scholarly journals Evaluation of T2-Weighted MRI for Visualization and Sparing of Urethra with MR-Guided Radiation Therapy (MRgRT) On-Board MRI

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3564
Author(s):  
Jonathan Pham ◽  
Ricky R. Savjani ◽  
Yu Gao ◽  
Minsong Cao ◽  
Peng Hu ◽  
...  
Keyword(s):  
Prostatic Urethra ◽  
Radiation Oncologist ◽  
Dice Coefficient ◽  
Significant Treatment ◽  
Genitourinary Toxicity ◽  
Mri Sequences ◽  
The Mean ◽  
Visibility Score ◽  
Planning Ct ◽  
Optimal Imaging

Purpose: To evaluate urethral contours from two optimized urethral MRI sequences with an MR-guided radiotherapy system (MRgRT). Methods: Eleven prostate cancer patients were scanned on a MRgRT system using optimized urethral 3D HASTE and 3D TSE. A resident radiation oncologist contoured the prostatic urethra on the patients’ planning CT, diagnostic 3T T2w MRI, and both urethral MRIs. An attending radiation oncologist reviewed/edited the resident’s contours and additionally contoured the prostatic urethra on the clinical planning MRgRT MRI (bSSFP). For each image, the resident radiation oncologist, attending radiation oncologist, and a senior medical physicist qualitatively scored the prostatic urethra visibility. Using MRgRT 3D HASTE-based contouring workflow as baseline, prostatic urethra contours drawn on CT, diagnostic MRI, clinical bSSFP and 3D TSE were evaluated relative to the contour on 3D HASTE using 95th percentile Hausdorff distance (HD95), mean-distance-to-agreement (MDA), and DICE coefficient. Additionally, prostatic urethra contrast-to-noise-ratios (CNR) were calculated for all images. Results: For two out of three observers, the urethra visibility score for 3D HASTE was significantly higher than CT, and clinical bSSFP, but was not significantly different from diagnostic MRI. The mean HD95/MDA/DICE values were 11.35 ± 3.55 mm/5.77 ± 2.69 mm/0.07 ± 0.08 for CT, 7.62 ± 2.75 mm/3.83 ± 1.47 mm/0.12 ± 0.10 for CT + diagnostic MRI, 5.49 ± 2.32 mm/2.18 ± 1.19 mm/0.35 ± 0.19 for 3D TSE, and 6.34 ± 2.89 mm/2.65 ± 1.31 mm/0.21 ± 0.12 for clinical bSSFP. The CNR for 3D HASTE was significantly higher than CT, diagnostic MRI, and clinical bSSFP, but was not significantly different from 3D TSE. Conclusion: The urethra’s visibility scores showed optimized urethral MRgRT 3D HASTE was superior to the other tested methodologies. The prostatic urethra contours demonstrated significant variability from different imaging and workflows. Urethra contouring uncertainty introduced by cross-modality registration and sub-optimal imaging contrast may lead to significant treatment degradation when urethral sparing is implemented to minimize genitourinary toxicity.

scholarly journals Daily Stereotactic Ultrasound Prostate Targeting: Inter-user Variability

2003 ◽  
Vol 2 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Martin Fuss ◽  
Sean X. Cavanaugh ◽  
Cristina Fuss ◽  
Dennis A. Cheek ◽  
Bill J. Salter
Keyword(s):  
Prostate Cancer ◽  
Gold Standard ◽  
Setup Error ◽  
Radiation Oncologist ◽  
Ultrasound Guided ◽  
Prostate Radiotherapy ◽  
Average Improvement ◽  
The Mean ◽  
Patient Setup ◽  
Planning Ct

We analyzed the inter-user variability of patient setup for prostate radiotherapy using a stereotactic ultrasound-targeting device. Setup variations in 20 prostate cancer patients were analyzed. Users were a radiation oncologist, a medical physicist, four radiation technologists (RTT) and a radiologist. The radiation oncologist, radiologist, physicist and two RTTs were experienced users of the system (>18 months of experience); two RTTs were users new to the system. Gold standard for this analysis was a control CT acquired immediately following ultrasound targeting. For inter-user variability assessments, the radiation oncologist provided a set of axial and sagittal freeze-frames (standard freeze-frames) for virtual targeting by all users. Additionally each user acquired individual freeze-frames for target alignments. We analyzed the range of virtual setups in each patient along the principal room axes based on standard and individual freeze-frames. The magnitude of residual setup error and percentage of setup change for each user was assessed by control CT/planning CT comparison with individual virtual shifts. A total of 184 alignments were analyzed. The range of virtual shifts between users was 2.7±1.4, 3.6±1.1, and 4.4±1.4 mm (mean±SD) in x, y and z-direction for setups based on standard freeze-frames and 3.9±2.6, 6.0±4.7, and 5.4±2.7 mm for setups based on individual freeze-frames. When only virtual shifts of experienced users were analyzed, the mean ranges were reduced by up to 2.4 mm. Average magnitude of initial setup error before ultrasound targeting was 14.3 mm. Average improvement of prostate setup was 63.1±23.4% in experienced and 35.14±37.7% in inexperienced users, respectively (p<0.0001). Only 5 of 184 (2.7%) virtual alignments would have introduced new larger setup errors (mean 3.2 mm, range 0.2 to 9.5 mm) than the magnitude of the initial setup error. We conclude that ultrasound guided treatment setup for patients treated for prostate cancer can be performed with high inter-user consistency and does lead to improved treatment setup in more than 97% of attempted setups. Experienced use is correlated with a reduced range of setups between users and higher degree of setup improvement when compared with users new to the system.

scholarly journals Narrow band imaging under less-air condition improves the visibility of superficial esophageal squamous cell carcinoma

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Taro Iwatsubo ◽  
Ryu Ishihara ◽  
Yasushi Yamasaki ◽  
Yusuke Tonai ◽  
Kenta Hamada ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Color Change ◽  
Narrow Band ◽  
Narrow Band Imaging ◽  
Endoscopic Observation ◽  
Flat Type ◽  
The Mean ◽  
Visibility Score

Abstract Background The current virtual chromoendoscopy equipment cannot completely detect superficial squamous cell carcinoma (SCC) in the esophagus, despite its development in the recent years. Thus, in this study, we aimed to elucidate the appropriate air volume during endoscopic observation to improve the visibility of esophageal SCC. Methods This retrospective study included a total of 101 flat type esophageal SCCs identified between April 2017 and January 2019 at the Department of Gastrointestinal Oncology, Osaka International Cancer Institute. Video images of narrow band imaging (NBI) under both less-air and standard-air conditions were recorded digitally. Videos were evaluated by five endoscopists. Relative visibility between less-air and standard-air conditions of the brownish area, brownish color change of the epithelium, and dilated intrapapillary capillary loop (IPCL) were graded as 5 (definitely better under less-air condition) to 1 (definitely worse under less-air condition), with 3 indicating average visibility (equivalent to standard-air observation). Results The mean (standard deviation) visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs under less-air condition were 3.94 (0.58), 3.73 (0.57), and 4.13 (0.60), respectively, which were significantly better than that under standard-air condition (p < 0.0001). Esophageal SCC evaluated as ≥ 4 in the mean visibility score of the brownish area, brownish color change of the epithelium, and dilated IPCLs accounted for 50% (51/101 lesions), 34% (34/101 lesions), and 67% (68/101 lesions), respectively. Conclusions The present results suggested that NBI with less air might improve the visibility of flat type esophageal SCC compared with NBI with standard air. Less-air NBI observation may facilitate the detection of flat type esophageal SCC. Trial registration The present study is a non-intervention trial.

scholarly journals OC-0157: Atlas-based segmentation of prostatic urethra in the planning CT of prostate cancer

2017 ◽  
Vol 123 ◽  
pp. S79-S80
Author(s):  
O. Acosta ◽  
M. Le Dain ◽  
C. Voisin ◽  
R. Bastien ◽  
C. Lafond ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostatic Urethra ◽  
Planning Ct

Once-Weekly Oral Alendronate 70 mg in Patients with Glucocorticoid-Induced Bone Loss: A 12-Month Randomized, Placebo-Controlled Clinical Trial

2009 ◽  
Vol 36 (8) ◽  
pp. 1705-1714 ◽  
Author(s):  
S. AUBREY STOCH ◽  
KENNETH G. SAAG ◽  
MARIA GREENWALD ◽  
ANTHONY I. SEBBA ◽  
STANLEY COHEN ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Bone Loss ◽  
Glucocorticoid Therapy ◽  
Percentage Change ◽  
Significant Treatment ◽  
Treatment Difference ◽  
Total Hip ◽  
The Mean ◽  
Total Body ◽  
Significant Treatment Difference

Objective.Glucocorticoid-induced osteoporosis is the most common iatrogenic form of osteoporosis. We evaluated the efficacy and safety of once-weekly bisphosphonate therapy for prevention and treatment of bone loss in patients on glucocorticoid therapy.Methods.We conducted a 12-month, multicenter, randomized, double-blind, placebo-controlled trial with 114 and 59 patients in the treatment and placebo arms, respectively. Participants were stratified according to the duration of prior oral glucocorticoid therapy at randomization. Participants received alendronate 70 mg once weekly (ALN OW) or placebo; all received supplemental daily calcium (1000 mg) and 400 IU vitamin D. Clinical evaluations were performed at baseline, 3, 6, 9, and 12 months.Results.At 12 months, there was a significant mean percentage increase from baseline in the ALN OW group for lumbar spine (2.45%), trochanter (1.27%), total hip (0.75%), and total body (1.70%) bone mineral density (BMD). Comparing ALN OW versus placebo at 12 months, a significant treatment difference for the mean percentage change from baseline was observed for lumbar spine (treatment difference of 2.92%; p ≤ 0.001), trochanter (treatment difference 1.66%; p = 0.007), and total hip (treatment difference 1.19; p = 0.008) BMD. Biochemical markers of bone remodeling also showed significant mean percentage decreases from baseline.Conclusion.Over 12 months ALN OW significantly increased lumbar spine, trochanter, total hip, and total body BMD compared with baseline among patients taking glucocorticoid therapy. A significant treatment difference versus placebo was observed at 12 months for the mean percentage change from baseline for lumbar spine, trochanter, and total hip.

Levels of first winter feeding in relation to performance of Cheviot hill ewes: VI. Life-time production form the hill

1968 ◽  
Vol 71 (2) ◽  
pp. 161-166 ◽  
Author(s):  
R. G. Gunn
Keyword(s):  
Life Time ◽  
Average Weight ◽  
Significant Treatment ◽  
Time Production ◽  
Treatment Groups ◽  
Production Form ◽  
The Mean ◽  
The Hill ◽  
North And South ◽  
Different Levels

SUMMARYThe effects of different levels of first-winter nutrition over 3 years were studied on the subsequent life-time production from the hill of groups of North and South Country Cheviot ewe hoggs (sheep between 6 months and 1½12 years).Lamb production was examined in terms of the percentage of lambs born and reared per ewe alive at each lambing and was expressed as a mean of five lamb crops. An overall measure of flock life-time production was calculated from the data on lamb production. This was the total number of lambs weaned at a mean 15 weeks in each treatment group over five lamb crops expressed as the mean per experimental animal alive at 6 months.All productive components were analysed for differences between breeds, treatments, and weight-classes, i.e. those animals above or below average weight at 6 months.There were no significant treatment differences in life-time production, although the treatment groups showed different trends with increasing age. Higher production in early life following higher levels of first-winter nutrition was associated with less efficient later production and poorer ewe survival in a hard hill environment.It is concluded that improvement in first-winter nutrition above that available on the hill is undesirable and uneconomic without equal improvement in adult nutrition.

scholarly journals Intra-fraction and Inter-fraction analysis of a dedicated immobilization device for intracranial radiation treatment.

2020 ◽  
Author(s):  
Chin Loon Ong ◽  
Niccolò Giaj Levra ◽  
Luca Nicosia ◽  
Vanessa Figlia ◽  
Davide Tomasini ◽  
...  
Keyword(s):  
Radiation Treatment ◽  
Median Number ◽  
Post Treatment ◽  
Patient Comfort ◽  
Radiation Oncologist ◽  
Median Dose ◽  
Treatment Delivery ◽  
The Mean ◽  
Pre Treatment ◽  
Immobilization Device

Abstract BACKGROUND:Immobilization devices are crucial to minimize patient positioning uncertainties in radiotherapy (RT) treatments. Accurate inter and intra-fraction motions is particularly important for intracranial and stereotactic radiation treatment which require high precision in dose delivery. Recently, a new immobilization device has been developed specifically for the radiation treatment of intracranial malignancies. To date, no data are available on the use of this device in daily clinical practice. The aim of this study is to investigate the intra and inter-fraction variations, patient comfort and radiographer confidence of the immobilization system from two distinct institutions: HagaZiekenhuis, Den Haag, Netherlands and IRCCS Ospedale Sacro Cuore Don Calabria, Negrar, Italy. MATERIAL AND METHOD:Sixteen patients (10 diagnosed with brain metastases and 6 with primary central nervous systemic tumor) from IRCCS Ospedale Sacro Cuore Don Calabria and 17 patients (all diagnosed with brain metastases tumor) from HagaZiekenhuis were included in this study. The median target volume was 436 cc (range 3.2-1628 cc) and 4.58cc (range 0.4-27.19cc) for IRCCS and Haga, respectively. For patients treated in IRCCS Sacro Cuore Don Calabria, the median dose prescription was 30 Gy (range 27-60 Gy) and median number of fractions 10 (range 3-30). In Haga the median dose prescription was 21 Gy (range 8-21 Gy) and the median number of fraction was 1 (range 1-3). The immobilization device was assembled during CT simulation. A short interview to the patient regarding the device’s comfort level was conducted at the end of the simulation procedure. Additionally, simulation setup time and radiographer (RTT) procedures (i.e. mask preparation) were evaluated. Prior to radiation treatment delivery, an automatic rigid match on the cranial bones between cone beam computed tomography (CBCT) and planning-CT was performed. A couch shift was performed subsequently. An extra post-treatment CBCT was acquire after the treatment delivery. This post-treatment CBCT was matched with pre-treatment CBCT to identify any possible intra-fraction motion. All online matches were validated by experienced radiation oncologist or RTT. A total of 126 CBCT’s were analyzed offline by radiation oncologist/medical physicist. The data of the pre-treatment CBCT match was used to quantify inter-fraction motion. The post-treatment CBCT was matched with pre-treatment CBCT to identify any possible intra-fraction motion.RESULTS:During the molding of the mask, all patients responded positive to the comfort. Median time required by the RTTs to assemble the immobilization system was 9 minutes (range 6-12 minutes). In terms of comfort, all patients reported a good-to high level of satisfaction. The RTTs also respond positively towards the use of the locking mechanism and clips. Results of positioning uncertainties were comparable between the two institutes. The mean inter-fraction motion for all translational and rotational directions were <2mm (SD <4mm) and <0.5°(SD < 1.5°), respectively, while the mean intra-fraction motions were <0.4mm (SD < 0.6mm) and 0.3° (SD < 0.5°).CONCLUSIONS:This study demonstrates the efficacy and feasibility of the immobilization device in the intracranial radiation treatment. Both patient comfort and preparation time by RTTs are considered adequate. In combination with online daily imaging procedure, this device can achieve submillimeter accuracy required for intracranial and stereotactic treatments.

An in silico comparative planning study investigating the predicted benefit of dysphagia-optimised volumetric arc therapy (Do-VMAT), relative to standard VMAT (S-VMAT), to reduce radiotherapy-associated dysphagia (RAD) in oropharyngeal cancers (OPC).

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e18540-e18540
Author(s):  
Imran Petkar ◽  
Alex Dunlop ◽  
Dualta McQuaid ◽  
Christopher Nutting
Keyword(s):  
Optimal Dose ◽  
Target Volume ◽  
Phase Iii ◽  
High Dose ◽  
Minimally Clinically Important Difference ◽  
Significant Treatment ◽  
Volumetric Arc Therapy ◽  
Dose Constraint ◽  
The Mean ◽  
Predicted Risk

e18540 Background: RAD is a significant treatment-related functional morbidity in OPC and is associated with irradiation of the pharyngeal constrictor muscle (PCM). This study investigated whether a novel PCM-sparing Do-VMAT technique reduced the risk of RAD, compared to S-VMAT. Methods: Twenty OPC patients who previously underwent radiotherapy (RT) to bilateral neck were selected for this retrospective study. For each patient, S-VMAT and Do-VMAT plans were created. In both arms, the mucosal and nodal tumour received 65 Gy while the remaining oropharynx and at-risk nodal levels received 54 Gy; delivered in 30 fractions over 6 weeks. For Do-VMAT, a mandatory mean dose constraint of < 50 Gy to the volume of the combined superior (SPCM) and middle PCM (MPCM) together with an optimal dose constraint of < 20 Gy to the volume of inferior PCM (IPCM), lying outside the high-dose clinical target volume, were additionally defined and optimised to minimise PCM dose. Normal tissue complication probabilities for physician-scored RAD at 6 months (RAD6M) were determined as per the model by Christianen et al in which the 2 variables were mean dose to SPCM and supraglottic larynx (SGL). Statistical analysis was performed using paired t tests. Results: All plans had adequate target volume coverage, and dose to critical organs were within acceptable parameters. Dose to the parotid and submandibular glands were similar between the 2 RT techniques. The mean integral dose was 110.8 Gy-litre (standard deviation 17.1) with S-VMAT and 103.4 Gy-litre (15.4) with Do-VMAT, p < 0.001. With Do-VMAT, the average of the mean dose to PCM, SPCM, MPCM, IPCM, and SGL were 9.3 Gy (1.4), 4.7 Gy (1.7), 7.4 Gy (3.6), 22.7 Gy (4.1), and 2.6 Gy (2.3) respectively lower than S-VMAT (p < 0.001 for all). The mean predicted risk for RAD6M was 31.0 % (4.4) with S-VMAT, and 23.9 % (3.8) with Do-VMAT, p < 0.001. The absolute reduction in estimated toxicity risk with Do-VMAT was > 5 %, the minimally clinically important difference, in every patient. Conclusions: Do-VMAT demonstrated clinically relevant reductions in the predicted risk of RAD, compared to S-VMAT, by reducing dose to the PCM in OPC. The clinical benefits of Do-VMAT is being prospectively evaluated in DARS (CRUK/14/014), a randomised phase III study.

scholarly journals The NIMO Scandinavian Study: A Prospective Observational Study of Iron Isomaltoside Treatment in Patients with Iron Deficiency

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Svein Oskar Frigstad ◽  
Anne Haaber ◽  
Antal Bajor ◽  
Jan Fallingborg ◽  
Per Hammarlund ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Prospective Observational Study ◽  
Intravenous Iron ◽  
Lower Probability ◽  
Significant Treatment ◽  
The Mean ◽  
Clinically Significant ◽  
High Doses ◽  
One Year ◽  
Over Time

Background. Intravenous iron allows for efficient and well-tolerated treatment in iron deficiency and is routinely used in diseases of the gastrointestinal tract. Objective. The aims of this study were to determine the probability of relapse of iron deficiency over time and to investigate treatment routine, effectiveness, and safety of iron isomaltoside. Methods. A total of 282 patients treated with iron isomaltoside were observed for two treatments or a minimum of one year. Results. Out of 282 patients, 82 had Crohn’s disease and 67 had ulcerative colitis. Another 133 patients had chronic blood loss, malabsorption, or malignancy. Patients who received an iron isomaltoside dose above 1000 mg had a 65% lower probability of needing retreatment compared with those given 1000 mg. A clinically significant treatment response was shown, but in 71/191 (37%) of patients, anaemia was not corrected. The mean dose given was 1100 mg, lower than the calculated total iron need of 1481 mg. Adverse drug reactions were reported in 4% of patients. Conclusion. Iron isomaltoside is effective with a good safety profile, and high doses reduce the need for retreatment over time. Several patients were anaemic after treatment, indicating that doses were inadequate for full iron correction. This trial is registered with NCT01900197.

The response of spring-calving cows to a high level of protein in the supplement given with grass silage during early lactation

1980 ◽  
Vol 30 (1) ◽  
pp. 23-28 ◽  
Author(s):  
F. J. Gordon
Keyword(s):  
Dry Matter ◽  
Body Condition Score ◽  
Experimental Period ◽  
Milk Composition ◽  
High Protein ◽  
Significant Treatment ◽  
Plasma Urea ◽  
Protein Supplements ◽  
Grass Silage ◽  
The Mean

ABSTRACTA randomized block experiment, using 30 British Friesian cows, was used to assess the effects of offering supplements containing 172 and 234 g crude protein per kg dry matter in addition to grass silage which had a very high digestible organic matter in the dry matter of 769 g/kg. The animals, which had a mean calving date of 1 February, were blocked according to calving date and lactation number and allocated at random within each block to the two treatments. The treatments were applied from day 8 of lactation until the animals went to pasture on 13 April and both supplements were offered at the same rate of 7·6 kg per day. The total yields of milk produced during the experimental period were 1626 and 1650 ±38·4 kg and the mean daily yields during the final week were 24·8 and 25·6 ± 0·58kg for the medium and high protein supplements respectively. The mean live weights for the two groups were 524 and 544 ± 5·5 kg, and body condition score 2·9 and 3·3 ± 0·34 for the medium and high protein supplements respectively at the end of the treatment period. No significant treatment effects on milk composition were recorded at any stage during the experiment. Analysis of blood samples taken during the final week of the experiment showed plasma urea levels, at 220 and 290± 18 mg/1 for the medium and high protein supplements respectively, to be significantly different.

A Subchronic Toxicity Study of Phosflex 51B in Sprague-Dawley Rats

2001 ◽  
Vol 20 (5) ◽  
pp. 269-274 ◽  
Author(s):  
Ralph I. Freudenthal ◽  
David Brandwene ◽  
Welmoed Clous
Keyword(s):  
Food Consumption ◽  
Clinical Chemistry ◽  
Female Rats ◽  
Male Rats ◽  
High Dose ◽  
Sprague Dawley ◽  
Significant Treatment ◽  
Sprague Dawley Rats ◽  
The Mean ◽  
Microscopic Pathology

Phosflex 51B is a flame retardant plasticizer that is blended with polyvinyl chloride films to effectively control product flammability. Its composition places it in the butylated triphenyl phosphate category. Previous studies have shown Phosflex 51B to have low acute toxicity, to lack teratogenic and mutagenic activity, and to not induce delayed peripheral neuropathy. The present study was conducted to determine the toxicity of Phosflex 51B after repeated dietary exposure. Four groups, each consisting of 20 male and 20 female Sprague-Dawley rats, received rodent diet containing either 0, 100, 400, or 1600 ppm for 90 days. Parameters measured include body weight, food consumption, clinical observations, hematology, clinical chemistry, and cholinesterase activity. Tissues were examined at necropsy for gross changes and were processed for microscopic pathology. There were no significant treatment-related effects on body weights, food consumption, hematology and clinical chemistry, or cholinesterase values. A significant increase was observed in the absolute and relative mean weights of livers in high-dose male rats, the mean relative fiver weights of the high-dose female animals, the mean relative kidney weights of the high-dose male rats, and the mean absolute weights of the adrenal glands from high-dose female rats. Neither gross nor microscopic pathology examinations revealed tissue changes in these organs or in any other organs. Although increases in fiver, kidney, and adrenal weights were observed in certain animals in the 1600-ppm high-dose group, the administration of Phosflex 51B did not result in significant treatment-related adverse effects at dietary dose levels of 100 and 400 ppm. The no-observable-effect level (NOEL) in this study is 400 ppm.

Sign in / Sign up

Export Citation Format

Share Document