Publications by authors named "Raymond Ko"

31 Publications

Ga-PSMA PET/CT versus CT and bone scan for investigation of PSA failure post radical prostatectomy.

Asian J Urol 2021 Apr 10;8(2):170-175. Epub 2020 Feb 10.

Nepean Urology Research Group, Nepean Hospital, Penrith New South Wales, Australia.

Objective: To evaluate the use of Gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography (Ga-PSMA PET/CT), compared with conventional CT abdomen/pelvis (CTAP) and whole body single photon emission CT bone scan (BS), for detection of local or distant metastasis following biochemical failure/recurrence in post-prostatectomy patients.

Methods: We conducted a review of our prospectively maintained, institutional database to identify 384 patients with post-prostatectomy biochemical failure/recurrence who underwent PSMA PET/CT, CTAP and BS from February 2015 to August 2017 in Nepean Hospital, tertiary referral centre. The results of the three imaging modalities were analysed for their ability to detect local recurrence and distant metastases. PSMA PET/CT and CTAP imaging were separately performed on the same day and the BS was performed within several days (mostly in 24 h). Difference in detection rates was determined between the modalities and the Chi square test was used to determine significance.

Results: A total of 384 patients were identified with a median prostate-specific antigen (PSA) of 0.465 ng/mL (interquartile range =0.19-2.00 ng/mL). Overall, PSMA PET/CT was positive for 245 (63.8%) patients whereas CTAP and BS were positive in 174 patients (45.3%). A total of 98 patients (25.5%) had local or distant metastasis detected on PSMA only, while 20 patients (5.2%) had recurrences detected on CTAP but not on PSMA PET/CT.

Conclusion: The use of PSMA PET/CT has a higher detection rate of predicted local or distant metastasis compared to CTAP and BS in the staging of patients with biochemical recurrences after radical prostatectomy.
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http://dx.doi.org/10.1016/j.ajur.2020.02.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8099644PMC
April 2021

Bladder infusion versus standard catheter removal for trial of void: a systematic review and meta-analysis.

World J Urol 2020 Aug 14. Epub 2020 Aug 14.

Nepean Urology Research Group, Nepean Hospital, Kingswood, NSW, 2747, Australia.

Purpose: To compare the efficacy and time-to-discharge of two methods of trial of void (TOV): bladder infusion versus standard catheter removal.

Methods: Electronic searches for randomized controlled trials (RCTs) comparing bladder infusion versus standard catheter removal were performed using multiple electronic databases from dates of inception to June 2020. Participants underwent TOV after acute urinary retention or postoperatively after intraoperative indwelling catheter (IDC) placement. Quality assessment and meta-analyses were performed, with odds ratio and mean time difference used as the outcome measures.

Results: Eight studies, comprising 977 patients, were included in the final analysis. Pooled meta-analysis demonstrated that successful TOV was significantly higher in the bladder infusion group compared to standard TOV (OR 2.41, 95% CI 1.53-3.8, p = 0.0005), without significant heterogeneity (I=19%). The bladder infusion group had a significantly shorter time-to-decision in comparison to standard TOV (weighted mean difference (WMD)-148.96 min, 95% CI - 242.29, - 55.63, p = 0.002) and shorter time-to-discharge (WMD - 89.68 min, 95% CI - 160.55, - 18.88, p = 0.01). There was no significant difference in complication rates between the two groups.

Conclusion: The bladder infusion technique of TOV may be associated with a significantly increased likelihood of successful TOV and reduced time to discharge compared to standard TOV practices.
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http://dx.doi.org/10.1007/s00345-020-03408-4DOI Listing
August 2020

Case of intermittent testicular torsion and de-torsion captured on scrotal ultrasound.

ANZ J Surg 2021 03 6;91(3):E135-E136. Epub 2020 Aug 6.

Nepean Urology Research Group, Nepean Hospital, Sydney, New South Wales, Australia.

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http://dx.doi.org/10.1111/ans.16161DOI Listing
March 2021

A prospective, matched comparison of ultra-low and standard-dose computed tomography for assessment of renal colic.

BJU Int 2020 09 23;126 Suppl 1:27-32. Epub 2020 Jun 23.

Nepean Urology Research Group, Kingswood, NSW, Australia.

Objective: To determine the diagnostic accuracy of ultra-low-dose computed tomography (ULDCT) compared with standard-dose CT (SDCT) in the evaluation of patients with clinically suspected renal colic, in addition to secondary features (hydroureteronephrosis, perinephric stranding) and additional pathological entities (renal masses).

Patients And Methods: A prospective, comparative cohort study was conducted amongst patients presenting to the emergency department with signs and symptoms suggestive of renal or ureteric colic. Patients underwent both SDCT and ULDCT. Single-blinded review of the image sets was performed independently by three board-certified radiologists.

Results: Among 21 patients, the effective radiation dose was lower for ULDCT [mean (SD) 1.02 (0.16) mSv] than SDCT [mean (SD) 4.97 (2.02) mSv]. Renal and/or ureteric calculi were detected in 57.1% (12/21) of patients. There were no significant differences in calculus detection and size estimation between ULDCT and SDCT. A higher concordance was observed for ureteric calculi (75%) than renal calculi (38%), mostly due to greater detection of calculi of <3 mm by SDCT. Clinically significant calculi (≥3 mm) were detected by ULDCT with high specificity (97.6%) and sensitivity (100%) compared to overall detection (specificity 91.2%, sensitivity 58.8%). ULDCT and SDCT were highly concordant for detection of secondary features, while ULDCT detected less renal cysts of <2 cm. Inter-observer agreement for the ureteric calculi detection was 93.9% for SDCT and 87.8% for ULDCT.

Conclusion: ULDCT performed similarly to SDCT for calculus detection and size estimation with reduced radiation exposure. Based on this and other studies, ULDCT should be considered as the first-line modality for evaluation of renal colic in routine practice.
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http://dx.doi.org/10.1111/bju.15116DOI Listing
September 2020

Long Pulse-Width Setting Improves Holmium-YAG Laser Lithotripsy - Enhanced Fragmentation and Retropulsion Characteristics of Renal Calculi in a Novel In-Vivo Setting.

Surg Technol Int 2020 Nov;37:168-170

Nepean Urology Research Group (NURG), Kingswood, NSW, Australia, Nepean Clinical School, University of Sydney, Kingswood, NSW, Australia.

The aim of this novel in vivo study was to characterize the effect of short pulse-width versus long pulse-width Holmium-YAG laser lithotripter settings on retropulsion and fragmentation in a real-life setting. A prospective, crossover study was conducted at a tertiary teaching hospital in NSW, Australia. Patients who underwent flexible ureteroscopy with laser lithotripsy for renal calculi in 2018 were included. All patients underwent flexible ureteroscopy using a Flexor® 10.7/12 French ureteric access sheath (Cook Medical LLC, Bloomington, IN, USA) and lithotripsy with a 30W Holmium-YAG laser (Rocamed, Monaco). Thirty-two renal calculi were subjected to 1 min of laser treatment using both short and long pulse-width settings. Using 5-point, operator-assessed Likert scales, the level of retropulsion and fragmentation efficacy were assessed. There was significantly less retropulsion and improved stone fragmentation (p<0.001) using the long pulse-width compared to the short pulse-width setting. Regardless of stone size, in vivo renal calculi lithotripsy with a long pulse-width significantly improves the efficacy of lithotripter treatment.
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November 2020

A Systematic Review and Meta-Analysis of Pelvic Drain Insertion After Robot-Assisted Radical Prostatectomy.

J Endourol 2020 04 23;34(4):401-408. Epub 2020 Mar 23.

Nepean Urology Research Group, Nepean Hospital, Kingswood, Australia.

To perform a systematic review and meta-analysis and to assess the clinical benefit of prophylactic pelvic drain (PD) placement after robot-assisted laparoscopic prostatectomy (RALP) with pelvic lymph node dissection (PLND) in patients with localized prostate cancer. An electronic search of databases, including Scopus, Medline, and EMbase, was conducted for articles that considered postoperative outcomes with PD placement and without PD (no drain) placement after RALP. The primary outcome was rate of symptomatic lymphocele (requiring intervention) and secondary outcomes were complications as described by the Clavien-Dindo classification system. Quality assessment was performed using the Modified Cochrane Risk of Bias Tool for Quality Assessment. Six relevant articles comprising 1783 patients (PD = 1253; ND = 530) were included. Use of PD conferred no difference in symptomatic lymphocoele rate (risk difference 0.01; 95% confidence interval [CI] -0.007 to 0.027), with an overall incidence of 2.2% (95% CI 0.013-0.032). No difference in low-grade (I-II; risk difference 0.035, 95% CI -0.065 to 0.148) or high-grade (III-V; risk difference -0.003, 95% CI -0.05 to 0.044) complications was observed between PD and ND groups. Low-grade (I-II) complications were 11.8% (95% CI 0-0.42) and 7.3% (95% CI 0-0.26), with similar rates of high-grade (III-V) complications, being 4.1% (95% CI 0.008-0.084) and 4.3% (95% CI 0.007-0.067) for PD and ND groups, respectively. PD insertion after RALP with extended PLND did not confer significant benefits in prevention of symptomatic lymphocoele or postoperative complications. Based on these results, PD insertion may be safely omitted in uncomplicated cases after consideration of clinical factors.
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http://dx.doi.org/10.1089/end.2019.0554DOI Listing
April 2020

Single use versus reusable digital flexible ureteroscopes: A prospective comparative study.

Int J Urol 2019 10 25;26(10):999-1005. Epub 2019 Aug 25.

Nepean Urology Research Group, Sydney, New South Wales, Australia.

Objectives: To compare the performance and surgical outcomes of two different single-use digital flexible ureteroscopes with a reusable video flexible ureteroscope.

Methods: Patients undergoing retrograde flexible ureteroscopy at Nepean Hospital, Sydney, Australia, were included in this study. Three different flexible ureteroscopes were used in this study: (i) single-use digital LithoVue (Boston Scientific, Marlborough, MA, USA); (ii) single-use digital PU3022A (Pusen, Zhuhai, China); and (iii) reusable digital URF-V2 (Olympus, Tokyo, Japan). Visibility and maneuverability was rated on a 5-point Likert scale by the operating surgeon. Operative outcomes and complications were collected and analyzed.

Results: A total of 150 patients were included in the present study. Of these, 141 patients had ureteroscopy for stone treatment, four for endoscopic combined intrarenal surgery and five for diagnostic/tumor treatment. There were 55 patients in the LithoVue group, 31 in the PU3022A group and 64 patients in the Olympus URF-V2 group. The URF-V2 group had higher visibility scores than both the single-use scopes and higher maneuverability scores when compared with the PU3022A. The LithoVue had higher visibility and maneuverability scores when compared with the PU3022A. There were no differences in operative time, rates of relook flexible ureteroscopes, scope failure or complication rates observed.

Conclusions: Single-use digital flexible ureteroscopes have visibility and maneuverability profiles approaching that of a reusable digital flexible ureteroscope. Single-use flexible ureteroscopes achieve similar clinical outcomes to the more expensive reusable versions.
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http://dx.doi.org/10.1111/iju.14091DOI Listing
October 2019

Editorial Comment.

Authors:
Raymond Ko

J Urol 2019 07 7;202(1):170. Epub 2019 Jun 7.

Department of Urology, University of Sydney, Nepean Hospital, Concord Hospital, Nepean Urology Research Group, Macquarie University Hospital , Sydney , New South Wales , Australia.

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http://dx.doi.org/10.1097/01.JU.0000558169.76885.2eDOI Listing
July 2019

ENCAPSULATED 3,4,3-LI(1,2-HOPO) IN CHITOSAN NANOPARTICLES FOR DECORPORATION VIA INHALATION.

Radiat Prot Dosimetry 2018 Dec;182(1):107-111

Department of Chemistry, Carleton University, Ottawa, Canada.

3,4,3-LI(1,2-HOPO) has been identified as an excellent alternative for DTPA for decorporating actinides, such as Pu and Am, after internal contamination. Efforts have been focused on its application through oral administration. When 3,4,3-LI(1,2-HOPO) was encapsulated with biocompatible, biodegradable nanoparticles made of chitosan, its release from the nanoparticles to lung fluid, observed in in vitro experiments, exhibited an extended release profile. These observations were very encouraging, as this nanomedicine could lead to a reduction in the dosing frequency required to achieve the decorporation efficacy of unformulated 3,4,3-LI(1,2-HOPO) itself. In vivo release tests as well as actinide decorporation experiments, using an inhalation exposure animal model, will follow.
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http://dx.doi.org/10.1093/rpd/ncy139DOI Listing
December 2018

A Rare Case of Ureteral IgG4 Disease Masquerading as Urothelial Carcinoma.

Urology 2018 Aug 22;118:e1-e2. Epub 2018 May 22.

Department of Urology, Nepean Hospital, Nepean Urology Research Group, Kingswood, NSW, Australia; The University of Sydney and Macquarie University Hospital, The University of Sydney, Sydney, Australia.

The present paper described a rare case of ureteral IgG4-related disease (IgG4-RD) that mimicked urothelial carcinoma. An otherwise healthy patient presented with computed tomography, ureteroscopic, and biopsy findings that were suspicious of urothelial carcinoma. The patient received a right nephroureterectomy. Histopathology showed ureteral IgG4-RD, without evidence of urothelial carcinoma. Accurate diagnosis of this rare entity should be based on clinical, biochemical, and histopathological findings.
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http://dx.doi.org/10.1016/j.urology.2018.05.019DOI Listing
August 2018

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK - SUMMARY OF THE SECOND EXERCISE.

Radiat Prot Dosimetry 2017 May;174(4):449-456

National Public Health Center, Budapest, Hungary.

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO Radiation Emergency Medical Preparedness and Assistance Network and the IAEA Response and Assistance Network, to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 h following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two-third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response.
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http://dx.doi.org/10.1093/rpd/ncw254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5723924PMC
May 2017

A study on the effect of the internal exposure to (210)Po on the excretion of urinary proteins in rats.

Radiat Environ Biophys 2016 May 9;55(2):161-9. Epub 2016 Mar 9.

Nuclear Technology Research Laboratory, Radiation Safety Research Center, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo, 201-8511, Japan.

This study was designed to assess the feasibility of a noninvasive urine specimen for the detection of proteins as indicators of internal exposure to ionizing radiation. Three groups of rats (five in each group) were intravenously injected with 1601 ± 376, 10,846 ± 591 and 48,467 ± 2812 Bq of (210)Po in citrate form. A sham-exposed control group of five rats was intravenously injected with sterile physiological saline. Daily urine samples were collected over 4 days following injection. Purification and pre-concentration of urinary proteins were carried out by ultrafiltration using a 3000 Da molecular weight cutoff membrane filter. The concentration of common urinary proteins, namely albumin, alpha-1-acid glycoprotein, immunoglobulins IgA and IgG, was measured by an enzyme-linked immunosorbent assay. Urinary excretion of albumin decreased dose-dependently (p < 0.05) 96 h post-injection relative to the control group. In contrast, no statistically significant effects were observed for other proteins tested. The dose-dependent decrease in urinary excretion of albumin observed in this study underscores the need for further research, which may lead to the discovery of new biomarkers that would reflect the changes in the primary target organs for deposition of (210)Po.
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http://dx.doi.org/10.1007/s00411-016-0639-4DOI Listing
May 2016

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK: SUMMARY OF A RECENT EXERCISE.

Radiat Prot Dosimetry 2016 Nov 23;171(3):351-357. Epub 2015 Sep 23.

Institut de Radioprotection et de Sûreté Nucléaire, Saint Paul Les Durance cedex, France.

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop their collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency. A recent exercise was conducted to test the participating laboratories for their capabilities in screening and in vitro assay of biological samples, performing internal dose assessment and providing advice on medical intervention, if necessary, using a urine sample spiked with a single radionuclide, Am. The laboratories were required to submit their reports according to the exercise schedule and using pre-formatted templates. Generally, the participating laboratories were found to be capable with respect to rapidly screening samples for radionuclide contamination, measuring the radionuclide in the samples, assessing the intake and radiation dose, and providing advice on medical intervention. However, gaps in bioassay measurement and dose assessment have been identified. The network may take steps to ensure that procedures and practices within this network be harmonised and a follow-up exercise be organised on a larger scale, with potential participation of laboratories from the networks coordinated by the International Atomic Energy Agency and the World Health Organization.
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http://dx.doi.org/10.1093/rpd/ncv386DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5723925PMC
November 2016

Motor cortex is required for learning but not for executing a motor skill.

Neuron 2015 May 16;86(3):800-12. Epub 2015 Apr 16.

Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. Electronic address:

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning.
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http://dx.doi.org/10.1016/j.neuron.2015.03.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5939934PMC
May 2015

EURADOS intercomparison on emergency radiobioassay.

Radiat Prot Dosimetry 2015 Dec 27;167(4):472-84. Epub 2014 Dec 27.

Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Madrid 28040, Spain.

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories.
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http://dx.doi.org/10.1093/rpd/ncu366DOI Listing
December 2015

Canada's efforts in developing capabilities in radiological population monitoring.

Health Phys 2011 Aug;101(2):112-7

Radiation Protection Bureau, Health Canada, Ottawa, ON, Canada K1A 1C1.

Population monitoring is an important component of radiological and nuclear emergency preparedness and response. Since 2002, Canada has been investing in developing national capabilities in radiological population monitoring. This paper summarizes Canada's efforts in developing methods and techniques in biological dosimetry and in vivo and in vitro bioassay techniques. There are still many gaps to fill that require further efforts. Integration of different monitoring methods and techniques in order to have the best assessment of radiation dose to support medical management and integration of Canada's efforts with international efforts are recommended.
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http://dx.doi.org/10.1097/HP.0b013e318213a719DOI Listing
August 2011

International workshop on emergency radiobioassay: considerations, gaps and recommendations.

Health Phys 2011 Aug;101(2):107-11

Radiation Protection Bureau, Health Canada, Ottawa, ON, Canada K1A 1C1.

An international workshop on emergency radiobioassay was held in Ottawa, Canada, 1-3 September 2010. Sixty-five scientists and public health officials from five countries attended the workshop and gave 36 presentations. During the workshop, many considerations were raised, gaps identified, and recommendations given for emergency radiobioassay for both preparedness and response in case of a radiological or nuclear incident. In short, some bioassay methods and protocols need to be developed, validated, and exercised; national and international radiobioassay laboratory networks should be established; and communications and collaborations among public health officials, monitoring experts, and medical staff are encouraged. All these activities are required to make us better prepared for an RN emergency.
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http://dx.doi.org/10.1097/HP.0b013e318213a5daDOI Listing
August 2011

Evaluating the performance of the ORTEC® Detective™ for emergency urine bioassay.

Radiat Prot Dosimetry 2011 Nov 8;147(3):474-9. Epub 2010 Dec 8.

Radiation Protection Bureau, Health Canada, Ottawa, Canada.

The performance of the ORTEC(®) Detective™ as a field deployable tool for emergency urine bioassay of (137)Cs, (60)Co, (192)Ir, (169)Yb and (75)Se was evaluated against ANSI N13.30. The tested activity levels represent 10 % RL (reference level) and 1 % RL defined by [Li C., Vlahovich S., Dai X., Richardson R. B., Daka J. N. and Kramer G. H. Requirements for radiation emergency urine bioassay techniques for the public and first responders. Health Phys (in press, 99(5), 702-707 (2010)]. The tests were conducted for both single radionuclide and mixed radionuclides at two geometries, one conventional geometry (CG) and one improved geometry (IG) which improved the MDAs (minimum detectable amounts) by a factor of 1.6-2.7. The most challenging radionuclide was (169)Yb. The measurement of the mixture radionuclides for (169)Yb at the CG did not satisfy the ANSI N13.30 requirements even at 10 % RL. At 1 % RL, (169)Yb and (192)Ir were not detectable at either geometry, while the measurement of (60)Co in the mixed radionuclides satisfied the ANSI N13.30 requirements only at the IG.
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http://dx.doi.org/10.1093/rpd/ncq464DOI Listing
November 2011

Method comparison for 241Am emergency urine bioassay.

Radiat Prot Dosimetry 2010 Oct 23;141(3):228-32. Epub 2010 Jun 23.

Radiation Protection Bureau, Health Canada, 775 Brookfield Rd, Ottawa, ON, Canada.

241Am is one of the high-risk radionuclides that might be used in a terrorist attack. 241Am in urine bioassay can identify the contaminated individuals who need immediate medical intervention and decontamination. This paper compares three methods for the measurement of 241Am in urine, namely liquid scintillation counting (LSC), inductively coupled plasma mass spectrometry (ICP-MS) and gamma spectrometry (GS), at two levels, 20 and 2 Bq l(-1). All three methods satisfied the ANSI N13.30 radio-bioassay criteria for accuracy and repeatability. ICP-MS offered the best sensitivity and fastest sample turnaround; however, the ICP-MS system used in this work may not be available in many bioassay laboratories. LSC and GS are more commonly available instruments. GS requires minimal or no sample preparation, which makes it a good candidate method. Moreover, the sample throughput can be significantly improved if the GS and LSC methods are automated.
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http://dx.doi.org/10.1093/rpd/ncq175DOI Listing
October 2010

An emergency urine bioassay method for 241Am by extraction chromatography and liquid scintillation counting.

Radiat Prot Dosimetry 2010 Sep 20;141(2):134-9. Epub 2010 May 20.

Radiation Protection Bureau, Health Canada, Ottawa, ON, Canada.

An emergency urine bioassay method has been developed for the determination of (241)Am in human urine samples. The method is based on extraction chromatographic separation of (241)Am from urine on a single DGA (N,N,N',N'-tetraoctyldiglycolamide) resin column followed by liquid scintillation counting of (241)Am. The minimum detectable activity (MDA) for the method was 0.02 Bq. Considering the volume of urine sample (17.2 ml) used by the method; the MDA was 1.3 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method were found to be -3.4 and 8.9 %, respectively, when urine samples were spiked with (241)Am (20 Bq l(-1)). Excellent linearity (r(2) > 0.999) was established over the range of 2-200 Bq l(-1). The method was also found to be robust (S(B)=10.2 %) against matrix effects from different urine samples. Performance of the rapid bioassay method for accuracy and repeatability were evaluated against the performance criteria for radiobioassay (ANSI N13.30) and found to be in compliance. Considering the simplicity, excellent analytical figures of merit and fast sample turnaround time (<1 h), it is a very promising rapid bioassay method for supporting the medical response to an emergency where internal contamination of (241)Am is involved.
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http://dx.doi.org/10.1093/rpd/ncq157DOI Listing
September 2010

Comparison of the thermal and histopathological effects of bipolar and monopolar electrosurgical resection of the prostate in a canine model.

BJU Int 2010 May 8;105(9):1314-7. Epub 2009 Oct 8.

The University of Western Ontario, London, Canada.

Objectives: To compare the thermal and histopathological effects of two commercially available bipolar systems and conventional monopolar transurethral resection of the prostate (TURP) in a canine model. Bipolar TURP is an alternative to monopolar electrosurgery for treating benign prostatic hyperplasia and has several potential clinical advantages, including the ability to use normal saline irrigation, enhanced haemostasis and less collateral thermal damage.

Material And Methods: In all, 12 adult male beagles were studied. After midline laparotomy and exposure of the bladder and prostate, two fibre-optic thermosensors were placed to record tissue temperatures; one sensor was placed into the substance of the prostate 2 cm from the urethra and the second in the prostatic-rectal groove on the capsular surface of the prostate to measure temperatures in the region of the neurovascular bundles. Through a midline cystotomy, antegrade TURP was performed using two different bipolar systems (Gyrus PlasmaKinetic and Vista, both from Gyrus-ACMI Corporation, Maple Grove, MN, USA) or a monopolar device (Force(TM) 2, Valleylab, Boulder, CO, USA). TURP was performed in each lateral lobe using 24 F resection loops. The dogs were humanely killed acutely and the prostates excised for histopathological assessment.

Results: When comparing intraprostatic temperature data, the mean (sem) temperature changes recorded for the monopolar group were significantly higher than in either the Gyrus or Vista bipolar groups, at 24.2 (3.9) degrees C vs 8.1 (1.5) degrees C and 6.8 (1.8) degrees C, respectively (P < 0.001). No measurable temperature elevations were recorded near the neurovascular bundles with any of the electrosurgery devices. The depth of thermal damage was greatest in the monopolar group at 0.59 (0.27) mm compared with the Gyrus and Vista groups at 0.07 (0.08) mm and 0.15 (0.02) mm, respectively (P < 0.001).

Conclusion: Bipolar TURP generated significantly less heat and histopathological evidence of thermal damage compared with monopolar TURP in the present canine model.
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http://dx.doi.org/10.1111/j.1464-410X.2009.08907.xDOI Listing
May 2010

Percutaneous nephrolithotomy for staghorn calculi: a single center's experience over 15 years.

J Endourol 2009 Oct;23(10):1669-73

Department of Surgery, The University of Western Ontario, London, Ontario, Canada .

Background And Purpose: Percutaneous nephrolithotomy (PCNL) for staghorn calculi is one of the more challenging endourologic procedures. Although excellent stone-free rates are universally reported in the literature, complication rates vary widely, especially related to the need for blood transfusion. The purpose of this study was to evaluate the outcomes of PCNL for patients with staghorn calculi in a large series of patients at a single, tertiary referral, endourologic stone center.

Patients And Methods: Between July 1990 and December 2005, 1338 patients underwent PCNL for renal stone disease at our institution. Among this group, 509 procedures were performed for patients with a partial or complete staghorn calculus. Data analysis included procedure time, length of hospital stay, number of access tracts, transfusion rates, other early and late complications, and stone-free status.

Results: Mean patient age was 53.8 years (range 4-84 yrs). The average procedure time was 104 minutes. Sixteen percent of the cases needed multiple access tracts (range 2-5), with the lower calix being the most commonly used in 64.1%, followed by the upper calix in 18.5% and the middle calix in 17.4%. Various intracorporeal lithotriptors were used, including ultrasound, pneumatic, electrohydraulic, and holmium:yttrium-aluminium-garnet laser. The transfusion rate among this group was 0.8%. There was no statistically significant difference in transfusion rates (0.7%-1.2% P = 0.24) or other major complications in patients who were treated with either a single tract or among those needing multiple tracts. Stone-free rates at hospital discharge and at 3 months follow-up were 78% and 91%, respectively.

Conclusion: PCNL is a safe and effective procedure in the management of staghorn calculi, with outcomes similar to those reported for percutaneous management of smaller volume nonstaghorn stones. Attention to accurate tract selection and placement as well as possession of the full array of endourologic equipment are essential to achieving an excellent outcome.
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http://dx.doi.org/10.1089/end.2009.1534DOI Listing
October 2009

Anti-adhesive coating and clearance of device associated uropathogenic Escherichia coli cystitis.

J Urol 2009 Oct 15;182(4):1628-36. Epub 2009 Aug 15.

Lawson Health Research Institute, London, Ontario, Canada.

Purpose: A previous study showed decreased uropathogen adherence using a novel anti-fouling coating consisting of mussel adhesive protein mimics conjugated to poly(ethylene glycol). We assessed the ability of methoxy polyethylene glycol-dihydroxyphenylalanine (Nerites Corp. Ltd., Madison, Wisconsin) coated ureteral stents to resist bacterial adherence, infection development and encrustation in a rabbit model of uropathogenic Escherichia coli cystitis.

Materials And Methods: Sof-Flex stent curls that were uncoated and coated with 3 coatings, including Surphys 002, 008 and 009, respectively, and uncoated Percuflex Plus stents were inserted transurethrally into the bladder of 50 male New Zealand White rabbits (Charles River Laboratories, Montreal, Quebec, Canada), followed by instillation of uropathogenic E. coli strain GR12 (10(7) cfu). Urine was examined for bacteria on days 0, 1, 3 and 7, and for cytokine levels on day 7. On day 7 the animals were sacrificed. Stent curls and bladders were harvested for analysis. In a parallel experiment stents were challenged in vitro for 7 days with GR12 in human urine.

Results: Surphys 009 coated devices showed decreased urine and stent bacterial counts compared to those in controls. Eight of 10 rabbits in the Surphys 009 group had sterile urine by day 3 vs 1 in each control group (p = 0.013), while stent adherent organisms were decreased by more than 75%. While no statistical differences were found in encrustation and bladder inflammation across the groups, immune scoring was lowest in the uncoated Sof-Flex control and Surphys 009 groups (p = 0.030).

Conclusions: Surphys 009 strongly resisted bacterial attachment, resulting in improved infection clearance over that of uncoated devices. However, this did not translate to decreased encrustation, which appeared to be independent of infection in this model.
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http://dx.doi.org/10.1016/j.juro.2009.06.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2807180PMC
October 2009

Percutaneous nephrolithotripsy in patients with diabetes mellitus.

J Endourol 2009 Jan;23(1):21-6

Division of Urology, Department of Surgery, The University of Western Ontario, London, Ontario, Canada.

Purpose: To compare the surgical outcomes in a cohort of patients with diabetes who were undergoing percutaneous nephrolithotripsy (PCNL) for renal stone disease to a nondiabetic group of patients at a single center.

Patients And Methods: Between July 1990 and December 2005, all patients scheduled for PCNL were prospectively included in a single-center database. Preoperative, intraoperative, and postoperative data were prospectively collected and analyzed. Primary outcomes evaluated were stone-free rates and complications, including the need for blood transfusion, while the secondary outcome was length of hospital stay. This report specifically reviews these outcomes in patients known to have diabetes at the time of surgery. Both outcomes were compared with those obtained in our nondiabetic patient population.

Results: Analysis of the data from 183 (13.7%) patients with diabetes of the 1338 patients undergoing PCNL revealed that patient age (63.1 years), surgical time (90.8 minutes), and complications (major 2.2%), including need for transfusion (0.5%) and stone-free rate (94.5%), were not significantly different from those observed in our nondiabetic patients. The average length of hospital stay was significantly longer in the diabetic group (4.4 days vs 3.9 days, P = 0.022). Uric acid stone composition was found to be the most common stone composition among the patients with diabetes in this study (41%).

Conclusions: PCNL can be performed with excellent stone-free rates and with an acceptable complication risk in the diabetic population. The incidence of uric acid stone disease appears to be significantly higher than previously reported and warrants heightened efforts directed toward stone prevention in this population.
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http://dx.doi.org/10.1089/end.2008.0282DOI Listing
January 2009

Occupational noise exposure during endourologic procedures.

J Endourol 2008 Aug;22(8):1609-11

Surgery/Division of Urology, Laval University, Quebec, Quebec, Canada.

Introduction: Long-term noise exposure in the workplace is a known cause of hearing loss. There has been limited study on the potential harm related to shock wave lithotripsy (SWL) or intracorporeal devices on patients and operating room personnel.

Patients And Methods: We used a digital sound meter to measure decibel levels in the operating room during several endourologic procedures. The decibel levels were recorded during SWL (Storz SLX-F2), percutaneous nephrolithotomy using single- and dual-probe ultrasonic lithotripters (Olympus LUS-2, CyberWand), and during ureteroscopy using the Versa Pulse Holmium:YAG laser. Findings were compared with the U.S. Department of Labor Occupational Health and Safety Administration and Canadian Centre for Occupational Health recommendations on permissible noise levels in the workplace.

Results: The background sound level in the operating room prior to endourologic procedures ranged between 58 and 60 dB. In the SWL control room, 5 m from the source, the mean sound level was 68 dB (range 64-75) during treatment. The mean corresponding decibel level recorded at the patient's head during SWL was 77 dB (range 73-83). Noises produced by intracorporeal lithotripters were recorded at the surgeon's head, 2 m from the source. Measurements of the CyberWand (dual-probe) device revealed a higher mean decibel reading of 93 dB (range 85-102). Noise levels recorded for the Olympus LUS-2 (single-probe) ultrasound and the holmium laser were 65 dB (62 -68) and 60 dB (58-62), respectively.

Conclusion: Although we noted that patients and urologists maybe exposed to significant noise levels during endourologic procedures, the duration of exposure is short. This risk appears to be minimal, based on current occupational guidelines, for most operating personnel.
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http://dx.doi.org/10.1089/end.2008.0178DOI Listing
August 2008

Current understanding of the molecular mechanisms of kidney cancer: a primer for urologists.

Can Urol Assoc J 2007 Jun;1(2 Suppl):S13-20

Divisions of Urology and Surgical Oncology, University of Western Ontario, London, Ont.

Renal cell carcinoma (RCC), the fifth leading malignant condition for men and tenth for women, accounts for 3% of all malignancies in Canada. It is a heterogeneous epithelial malignancy with different subtypes and varied tumour biology. Although most cases of RCC are sporadic, up to 4% of patients have an inherited predisposition for the disease. In this article, we review the current molecular genetics of the different subtypes in hereditary and sporadic RCC. Significant developments in understanding the underlying genetic basis of RCC over the last 2 decades are attributed to intensive research about rare inherited renal cancer syndromes and the identification of the genes responsible for them. Many of these genes are also found in sporadic RCC. Understanding the molecular mechanisms involved in the pathogenesis of RCC has aided the development of molecular-targeted drugs for this disease.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2422955PMC
http://dx.doi.org/10.5489/cuaj.63DOI Listing
June 2007

First prize: Novel uropathogen-resistant coatings inspired by marine mussels.

J Endourol 2008 Jun;22(6):1153-60

Department of Surgery, Division of Urology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.

Background And Purpose: Success in the prevention of urinary device infections has been elusive, largely due to multiple bacterial attachment strategies and the development of urinary conditioning films. We investigated a novel anti-fouling coating consisting of mussel adhesive protein mimics conjugated to polyethylene glycol (mPEG-DOPA(3)) for its potential to resist conditioning film formation and uropathogen attachment in human urine.

Methods: Model TiO(2) -coated silicon disks ( approximately 75 mm(2)) were either coated with mPEG-DOPA(3) or left uncoated and sterilized using ethylene oxide gas. For bacterial attachment experiments, coated and uncoated surfaces were separately challenged with bacterial strains comprising six major uropathogenic species for 24 hours at 37 degrees C in human pooled urine. Starting inoculum for each strain was 10(5) CFU/mL and 0.5 mL was used per disk. Following incubation, the disks were thoroughly rinsed in phosphate buffered saline to remove non-adherent and weakly-adherent organisms and cell scrapers were employed to dislodge those that were firmly attached. Adherent bacteria were quantitated using dilution plating. Representative disks were also examined using scanning electron microscopy, energy dispersive x-ray analysis, and live/dead viability staining.

Results: The mPEG-DOPA(3) coating significantly resisted the attachment of all uropathogens tested, with a maximum >231-fold reduction in adherence for Escherichia coli GR-12, Enterococcus faecalis 23241, and Proteus mirabilis 296 compared to uncoated TiO(2) disks. Scanning electron microscopy and viability staining analyses also reflected these results and demonstrated the ability of the coating to resist urinary constituent adherence as well.

Conclusion: Model surfaces coated with mPEG-DOPA(3) strongly resisted both urinary film formation and bacterial attachment in vitro. Future in vitro and in vivo studies will be conducted to assess whether similar findings can be demonstrated when these polymer coatings are applied to urologic devices.
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http://dx.doi.org/10.1089/end.2008.0049DOI Listing
June 2008

Percutaneous nephrolithotomy made easier: a practical guide, tips and tricks.

BJU Int 2008 Mar 8;101(5):535-9. Epub 2007 Oct 8.

Division of Urology, Department of Surgery, The University of Western Ontario, London, Canada.

Percutaneous nephrolithotomy (PCNL) plays an integral role in managing large renal stones. Establishing percutaneous renal access is the most crucial step in the procedure and requires a thorough understanding of renal, retroperitoneal and thoracic anatomy to minimize the risk of complications. Moreover, access to fluoroscopy and the proper equipment are critical to ensuring complete stone removal. In this review we describe the technique of PCNL used in a high-volume endourology centre, where the urologist is involved in all aspects of the procedure.
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http://dx.doi.org/10.1111/j.1464-410X.2007.07259.xDOI Listing
March 2008

C-arm laser positioning device to facilitate percutaneous renal access.

Urology 2007 Aug;70(2):360-1

Department of Surgery, Division of Urology, University of Western Ontario Schulich School of Medicine and Dentistry, London, Ontario, Canada.

Renal access is the most crucial step in the performance of percutaneous nephrolithotomy and is a difficult skill to acquire for novice surgeons. We report on a simple fluoroscopic technique based on the laser positioning device that emits an aiming beam common to modern fluoroscopy C-arm units.
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http://dx.doi.org/10.1016/j.urology.2007.05.013DOI Listing
August 2007

Transitional-cell carcinoma recurrence rate after nephroureterectomy in patients who undergo open excision of bladder cuff v transurethral incision of the ureteral orifice.

J Endourol 2007 Jul;21(7):730-4

Division of Urology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.

Background And Purpose: The gold standard treatment for upper-tract transitional-cell carcinoma is radical nephroureterectomy, but management of the distal ureter is not standardized. Two treatment options to detach the distal ureter are open cystotomy (OC) and excision of a bladder cuff or transurethral incision of the ureteral orifice (TUIUO). We compared the clinico-pathologic outcomes of these two techniques.

Patients And Methods: Hospital records were reviewed on all 51 patients who had undergone open or laparoscopic nephroureterectomy at our institution between 1 January 1990 and 30 June 2005. Patient demographics, intraoperative parameters, and pathology data were collected. The mean follow-up was 23.2 months (range 4.5-75 months) and 22.1 months (range 1-50 months) for the OC and TUIUO groups, respectively. There were no significant differences in sex, age at operation, American Society Anesthesiologists risk score, previous transitional-cell tumors, pathologic tumor grade and stage, or metastatic disease status in the two groups.

Results: Five patients had an unplanned incomplete ureterectomy. The bladder recurrence rates were similar in the OC group (22.2%; 6/27) and the TUIUO group (26.3%; 5/19). There were no pelvic recurrences in either group. Four of the five patients who had an incomplete ureterectomy had tumor recurrences, three in the form of metastatic disease.

Conclusion: Management of the distal ureter by TUIUO in appropriate patients offers the same rate of bladder recurrence as OC. Incomplete ureterectomy results in a significantly higher rate of recurrence, often associated with the development of metastatic disease.
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http://dx.doi.org/10.1089/end.2006.0374DOI Listing
July 2007