SuperMap algorithm: an efficient, safe and accurate modality for mapping and eliminating challenging cardiac arrhythmias.

Even with the development of advanced catheter-based mapping systems, there remain several challenges in the electrophysiological evaluation and elimination of atrial arrhythmias. For instance, atrial tachycardias with irregular rates cannot be reliably mapped by systems that require stability in order to sequentially gather data points to be organized thereafter. Separately, these arrhythmias often arise following initial ablation for atrial fibrillation, posing logistic challenges. Here, we present the available literature summarizing the use of a non-contact mapping catheter, the AcQMap catheter, in conjunction with SuperMap, an algorithm that compiles a large number of non-contact data points from multiple catheter positions within the atria. These studies demonstrate the efficiency, safety and accuracy of this technology.

Irregular heart rhythms (arrhythmias) are often treatable with medications, but sometimes require expert evaluation in a cardiac electrophysiology laboratory. They are often studied and treated using thin, flexible catheters which enter the body through blood vessels in the leg and reach the internal walls of the heart. Time, expertise and specialized equipment are necessary to identify characteristics specific to each patient's arrhythmia. For each arrhythmia, a unique electrical blueprint is created before trying to eliminate it. The fleeting nature of certain arrhythmias can make it difficult to generate these blueprints, and many take a lot of time to accurately identify, leading to procedural challenges. Here we evaluate studies discussing the use of a new catheter (AcQMap) and its accompanying strategy for identifying arrhythmias. Unlike traditional catheters that require direct contact with the internal walls of the heart, the AcQMap catheter floats within these blood-filled chambers and does not touch the walls when obtaining data points. Instead, using ultrasound waves and electrical signals, it can generate data points to create blueprints. This technology also uses a new algorithm that enables the catheter to move freely within the heart, obtaining numerous data points and grouping them together to create maps efficiently and safely, even for fleeting or challenging arrhythmias.

Effect of Focal Zone Size on Treatment Outcomes and Renal Injury Following Extracorporeal Shockwave Lithotripsy of Renal Calculi: A Prospective Randomized Study.

Background: The narrower focal zone (FZ) size of modern lithotripter was considered as one of the factors that resulted in suboptimal treatment result of extracorporeal shockwave lithotripsy (SWL). Therefore, we investigate the efficacy and safety of standard narrow or extended (FZ) sizes in SWL for patients with renal stones. Materials and Methods: In this prospective study conducted between April 2018 and October 2022, patients with renal stones were randomized to receive SWL with either standard or extended FZ. Treatment was delivered using a Modulith SLX-F2 lithotripter with a maximum of 3000 shocks at 1.5 Hz. The primary outcome was treatment success 12 weeks after a single SWL session, defined as the absence of a stone or stone fragment <4 mm on computed tomography. Secondary outcomes included the incidence of perinephric hematoma, stone-free rate (SFR), and changes in the urinary levels of acute renal injury markers. Results: A total of 320 patients were recruited, and 276 patients were randomized into the two groups. The two groups had similar baseline parameters. The treatment success rate was significantly better for standard FZ (74.3%) than the extended FZ group (59.3%) (p = 0.009). Standard FZ also had a significantly better SFR (Grade-A, 36.8% vs 23.0%, p = 0.013) and less pain after treatment. Both groups had similar perinephric hematoma formation rates, unplanned hospital admission rates, and changes in urinary acute renal injury markers. Conclusions: The standard narrow FZ has better treatment efficacy and similar safety compared with the extended FZ during SWL for renal stones. This clinical trial has been registered in the public domain (CCRBCTR) under trial number CUHK_CCRB00510.

Health-Related Quality of Life Assessment in Prostate Cancer Patient Undergoing Androgen Deprivation Therapy: Real-World Experience in the READT Study.

PURPOSE: To investigate the effect of androgen deprivation therapy (ADT) on health-related quality of life (HRQOL) in Asian men with all stages of prostate cancer. MATERIALS AND METHODS: READT (real-life evaluation of the effect of ADT in prostate cancer patients in Asia) was a multi-center, prospective observational study involving six sites across four Asian populations. We enrolled eligible prostate cancer patients, who opted for ADT alone or in combination without prior neoadjuvant or adjuvant ADT within 12 months. The EuroQoL-5 dimensions, 5 level scale (EQ-5D-5L) utility index scores and visual analog scale (VAS) were evaluated at baseline, month 6 and month 12. RESULTS: A total of 504 patients were recruited into READT between September 2016 and May 2020 with 52.9% diagnosed with metastatic prostate cancer. The EQ-5D-5L was evaluable in 442/504 (87.7%) of patients. Overall baseline EQ-5D-5L utility index score was 0.924 (interquartile range [IQR] 0.876-1.000). We observed a statistically significant difference in baseline EQ-5D-5L utility index score among different populations with a median EQ-5D-5L utility index score of 1 for Taiwan & Hong Kong, 0.897 for China and 0.838 for Malaysia. Similar trend was observed throughout multiple treatment time-points. Stage IV prostate cancer were significantly associated with a lower baseline EQ-5D-5L utility index score compared to stage I-III prostate cancer, producing a median disutility value of -0.080. Participants had a high median VAS (80, IQR 70-90), indicating good overall health on average during ADT initiation. CONCLUSIONS: The study highlights the differences in health state utility index scores among various Asian prostate cancer patients receiving ADT at real-world setting. Our findings will be informative and useful in cost-effectiveness evaluation and policy decision making.

Adverse metabolic consequences of androgen deprivation therapy (ADT) on Asian patients with prostate cancer: Primary results from the real-life experience of ADT in Asia (READT) study.

BACKGROUND: Androgen deprivation therapy (ADT) use in prostate cancer (PCa) has seen a rising trend. We investigated the relationship between ADT and adverse changes in metabolic parameters in an Asian population. METHODS: This is an international prospective multicenter single-arm cohort yielded from the real-life experience of ADT in Asia (READT) registry. Consecutive ADT-naïve patients diagnosed of PCa and started on ADT were prospectively recruited from 2016 and analyzed. Baseline patient characteristics, PCa disease status, and metabolic parameters were documented. Patients were followed up at 6-month interval for up to 5 years. Metabolic parameters including body weight, lipid profiles, and glycemic profiles were recorded and analyzed. RESULTS: 589 patients were eligible for analysis. ADT was associated with adverse glycemic profiles, being notable at 6 months upon ADT initiation and persisted beyond 1 year. Comparing to baseline, fasting glucose level and hemoglobin A1c level increased by 4.8% (p < 0.001) and 2.7% (p < 0.001), respectively. Triglycerides level was also elevated by 16.1% at 6th month and by 20.6% at 12th month compared to baseline (p < 0.001). Mean body weight was 1.09 kg above baseline at 18th month (p < 0.001). CONCLUSION: ADT was associated with adverse metabolic parameters in terms of glycemic profiles, lipid profiles, and body weight in the Asian population. These changes developed early in the treatment and can persist beyond the first year. Regular monitoring of the biochemical profiles during treatment is paramount in safeguarding the patients' metabolic health.

A tool for monitoring cell type-specific focused ultrasound neuromodulation and control of chronic epilepsy.

Focused ultrasound (FUS) is a powerful tool for noninvasive modulation of deep brain activity with promising therapeutic potential for refractory epilepsy; however, tools for examining FUS effects on specific cell types within the deep brain do not yet exist. Consequently, how cell types within heterogeneous networks can be modulated and whether parameters can be identified to bias these networks in the context of complex behaviors remains unknown. To address this, we developed a fiber Photometry Coupled focused Ultrasound System (PhoCUS) for simultaneously monitoring FUS effects on neural activity of subcortical genetically targeted cell types in freely behaving animals. We identified a parameter set that selectively increases activity of parvalbumin interneurons while suppressing excitatory neurons in the hippocampus. A net inhibitory effect localized to the hippocampus was further confirmed through whole brain metabolic imaging. Finally, these inhibitory selective parameters achieved significant spike suppression in the kainate model of chronic temporal lobe epilepsy, opening the door for future noninvasive therapies.

Oral antibiotics perturbation on gut microbiota after prostate biopsy.

Introduction: The use of antibiotics may induce the changes in gut microbiota. Previous studies have shown conflicting results on whether the changed gut microbiota by antibiotics can be recovered. Our study aims to investigate whether the gut microbiota could be recovered after a single dose of oral co-amoxiclav before transrectal ultrasound-guided transperineal prostate biopsy (TPPBx) in 5 weeks' time. Methods: Fifteen patients with elevated serum prostate-specific antigen (PSA) were recruited to provide pre-antibiotic and post-antibiotic fecal samples. The V4 region of 16S rRNA was sequenced. Analysis was performed by QIIME2. Alpha- and beta-diversities were analyzed, as well as the differential enrichment by Linear discriminant analysis Effect Size (LEfSe) analysis. Results: Both the alpha- and beta-diversities of the pre- and post-antibiotic fecal samples were significantly different. Genera that are associated with alleviation of inflammation were enriched in the pre-antibiotic fecal samples, while the inflammation-associated genera were more enriched in the post-antibiotic fecal samples. Conclusion: A single dose of oral co-amoxiclav before TPPBx could have led to a change of gut microbiota that cannot be recovered in 5 weeks' time. Microbiome studies on prostate cancer patients should be cautioned on the use of post-prostate biopsy fecal sampling. Further studies should be conducted for the impact on gut microbiome for TPPBx alone.

Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound.

Transcranial focused ultrasound with the InSightec Exablate system uses thermal ablation for the treatment of movement and mood disorders and blood brain barrier disruption for tumor therapy. The system uses computed tomography (CT) images to calculate phase corrections that account for aberrations caused by the human skull. This work investigates whether magnetic resonance (MR) images can be used as an alternative to CT images to calculate phase corrections. Phase corrections were calculated using the gold standard hydrophone method and the standard of care InSightec ray tracing method. MR binary image mask, MR-simulated-CT (MRsimCT), and CT images of three ex vivo human skulls were supplied as inputs to the InSightec ray tracing method. The degassed ex vivo human skulls were sonicated with a 670 kHz hemispherical phased array transducer (InSightec Exablate 4000). 3D raster scans of the beam profiles were acquired using a hydrophone mounted on a 3-axis positioner system. Focal spots were evaluated using six metrics: pressure at the target, peak pressure, intensity at the target, peak intensity, positioning error, and focal spot volume. Targets at the geometric focus and 5 mm lateral to the geometric focus were investigated. There was no statistical difference between any of the metrics at either target using either MRsimCT or CT for phase aberration correction. As opposed to the MRsimCT, the use of CT images for aberration correction requires registration to the treatment day MR images; CT misregistration within a range of ± 2 degrees of rotation error along three dimensions was shown to reduce focal spot intensity by up to 9.4%. MRsimCT images used for phase aberration correction for the skull produce similar results as CT-based correction, while avoiding both CT to MR registration errors and unnecessary patient exposure to ionizing radiation.

Improving Transcranial Acoustic Targeting: The Limits of CT-Based Velocity Estimates and the Role of MR.

Transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) enables the noninvasive treatment of the deep brain. This capacity relies on the ability to focus acoustic energy through the in-tact skull, a feat that requires accurate estimates of the acoustic velocity in individual patient skulls. In current practice, these estimates are generated using a pretreatment computed tomography (CT) scan and then registered to a magnetic resonance (MR) dataset on the day of the treatment. Treatment safety and efficacy can be improved by eliminating the need to register the CT data to the MR images and by improving the accuracy of acoustic velocity measurements. In this study, we examine the capacity of MR to supplement or replace CT as a means of estimating velocity in the skull. We find that MR can predict velocity with less but comparable accuracy to CT. We then use micro-CT imaging to better understand the limitations of Hounsfield unit (HU)-based estimates of velocity, demonstrating that the macrostructure of pores in the skull contributes to the acoustic velocity of the bone. We find evidence that detailed T2 measurements provide information about pore macrostructure similar to the information obtained with micro-CT, offering a potential clinical mechanism for improving patient-specific estimates of acoustic velocity in the human skull.

Risks of metabolic diseases and androgen deprivation therapy for prostate cancer in a Chinese population: a prospective multi-centre cohort study.

PURPOSE: Androgen deprivation therapy (ADT) use in prostate cancer (PCa) has seen a rising trend. We are looking into the relationship between ADT and development of metabolic diseases in Chinese patients. METHODS: This is a prospective multi-centre cohort yielded from the READT database (Real-life experience of ADT in Asia), in which patients diagnosed of PCa and offered ADT were prospectively recruited since 2016. Chinese patients recruited from Hong Kong were selected and compared to another cohort of newly diagnosed PCa patients in Hong Kong (HK-Cap database), which was collected prospectively and retrieved retrospectively for this study. Patient outcomes are followed through for 2 years. We compared between the groups the new diagnoses of hypertension, diabetes and hyper-lipidaemia, as well as the initiation of related medication for these conditions. Baseline characteristics including pre-treatment comorbidities, medications and tumour characteristics are documented. RESULTS: 151 patients receiving ADT (from READT database) and 447 patients not receiving ADT (from HK-Cap database) were analysed. ADT is related to higher risks of developing any of concerned medical co-morbidities (23.8% vs 13.0*, p = 0.001) and new-onset DM (16.6% vs 4.4%, p < 0.001). Initiation of new medications is also more common in ADT patients. New anti-hypertensives (37.8% vs 12.5%, p < 0.001), oral hypoglycemic agents (12.6% vs 4.9%, p = 0.001), insulin (4.0% vs 0.05%, p = 0.001) and statin (23.7% vs 12.8%, p = 0.023) are more commonly added in ADT cohort. CONCLUSION: Chinese receiving ADT are exposed to increased risks of new-onset hypertension, diabetes and hyper-lipidaemia, and a higher likelihood of stepping up pharmaceutical control for pre-existing comorbidities. This highlights physicians' role to monitor metabolic profiles in at-risk men upon offering ADT.

Knowledge and insights from a maturing international clinical quality registry.

Since 2017, the TrueNTH Global Registry (TNGR) has aimed to drive improvement in patient outcomes for individuals with localized prostate cancer by collating data from healthcare institutions across 13 countries. As TNGR matures, a systematic evaluation of existing processes and documents is necessary to evaluate whether the registry is operating as intended. The main supporting documents: protocol and data dictionary, were comprehensively reviewed in a series of meetings over a 10-month period by an international working group. In parallel, individual consultations with local institutions regarding a benchmarking quality-of-care report were conducted. Four consensus areas for improvement emerged: updating operational definitions, appraisal of the recruitment process, refinement of data elements, and improvement of data quality and reporting. Recommendations presented were drawn from our collective experience and accumulated knowledge in operating an international registry. These can be readily generalized to other health-related reporting programs beyond clinical registries.

Joint object classification and turbulence strength estimation using convolutional neural networks.

In a recent paper, Kee et al. [Appl. Opt.59, 9434 (2020)APOPAI0003-693510.1364/AO.405663] use a multilayer perceptron neural network to classify objects in imagery after degradation through atmospheric turbulence. They also estimate turbulence strength when prior knowledge of the object is available. In this work, we significantly increase the realism of the turbulence simulation used to train and evaluate the Kee et al. neural network. Second, we develop a new convolutional neural network for joint character classification and turbulence strength estimation, thereby eliminating the prior knowledge constraint. This joint classifier-estimator expands applicability to a broad range of remote sensing problems, where the observer cannot access the object of interest directly.

A cross-sectional study on gut microbiota in prostate cancer patients with prostatectomy or androgen deprivation therapy.

BACKGROUND: Androgen deprivation therapy (ADT), either by medical or surgical castration, is the backbone for standard treatment of locally advanced or metastatic prostate cancer, yet it is also associated with various metabolic and cardiovascular complications. Recent evidence have shown that obesity, insulin resistance, or metabolic disturbances can be associated with changes in the gut microbiome, while animal studies also show that castration is associated with changes in the gut microbiome. This study aims to investigate whether the fecal microbiota in prostate cancer patients who had undergone prostatectomy or ADT are different, and explore changes in phylogeny and pathways that may lead to side effects from ADT. METHODS: A total of 86 prostate cancer patients (56 patients on ADT and 30 patients with prostatectomy) were recruited. The fecal microbiota was analyzed by the 16S rRNA gene for alpha- and beta-diversities by QIIME2, as well as the predicted metabolic pathways by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2. RESULTS: The alpha-diversity was significantly lower in the ADT group. The beta-diversity was significantly different between the groups, in which Ruminococcus gnavus and Bacteroides spp were having higher relative abundance in the ADT group, whereas Lachnospira and Roseburia were reduced. The Firmicutes-to-Bacteroidetes ratio is noted to be lower in the ADT group as well. The functional pathway prediction showed that the biosynthesis of lipopolysaccharide (endotoxin) and propanoate was enriched in the ADT as well as the energy cycle pathways. This study is limited by the cross-sectional design and the clinical heterogeneity. CONCLUSIONS: There is a significant difference in gut microbiome between prostate cancer patients on ADT and prostatectomy. We theorize that this difference may contribute to the development of metabolic complications from ADT. Further longitudinal studies are awaited.

Transcranial focused ultrasound phase correction using the hybrid angular spectrum method.

The InSightec Exablate system is the standard of care used for transcranial focused ultrasound ablation treatments in the United States. The system calculates phase corrections that account for aberrations caused by the human skull. This work investigates whether skull aberration correction can be improved by comparing the standard of care InSightec ray tracing method with the hybrid angular spectrum (HAS) method and the gold standard hydrophone method. Three degassed ex vivo human skulls were sonicated with a 670 kHz hemispherical phased array transducer (InSightec Exablate 4000). Phase corrections were calculated using four different methods (straight ray tracing, InSightec ray tracing, HAS, and hydrophone) and were used to drive the transducer. 3D raster scans of the beam profiles were acquired using a hydrophone mounted on a 3-axis positioner system. Focal spots were evaluated using six metrics: pressure at the target, peak pressure, intensity at the target, peak intensity, positioning error, and focal spot volume. For three skulls, the InSightec ray tracing method achieved 52 ± 21% normalized target intensity (normalized to hydrophone), 76 ± 17% normalized peak intensity, and 0.72 ± 0.47 mm positioning error. The HAS method achieved 74 ± 9% normalized target intensity, 81 ± 9% normalized peak intensity, and 0.35 ± 0.09 mm positioning error. The InSightec-to-HAS improvement in focal spot targeting provides promise in improving treatment outcomes. These improvements to skull aberration correction are also highly relevant for the applications of focused ultrasound neuromodulation and blood brain barrier opening, which are currently being translated for human use.

Acoustic Attenuation: Multifrequency Measurement and Relationship to CT and MR Imaging.

Transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) is gaining significant acceptance as a noninvasive treatment for motion disorders and shows promise for novel applications such as blood-brain barrier opening for tumor treatment. A typical procedure relies on CT-derived acoustic property maps to simulate the transfer of ultrasound through the skull. Accurate estimates of the acoustic attenuation in the skull are essential to accurate simulations, but there is no consensus about how attenuation should be estimated from CT images and there is interest in exploring MR as a predictor of attenuation in the skull. In this study, we measure the acoustic attenuation at 0.5, 1, and 2.25 MHz in 89 samples taken from two ex vivo human skulls. CT scans acquired with a variety of X-ray energies, reconstruction kernels, and reconstruction algorithms, and MR images acquired with ultrashort and zero echo time sequences are used to estimate the average Hounsfield unit value, MR magnitude, and T2* value in each sample. The measurements are used to develop a model of attenuation as a function of frequency and each individual imaging parameter.

Effect of androgen deprivation therapy on cardiovascular function in Chinese patients with advanced prostate cancer: a prospective cohort study.

Androgen deprivation therapy (ADT) is the standard treatment for advanced prostate cancer, but its effect on cardiovascular and metabolic function in Asian patients is still inconclusive. We prospectively assess the effects of ADT on 36 patients with advanced prostate cancer, with reference to another 24 prostate cancer patients not requiring ADT, for 2 years. Patients' anthropometric, metabolic and vascular parameters were assessed every six-monthly. The baseline parameters of the two groups were comparable. There was a significant negative effect of the usage of ADT on the changes in BMI (p = 0.020), waist to hip ratio (p = 0.005), body fat percentage (p = 0.012), and high-density-lipoprotein (p = 0.012). ADT-patients were 4.9 times more likely to have metabolic syndrome at 24 months. (CI 0.889-27.193, p = 0.068). The Framingham risk score (p = 0.018) and pulse-wave-velocity (p = 0.024) for ADT-group were also significantly higher than controls, which signified increase in cardiovascular risk. Although there was no statistically significant difference in ischemic cardiovascular events between two groups, a trend for more events in ADT-group was observed. Therefore, Asian patients have increased cardiovascular and metabolic risks after being treated with ADT for two years. Appropriate counselling and monitoring of associated complications with ADT are essential.

Anatomic and Thermometric Analysis of Cranial Nerve Palsy after Laser Amygdalohippocampotomy for Mesial Temporal Lobe Epilepsy.

BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive therapy for treating medication-resistant mesial temporal lobe epilepsy. Cranial nerve (CN) palsy has been reported as a procedural complication, but the mechanism of this complication is not understood. OBJECTIVE: To identify the cause of postoperative CN palsy after LITT. METHODS: Four medial temporal lobe epilepsy patients with CN palsy after LITT were identified for comparison with 22 consecutive patients with no palsy. We evaluated individual variation in the distance between CN III and the uncus, and CN IV and the parahippocampal gyrus using preoperative T1- and T2-weighted magnetic resonance (MR) images. Intraoperative MR thermometry was used to estimate temperature changes. RESULTS: CN III (n = 2) and CN IV palsies (n = 2) were reported. On preoperative imaging, the majority of identified CN III (54%) and CN IV (43%) were located within 1 to 2 mm of the uncus and parahippocampal gyrus tissue border, respectively. Affected CN III and CN IV were more likely to be found < 1 mm of the tissue border (PCNIII = .03, PCNIV < .01; chi-squared test). Retrospective assessment of thermal profile during ablation showed higher temperature rise along the mesial temporal lobe tissue border in affected CNs than unaffected CNs after controlling for distance (12.9°C vs 5.8°C; P = .03; 2-sample t-test). CONCLUSION: CN palsy after LITT likely results from direct heating of the respective CN running at extreme proximity to the mesial temporal lobe. Low-temperature thresholds set at the border of the mesial temporal lobe in patients whose CNs are at close proximity may reduce this risk.

A rapid beam simulation framework for transcranial focused ultrasound.

Transcranial focused ultrasound is a non-invasive therapeutic modality that can be used to treat essential tremor. Beams of energy are focused into a small spot in the thalamus, resulting in tissue heating and ablation. Here, we report on a rapid 3D numeric simulation framework that can be used to predict focal spot characteristics prior to the application of ultrasound. By comparing with magnetic resonance proton resonance frequency shift thermometry (MR thermometry) data acquired during treatments of essential tremor, we verified that our simulation framework can be used to predict focal spot position, and with patient-specific calibration, predict focal spot temperature rise. Preliminary data suggests that lateral smearing of the focal spot can be simulated. The framework may also be relevant for other therapeutic ultrasound applications such as blood brain barrier opening and neuromodulation.

Effect of Stepwise Voltage Escalation on Treatment Outcomes following Extracorporeal Shock Wave Lithotripsy of Renal Calculi: A Prospective Randomized Study.

PURPOSE: In this study we assessed the effects of a ramping protocol in patients undergoing extracorporeal shock wave lithotripsy of renal stones. MATERIALS AND METHODS: In this prospective study patients with renal stones were randomized to receive shock wave lithotripsy delivered using a ramping protocol in group 1 (first 1,000 shocks at energy level 5 followed by 1,000 shocks at energy level 6 and 1,000 final shocks at energy level 7) and a fixed voltage protocol in group 2 (all 3,000 shocks at energy level 7). Treatment was administered using a Modulith® SLX-F2. The primary outcome was treatment success 12 weeks after a single shock wave lithotripsy session, defined as lack of a stone or a less than 4 mm stone fragment on computerized tomography. Other outcomes included the stone-free rate and the perinephric hematoma incidence. RESULTS: A total of 300 patients (150 per group) were recruited between February 2016 and June 2018. The 2 groups did not differ in baseline parameters. Group 1 received 14.8% lower energy than group 2, which was significant (p <0.001). The treatment success rate in groups 1 and 2 was 67.8% and 73.6%, respectively, which did not statistically differ (group 1 crude OR 0.753, 95% CI 0.456-1.244, p=0.268). The stone-free rate in groups 1 and 2 was 36.6% and 41.9%, respectively, which did not differ statistically between the groups. However, in groups 1 and 2 perinephric hematoma developed in 23.8% and 43.8% of patients, respectively, which was a statistically significant difference (p <0.001). CONCLUSIONS: The fixed voltage shock wave lithotripsy and ramping protocols provided similar treatment success rates for renal stones. However, the ramping protocol reduced the incidence of perinephric hematoma after shock wave lithotripsy.