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1.
Orthod Craniofac Res ; 27(4): 535-543, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38321788

ABSTRACT

OBJECTIVE: To investigate the accuracy of artificial intelligence-assisted growth prediction using a convolutional neural network (CNN) algorithm and longitudinal lateral cephalograms (Lat-cephs). MATERIALS AND METHODS: A total of 198 Japanese preadolescent children, who had skeletal Class I malocclusion and whose Lat-cephs were available at age 8 years (T0) and 10 years (T1), were allocated into the training, validation, and test phases (n = 161, n = 17, n = 20). Orthodontists and the CNN model identified 28 hard-tissue landmarks (HTL) and 19 soft-tissue landmarks (STL). The mean prediction error values were defined as 'excellent,' 'very good,' 'good,' 'acceptable,' and 'unsatisfactory' (criteria: 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively). The degree of accurate prediction percentage (APP) was defined as 'very high,' 'high,' 'medium,' and 'low' (criteria: 90%, 70%, and 50%, respectively) according to the percentage of subjects that showed the error range within 1.5 mm. RESULTS: All HTLs showed acceptable-to-excellent mean PE values, while the STLs Pog', Gn', and Me' showed unsatisfactory values, and the rest showed good-to-acceptable values. Regarding the degree of APP, HTLs Ba, ramus posterior, Pm, Pog, B-point, Me, and mandibular first molar root apex exhibited low APPs. The STLs labrale superius, lower embrasure, lower lip, point of lower profile, B', Pog,' Gn' and Me' also exhibited low APPs. The remainder of HTLs and STLs showed medium-to-very high APPs. CONCLUSION: Despite the possibility of using the CNN model to predict growth, further studies are needed to improve the prediction accuracy in HTLs and STLs of the chin area.


Subject(s)
Anatomic Landmarks , Artificial Intelligence , Cephalometry , Malocclusion, Angle Class I , Neural Networks, Computer , Humans , Cephalometry/methods , Child , Female , Male , Anatomic Landmarks/diagnostic imaging , Malocclusion, Angle Class I/diagnostic imaging , Algorithms , Maxillofacial Development , Forecasting , Mandible/diagnostic imaging , Mandible/growth & development
2.
Otol Neurotol ; 44(10): e715-e721, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37758320

ABSTRACT

OBJECTIVE: Parents often experience uncertainty during decision-making for their child's cochlear implantation (CI) surgery, and online forums provide insight on parental opinions that might not be expressed in clinic. This study aims to evaluate parental perspectives and concerns about pediatric CI using social media analysis. STUDY DESIGN: Qualitative study. SETTING: Three online forums involving parental posts about pediatric CI. INTERVENTION/METHODS: Forums were queried using keywords (e.g., "cochlear implant") to gather all U.S. parent-initiated posts about pediatric CI from 2006 to 2021. Thematic content analysis was performed to classify posts by overarching domain, themes, and subthemes. Posts were reviewed for thematic synthesis and double coded. Descriptive statistics were calculated for each theme by unique users. RESULTS: A total of 79 posts by 41 unique users were analyzed. Themes relating to decision for CI included facilitators, inhibitors, resources, and feelings. Parents posted about lack of benefit from hearing aids promoting decision for CI and high cost as an inhibitor. Some expressed concern about making a major decision for a minor. Parents often mentioned their child's healthcare providers and social media as resources. CONCLUSION: Through social media posts, parental priorities and concerns for decision-making of CI surgery were identified. Findings may guide discussions between physicians and parents and facilitate shared decision-making about CI.


Subject(s)
Cochlear Implantation , Cochlear Implants , Social Media , Humans , Child , Parents , Qualitative Research
3.
BJS Open ; 4(3): 456-466, 2020 06.
Article in English | MEDLINE | ID: mdl-32277807

ABSTRACT

BACKGROUND: Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM. METHOD: This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three-dimensional construction software; cut-off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence-free survival (RFS) were determined using multivariable and Kaplan-Meier analyses. RESULTS: Some 94 patients were included. TTV cut-off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5-year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection. CONCLUSION: TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.


ANTECEDENTES: Aunque el volumen total del tumor (total tumour volume, TTV) puede tener valor pronóstico tras la resección hepática (hepatic resection, HR) en algunas neoplasias sólidas, no se conoce su importancia en las metástasis hepáticas de cáncer colorrectal (colorectal liver metastases, CRLMs). Este estudio analizó el valor pronóstico del TTV en pacientes con CRLMs resecables. MÉTODOS: Revisión retrospectiva de pacientes a los que se realizó una HR por CRLMs entre 2008 y 2017 en un solo centro. El TTV se estimó a partir de imágenes de tomografía computarizada utilizando un programa de reconstrucción 3D; se determinaron los valores de corte mediante un análisis de las características operativas del receptor. Se identificaron los posibles factores pronósticos y se calcularon la supervivencia global (overall survival, OS) y la supervivencia libre de recidiva (recurence-free survival, RFS) mediante análisis multivariados y de Kaplan-Meier. RESULTADOS: Se incluyeron 94 pacientes. Los valores de corte del TTV para la OS y la RFS fueron de 100 mL y 10 mL, respectivamente. En el análisis multivariable para la OS, se incluyeron los tumores del colon derecho, las metástasis linfáticas primarias y la metástasis hepática bilobar; un TTV ≥ 100 mL se asoció de forma independiente con una peor OS (cociente de riesgos instantáneos, hazard ratio, HR, 6,34, i.c. del 95% 2,08-17,9; P = 0,002). En el anáisis para la RFS, se incluyeron tumores primarios de colon derecho y las metástasis linfáticas primarias; un TTV ≥ 10 mL predijo de forma independiente una peor RFS (HR 1,90, i.c. del 95% 1,12-3,57; P = 0,017). Las tasas de OS a los 5 años con TTVs ≥ 100 mL versus < 100 mL fueron del 41% versus 67% (P = 0,006); las tasas de RFS respecto a TTVs ≥ 10 mL versus < 10 mL fueron del 14% versus 58% (P = 0,009). Un TTV ≥ 100 mL conllevó una tasa más elevada (80%) de recidivas no resecables después de la HR inicial. CONCLUSIÓN: El TTV se asoció con la RFS y la OS tras la HR por CRLMs; unos valores ≥ 100 mL conllevan una tasa más elevada de recidiva irresecable.


Subject(s)
Colorectal Neoplasms/pathology , Liver Neoplasms/secondary , Tumor Burden , Aged , Colorectal Neoplasms/mortality , Colorectal Neoplasms/surgery , Female , Humans , Japan , Liver Neoplasms/mortality , Liver Neoplasms/surgery , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Recurrence, Local/surgery , Prognosis , Retrospective Studies , Survival Analysis , Time Factors
4.
Orthod Craniofac Res ; 21(1): 63-70, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29271058

ABSTRACT

OBJECTIVES: To estimate the optimal bending angles in the running loop for mesial translation of a mandibular second molar using indirect skeletal anchorage and to clarify the mechanics of tipping and rotating the molar. METHODS: A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying the force systems. RESULTS: When using a running loop without bends, the molar tipped mesially 14.4° and lingually 0.6°, rotated counterclockwise 4.1°, and the incisors retracted 0.02 mm and intruded 0.05 mm. These angles were about the same as those estimated by the beam theory. When the amount of tip back and toe-in angles was 11.0°, mesial translation of the molar was achieved, and incisors retracted 0.10 mm and intruded 0.30 mm. CONCLUSIONS: Mesial translation of a mandibular second molar without any significant movement of anterior teeth was achieved during protraction by controlling the tip back and toe-in angles and enhancing anterior anchorage with the combined use of a running loop and indirect skeletal anchorage.


Subject(s)
Mandible , Molar , Orthodontic Anchorage Procedures/methods , Tooth Movement Techniques/methods , Computer Simulation , Dental Stress Analysis , Finite Element Analysis , Humans , Mesial Movement of Teeth , Models, Dental , Radiography, Panoramic , Stress, Mechanical , Tomography, X-Ray Computed
5.
Eur J Ophthalmol ; 27(6): 746-750, 2017 Nov 08.
Article in English | MEDLINE | ID: mdl-28430331

ABSTRACT

PURPOSE: To evaluate factors associated with response to intravitreal bevacizumab (IVB) and intravitreal triamcinolone acetonide (IVTA) in diabetic macular edema (DME). METHODS: Ninety-one eyes of 88 patients diagnosed with DME were enrolled in this retrospective chart review. Group 1 included eyes that showed good response to IVB. Group 2 included eyes that did not respond to IVB but responded to IVTA. Group 3 included eyes that responded to neither. Clinical factors, HbA1c, and optical coherence tomography (OCT) findings including patterns of macular edema were compared among the 3 groups. RESULTS: A total of 44, 27, and 20 eyes were included in groups 1, 2, and 3, respectively. HbA1c was higher in group 3 than in the other groups. Proportion of full (combination of all patterns) type edema was higher in group 3 than in the other 2 groups. In group 1, the proportion of sponge-like diffuse retinal thickening type was higher and cystoid macular edema type was lower than in the other groups. CONCLUSIONS: The degree of diabetic control and morphologic subtypes with OCT should be considered to better predict the prognosis after treatment in DME.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Bevacizumab/therapeutic use , Diabetic Retinopathy/drug therapy , Glucocorticoids/therapeutic use , Macular Edema/drug therapy , Triamcinolone Acetonide/therapeutic use , Adult , Aged , Antibodies, Monoclonal, Humanized/therapeutic use , Diabetic Retinopathy/physiopathology , Drug Therapy, Combination , Female , Glycated Hemoglobin/analysis , Humans , Intravitreal Injections , Male , Middle Aged , Retrospective Studies , Tomography, Optical Coherence , Visual Acuity/physiology
6.
Clin Oncol (R Coll Radiol) ; 27(1): 16-21, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25445554

ABSTRACT

AIMS: There are limited outcome data after radiotherapy treatment for clinically localised, castration-resistant prostate cancer. We report our single institution experience on patient outcomes in this group using high-dose palliative radiotherapy (HDPRT). MATERIALS AND METHODS: A retrospective review of patient hospital records was conducted in prostate cancer patients treated with palliative intent radiotherapy and restricted to those who had castration-resistant disease, no evidence of regional or distant disease and who received a local radiotherapy dose equivalent to 40 Gy or greater. RESULTS: Fifty-one patients met the study criteria, 88% of these had high-risk disease at initial diagnosis. The median time to delivery of HDPRT was 66 months and the median follow-up from HDPRT was 54 months. Grade 3 or worse toxicity was experienced in 8%. The estimated freedom from local failure, cause-specific survival and overall survival at 5 years were 81, 65 and 35%, respectively. Local procedures were a significant contributor to local morbidity, with the most common procedure a transurethral resection of the prostate (27% patients). Only two patients died from complications of local failure. CONCLUSION: HDPRT was well tolerated and provided a high rate of local control in a clinically localised castration-resistant prostate cancer population. Although prostate cancer remained the most frequent cause of death, some patients had extended survival without evidence of disease progression.


Subject(s)
Palliative Care/methods , Prostatic Neoplasms, Castration-Resistant/radiotherapy , Aged , Aged, 80 and over , Dose-Response Relationship, Radiation , Humans , Male , Middle Aged , Radiotherapy Dosage , Retrospective Studies , Treatment Failure , Treatment Outcome
7.
Clin Oncol (R Coll Radiol) ; 26(12): 789-96, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25242000

ABSTRACT

AIMS: To evaluate the effect of incorporating daily ultrasound scanning to reduce variation in bladder filling before prostate bed radiotherapy. The primary aim was to confirm that coverage of the planning target volume (PTV) with the 95% isodose was within tolerance when the ultrasound-determined bladder volume was within individualised patient limits. MATERIALS AND METHODS: Cone beam computed tomography (CBCT) images were acquired on 10 occasions during the course of treatment to assess systematic changes in rectal or bladder volume as part of a standard offline image-guided radiotherapy (IGRT) protocol. In addition, through a two-part study an ultrasound scan of the bladder was added to the IGRT protocol. In the Part 1 study, the ultrasound-determined bladder volume at the time of treatment simulation in 26 patients was compared with the simulation computed tomography cranio-caudal bladder length. The relationship between the two was used to establish bladder volume tolerance limits for the interventional component of the Part 2 study. In the Part 2 study, 24 patients underwent ultrasound scanning before treatment. When bladder volumes were outside the specified limits, they were asked to drink more water or void as appropriate until the volume was within tolerance. RESULTS: Based on the results of the Part 1 study, a 100 ml tolerance was applied in the Part 2 study. Seventy-six per cent of patients found to have bladder volumes outside tolerance were able to satisfactorily adjust their bladder volumes on demand. Comparing the bladder volumes with the CBCT data revealed that the bladder scanner correctly predicted that the target volume would be accurately targeted (using surrogate end points) in 83% of treatment fractions. CONCLUSION: A simple hand-held ultrasound bladder scanner provides a practical, inexpensive, online solution to confirming that the bladder volume is within acceptable, patient-specific limits before treatment delivery, with the potential to improve overall treatment accuracy.


Subject(s)
Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods , Urinary Bladder/diagnostic imaging , Cone-Beam Computed Tomography/methods , Humans , Male , Patient Compliance , Regression Analysis , Ultrasonography , Urinary Bladder/anatomy & histology
8.
J Clin Pediatr Dent ; 37(4): 421-7, 2013.
Article in English | MEDLINE | ID: mdl-24046994

ABSTRACT

It can be difficult to formulate a definitive diagnosis and treatment plan for patients with hypodontia while dental development is still in progress. Proper radiographs should be used periodically to check for the possibility of delayed tooth development to reduce the potential of misdiagnosis and improper treatment. This article presents a case with orthodontic treatment of hypodontia and delayed development of a maxillary second premolar.


Subject(s)
Bicuspid/physiopathology , Malocclusion, Angle Class III/complications , Open Bite/complications , Orthodontics, Corrective/methods , Anodontia/diagnostic imaging , Anodontia/therapy , Cephalometry , Child , Extraoral Traction Appliances , Female , Humans , Malocclusion, Angle Class III/diagnostic imaging , Maxilla , Orthodontics, Corrective/instrumentation , Radiography , Tooth Eruption
9.
J Clin Pediatr Dent ; 37(3): 329-34, 2013.
Article in English | MEDLINE | ID: mdl-23855181

ABSTRACT

During the mixed dentition stage, adolescents experience rapid dental and skeletal development. Unfortunately, many of them do not visit the orthodontist early enough and miss out on the opportunity to take advantage of preventive and interceptive orthodontic treatment. This article describes the management of regaining leeway space and correcting anterior crossbite using a modified maxillary molar distalizing appliance.


Subject(s)
Malocclusion/therapy , Orthodontic Appliance Design , Orthodontic Appliances , Tooth Movement Techniques/methods , Cephalometry/methods , Child , Dentition, Mixed , Follow-Up Studies , Humans , Male , Malocclusion, Angle Class II/therapy , Molar/pathology , Orthodontic Anchorage Procedures/instrumentation , Orthodontic Brackets , Orthodontic Wires , Palatal Expansion Technique/instrumentation , Patient Care Planning
10.
Sci Rep ; 3: 1325, 2013.
Article in English | MEDLINE | ID: mdl-23429577

ABSTRACT

An in situ platform for characterizing plasma-materials interactions at the nanoscale in the transmission electron microscope (TEM) has been demonstrated. Integrating a DC microplasma device, having plane-parallel electrodes with a 25 nm thick Au film on both the cathode and anode and operating in 760 Torr of Ar, within a TEM provides real-time observation of Au sputtering and island formation with a spatial resolution of < 100 nm. Analyses of TEM and atomic force microscopy images show the growth of Au islands to proceed by a Stranski-Krastanov process at a rate that varies linearly with the discharge power and is approximately a factor of 3 larger than the predictions of a DC plasma sputtering model. The experiments reported here extend in situ TEM diagnostics to plasma-solid and plasma-liquid interactions.

11.
Spinal Cord ; 51(2): 126-33, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22945747

ABSTRACT

STUDY DESIGN: Retrospective database analysis. OBJECTIVES: To describe comorbidities, pain-related pharmacotherapy, healthcare resource use and costs among patients with spinal cord injury (SCI) newly prescribed pregabalin. SETTING: United Kingdom (UK). METHODS: Using The Health Improvement Network database, SCI patients newly prescribed (index event) pregabalin (N=72; average age 48 years; 53% female) were selected. Study measures were evaluated during both the 9-months pre-index and follow-up periods. RESULTS: Prevalent comorbidities included musculoskeletal disorders (51.4%), digestive disorders (23.6%) and urogenital disorders (20.8%). Opioids were the most frequently prescribed medications (pre-index, 58.3%; follow-up, 61.1%, P=not significant (NS)) followed by nonsteroidal anti-inflammatory drugs (43.1 and 45.8%, P=NS). Use of anti-epileptics (other than pregabalin) recommended for SCI neuropathic pain decreased (25.0 vs 12.5%, P=0.0290), whereas sedative/hypnotic use (18.1 vs 26.4%, P=0.034) increased during follow-up. Over 50% of patients had visits to specialists, and at least 1 in every 10 had laboratory/radiology-related visits. There were numerical decreases in proportions of patients with emergency room visits (22.2 vs 13.9%, P=NS) and hospitalizations (16.7 vs 12.5%, P=NS) during follow-up. Medication costs were higher during follow-up (median, £ 561.4 vs £ 889.5, P<0.0001). Costs of outpatient visits were similar during both study periods (£ 1082.1 vs £ 1066.1) as were total medical costs (£ 1689.0 vs £ 2169.4) when costs of pregabalin prescriptions were excluded. Inclusion of pregabalin costs resulted in higher (P<0.0001) total medical costs during follow-up. CONCLUSION: SCI patients had a high comorbidity, medication and healthcare resource use burden in clinical practice. Further research with larger sample sizes and more comprehensive data sources may serve to clarify study findings.


Subject(s)
Analgesics/economics , Spinal Cord Injuries/drug therapy , Spinal Cord Injuries/economics , gamma-Aminobutyric Acid/analogs & derivatives , Adult , Analgesics/therapeutic use , Comorbidity , Female , Health Care Costs , Health Resources/economics , Humans , Male , Middle Aged , Pregabalin , Spinal Cord Injuries/epidemiology , United Kingdom/epidemiology , gamma-Aminobutyric Acid/economics , gamma-Aminobutyric Acid/therapeutic use
12.
Clin Oncol (R Coll Radiol) ; 24(8): e93-9, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22694787

ABSTRACT

AIMS: To compare the treatment time and cost of prostate cancer fiducial marker image-guided radiotherapy (IGRT) using orthogonal kilovoltage imaging (KVI) and automated couch shifts and orthogonal electronic portal imaging (EPI) and manual couch shifts. MATERIALS AND METHODS: IGRT treatment delivery times were recorded automatically on either unit. Costing was calculated from real costs derived from the implementation of a new radiotherapy centre. To derive cost per minute for EPI and KVI units the total annual setting up and running costs were divided by the total annual working time. The cost per IGRT fraction was calculated by multiplying the cost per minute by the duration of treatment. A sensitivity analysis was conducted to test the robustness of our analysis. Treatment times without couch shift were compared. RESULTS: Time data were analysed for 8648 fractions, 6057 from KVI treatment and 2591 from EPI treatment from a total of 294 patients. The median time for KVI treatment was 6.0 min (interquartile range 5.1-7.4 min) and for EPI treatment it was 10.0 min (interquartile range 8.3-11.8 min) (P value < 0.0001). The cost per fraction for KVI was A$258.79 and for EPI was A$345.50. The cost saving per fraction for KVI varied between A$66.09 and A$101.64 by sensitivity analysis. In patients where no couch shift was made, the median treatment delivery time for EPI was 8.8 min and for KVI was 5.1 min. CONCLUSIONS: Treatment time is less on KVI units compared with EPI units. This is probably due to automation of couch shift and faster evaluation of imaging on KVI units. Annual running costs greatly outweigh initial setting up costs and therefore the cost per fraction was less with KVI, despite higher initial costs. The selection of appropriate IGRT equipment can make IGRT practical within radiotherapy departments.


Subject(s)
Prostatic Neoplasms/economics , Prostatic Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/economics , Radiotherapy, Image-Guided/economics , Radiotherapy, Image-Guided/methods , Costs and Cost Analysis , Humans , Male , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Conformal/economics , Radiotherapy, Conformal/methods , Radiotherapy, Intensity-Modulated/economics , Radiotherapy, Intensity-Modulated/methods
13.
Br J Radiol ; 85(1015): 1011-7, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22253345

ABSTRACT

OBJECTIVES: To report on complications from transrectal ultrasound-guided insertion of fiducial markers for prostate image-guided radiotherapy. METHODS: 234 patients who underwent transrectal fiducial marker insertion for prostate cancer image-guided radiotherapy were assessed retrospectively by questionnaire with regard to the duration and severity of eight symptoms experienced following the procedure. Pain during the implantation procedure was assessed according to the Wong-Baker faces pain scale. RESULTS: Of 234 patients, 32% had at least one new symptom after the procedure. The commonest new symptom following the procedure was urinary frequency affecting 16% of patients who had not been troubled by frequency beforehand. Haematuria, rectal bleeding, dysuria and haematospermia affected 9-13% of patients, mostly at Grade 1 or 2. Pain, obstruction, and fever and shivers affected 3-4% of patients. Grade 3 rectal bleeding, haematuria, fever and shivers, and urinary frequency affected 0.5-1.5% of patients. Only one patient had a Grade 4 complication (i.e. fever and shivers). Overall, 9% of patients had symptoms lasting more than 2 weeks. The commonest symptoms that lasted more than 2 weeks were frequency, dysuria, obstructive symptoms and rectal bleeding. Mean pain score during the procedure was 1.1 (range 0-5). CONCLUSION: Transrectal ultrasound-guided fiducial marker insertion for image-guided radiotherapy is well tolerated in the majority of prostate cancer patients. Most symptoms were Grade 1 or 2 in severity. Symptoms in the majority of patients last under 2 weeks. The most serious complication was sepsis in our study.


Subject(s)
Fiducial Markers/adverse effects , Prostatic Neoplasms/radiotherapy , Radiotherapy, Image-Guided/methods , Aged , Aged, 80 and over , Fever/epidemiology , Fever/etiology , Fever/physiopathology , Follow-Up Studies , Hematuria/epidemiology , Hematuria/etiology , Hematuria/physiopathology , Humans , Incidence , Male , Middle Aged , Pain/epidemiology , Pain/etiology , Pain/physiopathology , Pain Measurement , Prostatic Neoplasms/pathology , Radiotherapy, Image-Guided/adverse effects , Retrospective Studies , Risk Assessment , Surveys and Questionnaires , Ultrasonography, Interventional/methods , Urinary Tract Infections/epidemiology , Urinary Tract Infections/etiology , Urinary Tract Infections/physiopathology
14.
Br J Radiol ; 85(1010): 176-82, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21976627

ABSTRACT

OBJECTIVES: The purpose of this study was to compare interfraction prostate displacement data between electronic portal imaging (EPI) and kilovoltage imaging (KVI) treatment units and discuss the impact of any difference on margin calculations for prostate cancer image-guided radiotherapy (IGRT). METHODS: Prostate interfraction displacement data was collected prospectively for the first 4 fractions in 333 patients treated with IGRT with daily pre-treatment EPI or KVI orthogonal imaging. Displacement was recorded in the anteroposterior (AP), left-right (LR) and superoinferior (SI) directions. The proportion of displacement <3 mm and the difference in median absolute displacements were calculated in all directions. RESULTS: 1088 image pairs were analysed in total, 448 by EPI and 640 by KVI. There were 23% (95% confidence interval [CI] 18-28%) more displacements under 3 mm for EPI than for KVI in the AP direction, 14% (95% CI 10-19%) more in the LR direction and 10% (95% CI 5-15%) more in the SI direction. The differences in absolute median displacement (KVI>EPI) were AP 1 mm, LR 1 mm and SI 0.5 mm. Wilcoxon rank-sum test showed that distributions were significantly different for all three dimensions (p<0.0001 for AP and LR and p=0.02 for SI). CONCLUSION: EPI has a statistically significant smaller set-up error distribution than KVI. We would expect that, because fiducial marker imaging is less clear for EPI, the clinical target volume to planning target volume margin would be greater when using IGRT; however, relying wholly on displacement data gives the opposite result. We postulate that this is owing to observer bias, which is not accounted for in margin calculation formulas.


Subject(s)
Prostate/diagnostic imaging , Prostatic Neoplasms/diagnostic imaging , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Conformal/methods , Radiotherapy, Image-Guided/methods , Fiducial Markers , Humans , Male , Prospective Studies , Prostatic Neoplasms/radiotherapy , Tomography, X-Ray Computed
15.
Med Phys ; 38(11): 5838-43, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22047347

ABSTRACT

PURPOSE: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. METHODS: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. RESULTS: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. CONCLUSIONS: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.


Subject(s)
Brachytherapy/instrumentation , Dose Fractionation, Radiation , Motion , Movement , Prostatic Neoplasms/physiopathology , Prostatic Neoplasms/radiotherapy , Humans , Male
16.
Clin Oncol (R Coll Radiol) ; 23(7): 449-53, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21376547

ABSTRACT

AIMS: To analyse the relationship between body mass index (BMI) and intrafraction displacement in patients undergoing prostate cancer image-guided radiotherapy. MATERIALS AND METHODS: An analysis was carried out on 151 prostate cancer patients treated with radical dose radiotherapy between January 2007 and March 2009. Patients had their height, weight and daily intrafraction prostate displacement data collected prospectively during fiducial marker image-guided radiotherapy with orthogonal imaging. For each of anterior-posterior, left-right and superior-inferior axes, a univariable linear regression analysis was carried out with the individual patient standard deviation of shift as the response variable and BMI as a continuous explanatory variable. RESULTS: Displacement measurements were recorded from 4764 pre- and post-treatment image sets. Patients were grouped according to BMI as normal weight (24%), overweight (52%), obese (18%), severely obese (3%) or morbidly obese (3%). For intrafraction displacement, a one unit increase in BMI affected the standard deviation of shift by: anterior-posterior -0.02 (95% confidence interval -0.040 to 0.000), left-right -0.006 (95% confidence interval -0.020 to 0.008) and superior-inferior -0.020 (95% confidence interval -0.037 to -0.003). CONCLUSIONS: Our data indicate that patients with a higher BMI have less intrafraction displacement of the prostate in the superior-inferior dimension compared with patients with a lower BMI. This has implications for individualised treatment margins for future prostate cancer patients undergoing image-guided radiotherapy. Further study is recommended.


Subject(s)
Prostatic Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods , Adolescent , Adult , Body Mass Index , Fiducial Markers , Humans , Male , Neoplasm Staging , Obesity/complications , Overweight/complications , Precision Medicine/methods , Prostatic Neoplasms/complications , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Radiography , Radiotherapy, Image-Guided , Radiotherapy, Intensity-Modulated , Young Adult
17.
Psychol Med ; 41(8): 1709-19, 2011 Aug.
Article in English | MEDLINE | ID: mdl-20809999

ABSTRACT

BACKGROUND: We investigated cerebral structural connectivity and its relationship to symptoms in never-medicated individuals with first-onset schizophrenia using diffusion tensor imaging (DTI). METHOD: We recruited subjects with first episode DSM-IV schizophrenia who had never been exposed to antipsychotic medication (n=34) and age-matched healthy volunteers (n=32). All subjects received DTI and structural magnetic resonance imaging scans. Patients' symptoms were assessed on the Positive and Negative Syndrome Scale. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values significantly correlated with symptom scores. RESULTS: In patients with first-episode schizophrenia, positive symptoms correlated positively with FA scores in white matter associated with the right frontal lobe, left anterior cingulate gyrus, left superior temporal gyrus, right middle temporal gyrus, right middle cingulate gyrus, and left cuneus. Importantly, FA in each of these regions was lower in patients than controls, but patients with more positive symptoms had FA values closer to controls. We found no significant correlations between FA and negative symptoms. CONCLUSIONS: The newly-diagnosed, neuroleptic-naive patients had lower FA scores in the brain compared with controls. There was positive correlation between FA scores and positive symptoms scores in frontotemporal tracts, including left fronto-occipital fasciculus and left inferior longitudinal fasciculus. This implies that white matter dysintegrity is already present in the pre-treatment phase and that FA is likely to decrease after clinical treatment or symptom remission.


Subject(s)
Brain/ultrastructure , Schizophrenia/pathology , Schizophrenic Psychology , Adult , Case-Control Studies , Diffusion Tensor Imaging , Female , Frontal Lobe/ultrastructure , Gyrus Cinguli/ultrastructure , Humans , Male , Psychiatric Status Rating Scales , Temporal Lobe/ultrastructure
18.
J Clin Pediatr Dent ; 36(2): 211-8, 2011.
Article in English | MEDLINE | ID: mdl-22524087

ABSTRACT

OBJECTIVE: The purpose of this study was to explore the 3-dimensional (3D) accuracy of magnetic resonance imaging (MRI) on cone-beam computed tomography (CBCT) images after the registration of MRI images on CBCT images. MATERIALS AND METHODS: Three Japanese adult females volunteered for this study. To transform digital imaging and communication in medicine (DICOM) data derived from MRI and CBCT images into polygon data, five software programs were used. CBCT and MRI images were obtained within one week, and both were registered by the iterative closest point (ICP) method. To assess the accuracy of the composite MRI-CBCT, the measurement errors of the MRI-CBCT were verified Measurement values were compared using frontal and cephalometric soft-tissue landmarks. Differences were analyzed using the non-parametric Mann-Whitney U test. RESULTS: There were no significant linear measurement errors (P > 0.05) when the images were measured from the superimposed MRI-CBCT images. CONCLUSION: The MRI images attained from MRI - CBCT registration showed accurate 3D linear measurements.


Subject(s)
Cone-Beam Computed Tomography , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging , Orthodontics , Adult , Cephalometry , Female , Humans , Image Processing, Computer-Assisted/methods , Models, Dental , Radiology Information Systems , Signal Processing, Computer-Assisted , Skull/anatomy & histology , Skull/diagnostic imaging , Software , Subtraction Technique
20.
J Med Imaging Radiat Oncol ; 54(6): 513-25, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21199428

ABSTRACT

External beam radiotherapy for prostate cancer has undergone substantial technological and clinical advances in the recent years. The Australian & New Zealand Faculty of Radiation Oncology Genito-Urinary Group undertook a process to develop consensus clinical practice guidelines for external beam radiotherapy for prostate carcinoma delivered with curative intent, aiming to provide guidance for clinicians on the appropriate integration of clinical evidence and newer technologies. Draft guidelines were presented and discussed at a consensus workshop in May 2009 attended by radiation oncologists, radiation therapists and medical physicists. Amended guidelines were distributed to radiation oncologists in Australia, New Zealand and Singapore for comment, and modifications were incorporated where appropriate. Evidence based recommendations for risk stratification, the role of image-guided and intensity-modulated radiation therapy, prescribed dose, simulation and treatment planning, the role and duration of neo-adjuvant/adjuvant androgen deprivation therapy and outcome reporting are presented. Central to the guidelines is the recommendation that image-guided radiation therapy should be used when definitive external beam radiotherapy for prostate cancer is prescribed. The consensus guidelines provide a co-operatively developed, evidence-based framework for contemporary treatment of prostate cancer with external beam radiotherapy.


Subject(s)
Prostatic Neoplasms/radiotherapy , Radiation Oncology , Radiotherapy, Intensity-Modulated/methods , Australia , Humans , Imaging, Three-Dimensional , Male , New Zealand , Singapore
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