Target Delineation in Radiosurgery for Cerebral Arteriovenous Malformations

1993 ◽  
Vol 34 (5) ◽  
pp. 457-463 ◽  
Author(s):  
W. Y. Guo ◽  
B. Nordell ◽  
B. Karlsson ◽  
M. Söderman ◽  
M. Lindqvist ◽  
...  

A study of 6 selected arteriovenous malformation (AVM) patients was performed to investigate the feasibility of delineating an AVM on MR images and to compare the AVM volume outlined on different images. Conventional stereotaxic angiograms, stereotaxic MR images and MR angiograms using several different pulse sequences were obtained prior to radiosurgery. Treatment plans were made from the conventional stereotaxic angiograms. These plans were then transferred to a separate dose planning computer which displayed the MR images with the superimposed isodose lines. The radiated volumes of AVM and brain tissue were measured from these MR images. Last, an assessment was made of the radiation volume needed for an appropriate treatment of the AVM if the treatment plan was made from the MR images rather than from the conventional stereotaxic angiogram. It was possible to delineate medium and large size AVM nidi on stereotaxic MR images based on an integration of information obtained from various pulse sequences. The estimated volumes of the AVM nidi were found to be larger on the conventional stereotaxic angiograms than on the stereotaxic MR images. Consequently, a dose plan based on a conventional stereotaxic angiogram would result in a higher integral dose to the brain with the same target dose. By using reliable MR information it is expected that the volume of brain exposed to radiation could be decreased and the adverse effects of stereotactic radiosurgery for AVM thereby minimized.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Masayoshi Koike ◽  
Mie Yoshimura ◽  
Yasushi Mio ◽  
Shoichi Uezono

Abstract Background Surgical options for patients vary with age and comorbidities, advances in medical technology and patients’ wishes. This complexity can make it difficult for surgeons to determine appropriate treatment plans independently. At our institution, final decisions regarding treatment for patients are made at multidisciplinary meetings, termed High-Risk Conferences, led by the Patient Safety Committee. Methods In this retrospective study, we assessed the reasons for convening High-Risk Conferences, the final decisions made and treatment outcomes using conference records and patient medical records for conferences conducted at our institution from April 2010 to March 2018. Results A total of 410 High-Risk Conferences were conducted for 406 patients during the study period. The department with the most conferences was cardiovascular surgery (24%), and the reasons for convening conferences included the presence of severe comorbidities (51%), highly difficult surgeries (41%) and nonmedical/personal issues (8%). Treatment changes were made for 49 patients (12%), including surgical modifications for 20 patients and surgery cancellation for 29. The most common surgical modification was procedure reduction (16 patients); 4 deaths were reported. Follow-up was available for 21 patients for whom surgery was cancelled, with 11 deaths reported. Conclusions Given that some change to the treatment plan was made for 12% of the patients discussed at the High-Risk Conferences, we conclude that participants of these conferences did not always agree with the original surgical plan and that the multidisciplinary decision-making process of the conferences served to allow for modifications. Many of the modifications involved reductions in procedures to reflect a more conservative approach, which might have decreased perioperative mortality and the incidence of complications as well as unnecessary surgeries. High-risk patients have complex issues, and it is difficult to verify statistically whether outcomes are associated with changes in course of treatment. Nevertheless, these conferences might be useful from a patient safety perspective and minimize the potential for legal disputes.


Author(s):  
Vassiliki Koufi ◽  
Flora Malamateniou ◽  
George Vassilacopoulos

Homecare is an important component of the continuum of care as it provides the potential to improve quality of life and quality of healthcare delivery while containing costs. Personal Health Record (PHR) systems are intended to reach patients outside of care settings and influence their behaviors thus allowing for more effective homecare services. To this end, these systems need to evolve well beyond providing a consolidated patient record, in ways that make it more widely applicable and valuable to health systems. The development of applications on top of PHR systems can allow them to function as a platform for both patients and healthcare professionals to exchange information and interact with the health system. This paper presents a prototype PHR-based system that aims at supporting chronic disease management at any point of care or decision making through familiar environments such as Google’s Android. In particular, it assists healthcare professionals in assessing an individual’s condition and in forming the appropriate treatment plan for him/her while it provides individuals with step-to-step guidance to their treatment plans.


2011 ◽  
Vol 27 (2) ◽  
pp. 81-87 ◽  
Author(s):  
Chantal Berens ◽  
Cilia L. M. Witteman ◽  
Monique O. M. van de Ven

Models of the psychodiagnostic process prescribe that clinicians should analyze explanations for their clients’ problems and subsequently use this information to decide upon the most appropriate treatment plan. However, studies of clinical practice suggest that the role of explanations is minimal, and that considering only symptoms gives clinicians enough information to plan treatment. In this experimental study we tested whether different explanations for the same problem are related to different treatment plans. Analyses of the responses given by 151 psychologists for cases of anorexia and conduct disorder in which the explanations were manipulated, suggest that explanations matter. Different explanations for the same constellation of symptoms were related to different treatment plans. This implies that clinical psychologists do not propose a treatment based on symptoms only. Implications of our findings are discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hsiu-Wen Ho ◽  
Ching-Chieh Yang ◽  
Hsiu-Man Lin ◽  
Hsiao-Yun Chen ◽  
Chun-Chiao Huang ◽  
...  

AbstractTo evaluate the potential benefit of HyperArc (HA) fractionated stereotactic radiotherapy (FSRT) for the benign brain lesion. Sixteen patients with a single deep-seated, centrally located benign brain lesion treated by CyberKnife (CK, G4 cone-based model) were enrolled. Treatment plans for HA with two different optimization algorithms (SRS NTO and ALDO) and coplanar RapidArc (RA) were generated for each patient to meet the corresponding treatment plan criteria. These four FSRT treatment plans were divided into two groups—the homogeneous delivery group (HA-SRS NTO and coplanar RA) and the inhomogeneous delivery group (HA-ALDO and cone-based CK)—to compare for dosimetric outcomes. For homogeneous delivery, the brain V5, V12, and V24 and the mean brainstem dose were significantly lower with the HA-SRS NTO plans than with the coplanar RA plans. The conformity index, high and intermediate dose spillage, and gradient radius were significantly better with the HA-SRS NTO plans than with the coplanar RA plans. For inhomogeneous delivery, the HA-ALDO exhibited superior PTV coverage levels to the cone-based CK plans. Almost all the doses delivered to organs at risk and dose distribution metrics were significantly better with the HA-ALDO plans than with the cone-based CK plans. Good dosimetric distribution makes HA an attractive FSRT technique for the treatment of benign brain lesions.


PEDIATRICS ◽  
1969 ◽  
Vol 44 (1) ◽  
pp. 101-108
Author(s):  
Conrad W. Wesselhoeft ◽  
Judson G. Randolph

The treatment of 27 infants presenting with omphalocele or gastroschisis was analyzed. Several different methods of therapy were available, but various treatment plans were chosen on an individual basis. The defects were classified according to the size of the anomaly, the presence or absence of sac rupture, and the presence of coexisting abnormalities. Infants with intact omphalocele sacs less than 5 cm in diameter were best treated by surgical closure of the musculofascial defect or by skin closure alone. Intact omphaloceles over 5 cm in diameter or those associated with other life-threatening anomalies were treated conservatively with local applications of mercurochrome. Ruptured omphalocele or gastroschisis required immediate surgical coverage. If skin closure was not possible, a plastic prosthesis of Silastic covered Marlex was useful as a temporary cover for the exposed intestine. Infectious complications from the exposed prosthesis were minimized by the use of 0.5% silver nitrate dressings. An overall survival rate of 70% was obtained using the most appropriate treatment plan for the particular anomaly.


Author(s):  
Pooja Prabhu ◽  
A. K. Karunakar ◽  
Sanjib Sinha ◽  
N. Mariyappa ◽  
G. K. Bhargava ◽  
...  

AbstractIn a general scenario, the brain images acquired from magnetic resonance imaging (MRI) may experience tilt, distorting brain MR images. The tilt experienced by the brain MR images may result in misalignment during image registration for medical applications. Manually correcting (or estimating) the tilt on a large scale is time-consuming, expensive, and needs brain anatomy expertise. Thus, there is a need for an automatic way of performing tilt correction in three orthogonal directions (X, Y, Z). The proposed work aims to correct the tilt automatically by measuring the pitch angle, yaw angle, and roll angle in X-axis, Z-axis, and Y-axis, respectively. For correction of the tilt around the Z-axis (pointing to the superior direction), image processing techniques, principal component analysis, and similarity measures are used. Also, for correction of the tilt around the X-axis (pointing to the right direction), morphological operations, and tilt correction around the Y-axis (pointing to the anterior direction), orthogonal regression is used. The proposed approach was applied to adjust the tilt observed in the T1- and T2-weighted MR images. The simulation study with the proposed algorithm yielded an error of 0.40 ± 0.09°, and it outperformed the other existing studies. The tilt angle (in degrees) obtained is ranged from 6.2 ± 3.94, 2.35 ± 2.61, and 5 ± 4.36 in X-, Z-, and Y-directions, respectively, by using the proposed algorithm. The proposed work corrects the tilt more accurately and robustly when compared with existing studies.


Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Andréia Veras Gonçalves ◽  
Demócrito de B. Miranda-Filho ◽  
Líbia Cristina Rocha Vilela ◽  
Regina Coeli Ferreira Ramos ◽  
Thalia V. B. de Araújo ◽  
...  

Congenital viral infections and the occurrence of septo-optic dysplasia, which is a combination of optic nerve hypoplasia, abnormal formation of structures along the midline of the brain, and pituitary hypofunction, support the biological plausibility of endocrine dysfunction in Zika-related microcephaly. In this case series we ascertained the presence and describe endocrine dysfunction in 30 children with severe Zika-related microcephaly from the MERG Pediatric Cohort, referred for endocrinological evaluation between February and August 2019. Of the 30 children, 97% had severe microcephaly. The average age at the endocrinological consultation was 41 months and 53% were female. The most frequently observed endocrine dysfunctions comprised short stature, hypothyroidism, obesity and variants early puberty. These dysfunctions occurred alone 57% or in combination 43%. We found optic nerve hypoplasia (6/21) and corpus callosum hypoplasia (20/21). Seizure crises were reported in 86% of the children. The most common—and clinically important—endocrine dysfunctions were pubertal dysfunctions, thyroid disease, growth impairment, and obesity. These dysfunctions require careful monitoring and signal the need for endocrinological evaluation in children with Zika-related microcephaly, in order to make early diagnoses and implement appropriate treatment when necessary.


2012 ◽  
Vol 11 (2) ◽  
pp. 7290.2011.00036 ◽  
Author(s):  
Vincent Keereman ◽  
Yves Fierens ◽  
Christian Vanhove ◽  
Tony Lahoutte ◽  
Stefaan Vandenberghe

Attenuation correction is necessary for quantification in micro–single-photon emission computed tomography (micro-SPECT). In general, this is done based on micro–computed tomographic (micro-CT) images. Derivation of the attenuation map from magnetic resonance (MR) images is difficult because bone and lung are invisible in conventional MR images and hence indistinguishable from air. An ultrashort echo time (UTE) sequence yields signal in bone and lungs. Micro-SPECT, micro-CT, and MR images of 18 rats were acquired. Different tracers were used: hexamethylpropyleneamine oxime (brain), dimercaptosuccinic acid (kidney), colloids (liver and spleen), and macroaggregated albumin (lung). The micro-SPECT images were reconstructed without attenuation correction, with micro-CT-based attenuation maps, and with three MR-based attenuation maps: uniform, non-UTE-MR based (air, soft tissue), and UTE-MR based (air, lung, soft tissue, bone). The average difference with the micro-CT-based reconstruction was calculated. The UTE-MR-based attenuation correction performed best, with average errors ≤ 8% in the brain scans and ≤ 3% in the body scans. It yields nonsignificant differences for the body scans. The uniform map yields errors of ≤ 6% in the body scans. No attenuation correction yields errors ≥ 15% in the brain scans and ≥ 25% in the body scans. Attenuation correction should always be performed for quantification. The feasibility of MR-based attenuation correction was shown. When accurate quantification is necessary, a UTE-MR-based attenuation correction should be used.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Stefan Gerlach ◽  
Christoph Fürweger ◽  
Theresa Hofmann ◽  
Alexander Schlaefer

AbstractAlthough robotic radiosurgery offers a flexible arrangement of treatment beams, generating treatment plans is computationally challenging and a time consuming process for the planner. Furthermore, different clinical goals have to be considered during planning and generally different sets of beams correspond to different clinical goals. Typically, candidate beams sampled from a randomized heuristic form the basis for treatment planning. We propose a new approach to generate candidate beams based on deep learning using radiological features as well as the desired constraints. We demonstrate that candidate beams generated for specific clinical goals can improve treatment plan quality. Furthermore, we compare two approaches to include information about constraints in the prediction. Our results show that CNN generated beams can improve treatment plan quality for different clinical goals, increasing coverage from 91.2 to 96.8% for 3,000 candidate beams on average. When including the clinical goal in the training, coverage is improved by 1.1% points.


Author(s):  
Ahmed Ibrahim Tawfik ◽  
Wael Hamza Kamr ◽  
Saher Ebrahim Taman

Abstract Background Comparing the diagnostic performance of widely used 2D FSE technique (fat-suppressed proton density; FS-PD) and the 3D technique (water-selective cartilage scan; WATS-c) in evaluation of the chondromalacia patella by using arthroscopy as reference standard Results Seventy-five adult patients were enrolled in this study. They underwent MRI examinations then arthroscopy done in 2–4 days after it. MRI was done using 2D (FS-PD) and 3D (WATS-c) sequences and MR images were compared by two radiologists separately, then grading of the cartilage lesions was performed according to modified Noyes grading system and comparison between grade 0–1, 2, and 3 lesions was done using arthroscopic findings as a reference. A false-negative result is considered if there was undergrading of chondromalacia and false-positive result if chondromalacia was overgraded. Each sequence sensitivity, specificity, and accuracy was calculated by both readers. For reader 1, the sensitivity is 69% for WATS-c and 80% for FS-PD and the accuracy is 90% for WATS-c and 92% for FS-PD and for reader 2, the sensitivity is 56% for WATS-c and 84% for FS-PD and the accuracy is 88% for WATS-c and 94% for FS-PD. Conclusion 2D FS-PD images showed better diagnostic performance than 3D WATS-c images for evaluating chondromalacia patella.


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