VMAT Planning With Xe-CT Functional Images Enables Radiotherapy Planning With Consideration of Lung Function.

Background/Aim: The most severe adverse event of radiotherapy in lung cancer is radiation pneumonitis (RP). Some indices commonly used to prevent RP are evaluated based on the anatomical lung volume. The irradiation dose may be more accurately assessed by using functional lung volume. We evaluated the usefulness of computed tomography (CT) incorporating functional ventilation images acquired by the inhalation of xenon (Xe) gas (Xe-CT functional images). Patients and Methods: Two plans were created for twelve patients: volumetric modulated arc therapy (VMAT) planning using conventional chest CT images (anatomical plans) and VMAT planning using Xe-CT functional images (functional plans), and the dosimetric parameters were compared. Results: Compared to the anatomical plans, the functional plans had significantly reduced V 20Gy in the high-functional lungs (p=0.005), but significant differences were not seen in the moderate-functional and low-functional lungs. Conclusion: The incorporation of Xe-CT functional images into VMAT plans enables radiotherapy planning with consideration of lung function.

Computed tomography pulmonary angiography and venography with a low dose of contrast medium.

The authors developed a method to ensure sufficient opacification of pulmonary vasculature for separate depiction of arteries and veins in three-dimensional form with a small dose of contrast medium utilizing a test injection to determine optimal timing of computed tomography (CT) scanning. The dose was determined by a simulation based on a pharmacokinetic model. The contrast medium was administered at a rate of 5.0 mL/s for 3 s, followed by helical scanning at the timing determined by a dynamic CT scanning following the test injection. Images of 20 consecutive patients acquired with a 64-row CT scanner were evaluated. Quality of vessel depiction was assessed on the basis of the following: HU values at the main pulmonary artery (MPA) and left atrium (LA), distance between the pleural surface and the distal end of the pulmonary vessels on three-dimensional CT pulmonary arteriography and venography (3D-CTPAV), and subjective visual assessment of quality of the 3D-CTPAV images. Time to generate the 3D-CTPAV images was recorded. The mean ± standard deviation (SD) of the HU values at MPA/LA and the distances to the pleural surface for pulmonary arteries/veins were 448.0 ± 123.1/277.3 ± 60.85 HU and 9.21 ± 3.60/10.7 ± 5.45 mm, respectively. The image quality was visually rated as excellent for all of the patients. The mean time ± SD to generate 3D-CTPAV images was 13.6 ± 6.7 min. In conclusion, three-dimensional images of the pulmonary vasculature can be created using 21 mL (including 6 mL for the test injection) of contrast medium.

Generation of ventilation/perfusion ratio map in surgical patients by dual-energy CT after xenon inhalation and intravenous contrast media.

BACKGROUND: While many studies have evaluated the change in lung volume before and after lung resection and correlated this with pulmonary function test results, there is very little evidence on the changes in ventilation perfusion ratio (V/Q) before versus after lung resection. In the present pilot study, we evaluated if V/Q mapping can be constructed using dual energy CT images. METHODS: Thirty-one lung cancer patients planned for pulmonary resection were included in this study. To evaluate ventilation, Xenon-enhanced CT was performed. This was immediately followed by perfusion CT. The two images were registered manually as well as using dedicated softwares, and division between ventilation pixels and perfusion pixels were done to produce the V/Q map. Also, in order to characterize the distribution of the V/Q, the following numerical indices were calculated; mean, median, mode, standard deviation (SD), coefficient of variation (CV), skewness, kurtosis, and fractal dimension (FD). Pulmonary function tests and blood gas parameters were measured using standard institutional procedures. RESULTS: In the whole group, VC, %VC, and FEV1 decreased significantly after resection. FEV1.0% was increased significantly after resection. No significant changes were seen in PaO2, PaCO2, and DLCO/VA before and after resection. The mean, median, mode, SD, skewness, kurtosis and FD of the V/Q did not change significantly before and after resection. A marginal but significant decrease in CV was seen before versus after resection. CONCLUSIONS: Overall, it was considered that the V/Q maps could be adequately generated in this study. With further accumulation of data, V/Q map generated by dual energy CT may become one of the potentially useful tools for functional lung imaging. TRIAL REGISTRATION: This trial was registered in University Medical Information Network in Japan ( UMIN000010023 ) on 13Feb2013.

Prediction of postoperative pulmonary function: preliminary comparison of single-breath dual-energy xenon CT with three conventional methods.

PURPOSE: To assess the use of xenon ventilation maps (Xe-images) for predicting postoperative pulmonary function. MATERIALS AND METHODS: After study approval by the institutional review board, written informed consent was obtained from 30 patients with lung tumors who underwent pre- and postoperative spirometry, pulmonary perfusion SPECT and dual-energy CT (80 kV and 140 kV/Sn) after single-breath inspiration of 35 % xenon. Xe-images were calculated by three-material decomposition. Sum of pixel values of the part to be resected (A) and of the whole lung (B) on Xe-images or lung perfusion SPECT, and volumes or the number of segments of the part to be resected (A) and of the whole lung (B) on Xe-images were enumerated, respectively. We multiplied (1 - A/B) by each preoperative value from spirometry for prediction. Predictions by each of the four methods were compared with postoperative values. RESULTS: Predicted values for vital capacity (VC), forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) by the four methods regressed significantly with measured values (R (2) = 0.56-0.77, p < 0.001 for all). CONCLUSION: Analysis of Xe-images can predict postoperative VC, FVC and FEV1 with accuracy comparable to that of CT volumetry.

Multidetector CT appearance of adhesion-induced small bowel obstructions: matted adhesions versus single adhesive bands.

Adhesive small bowel obstruction (SBO) is a common cause of abdominal pain after surgery or peritonitis. The role of computed tomography (CT) in the evaluation of SBO has expanded. Diagnosis of adhesive SBO, however, remains challenging. Adhesions causing SBO are classified as either matted adhesions or single adhesive bands, and both types have different mechanisms that lead to SBO. In patients with matted adhesions, SBO results from angulation and kinking or from torsion of the intestines. In patients with adhesive bands, SBO results from compression of the intestine caused by the band itself. Recent advances in spatial resolution using multidetector CT (MDCT) have enabled detailed assessment of the configuration of the SBO site. Presented in this pictorial essay are characteristic MDCT findings regarding the mechanism of the obstruction process of adhesive SBO.

Cystic artery bleeding due to blunt gallbladder injury: computed tomography findings and treatment with transcatheter arterial embolization.

Blunt gallbladder injury is rare, and bleeding from the cystic artery due to blunt trauma is even rarer. We report herein a case of extraluminal bleeding of the gallbladder in a patient following blunt abdominal trauma. Contrast-enhanced computed tomography revealed pericholecystic fluid and extravasation of contrast material in the subcapsular liver space adjacent to the gallbladder. Abdominal digital subtraction angiography revealed pseudoaneurysm originating from a branch of the cystic artery. Successful treatment was achieved using selective transcatheter embolization, and cholecystectomy was not required.

Relation between pulmonary embolus volume quantified by multidetector computed tomography and clinical status and outcome for patients with acute pulmonary embolism.

PURPOSE: The aim of this study was to determine whether pulmonary embolus volume (PEV) obtained with multi-detector row computed tomography is related to clinical status and outcomes. MATERIALS AND METHODS: Subjects comprised 48 patients with acute pulmonary embolism (PTE). PEV was measured by tracing the contours manually and compared between sets of two groups divided by clinical status. Correlations of PEV to blood gases and D-dimer levels were investigated. PEV was tested as a predictor of clinical probability of acute PTE using Wells' criteria and as a predictor of survival after PTE by logistic regression analysis. RESULTS: The PEV was greater in groups with respiratory symptoms (P < 0.001), PTE as pretest clinical diagnosis (P = 0.027), and heart rate >100 beats/min (P < 0.001). It was smaller in subjects with concurrent malignancy (P = 0.02). It was correlated with PaCO(2) (P = 0.04, rho = -0.37) and the D-dimer level (P = 0.002, rho = 0.46); it was not a predictor of clinical probability of acute PTE or survival after PTE. The survival rate did not differ between groups with PEV > 10 ml (8/9) or

Evaluation of quality of life and psychological response in cancer patients treated with radiotherapy.

PURPOSE: The importance of the quality of life (QOL) and mental condition of patients being treated for cancer is now recognized. In this study, we evaluated QOL and mental condition in patients with cancer before and after radiotherapy. MATERIALS AND METHODS: The subjects were 170 patients who had undergone radiotherapy. The examination of QOL was performed using the quality of life questionnaire for cancer patients treated with anticancer drugs (QOL-ACD), and mental condition (anxiety and depression) was examined using the hospital anxiety and depression scale (HADS). These examinations were performed at the start of radiotherapy and immediately after radiotherapy. RESULTS: The QOL score was slightly higher in all patients after the completion of radiotherapy than before the start of radiotherapy. In the palliative radiotherapy group, QOL score was significantly improved by treatment. Anxiety and depression were improved after radiotherapy. There was a correlation between the degrees of improvement of the HADS and QOL score. CONCLUSION: We could treat cancer patients by radiotherapy without reducing their QOL, and improvement in QOL was significant in the palliative radiotherapy group. Mental condition was also improved after radiotherapy.

Arteriovenous malformation of the gallbladder: CT and angiographic findings.

We encountered a case of arteriovenous malformation (AVM) of the gallbladder in a patient with hepatocellular carcinoma (HCC). Contrast-enhanced computed tomography (CT) showed serpentine vessels around and within the gallbladder wall. Angiography showed dilated and tortuous cystic arteries, a racemose vascular network, and early-filling cystic veins. Transcatheter arterial embolization of two cystic arteries feeding the AVM was performed with platinum microcoils prior to transcatheter arterial chemoembolization for HCC to prevent embolic particles from flowing into these arteries. Follow-up contrast-enhanced CT showed blood flow in the gallbladder AVM, which appeared to be fed by the arterial collaterals.

Extraosseous accumulation of 99mTc-MDP in lymph node metastases of small cell carcinoma of the esophagus.

We report a case of esophageal carcinoma that showed extraosseous accumulation of 99mTc-MDP in lymph node metastases to the cervical and paracardial lymph nodes. There are few cases showing abnormal extraosseous accumulation of 99mTc-MDP in esophageal cancer lesion. The patient was a 53-year-old man with advanced esophageal cancer. Bone scintigraphy demonstrated extraosseous accumulations in left supraclavicular and paracardial lymph node metastases. The histopathological diagnosis was small cell carcinoma of the esophagus, which is a rare disease with aggressive behavior and poor prognosis. Our patient underwent 2 courses of systemic chemotherapy (CDDP + VP16), but died of rapidly growing systemic metastases 5 months after the initial treatment.

Adult embryonal rhabdomyosarcoma in axilla.

A case of embryonal rhabdomyosarcoma (RMS) arising from an axillary space is described. RMS is one of the most common soft-tissue neoplasms in children, but adult embryonal RMS is rare. The patient was a 55-year-old man with a tumor of the left axillary area. RMS arising from an axillary area is also uncommon. The histological diagnosis was embryonal RMS. He received irradiation combined with chemotherapy (VAC: VCR, act-D, CPA) for the primary and metastatic lesions, obtained complete remission, and has remained disease-free for over four years as of this report.

Gallium-67 demonstration of extensive soft-tissue involvement of multiple myeloma.

A 46-year-old woman with multiple myeloma presented with neurological symptoms in the right upper extremity. After MR imaging of the cervical spine failed to show the cause of her symptoms, Ga-67 scintigraphy demonstrated increased uptake in multiple areas including the right supraclavicular region and bilateral lower extremities. Histology of the specimen obtained from the left thigh proved soft-tissue involvement of myeloma, and extensive extramedullary involvement was diagnosed. Radiotherapy to the right supraclavicular mass relieved her symptoms. Although Ga-67 scintigraphy is generally considered of limited value in multiple myeloma, this modality contributed to the development of an appropriate strategy in this patient with extensive extramedullary involvement.

Intense Ga-67 accumulation in pure primary mediastinal seminomas.

The authors examined three patients with pure primary mediastinal seminomas, all of whom had marked Ga-67 uptake on scintigraphy. The unusual presentation of sclerotic bone metastases with remarkable extraosseous soft tissue involvement was observed in one patient. Another had a seminoma associated with a multiloculated thymic cyst, which is a rare lesion.

Scintigraphic findings of MALT lymphoma of the thyroid.

Mucosa-associated lymphoid tissue (MALT) lymphoma has been established as a distinct entity among non-Hodgkin's lymphomas, and the most common primary site is the stomach. We describe scintigraphic findings in a patient with MALT lymphoma of the thyroid. A 71-year-old woman with Hashimoto's thyroiditis suffered from rapid cervical swelling, and ultrasonography and CT revealed a thyroid nodule. The nodule showed accumulation of 99mTc pertechnetate comparable to the surrounding thyroid tissue, mimicking a benign nodule. Both 67Ga and 201Tl imaging visualized the lesion as an increased uptake area. After radiotherapy, abnormally increased uptake disappeared on 67Ga images, which predicted a favorable outcome. MALT lymphoma of the thyroid may be visualized as a warm nodule on 99mTc pertechnetate scintigraphy.