Diagnostic performance of two ultrasound techniques for the detection of cleft palate without cleft lip: axial-transverse and equal sign.

OBJECTIVE: There is no study that compares the diagnostic performance of ATV and ESV techniques in detecting cleft palate. We aimed to evaluate the diagnostic accuracy of two ultrasound techniques: axial-transverse (ATV) and "equal sign" view (ESV), in detecting fetal cleft palate without cleft lip. PATIENTS AND METHODS: This prospective study was conducted from March 2019 to January 2022 in a tertiary referral hospital. Secondary palates were assessed with ATV and ESV by two experienced fetal medicine specialists who were blinded to each other's ultrasound findings. Final diagnosis was done according to postnatal physical examination. The sensitivity and specificity of the two techniques were calculated. RESULTS: A total of 311 pregnancies which met the study criteria were evaluated. Postnatal physical examination showed that 13 (0.4%) neonates had cleft palate only (CPO). According to final diagnosis the sensitivity, specificity, positive predictive value and negative predictive value for ATV were 100%, 98.7%, 76.4%, 100% and 100% for ESV were 76.9%, 97.8%, 58.9% and 99%, respectively. CONCLUSIONS: ATV in 2D ultrasound provides higher sensitivity and specificity than ESV in detecting CPO.

Which morphological abnormalities better define the elongation of transverse aortic arch: a magnetic resonance angiography study.

BACKGROUND: The aim of the study is to investigate the relation between morphological abnormalities that might indicate elongation of transverse aortic arch (ETA) and various aortic and thoracic measurements, and to determine which morphological criteria define the elongated transverse arch better. MATERIALS AND METHODS: Patients under 40 years of age who underwent contrast enhanced thoracic magnetic resonance angiography were included in the study. Images were evaluated for the presence of morphological arch abnormalities such as late take off (LTO) of left subclavian artery (LSA), flattening of the arch, and kinking at the posterior or anterior contour of the lesser curvature. Various aortic and thoracic measurements, including the distance between the orifices of the left common carotid artery (LCCA) and LSA, were made. Statistical relation between morphological abnormalities and these measurements was analysed. The effect of morphological abnormalities and their combinations on the distance between LCCA and LSA orifices was evaluated by linear regression analysis. RESULTS: Ninety three cases were included in the study. All morphological abnormalities and most of their combinations show statistically significant relation with longer LCCA to LSA distance. The parameters that most affected this distance were combination of flattening with LTO of LSA, anterior kinking and combination of anterior kinking with both flattening and LTO, respectively. CONCLUSIONS: Our study showed that the finding which best defines ETA is the combination of LTO and arch flattening. Therefore, we recommend using this combination in the diagnosis of ETA instead of the classical diagnostic criteria including combination of LTO and posterior kinking.

Indications of Online Adaptive Replanning Based On Organ Deformation.

PURPOSE: Although vital to account for interfractional variations during radiation therapy, online adaptive replanning (OLAR) is time-consuming and labor-intensive compared with the repositioning method. Repositioning is enough for minimal interfractional deformations. Therefore, determining indications for OLAR is desirable. We introduce a method to rapidly determine the need for OLAR by analyzing the Jacobian determinant histogram (JDH) obtained from deformable image registration between reference (planning) and daily images. METHODS AND MATERIALS: The proposed method was developed and tested based on daily computed tomography (CT) scans acquired during image guided radiation therapy for prostate cancer using an in-room CT scanner. Deformable image registration between daily and reference CT scans was performed. JDHs were extracted from the prostate and a uniform surrounding 10-mm expansion. A classification tree was trained to determine JDH metrics to predict the need for OLAR for a daily CT set. Sixty daily CT scans from 12 randomly selected prostate cases were used as the training data set, with dosimetric plans for both OLAR and repositioning used to determine their class. The resulting classification tree was tested using an independent data set of 45 daily CT scans from 9 other patients with 5 CT scans each. RESULTS: Of a total of 27 JDH metrics tested, 5 were identified predicted whether OLAR was substantially superior to repositioning for a given fraction. A decision tree was constructed using the obtained metrics from the training set. This tree correctly identified all cases in the test set where benefits of OLAR were obvious. CONCLUSIONS: A decision tree based on JDH metrics to quickly determine the necessity of online replanning based on the image of the day without segmentation was determined using a machine learning process. The process can be automated and completed within a minute, allowing users to quickly decide which fractions require OLAR.

Transinguinal laparoscopic evaluation of contralateral side during unilateral inguinal hernia repair for children.

BACKGROUND: Inguinal hernia repair is a common procedure in daily pediatric surgical practice. OBJECTIVES: The present study was planned to find out whether transinguinal laparoscopic exploration (TILE) of the contralateral groin is effective in reducing the need of operation for contralateral metachronous inguinal hernia (CMIH) in children. STUDY DESIGN: Charts of 1103 children who underwent inguinal hernia repair between 2006 and 2016 were retrospectively analyzed. Eighty-eight children with bilateral hernia at the presentation were excluded, and 705 patients whose parents could be contacted by phone to get the latest information about children's condition were included in the study. RESULTS: Of the 705 children with unilateral inguinal hernia repair, 362 (51.4%) and 343 (48.6%) of them had right-sided and left-sided inguinal hernia, respectively. Transinguinal laparoscopic exploration was performed in 479 of the 705 children with unilateral hernia and a hernia or contralateral patent processus vaginalis (PPV) was found and ligated in %28.3 (n = 136) of them. Mean follow-up time was 60 ± 36 months. Fifteen (4.3%) of 479 patients who had TILE and 31 (13.6%) of 226 the patients who did not have TILE developed CMIH. When the videos of 15 patients who developed CMIH were reviewed, overlooked PPV was found in 10 (3.3%) patients who had TILE during early phases of institutional learning curve. DISCUSSION AND CONCLUSIONS: TILE of the contralateral side during pediatric inguinal hernia repair is a simple and effective method to evaluate contralateral PPV. This approach clearly and significantly reduces the need of operation for a metachronous hernia at a later date.

A Technique to Rapidly Generate Synthetic Computed Tomography for Magnetic Resonance Imaging-Guided Online Adaptive Replanning: An Exploratory Study.

PURPOSE: To develop an automatic, accurate, atlas-based technique for synthetic computed tomography (sCT) generation to be used for online adaptive replanning during magnetic resonance imaging (MRI)-guided radiation therapy (RT). METHODS AND MATERIALS: The proposed method uses deformable image registration (DIR) of daily MRI and reference computed tomography (CT) with additional corrections to maintain bone rigidity and to transfer random air regions by thresholding. The DIR is performed with constraints on the bony structures using a special algorithm of ADMIRE (Elekta). The air regions are delineated from low-signal regions on the daily MRI and forced to air density. The bone regions in the MRI (already determined from the CT) are separated from the air regions because both bone and air have low signal density in MRI. All these steps are automated. The generated sCT is compared with reference CT and the alternative voxel-based CT (bCT) for 4 extracranial sites (head and neck, thorax, abdomen, pelvis) in terms of mean absolute error (MAE), gamma analysis of 3-dimensional doses, and dose volume histogram parameters. RESULTS: Both MAE and dosimetric analysis results were favorable for the proposed sCT generation method. The average MAE for the sCT/bCT were 25.5/66.7, 25.9/65.3, 24.8/44.2 and 16.6/47.7 for head and neck, thorax, abdomen, and pelvis, respectively, and the gamma analysis (1.5%, 2 mm) yielded 98.7/97.1, 99.1/93.9, 99.5/99.4, 99.7/99.4, respectively, for those sites. CONCLUSIONS: The proposed method generates equal or more accurate sCT than those from the bulk density assignment, without the need for multiple MRI sequences. This method can be fully automated and applicable for online adaptive replanning.

Elongated transverse aortic arch in subjects without turner syndrome: A preliminary computed tomography study.

The purpose of the present study was to investigate the presence of an elongated transverse aortic arch (ETA), which has been reported to be specific for Turner syndrome, in a population without Turner syndrome. A set of 1,012 patients (713 men, 299 women) under 40 years old, who underwent thoracic CT examination in our radiology department between July 2016 and December 2016, were included in the study. CT scans were performed by 16-slice scanners. CT images were retrieved from the picture archiving and communication system and retrospectively re-assessed by two radiologists. Diagnostic criteria for ETA, which are late take-off of the left subclavian artery (LSA), convex kinking of the inferior aortic arch along the lesser curvature and flattening of the transverse aortic arch, were searched in each case. The mean age of the study population was 25.5 ± 10.0 years. Late take-off of the LSA was detected in 17 (1.7%) subjects (10 men, 7 women). In six of these, the other criteria for ETA were not met. However, in the other 11 (1.1% of the study population) cases, in addition to late take-off of the LSA, aortic morphology was compatible with ETA. The dimensions of the aortic root and the ascending and descending aorta were within normal limits in all 17 cases. Our results supported the presence of ETA in subjects without Turner syndrome with ∼1.1% frequency. This is the first preliminary report regarding the frequency of ETA in non-Turner subjects. Clin. Anat. 31:887-890, 2018. © 2018 Wiley Periodicals, Inc.

The perinatal effects of maternal caffeine intake on fetal and neonatal brain levels of testosterone, estradiol, and dihydrotestosterone in rats.

Testosterone, estradiol, and dihydrotestosterone are the main sex steroid hormones responsible for the organization and sexual differentiation of brain structures during early development. The hypothalamo-pituitary-adrenocortical axis, adrenal cells, and gonads play a key role in the production of sex steroids and express adenosine receptors. Caffeine is a non-selective adenosine antagonist; therefore, it can modulate metabolic pathways in these tissues. Besides, the proportion of pregnant women that consume caffeine is ∼60%. That is why the relationship between maternal caffeine consumption and fetal development is important. Therefore, we aimed to investigate this modulatory effect of maternal caffeine consumption on sex steroids in the fetal and neonatal brain tissues. Pregnant rats were treated with a low (0.3 g/L) or high (0.8 g/L) dose of caffeine in their drinking water during pregnancy and lactation. The testosterone, estradiol, and dihydrotestosterone levels in the frontal cortex and hypothalamus were measured using radioimmunoassay at embryonic day 19 (E19), birth (PN0), and postnatal day 4 (PN4). The administration of low-dose caffeine increased the body weight in PN4 male and female rats and anogenital index in PN4 males. The administration of high-dose caffeine decreased the adrenal weight in E19 male rats and increased testosterone levels in the frontal cortex of E19 female rats and the hypothalamus of PN0 male rats. Maternal caffeine intake during pregnancy affects sex steroid levels in the frontal cortex and hypothalamus of the offspring. This concentration changes of the sex steroids in the brain may influence behavioral and neuroendocrine functions at some point in adult life.

An online replanning method using warm start optimization and aperture morphing for flattening-filter-free beams.

PURPOSE: In a situation where a couch shift for patient positioning is not preferred or prohibited (e.g., MR-linac), segment aperture morphing (SAM) can address target dislocation and deformation. For IMRT/VMAT with flattening-filter-free (FFF) beams, however, SAM method would lead to an adverse translational dose effect due to the beam unflattening. Here the authors propose a new two-step process to address both the translational effect of FFF beams and the target deformation. METHODS: The replanning method consists of an offline and an online step. The offline step is to create a series of preshifted-plans (PSPs) obtained by a so-called "warm start" optimization (starting optimization from the original plan, rather than from scratch) at a series of isocenter shifts. The PSPs all have the same number of segments with very similar shapes, since the warm start optimization only adjusts the MLC positions instead of regenerating them. In the online step, a new plan is obtained by picking the closest PSP or linearly interpolating the MLC positions and the monitor units of the closest PSPs for the shift determined from the image of the day. This two-step process is completely automated and almost instantaneous (no optimization or dose calculation needed). The previously developed SAM algorithm is then applied for daily deformation. The authors tested the method on sample prostate and pancreas cases. RESULTS: The two-step interpolation method can account for the adverse dose effects from FFF beams, while SAM corrects for the target deformation. Plan interpolation method is effective in diminishing the unflat beam effect and may allow reducing the required number of PSPs. The whole process takes the same time as the previously reported SAM process (5-10 min). CONCLUSIONS: The new two-step method plus SAM can address both the translation effects of FFF beams and target deformation, and can be executed in full automation except the delineation of target contour required by the SAM process.

Technical Note: A fast online adaptive replanning method for VMAT using flattening filter free beams.

PURPOSE: To develop a fast replanning algorithm based on segment aperture morphing (SAM) for online replanning of volumetric modulated arc therapy (VMAT) with flattening filter free (FFF) beams. METHODS: A software tool was developed to interface with a VMAT research planning system, which enables the input and output of beam and machine parameters of VMAT plans. The SAM algorithm was used to modify multileaf collimator positions for each segment aperture based on the changes of the target from the planning (CT/MR) to daily image [CT/CBCT/magnetic resonance imaging (MRI)]. The leaf travel distance was controlled for large shifts to prevent the increase of VMAT delivery time. The SAM algorithm was tested for 11 patient cases including prostate, pancreatic, and lung cancers. For each daily image set, three types of VMAT plans, image-guided radiation therapy (IGRT) repositioning, SAM adaptive, and full-scope reoptimization plans, were generated and compared. RESULTS: The SAM adaptive plans were found to have improved the plan quality in target and/or critical organs when compared to the IGRT repositioning plans and were comparable to the reoptimization plans based on the data of planning target volume (PTV)-V100 (volume covered by 100% of prescription dose). For the cases studied, the average PTV-V100 was 98.85% ± 1.13%, 97.61% ± 1.45%, and 92.84% ± 1.61% with FFF beams for the reoptimization, SAM adaptive, and repositioning plans, respectively. The execution of the SAM algorithm takes less than 10 s using 16-CPU (2.6 GHz dual core) hardware. CONCLUSIONS: The SAM algorithm can generate adaptive VMAT plans using FFF beams with comparable plan qualities as those from the full-scope reoptimization plans based on daily CT/CBCT/MRI and can be used for online replanning to address interfractional variations.

Takayasu's arteritis as the aetiology of unresolved fever in an adult patient with cystic fibrosis.

Vasculitis is an unusual complication of cystic fibrosis (CF), normally affecting patients with more severe lung disease. Typical presentation is with skin disease but other organ involvement has been reported. Systemic response to bacterial colonisation and immune complex deposition secondary to chronic airway inflammation is thought to be underlying mechanism of the disease. The authors describe a 28-year-old female Turkish patient with CF presented with fever and arthralgias. The patient was known to have chronic Pseudomonas infection; therefore, a respiratory tract infection was assumed and the patient was treated with imipenem and amikacin for 14 days. Following through investigations of fever of unknown origin, Takayasu's arteritis was identified and the patient responded well to immunosuppression with corticosteroid.

Gradient maintenance: A new algorithm for fast online replanning.

PURPOSE: Clinical use of online adaptive replanning has been hampered by the unpractically long time required to delineate volumes based on the image of the day. The authors propose a new replanning algorithm, named gradient maintenance (GM), which does not require the delineation of organs at risk (OARs), and can enhance automation, drastically reducing planning time and improving consistency and throughput of online replanning. METHODS: The proposed GM algorithm is based on the hypothesis that if the dose gradient toward each OAR in daily anatomy can be maintained the same as that in the original plan, the intended plan quality of the original plan would be preserved in the adaptive plan. The algorithm requires a series of partial concentric rings (PCRs) to be automatically generated around the target toward each OAR on the planning and the daily images. The PCRs are used in the daily optimization objective function. The PCR dose constraints are generated with dose-volume data extracted from the original plan. To demonstrate this idea, GM plans generated using daily images acquired using an in-room CT were compared to regular optimization and image guided radiation therapy repositioning plans for representative prostate and pancreatic cancer cases. RESULTS: The adaptive replanning using the GM algorithm, requiring only the target contour from the CT of the day, can be completed within 5 min without using high-power hardware. The obtained adaptive plans were almost as good as the regular optimization plans and were better than the repositioning plans for the cases studied. CONCLUSIONS: The newly proposed GM replanning algorithm, requiring only target delineation, not full delineation of OARs, substantially increased planning speed for online adaptive replanning. The preliminary results indicate that the GM algorithm may be a solution to improve the ability for automation and may be especially suitable for sites with small-to-medium size targets surrounded by several critical structures.

A phase I/II study piloting accelerated partial breast irradiation using CT-guided intensity modulated radiation therapy in the prone position.

BACKGROUND AND PURPOSE: External beam accelerated partial breast irradiation (EB-aPBI) is noninvasive with broader potential applicability than aPBI using brachytherapy. However, it has inherent challenges in daily reproducibility. Image-guide radiotherapy (IGRT) can improve daily reproducibility, allowing smaller treatment margins. Our institution proposed IG-IMRT in the prone position to evaluate dose homogeneity, conformality, normal tissue avoidance, and reliable targeting for EB-aPBI. We report preliminary results and toxicity from a phase I/II study evaluating the feasibility of EB-aPBI in the prone position using IG-IMRT. MATERIALS AND METHODS: Twenty post-menopausal women with node-negative breast cancer, excised tumors <3.0 cm, negative sentinel lymph node biopsy, and surgical clips demarcating the lumpectomy cavity underwent prone EB-aPBI using IG-IMRT on an IRB-approved phase I/II study. All patients underwent CT planning in the prone position. The lumpectomy cavity PTV represented a 2.0 cm expansion. 38.5 Gy was delivered in 10 fractions over 5 days, such that 95% of the prescribed dose covered >99% of the PTV. Dose constraints for the whole breast, lungs and heart were met. RESULTS: The median patient age was 61.5. Mean tumor size was 1.0 cm. 35% of patients had DCIS. Median PTV was 243 cc (108-530) and median breast reference volume was 1698 cc (647-3627). Average daily shifts for IGRT were (0.6, -4.6, 1.7 mm) with standard deviations of (6.3, 6.5, 6.4mm). Acute toxicity was G1 erythema in 80%, and G2 erythema, G2 fatigue, and G2 breast pain each occurred in 1 patient. With a median follow-up of 18.9 months (12-35), 40% of patients have G1 fibrosis and 30% have G1 hyperpigmentation. 95% of patients have good to excellent cosmesis. There have been no recurrences. CONCLUSIONS: These data demonstrate that EB-aPBI in the prone position using IG-IMRT is well tolerated, yields good dosimetric conformality, and results in promising early toxicity profiles.

Comparison of various online strategies to account for interfractional variations for pancreatic cancer.

PURPOSE: To identify practical techniques to address the large interfractional variations for pancreas irradiation by comparing various used/proposed online strategies. METHODS AND MATERIALS: The daily computed tomography (CT) images acquired using a respiration-gated in-room CT (CTVision; Siemens) for 10 pancreatic cancer patients treated with image guided radiation therapy (IGRT) were analyzed. The contours of the pancreas and organs at risk on each daily CT set were generated by populating from the planning CT using a deformable registration tool (ABAS; Elekta) with manual editing. Nine online strategies were considered: (1) standard IGRT (ie, IGRT with 0-mm additional margin [AM]); (2) IGRT with 2-mm AM; (3) IGRT with 5-mm AM; (4) IGRT with plan renormalized to maintain 95% planning target volume (PTV) coverage; (5) full-scale reoptimization; (6) reoptimization starting from the original plan; (7) segment aperture morphing (SAM) from the original plan, based on PTV shape change; (8) SAM plus segment weight optimization; and (9) reoptimization starting from the SAM plan. One-way analysis of variance was applied to plan qualities for the 9 strategies to assess statistical significance in difference. RESULTS: The 3 IGRT strategies (1-3) lead to either inadequate PTV coverage or higher doses to critical structures, indicating that the additional margins alone are not adequate to account for the changes. The full-scale reoptimization results in the best plan but requires the delineation of several structures, which is time consuming. The SAM strategy (7) was the fastest one, because it requires delineating only 1 structure (target), and its plan quality was comparable to that for the full-scale reoptimization. CONCLUSION: Online replanning strategies can lead to either reduced organs-at-risk dose and/or improved target coverage as compared with the current practice of IGRT. The SAM-based online replanning is comparable to full-scale reoptimization and is efficient for practical use.

Immunohistochemical expression of nitric oxide synthase enzymes (iNOS, eNOS, nNOS) in the estrual and luteal phases of the sexual cycle in the cow oviduct.

This study was aimed to determine staining intensity, cellular localization and distribution of the nitric oxide synthase (NOS) enzymes during the sexual cycle in the cow oviduct. Oviduct samples belonging to 20 cows, 10 of which were in the estrual phase and 10 in the luteal phase of the sexual cycle, were examined by an immunohistochemical procedure to determine the presence of the NOS enzymes. In the epithelial cells of the isthmus, endothelial NOS (eNOS) expression showed a strong positive reaction during the estrual phase and a weak positive reaction during the luteal phase in the endothelium and smooth muscle of the blood vessels found in the serosa and lamina propria. eNOS expression was not observed in the epithelium of either the ampulla or the fimbria in the two particular phases of the sexual cycle. The eNOS reactions observed in the blood vessel wall in these regions were stronger during the estrual phase. eNOS activity was not observed in the tunica muscularis in any of the regions of the oviduct. During the estrual phase, it was observed that inducible NOS expression showed a stronger positive reaction in the epithelium and muscle layer of the isthmus and ampulla and in the epithelium of the fimbria, compared to the luteal phase. Neuronal NOS immunoreactivity was observed in the epithelial cells of all oviduct regions and in the muscle layer of the isthmus and ampulla and did not display any significant difference between the estrual and luteal phases.

The role of brain perfusion SPECT in Moyamoya disease.

Moyamoya disease (MMD) is a cerebrovascular disorder involving stenosis of brain vessels. Brain perfusion SPECT in MMD demonstrates impaired perfusion in ischemic areas. We present a 6-year-old boy with MMD. The patient had numbness on the right arm and simultaneous electroencephalography changes while studying arms up on the table. To differentiate seizure and ischemic symptoms, brain perfusion SPECT studies were obtained when the patient was asymptomatic (SPECT-A) and during the symptoms-EEG changes (SPECT-B). SPECT-A showed perfusion defect on the right frontal cortex, hypoperfusion on the right parieto-occipital region and slightly increased perfusion on the left parietal cortex. SPECT-B displayed significant hyperperfusion on the left parietal cortex; hypoperfusion on the right parietal, right temporal, right parieto-occipital and left frontal cortex. Additionally, brain perfusion SPECT of the child's younger brother diagnosed with MMD showed decreased regional cerebral perfusion. Physiopathological mechanisms of our patient's SPECT findings and indications of brain perfusion SPECT in MMD were also discussed.

El papel del SPECT cerebral de perfusion en la enfermedad de moyamoya / The role of brain perfusion SPECT in moyamoya disease

La enfermedad de moyamoya (EdM) es una alteración cerebrovascular que implica la estenosis de los vasos cerebrales. La SPECT de perfusión cerebral en la EdM demuestra alteración de la perfusión en las zonas isquémicas. Presentamos el caso de un niño de 6 años con EdM que presentaba adormecimiento en el brazo derecho y alteraciones en el EEG cuando estudiaba con los brazos sobre la mesa. Para diferenciar entre crisis epiléptica y síntomas isquémicos se efectuaron estudios cuando el paciente estaba asintomático (SPECT-A) y durante los síntomas con cambios en el EEG (SPECT-B). La SPECT-A mostró defecto de perfusión frontal derecho, hipoperfusión parieto-occipital derecha y leve incremento de la perfusión en la corteza parietal izquierda. La SPECT-B mostró hiperperfusión significativa en la corteza parietal izquierda e hipoperfusión en el parietal, temporal y región parieto-occipital derechos y corteza frontal izquierda. Además, la SPECT de perfusión cerebral de un hermano menor del niño diagnosticado de EdM mostró disminución de la perfusión cerebral regional. Se discuten los mecanismos fisiopatológicos de estos hallazgos y las indicaciones de la SPECT de perfusión cerebral en la EdM(AU)

Moyamoya disease (MMD) is a cerebrovascular disorder involving stenosis of brain vessels. Brain perfusion SPECT in MMD demonstrates impaired perfusion in ischemic areas. We present a 6-year-old boy with MMD. The patient had numbness on the right arm and simultaneous electroencephalography changes while studying arms up on the table. To differentiate seizure and ischemic symptoms, brain perfusion SPECT studies were obtained when the patient was asymptomatic (SPECT-A) and during the symptoms-EEG changes (SPECT-B). SPECT-A showed perfusion defect on the right frontal cortex, hypoperfusion on the right parieto-occipital region and slightly increased perfusion on the left parietal cortex. SPECT-B displayed significant hyperperfusion on the left parietal cortex; hypoperfusion on the right parietal, right temporal, right parieto-occipital and left frontal cortex. Additionally, brain perfusion SPECT of the child's younger brother diagnosed with MMD showed decreased regional cerebral perfusion. Physiopathological mechanisms of our patient's SPECT findings and indications of brain perfusion SPECT in MMD were also discussed(AU)

Interfractional target variations for partial breast irradiation.

PURPOSE: In this work, we quantify the interfractional variations in the shape of the clinical target volume (CTV) by analyzing the daily CT data acquired during CT-guided partial breast irradiation (PBI) and compare the effectiveness of various repositioning alignment strategies considered to account for the variations. METHODS AND MATERIALS: The daily CT data for 13 breast cancer patients treated with PBI in either prone (10 patients) or supine (3 patients) with daily kV CT guidance using CT on Rails (CTVision, Siemens, Malvern, PA) were analyzed. For approximately 25 points on the surface of the CTV, deformation vectors were calculated by means of deformable image registration and verified by visual inspection. These were used to calculate the distances along surface normals (DSN), which directly related to the required margin expansions for each point. The DSN values were determined for seven alignment methods based on volumetric imaging and also two-dimensional projections (portal imaging). RESULTS: The margin expansion necessary to cover 99% of all points for all days was 2.7 mm when utilizing the alignment method based on deformation field data (the best alignment method). The center-of-mass based alignment yielded slightly worse results (a margin of 4.0 mm), and shifts obtained by operator placement (7.9 mm), two-dimensional-based methods (7.0-10.1 mm), and skin marks (13.9 mm) required even larger margin expansions. Target shrinkage was evident for most days by the negative values of DSN. Even with the best alignment, the range of DSN values could be as high as 7 mm, resulting in a large amount of normal tissue irradiation, unless adaptive replanning is employed. CONCLUSION: The appropriate alignment method is important to minimize the margin requirement to cover the significant interfractional target deformations observed during PBI. The amount of normal tissue unnecessarily irradiated is still not insignificant, and can be minimized if adaptive radiotherapy is applied.

Internal margin assessment using cine MRI analysis of deglutition in head and neck cancer radiotherapy.

PURPOSE: Intensity-modulated radiation therapy (IMRT) is a promising treatment modality for patients with head and neck cancer (HNC). The dose distributions from IMRT are static and, thus, are unable to account for variations and/or uncertainties in the relationship between the patient (region being treated) and the beam. Organ motion comprises one such source of this uncertainty, introduced by physiological variation in the position, size, and shape of organs during treatment. In the head and neck, the predominant source of this variation arises from deglutition (swallowing). The purpose of this study was to investigate whether cinematographic MRI (cine MRI) could be used to determine asymmetric (nonuniform) internal margin (IM) components of tumor planning target volumes based on the actual deglutition-induced tumor displacement. METHODS: Five head and neck cancer patients were set up in treatment position on a 3 T MRI scanner. Two time series of single-slice, sagittal, cine images were acquired using a 2D FLASH sequence. The first time series was a 12.8 min scan designed to capture the frequency and duration of deglutition in the treatment position. The second time series was a short, 15 s scan designed to capture the displacement of deglutition in the treatment position. Deglutition frequency and mean swallow duration were estimated from the long time series acquisition. Swallowing and resting (nonswallowing) events were identified on the short time series acquisition and displacement was estimated based on contours of gross tumor volume (GTV) generated at each time point of a particular event. A simple linear relationship was derived to estimate 1D asymmetric IMs in the presence of resting- and deglutition-induced displacement. RESULTS: Deglutition was nonperiodic, with frequency and duration ranging from 2.89-24.18 mHz and from 3.86 to 6.10 s, respectively. The deglutition frequency and mean duration were found to vary among patients. Deglutition-induced maximal GTV displacements ranged from 0.00 to 28.36 mm with mean and standard deviation of 4.72 +/- 3.18, 3.70 +/- 2.81, 2.75 +/- 5.24, and 10.40 +/- 10.76 mm in the A, P, I, and S directions, respectively. Resting-induced maximal GTV displacement ranged from 0.00 to 5.59 mm with mean and standard deviation of 3.01 +/- 1.80, 1.25 +/- 1.10, 3.23 +/- 2.20, and 2.47 +/- 1.11 mm in the A, P, I, and S directions, respectively. For both resting and swallowing states, displacement along the S-I direction dominated displacement along the A-P direction. The calculated IMs were dependent on deglutition frequency, ranging from 3.28-4.37 mm for the lowest deglutition frequency patient to 3.76-6.43 mm for the highest deglutition frequency patient. A statistically significant difference was detected between IMs calculated for P and S directions (p = 0.0018). CONCLUSIONS: Cine MRI is able to capture tumor motion during deglutition. Swallowing events can be demarcated by MR signal intensity changes caused by anatomy containing fully relaxed spins that move medially into the imaging plane during deglutition. Deglutition is nonperiodic and results in dynamic changes in the tumor position. Deglutition-induced displacements are larger and more variable than resting displacements. The nonzero mean maximum resting displacement indicates that some tumor motion occurs even when the patient is not swallowing. Asymmetric IMs, derived from deglutition frequency, duration, and directional displacement, should be employed to account for tumor motion in HNC RT.

Electron microscopy of contractile bands and quality characteristics in high-voltage electrical stimulation broiler breast meat.

In this study, 20 broilers were used to examine the effect of high-voltage electrical stimulation (HVES) on meat quality and the microstructure of the pectoralis muscle. After slaughter, carcasses were randomly distributed into 2 treatment groups (n = 10). In the first group, carcasses were electrically stimulated (500 V, 100 Hz) for 60 s. Carcasses in the second group (nonelectrical stimulation) were used as a control. Meat quality was evaluated by the rate of pH, water-holding capacity, cooking loss, color (L*, a*, b*), shear force, and sarcomere length. As a result, HVES increased the rate of muscle pH decline (P < 0.001). High-voltage electrical stimulation had no effect on water-holding capacity and cooking loss values. Only L* (lightness) values were improved during the storage time (P < 0.01). Tenderness (P < 0.001) and sarcomere length (P < 0.05) values were significantly increased at 2 and 5 d postmortem. In addition, microstructure examination demonstrated that the stimulated muscles had longer sarcomeres; however, the A-, I-, and Z-bands and the mitochondrial membrane structure were intact in HVES and nonelectrically stimulated carcasses. The results showed that HVES is a useful method for improving the tenderness of broiler breast meat.