range:37–75] years old, Eastern Cooperative Oncology Group performance status 0/1 [5%/95%], male/female [65%/35%]) were enrolled and received combination therapy (17 received 12 mg anlotinib, 3 received 10 mg anlotinib; and all received 200 mg penpulimab). At data cut-off (Jan 25, 2021), the confirmed ORR was 50.0% (10/20, 1 complete response and 9 partial response) and DCR was 75.0% (15/20). 9 PFS events (45%) had occurred, and the median PFS was 4.7 months (95% CI: 3.6-not reached). Grade 3 treatment-related adverse events (TRAEs) occurred in 30% (6/20, 2 hypertension, 1 hypertriglyceridaemia, 1 gamma-glutamyltransferase increased, 1 palmar-plantar erythrodysaesthesia syndrome and 1 hyponatraemia) of patients, No Grade 4 or 5 TRAEs had occurred. Conclusions: Penpulimab plus anlotinib showed favorable antitumor activity and an acceptable safety profile in SCLC patients who failed to platinum-based systemic chemotherapy. This new combination therapy warrants further evaluation for the treatment of SCLC. Clinical trial information: NCT04203719.

"Association of Genetic Syndrome and Chest Tumor: Is it Just A Coincidence?"

Hani Saiedi1, Massimiliano Rossi2,3, Corinne Collet4, Pauline Monin2, Francois Tronc1 and Stephane Collaud1* Author Affiliations 1Department of Thoracic Surgery, Louis Pradel Hospital, France 2Department of Medical Genetics, Maternity and Childhood Hospital, Bron, France 3INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, GENDEV Team, Bron, France 4Department of Biochemistry and Molecular Biology, Lariboisiere Hospital-APHP, Paris, France Received:April 22, 2021, | Published: May 03, 2021 Corresponding author:Stephane Collaud, Department of Thoracic Surgery, Louis Pradel Hospital, 28 Avenue Doyen Jean Lépine, 69500 Bron, France DOI: 10.26717/BJSTR.2021.35.005711

Protective effect of melatonin entrapped PLGA nanoparticles on radiation-induced lung injury through the miR-21/TGF-β1/Smad3 pathway

Radiation-induced lung injury (RILI) is a complication commonly found in victims suffering from nuclear accidents and patients treated with chest tumor radiotherapy, and drugs are limited for effective prevention and treatment. Melatonin (MET) has an anti-radiation effect, but its metabolic period in the body is short. In order to prolong the metabolism period of MET, we prepared MET entrapped poly (lactic-co-glycolic acid) nanoparticles (MET/PLGANPS) for the treatment of RILI. As a result, the release rate of MET/PLGANPS in vitro was lower than MET, with stable physical properties, and it caused no changes in histopathology and biochemical indicators. After 2 weeks and 16 weeks of irradiation with the dose of 15 Gy, MET and MET/PLGANPS could reduce the expression of caspase-3 proteins, inflammatory factors, TGF-β1 and Smad3 to alleviate radiation-induced lung injury. MET/PLGANPS showed better therapeutic effect on RILI than MET. In addition, we also found that high expression of miR-21 could increase the expression levels of TGF-β1, and inhibit the protective effect of MET/PLGANPS. In conclusion, MET/PLGANPS may alleviate RILI by inhibiting the miR-21/TGF-β1/Smad3 pathway, which would provide a new target for the treatment of radiation-induced lung injury.

P28.02 Individualized Nutritional Management in Patients Eligible for Thoracic Surgery Experience of a Chest Tumor Center in Brazil

Lung cancer (LC) has an increased incidence and early diagnosis can be instituted as a curative measure for these patients. Surgery is the treatment of choice for early-stage disease, which can be combined with systemic treatment. The personalized nutritional intervention in these patients can contribute to an adequate pre and postoperative and subsequent chemotherapy treatment. Research in these areas is necessary to establish a diet that will guarantee an adequate caloric and protein intake in these patients in order to preserve nutritional status and quality of life. The objective is to describe an experience report of a nutritional intervention protocol applied pre- and postoperatively in patients undergoing thoracic surgery at a referral center. This is a qualitative, descriptive, experience report type study carried out in an oncology clinic. The protocol used in the unit consists of the application of nutritional risk tracking instruments, the Patient-Generated Subjective Global Assessment (PG-SGA) and subsequent assessment of nutritional status by anthropometric methods (weight, history of weight loss, height, body mass, calf perimeter, food history (24-hour recall for 3 consecutive days), laboratory tests (blood count, blood glucose, glycosylated hemoglobin, albumin, protein C reactive) and comorbidities. with nutritional risk, considered in our center as patients with unintentional weight loss, low force palm pressure by dynamometry according to the European Working Group on Sarcopenia in Older People (EWGSOP), low protein intake according to the guidelines of the European Society for Clinical Nutrition and Metabolism (ESPEN) and American Society for Parenteral and Enteral Nutrition (ASPEN). Patients at high risk of malnutrition are chosen to receive immunomodulatory nutritional therapy between 7 and 14 days pre- and postoperatively, as shown in figure 1. Adequate nutritional status appears to be achieved when this protocol is completed. The referral of patients with chest tumors eligible for surgery to nutrition, allows an early and more effective nutritional intervention. Having this flow as a service routine allows the patient a better response to treatment and a positive impact on their quality of life.

Automated determination of chest characteristics of Indonesians as the basis of chest dosimetrical phantom design

Abstract Purpose: The purpose of this study was to develop software to automatically measure the main areas of the chest, i.e. soft tissue, bone, and air and to implement it in Kraton Regional General Hospital for designing a specific dosimetrical phantom for chest digital radiography (DR) examination. Methods: This study was a retrospective study on all DR images from 2015 to 2019, and computed tomography (CT) images of 102 patients in Digital Imaging and Communications in Medicine (DICOM) format files scanned from January-December 2019 at the Kraton Regional General Hospital. We evaluated the number of basic DR chest examinations compared to all DR radiological examinations. We developed a MatLab graphical user interface (GUI) for automated measurement of the areas of the main chest components (soft tissue, bone, and air). We computed the areas of the main components of the chest in order to develop a specific chest phantom for DR in the hospital. In order to compute the areas of the main components, we used chest CT images of patients with clinical indications of chest tumors. Results: The basic DR chest examination comprised 59.5% of all DR examinations in the hospital during 2015-2019. The average areas of soft tissue, bone, and air within the chest in all patients were 331, 20, and 125 cm2, respectively, with values of 345, 23, and 139 cm2 for males, and 309, 15, and 103 cm2 for females. The areas were also dependent on age with values of 121, 10, 55 cm2 for patients aged 5-11 years, 371, 27, and 88 cm2 for patients aged 12-25 years, 322, 22, and 131 cm2 for patients aged 26-45 years, and 334, 19, and 126 cm2 for patients > 45 years old. Conclusion: A GUI for computing the main composition of the chest was successfully developed. The areas of chest male patients were greater than female patients. The areas of soft tissue, bone, and air were dependent on the patient’s age. Therefore, the design of dosimetrical DR phantom must consider the gender and age of the patient.

Pathologic concordance of resected metastatic nonseminomatous germ cell tumors in the chest

ObjectiveMen with metastatic nonseminomatous germ cell tumors (NSGCTs) often present with residual chest tumors after chemotherapy. We examined the pathologic concordance of intrathoracic disease and outcomes based on the worst pathology of disease resected at first thoracic surgery. MethodsA retrospective analysis was performed of consecutive patients undergoing thoracic resection for metastatic NSGCT in our institution between 2005 and 2018. ResultsEighty-nine patients (all men) were included. The median age was 29 years (interquartile range [IQR], 23-35 years). Primary sites were testis (n = 84; 94.4%) and retroperitoneum (n = 5; 5.6%). Eighty-seven patients received chemotherapy before undergoing surgery. Nineteen patients (21.3%; group 1) had malignancy resected at first surgery (OR1), and the other 70 patients had benign disease at OR1 (78.7%; group 2). Concordant pathology between lungs was 85.2% in group 1 and 91% in group 2, and between lung and mediastinum was 50% in group 1 and 72.7% in group 2. Despite no teratoma at OR1, 3 patients (15.8%) in group 2 had resection of teratoma (n = 2) or malignancy (n = 1) at future surgery. After a mean follow-up of 65.5 months (IQR, 23.1-89.2 months) for group 1 and 47.7 months (IQR, 13.0-75.1 months) for group 2, overall survival was significantly worse for group 1 (68.4% vs 92.9%; P = .03). ConclusionsThe wide range of pathology resected in patients with intrathoracic NSGCT metastases requires careful decision making regarding treatment. Pathologic concordance between lungs is better than that between lung and mediastinum in patients with intrathoracic NSGCT metastases. Aggressive surgical management should be considered for all residual disease due to the low concordance between sites and the potential for excellent long-term survival even in patients with chemotherapy-refractory disease.

Accuracy and Influence Analysis of 4D CBCT Automatic Registration Algorithm under the Guidance of Chest Tumor Image

In order to provide guidance for clinical use of four-dimensional cone-beam CT (4D CBCT), the accuracy of image registration and its influencing factors were analyzed using the automatic registration method when 4D CBCT was used as an image guidance strategy for patients with chest tumors. The respiratory motion model and two kinds of lung plug-ins were used to simulate two types of tumors and their movements in the chest. 4D CT was scanned for each kind of simulated tumor, and 4D CBCT was scanned under various artificial positioning errors. For the registration of 4D CBCT, the manual and automatic registration methods were used for each group. There were more obvious mismatches in the intrapulmonary adhesion tumor group. When the masks were created based on the size of the target area or expanding the target area by 0.5 cm, the results between the automatic registration and manual registration were statistically different. There were no significant mismatches in the isolated lung tumor group, and there was no statistical difference between the results of automatic registration and manual registration. When 4D CBCT is used as an image guidance strategy for patients with chest tumors, the automatic registration procedure should not be used for tumors adhering to chest wall and mediastinum. For solitary lung tumors, the automatic registration method and the manual registration method have similar registration accuracy, but significant mismatches need to be excluded.

PO-1424: Fast model for evaluation of the thyroid dosimetry during chest tumor radiotherapy

PO-1424: Fast model for evaluation of the thyroid dosimetry during chest tumor radiotherapy

Extracellular Volume Fraction of Cardiac MRI in the Detection of Cardiac Toxicity from Radiotherapy

Extracellular volume (ECV) fraction, a cardiac MRI (CMR) marker of myocardial tissue remodeling and fibrosis, is analyzed in this proof of concept study to detect myocardial fibrosis in patients with previous thoracic radiotherapy. Twenty-eight patients with no cardiac history and chest tumors treated with radiotherapy, with a heart dose V5Gy ≥ 10%, underwent CMRs (1.5T, Siemens Aera, Erlangen, Germany) on a cross sectional study protocol. Estimation of the ECV (extracellular matrix) required measurement of T1 mapping values before and after administration of gadolinium-based contrast agents, in addition to the patients’ hematocrit value at the time of scan. Cardiac dosimetric variables were gathered from cumulative dose-volume histograms of delivered radiotherapy plans. Mann-Whitney-U tests were performed between ECV fractions and various clinical variables. Spearman’s correlation coefficients were calculated between dosimetric variables and ECV fractions at the left ventricle (LV) base, mid, and apex. Mean time from radiotherapy to CMR was 46.4 months (range 1.7-344.5). Mean V5Gy heart volume was 43.1% (range 10-97%). The cohort consisted of 14 (50%) patients with lung, 9 (32%) with breast, and 5 (18%) with other primary tumors. The median ECV at LV base, mid, and apex was 28% (25-30%), 27% (25-29%), and 30% (27-32%), respectively. Abnormal LV ECV fractions above reported reference range (25.3 ± 3.5%)1 included 8 patients (28.6%) at base, 8 (28.6%) at mid, and 15 (53.6%) at apex. Eighteen patients (64.2%) demonstrated at least 1 abnormal ECV value. There were trends/significant correlations between cardiac LV doses (V10Gy/V20Gy/V30Gy/V40Gy) and ECV fractions at mid LV (p = 0.095, 0.045, 0.043, 0.035, respectively) and at base (p = 0.14, 0.12, 0.043, 0.083, respectively). There were also trends/significant correlations between cardiac LV max dose/mean dose and ECV fractions: at mid ventricle (p = 0.016 and 0.07) and at base (p = 0.068 and 0.072). There were no dosimetric correlations to LV apex ECV fraction. Smoking history as measured in pack years was also correlated with higher ECV fraction at the LV base/mid/apex (p = 0.13/0.03/0.04), consistent with prior literature. There was no significant difference between ECV fractions and other clinical factors, such as chemotherapy use or hypertension diagnosis. Approximately ∼65% of thoracic radiotherapy patients have abnormal ECV fraction values, but this is confounded by preexisting clinical factors such as smoking. There were correlations between higher LV dose and greater ECV fraction size at the LV base and mid LV. This may represent imaging measurement of radiation-induced myocardial fibrosis. Further prospective study is needed to validate this finding.

Glucosamine protects against radiation-induced lung injury via inhibition of epithelial-mesenchymal transition.

Radiotherapy is one of the most important treatments for chest tumours. Although there are plenty of strategies to prevent damage to normal lung tissues, it cannot be avoided with the emergence of radiation‐induced lung injury. The purpose of this study was to investigate the potential radioprotective effects of glucosamine, which exerted anti‐inflammatory activity in joint inflammation. In this study, we found glucosamine relieved inflammatory response and structural damages in lung tissues after radiation via HE staining. Then, we detected the level of epithelial‐mesenchymal transition marker in vitro and in vivo, which we could clearly observe that glucosamine treatment inhibited epithelial‐mesenchymal transition. Besides, we found glucosamine could inhibit apoptosis and promote proliferation of normal lung epithelial cells in vitro caused by radiation. In conclusion, our data showed that glucosamine alleviated radiation‐induced lung injury via inhibiting epithelial‐mesenchymal transition, which indicated glucosamine could be a novel potential radioprotector for radiation‐induced lung injury.

Cardiac MRI utilizing late gadolinium enhancement (LGE) and T1 mapping in the detection of radiation induced heart disease

Background and purposeRadiotherapy has been associated with late dose-dependent cardiovascular toxicity. In this cross-sectional pilot study, radiation dose distributions were correlated with areas of localized and diffuse myocardial fibrosis as measured by novel cardiac MRI (CMR) sequences including late gadolinium enhancement (LGE) and T1 mapping with the goal to identify early markers of myocardial damage.Materials and methodsTwenty-eight patients with chest tumors including lung, breast, esophagus, and lymphoma underwent CMR per study protocol on average 46.4 months (range 1.7–344.5) after radiotherapy. Patients without pretreatment cardiac history were included if the volume of heart receiving 5 Gy or more was at least 10% (V5Gy ≥ 10%). The association of LGE with cardiac dosimetric factors, clinical factors (e.g., tumor type, smoking history, BMI), and T1 values was analyzed.ResultsCardiac maximum (Dmax) and mean dose (Dmean) equivalent to doses delivered in 2 Gy fractions (EQD2) were on average 50.9 Gy (range 6.2–108.0) and 8.2 Gy (range 1.0–35.7), respectively, compared to 60.8 Gy (40.8–108.0) and 6.8 Gy (1.8–21.8) among the 9 patients with LGE. Doses were not different between patients with and without LGE (p = 0.16 and 0.56, respectively). The average T1 value of the left ventricle myocardium was 1009 ms (range 933–1117). No significant correlation was seen for heart Dmax and Dmean and T1 values (p = 0.14 and 0.58, respectively). In addition, no significant association between clinical factors and the development of LGE was identified.ConclusionsNo relation between cardiac doses, the presence of LGE or T1 values was observed. Further study is needed to determine the benefit of CMR for detecting radiotherapy-related myocardial fibrosis.