Évaluation tomodensitométrique des variations anatomiques du toit de l'os ethmoïde chez l'adulte noir / Computed tomography evaluation of anatomical variations of the ethmoid bone roof in black adults

Etudier à la tomodensitométrie, les variations anatomiques du toit de l'os ethmoïde en déterminant la prévalence des variantes à haut risque. Matériels et méthodes: Etude transversale, avec une collecte rétrospective, descriptive et analytique menée sur une période de 06 mois dans deux services de radiologie et imagerie médicale à Lomé. Elle portait sur des examens de tomodensitométrie normaux des sinus de l'adulte. Résultats: L'âge moyen était de 50,69 ± 16,18 ans. La profondeur moyenne de la fosse olfactive dans le sexe masculin était de 4,03± 1,40 mm contre 4,45±1,59 mm dans le sexe féminin (p=0,0136). Le type III de Keros a été retrouvé dans 11 cas (3,5%). L'asymétrie de la profondeur de la fosse olfactive a été observée chez 107 (69%) patients. L'angle de Gera mesurait en moyenne 58,5±14,6 degrés et 60 (19,4%) toits de l'ethmoïde étaient classés dans le type III. On notait une asymétrie de l'angle de Gera chez 102 (65,8%) patients. La longueur moyenne de la lamelle latérale de la lame criblée était de 5,34 ± 1,4 mm. La longueur moyenne de la fovéa ethmoïdale chez les hommes était de 10 ± 2,5 mm contre 9,3 ± 2,2 chez les femmes (p=0,0078). Il existait une corrélation linéaire positive entre la profondeur de la fosse olfactive et l'angle de Gera (r=0,498; p=0,002). Conclusion: La fréquence élevée de l'asymétrie du toit ethmoïdal suggère que ces variations soient précisées par les radiologues dans les compte-rendu des examens de tomodensitométrie des sinus pour bilan préopératoire

Assessment of Adult's Abdominopelvic Computed Tomography Radiation Doses in Amhara Region, Ethiopia

BACKGROUND: Computed Tomography plays a priceless role for diagnostic and therapeutic purpose; however,applying an optimized Computed Tomography Technique to produce qualified image while delivering minimum radiation dose to patients is the common challenge. The main objective of this study was to establish local diagnostic reference levels for adult patients who visited abdominopelvic Computed Tomography examination. METHODS: A total of 158 patients who had taken abdominopelvic Computed Tomography examination from three selectedAmhara region hospitals were investigated. Both prospective and retrospective techniques of data collection were used while collecting the data in the entire sample. Two GE - Optima Computed Tomography 540 (16 slices) and one Phillips ­ Brilliance (64slices), were employed during data collections. Data for patient demographics scan protocols, Computed Tomography dose descriptors and machine specifications were collected and analyzed by using SPSS software version 26. RESULTS: The third quartile estimated computed tomography dose index volume and dose length product, which is the local Diagnostic Reference Levels, were 12 mGy and 1904 cm.mGy respectively. The investigated local Diagnostic Reference Levels of Computed Tomography Dose index volume (mGy) was comparable to other international Diagnostic Reference Levels. However, the third quartile value of dose length product (cm.mGy) was higher than other reported international Diagnostic Reference Levels. CONCLUSION: The values of local Diagnostic Reference Levels presented in this work can be used as a baseline upon which future dose measurements can be compared in Amhara region

Fibrous Dysplasia treated with virtual planning ­ report of two cases

Fibrous dysplasia (FD) is part of a rare group of bone dysplasia. It exhibits benign behavior and can lead to osteolytic lesions, deformities, and fractures. The treatment is challenging, and accurate removal of the lesion is necessary to restore function and esthetics. Here we present two cases of FD where virtual planning with presurgical computed tomography (CT) was used for the production of a surgical guide for bone contouring. First, CT image reconstruction was performed to mirror the patient's original anatomy. Then, three surgical guides that determined the area and depth of bone wear were prepared and used in the relevant sequence during the actual surgeries, which were successfully performed in both patients. This technique is termed the template guide holes (TGH) technique. The findings from this report suggest that presurgical virtual planning and guide preparation allows direct and objective measurement of the level of bone wear and improves the functional and esthetic outcomes of surgery for FD. In particular, the TGH technique is safe and allows adequate preoperative surgical simulation, reduces the surgical duration, and increases the predictability of the final result.

Four-Dimensional Thoracic CT in Free-Breathing Children

In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.

Benefit of Four-Dimensional Computed Tomography Derived Ejection Fraction of the Left Atrial Appendage to Predict Thromboembolic Risk in the Patients with Valvular Heart Disease

BACKGROUND AND OBJECTIVES: Decreased left atrial appendage (LAA) emptying velocity in transesophageal echocardiography (TEE) is related with higher incidence of thrombus and increased risk of stroke. Patients with valve disease are at higher risk of thrombus formation before and after surgery. The aim of this study was to investigate the role of 4-dimensional cardiac computed tomography (4DCT) to predict the risk of thrombus formation. METHODS: Between March 2010 to March 2015, total of 62 patients (mean 60±15 years old, male: 53.2%) who underwent 4DCT and TEE for cardiac valve evaluation before surgery were retrospectively included in the current study. Fractional area change in TEE view and emptying velocity at left atrial appendage in TEE view (VeTEE) were measured. Ejection fraction (EF) of left atrial appendage in computed tomography (EFCT) was calculated by 4DCT with full volume analysis. The best cut-off value of EFCT predicting presence of spontaneous echo contrast (SEC) or thrombus was evaluated, and correlation between the parameters were also estimated. RESULTS: SEC or thrombus was observed in 45.2%. EFCT and VeTEE were significantly correlated (r=0.452, p < 0.001). However, fractional area change measured by TEE showed no correlation with VeTEE (r=0.085, p=0.512). EFCT < 37.5% best predicted SEC or thrombus in the patients with valve disease who underwent 4DCT and TEE (area under the curve, 0.654; p=0.038). CONCLUSIONS: In the patients who underwent 4DCT for cardiac valve evaluation before surgery, EFCT by volume analysis might have additional role to evaluate LAA function and estimate the risk of thrombus.

High-quality reconstruction of four-dimensional cone beam CT from motion registration prior image / 南方医科大学学报

Four-dimensional cone beam CT (4D-CBCT) imaging can provide accurate location information of real-time breathing for imaging-guided radiotherapy. How to improve the accuracy of 4D-CBCT reconstruction image is a hot topic in current studies. PICCS algorithm performs remarkably in all 4D-CBCT reconstruction algorithms based on CS theory. The improved PICCS algorithm proposed in this paper improves the prior image on the basis of the traditional PICCS algorithm. According to the location information of each phase, the corresponding prior image is constructed, which completely eliminates the motion blur of the reconstructed image caused by the mismatch of the projection data. Meanwhile, the data fidelity model of the proposed method is consistent with the traditional PICCS algorithm. The experimental results showed that the reconstructed image using the proposed method had a clearer organization boundary compared with that of images reconstructed using the traditional PICCS algorithm. This proposed method significantly reduced the motion artifact and improved the image resolution.

Four-Dimensional CT of the Diaphragm in Children: Initial Experience

OBJECTIVE: To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. MATERIALS AND METHODS: In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. RESULTS: Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p < 0.0001), while the normal diaphragm motion was significantly smaller than the motion of the contralateral normal diaphragm in paralysis (4.5 ± 2.1 mm vs. 7.6 ± 3.8 mm, p = 0.01). Basal lung density change of the affected side was significantly smaller than that of the contralateral side in diaphragm paralysis (89 ± 73 Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). CONCLUSION: The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children.

Moderate hypofractionated image-guided thoracic radiotherapy for locally advanced node-positive non-small cell lung cancer patients with very limited lung function: a case report

Patients with locally advanced lung cancer and very limited pulmonary function (forced expiratory volume in 1 second [FEV1] ≤ 1 L) have dismal prognosis and undergo palliative treatment or best supportive care. We describe two cases of locally advanced node-positive non-small cell lung cancer (NSCLC) patients with very limited lung function treated with induction chemotherapy and moderate hypofractionated image-guided radiotherapy (Hypo-IGRT). Hypo-IGRT was delivered to a total dose of 45 Gy to the primary tumor and involved lymph nodes. Planning was based on positron emission tomography-computed tomography (PET/ CT) and four-dimensional computed tomography (4D-CT). Internal target volume (ITV) was defined as the overlap of gross tumor volume delineated on 10 phases of 4D-CT. ITV to planning target volume margin was 5 mm in all directions. Both patients showed good clinical and radiological response. No relevant toxicity was documented. Hypo-IGRT is feasible treatment option in locally advanced node-positive NSCLC patients with very limited lung function (FEV1 ≤ 1 L).

Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer

PURPOSE: To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. MATERIALS AND METHODS: We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. RESULTS: The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. CONCLUSION: As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.

Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer

PURPOSE: To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. MATERIALS AND METHODS: We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. RESULTS: The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. CONCLUSION: As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.

Motion-compensated compressed sensing four-dimensional cone-beam CT reconstruction / 南方医科大学学报

Restriction by hardware caused the very low projection number at a single phase for 4-dimensional cone beam (4D-CBCT) CT imaging, and reconstruction using conventional reconstruction algorithms is thus constrained by serious streak artifacts and noises. To address this problem, we propose an approach to reconstructing 4D-CBCT images with multi-phase projections based on the assumption that the image at one phase can be viewed as the motion-compensated image at another phase. Specifically, we formulated a cost function using multi-phase projections to construct the fidelity term and the TV regularization method. For fidelity term construction, the projection data of the current phase and those at other phases were jointly used by reformulating the imaging model. The Gradient-Projection-Barzilai-Line search (GPBL) method was used to optimize the complex cost function. Physical phantom and patient data results showed that the proposed approach could effectively reduce the noise and artifacts, and the introduction of additional temporal correlation did not introduce new artifacts or motion blur.

A Retrospective Review of Imaging and Operative Modalities Performed in Patients with Primary Hyperparathyroidism at a Mid-Volume Surgical Centre in Southeast Asia

<p><b>INTRODUCTION</b>A paradigm shift appears to have occurred worldwide in surgery for primary hyperparathyroidism with the advent of sensitive preoperative imaging techniques. Preoperative imaging for parathyroid adenoma localisation was not found to be useful in a study conducted in Singapore in the 1990s. This study aimed to explore what the change has been in preoperative localisation tools compared to the previous study and if the ability of these tools to correctly localise pathologic parathyroid glands has improved.</p><p><b>MATERIALS AND METHODS</b>A retrospective review of patients who had surgery for primary hyperparathyroidism at our institution during the period 2005 to 2014 was carried out. Individuals with positive, as opposed to those with negative preoperative imaging, were compared with regard to whether they underwent limited focal or bilateral neck exploration. Length of hospital stay (LOHS) was also compared between patients who underwent limited versus bilateral exploration.</p><p><b>RESULTS</b>Fifty-eight patients who had preoperative imaging and surgery were evaluated. True positive rates of sestamibi, ultrasound and 4-dimensional (4D) computed tomography (CT) scans were 63.8%, 72.4% and 90%, respectively. Eighty percent of patients who had positive localisation had limited exploration. LOHS was 2.8 days (1.6, 4.8) and 4.3 days (2.1, 9.0) for limited and bilateral exploration respectively, P = 0.011.</p><p><b>CONCLUSION</b>Our study highlights the marked change in the surgical landscape for primary hyperparathyroidism in the last 2 decades in Singapore. Improved preoperative localisation has resulted in a swing from predominantly bilateral, to limited exploration in almost all cases of primary hyperparathyroidism due to solitary adenoma. LOHS was significantly shorter in patients who had limited as compared to those who had bilateral exploration.</p>

Avaliação tomográfica dinâmica pré e pós-reconstrução do ligamento patelofemoral medial de pacientes com instabilidade patelar recidivante / Dynamic computerized tomography for analyzing patients with patellar instability before and after medial patellofemoral ligament reconstruction

A instabilidade patelar é uma patologia comum dentro da especialidade da cirurgia do joelho. O principal fator estabilizador dessa articulação é o ligamento patelofemoral medial, sendo esta a principal estrutura a ser reconstruída no tratamento cirúrgico da instabilidade patelar. Apesar de sua reconstrução apresentar excelentes resultados clínicos, não se sabe ao certo o real efeito in vivo desse procedimento no movimento da patela ao redor do fêmur. A avaliação da articulação patelofemoral tradicionalmente é feita através de exames de imagem estáticos. Com a evolução dos aparelhos de tomografia computadorizada, se tornou possível realizar esse exame durante movimento ativo, técnica ainda pouco utilizada para estudo de articulações como o joelho. O objetivo deste estudo foi padronizar o uso da tomografia de 320 fileiras de detectores para estudo dinâmico da articulação patelofemoral em pacientes com instabilidade patelar recidivante pré e pós-reconstrução do ligamento patelofemoral medial, analisando o efeito da cirurgia no trajeto da patela ao longo do arco de movimento. Foram selecionados 10 pacientes com instabilidade patelar e indicação de reconstrução do ligamento patelofemoral medial isolada, que foram submetidos à tomografia antes e após um mínimo de 6 meses da cirurgia. Os parâmetros anatômicos avaliados foram os ângulos de inclinação da patela e distância da patela ao eixo da tróclea através de um programa de computador desenvolvido especificamente para esse fim. Foram aplicados os escores clínicos de Kujala e Tegner e calculada a radiação dos exames. O protocolo escolhido para aquisição de imagens na tomografia foi: potencial do tubo de 80 kV, carga transportável de 50 mA, espessura de corte de 0,5 mm e tempo de aquisição de 10 segundos, o que gerou um DLP (dose length product) de 254 mGycm e uma dose efetiva estimada de radiação de 0,2032 mSv. O paciente realizava uma extensão ativa do joelho contra a gravidade. Os resultados não mostraram mudança...

Patellar instability is a common pathology in the practice of knee surgeons. The most important stabilizing structure in the patellofemoral joint is the medial patellofemoral ligament. This ligament is the main structure to be reconstructed during surgery for patellofemoral instability. Although clinical results for this procedure are excellent, the real in vivo effect of medial patellofemoral ligament reconstruction on patellar tracking is unknown. The study of this joint is usually made with static imaging. With the recent evolution of tomographers, it is now possible to analyze anatomical structures moving during active range of motion. This technique (dynamic computerized tomography) has not been routinely used to study joints as the knee. This study had the purpose of standardizing the use of 320-detector row computerized tomography for the patellofemoral joint, analyzing patients before and after surgical reconstruction of medial patellofemoral ligament. We selected 10 patients with patellofemoral instability referred to isolated medial patellofemoral ligament reconstruction surgery, and submitted them to a dynamic computerized tomography before and at a minimum of 6 months after surgery. Patellar tilt angles and shift distance were analyzed using a computer software specifically designed for this purpose. Kujala and Tegner scores were applied and the radiation of the exams was recorded. The protocol for imaging acquisition was: tube potential of 80 kV, 50 mA, slice thickness of 0.5 mm and 10 seconds of acquisition duration. This produced a DLP (dose length product) of 254 mGycm and a radiation effective estimated dose of 0.2032 mSv. There were no changes in patellar tracking after medial patellofemoral ligament reconstruction. There was no instability relapse. Clinical scores showed an average improvement of 22.33 points for Kujala (p=0.011) and of 2 levels for Tegner (p=0.017).

Super-resolution reconstruction of lung 4D-CT images based on fast sub-pixel motion estimation / 南方医科大学学报

Super-resolution image reconstruction techniques play an important role for improving image resolution of lung 4D-CT. We presents a super-resolution approach based on fast sub-pixel motion estimation to reconstruct lung 4D-CT images. A fast sub-pixel motion estimation method was used to estimate the deformation fields between "frames", and then iterative back projection (IBP) algorithm was employed to reconstruct high-resolution images. Experimental results showed that compared with traditional interpolation method and super-resolution reconstruction algorithm based on full search motion estimation, the proposed method produced clearer images with significantly enhanced image structure details and reduced time for computation.

A Survey of Stereotactic Body Radiotherapy in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study is to investigate the current status of stereotactic body radiotherapy (SBRT) in Korea. A nationwide survey was conducted by the Korean Stereotactic Radiosurgery Group of the Korean Society for Radiation Oncology (KROG 13-13). MATERIALS AND METHODS: SBRT was defined as radiotherapy with delivery of a high dose of radiation to an extracranial lesion in < or = 4 fractions. A 16-questionnaire survey was sent by e-mail to the chief of radiation oncology at 85 institutions in June 2013. RESULTS: All institutions (100%) responded to this survey. Of these, 38 institutions (45%) have used SBRT and 47 institutions (55%) have not used SBRT. Regarding the treatment site, the lung (92%) and liver (76%) were the two most common sites. The most common schedules were 60 Gy/4 fractions for non-small cell lung cancer, 48 Gy/4 fractions for lung metastases, 60 Gy/3 fractions for hepatocellular carcinoma, and 45 Gy/3 fractions or 40 Gy/4 fractions for liver metastases. Four-dimensional computed tomography (CT) was the most common method for planning CT (74%). During planning CT, the most common method of immobilization was the use of an alpha cradle/vacuum-lock (42%). CONCLUSION: Based on this survey, conduct of further prospective studies will be needed in order to determine the appropriate prescribed doses and to standardize the practice of SBRT.

Comparison of the volume and localization of internal gross target volume and planning target volume delineated by clips and seroma based on 4D-CT scan for external-beam partial breast irradiation after breast conserving surgery / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the differences in volume and localization of the internal gross target volume and planning target volume delineated by clips and/or seroma based on four-dimensional computed tomography (4D-CT) during free-breathing in breast cancer patients after breast conserving surgery.</p><p><b>METHODS</b>Fifteen breast cancer patients after breast-conserving surgery (BCS) were recruited for external-beam partial breast irradiation (EB-PBI). On the ten sets CT images, the gross tumor volumes (GTV) formed by the clips, the seroma, and both the clips and seroma were delineated and defined as GTVc, GTVs and GTVc+s, respectively. Ten GTVc, GTVs and GTVc+s on the ten sets CT images produced the IGTVc, IGTVs, IGTVc+s. The PTVc, PTVs, PTVc+s were created by adding 15 mm to the IGTVc, IGTVs, IGTVc+s, respectively. The IGTV and PTV volume and distance between the centers of IGTVc, IGTVs, IGTVc+s and PTVc, PTVs, PTVc+s were all recorded. Conformity index (CI) and degree of inclusion (DI) were calculated for IGTV/IGTV and PTV/PTV, respectively.</p><p><b>RESULTS</b>The volume of IGTVc+s[(35.73 ± 19.77) cm³] was significantly larger than the IGTVc [(28.35 ± 17.54) cm³] and IGTVs [(24.19 ± 21.53) cm³] (P < 0.05), and the volume of PTVc+s [(191.59 ± 69.74) cm³] was significantly larger than that of the PTVc [(161.53 ± 61.07) cm³] and PTVs [(148.98 ± 62.22)cm³] (P < 0.05). There were significant differences between the DIs of IGTVc in IGTVc+s and IGTVc+s in IGTVc, the DIs of IGTVs in IGTVc+s and IGTVc+s in IGTVs, the DIs of PTVc in PTVc+s and PTVc+s in PTVc, and the DIs of PTVs vs. PTVc+s and PTVc+s in PTVs (P < 0.05 for all). The CI of IGTVc/IGTVc+s (0.63 ± 0.14) and the CI of IGTVs/IGTVc+s (0.54 ± 0.17) were significant larger than that of the CI of IGTVc/IGTVs (0.40 ± 0.14)(P < 0.05). There were non-significant differences among the CI of PTVc/PTVs, PTVc/PTVc+s and PTVs/PTVc+s (0.73 ± 0.12, 0.78 ± 0.13 vs. 0.75 ± 0.17). The DIs and CIs of IGTV/IGTV and PTV/PTV were negatively correlated with their centroid distance (P < 0.05).</p><p><b>CONCLUSIONS</b>There are volume difference and spatial mismatch between the target volumes delineated on the basis of surgical clips and seroma. The DI and CI between the PTVs are larger than that between the IGTV. External-beam partial breast irradiation should be implemented based on the PTV that is defined based on both seroma and surgical clips.</p>

4D-CT-based plan target volume (PTV) definition compared with conventional PTV definition using general margin in radiotherapy for lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the dosimetric benefit of 4D-CT in the planning target volume (PTV) definition process compared with conventional PTV definition using general margin in radiotherapy of lung cancer.</p><p><b>METHODS</b>A set of 4D-CT images and multiphase helical CT scans were obtained in 10 patients with lung cancer. The radiotherapeutic plans based on PTV determined by 4D-CT and in addition of general margin were performed, respectively. The 3D motion of the centroid of GTV and the 3D spatial motion vectors were calculated. The differences of the two kinds of PTVs, mean lung dose (MLD), V5,V10,V15,V20 of total lung, mean heart dose (MHD), V30 and V40 of heart, D99 and D95 were compared, and the correlation between them and the 3D spatial motion vector was analyzed.</p><p><b>RESULTS</b>The PTV4D in eight patients were smaller than PTVconv, with a mean reduction of (13.0 ± 8.0)% (P = 0.018). In other two patients, whose respiration motion was great, PTV4D was larger than PTVconv. The mean 3D spatial motion vector of GTV centroid was (0.78 ± 0.72)cm. By using 4D-CT, the mean reduction of MLD was (8.6 ± 9.9)% (P = 0.037). V5, V10, V15, V20 of total lung were decreased averagely by (7.2 ± 10.5)%, (5.5 ± 8.9)%, (6.5 ± 8.4)% and (5.7 ± 7.4)%, respectively (P < 0.05 for all). There was a significant positive correlation between PTV4D/PTVconv and the 3D spatial motion vector of the GTV centroid (P = 0.008). A significant inverse correlation was found between D994D/D99conv and the 3D spatial motion vector of the GTV centroid (P = 0.002). D994D/D99conv, (MLDconv-MLD4D) /MLDconv, total lung (V5conv-V54D)/V5conv, total lung (V10conv-V104D)/V10conv, (MHDconv-MHD4D)/MHDconv, heart (V30conv-V304D)/V30conv were inversely correlated with PTV4D/PTVconv (P < 0.05 for all).</p><p><b>CONCLUSIONS</b>4D-CT can be used to evaluate the respiration motion of lung tumor accurately. The 4D-CT-based PTV definition and radiotherapeutic planing can reduce the volume of PTV in patients with small respiration motion, increase the intra-target dose, and decrease the dose of normal tissue sequentially. For patients with large respiration motion, especially those more than 1.5-2 cm, this method can avoid target miss, meanwhile, not increase the dose of normal tissue significantly.</p>

Localization of Parathyroid Adenoma and Minimally Invasive Parathyroidectomy: A Review / 대한내분비외과학회지

More than 80% of cases of patients with sporadic primary hyperparathyroidism are caused by a single parathyroid adenoma. Therefore, traditional bilateral neck exploration has been replaced by minimally invasive parathyroidectomy (MIP) in recent years. Benefits, of MIP include decreased pain and complications, a shorter length of hospital stay, and improved cosmesis. Preoperative imaging studies for localization and intraoperative PTH assay (IoPTH) play an essential role for in MIP. The standard imaging studies are cervical ultrasound and 99mTc sestamibi scanning (with SPECT/CT), while 4D CT is attracting significant interest. The half-life of PTH is less than 5 minutes and PTH rapidly drops after the resection of target lesions. These characteristics of PTH enable IoPTH. If target lesions are localized by recent imaging studies and IoPTH is adopted, MIP can be performed successfully in patients with primary hyperparathyroidism.

Emergency embolization after resection of a laryngeal Schwannoma / Embolizacao de urgencia apos resseccao de schwanoma de laringe

Schwannoma is a rare cause of benign tumors of the larynx. The first-choice treatment is surgical resection. The objective of this paper is to report on a rare case of a young female patient who suffered severe intraoperative hemorrhaging during surgical resection of a laryngeal Schwannoma and needed emergency embolization.

O schwanoma representa etiologia rara de tumor benigno de laringe, tendo como principal tratamento a ressecção cirúrgica. O objetivo deste trabalho é relatar um caso raro de paciente jovem submetido à ressecção cirúrgica de schwanoma laríngeo, evoluindo, no transperatório, para complicação hemorrágica grave e necessitando de embolização de urgência.