MTMuhammed Tosun

Muhammed Tosun

*This is an algorithmically generated author record based on publicly available information.

Muhammed Tosun has a total of 20 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Program-level evaluation of population-based HPV screening in Van, Türkiye: screening activity, test positivity, genotype distribution and follow-up data capture in a retrospective record-based study

    by Adem Yağan, Muhammed Tosun

    Background: Province-level evidence on the implementation of population-based HPV screening in eastern Türkiye remains limited. This study aimed to describe screening activity relative to the programme-defined target population, HPV test positivity, recorded genotype patterns, histopathological diagnoses, and available follow-up information within the cervical cancer screening programme in Van Province. Methods: This retrospective, record-based programme evaluation used aggregated programme data from 2022 through the first two months of 2026 and individual-level records for HPV-positive women from 2023–2025. Annual screening activity ratios were calculated using programme-defined target populations. Age and recorded genotype distributions were described among HPV-positive women. Histopathological diagnoses and referral-related information were reported as available programme records because individual-level linkage and complete pathway denominators were unavailable. Temporal change in programme HPV test positivity was assessed using the Cochran-Armitage trend test. Results: Across the study periods, annual screening counts summed to 94,123 records, with 2,078 HPV-positive results (2.21%). The screening activity ratio increased from 17.1% in 2022 to 95.5% in 2024 and decreased to 67.9% in 2025. Observed programme HPV test positivity declined from 3.17% in 2022 to 1.80% in 2025 (p for trend < 0.001). Among 1,810 HPV-positive women with individual-level data, the mean age was 44.5 years. HPV16 was the most frequently recorded specific genotype (36.4%), HPV16 and/or HPV18 was recorded in 43.8%, and at least one recorded oncogenic genotype targeted by the nine-valent vaccine was identified in 55.4%. Multiple specifically identified HPV genotypes were recorded in 16.5%. Programme records contained 394 histopathological diagnoses during 2023–2025, including three invasive cervical cancer records. Available follow-up data did not permit calculation of referral, hospital attendance, colposcopy, biopsy, or treatment completion rates. Conclusions: HPV screening activity in Van varied substantially across years, while observed programme test positivity declined during 2022–2025; this decline should not be interpreted as evidence of reduced population HPV prevalence. Recorded genotype findings were dominated by HPV16, but variation in type-specific reporting limits temporal interpretation. Improved standardization of genotype reporting and individual-level linkage across screening, referral, diagnosis, histopathology, and treatment would strengthen programme monitoring.

  • Open Access

    Assessment of Sling Characteristics After Transobturator Tape Placement Using Transperineal Ultrasonography: Relationship with Continence and Dyspareunia—A Cross-Sectional Study

    by Mehmet Koçoğlu, Oya Soylu Karapınar, Muhammed Tosun, Berna Haliloğlu Peker

    Background/Objectives: Stress urinary incontinence (SUI) is a common condition that adversely affects women’s quality of life, and transobturator tape (TOT) surgery is one of the most commonly used treatments; however, the determinants of surgical success and postoperative complications remain incompletely understood. The aim of this study was to evaluate the association between postoperative transperineal ultrasound (TPUS) findings and surgical outcomes after TOT surgery for SUI, with particular emphasis on the relationship between sling arm morphology and postoperative dyspareunia. Methods: In this single-centre, cross-sectional follow-up study of a retrospectively identified cohort, 74 of 148 women who underwent TOT surgery between February 2019 and November 2024 were evaluated. TPUS was used to assess sling position, morphology, mobility, deformability, symphysis pubis–sling distance (SP-TAPE), urethral concordance, and bladder wall thickness. Patient-reported outcomes were evaluated using the I-QOL, UDI-6, IIQ-7, and OAB-V8 questionnaires. Factors independently associated with surgical success were identified using multivariable logistic regression analysis. Results: Objective surgical success was achieved in 71.6% of patients, whereas 91.9% reported satisfaction with the outcome. Concordant movement of the sling with the urethra (OR 8.963, 95% CI 1.612–49.857, p = 0.012), a shorter SP-TAPE distance during Valsalva (OR 0.337, 95% CI 0.181–0.629, p = 0.001) and a thinner bladder wall (OR 0.375, 95% CI 0.185–0.759, p = 0.006) were independently associated with objective success. Although sling arm morphology was not associated with surgical success (p = 0.797), among sexually active women (n = 61), curved sling arms were strongly associated with postoperative dyspareunia (75.0% vs. 27.3%; OR 8.00, 95% CI 2.54–25.22, p < 0.001). Bladder wall thickness correlated moderately with all four instruments (|r| = 0.551–0.667; all p < 0.001), inversely with I-QOL and positively with UDI-6, IIQ-7, and OAB-V8. Conclusions: Successful TOT surgery depends not only on appropriate sling localization but also on concordant sling–urethral movement and favourable dynamic sling behaviour. Although sling arm morphology was not associated with continence outcomes, its association with postoperative dyspareunia highlights the importance of evaluating both functional cure and postoperative quality of life. In the absence of preoperative data, this association should be regarded as exploratory. TPUS provides clinically valuable information for the postoperative assessment of outside-in transobturator slings; because all assessments were performed at a single visit, the relationships reported here are associations rather than demonstrated predictive relationships.

  • Open Access

    Development and Internal Validation of the AP-Score for Predicting Percutaneous Nephrostomy Use in Acute Obstructive Pyelonephritis

    by Hakan Şığva, Mehmet Sevim, Arif Mehmet Duran, Muhammed Tosun, Ömer Büyüktepe, Fatih Gökalp

    Background/Objectives: Acute obstructive pyelonephritis (AOP) is a urological emergency requiring urgent decompression. We aimed to develop and internally validate an interpretable admission-based score (AP-Score) to predict the likelihood of undergoing percutaneous nephrostomy (PCN) and to test whether it outperforms hydronephrosis grade alone. Methods: We retrospectively analyzed 231 adults with AOP treated with antibiotics alone, double-J stenting, or PCN at a single center. Four admission variables (temperature, C-reactive protein [CRP], serum creatinine, and hydronephrosis grade) were evaluated by multivariable logistic regression and likelihood ratio testing. Discrimination was compared against hydronephrosis grade alone using the DeLong test; calibration and clinical usefulness were assessed, and optimism was estimated using 1000 bootstrap resamples. Results: In the likelihood ratio test, while adding CRP to hydronephrosis grade significantly improved model fit (p < 0.001), serum creatinine provided a smaller additional contribution (p = 0.013). The AP-Score (0–8 points) combined these three variables included in the model; in the categorical model, the grade of hydronephrosis and CRP appeared as independent predictors, whereas creatinine was included due to its contribution on a continuous scale. The score achieved an AUC of 0.830 (95% CI 0.771–0.886), performing significantly better than the model using only the grade of hydronephrosis (AUC 0.772; ΔAUC = +0.058, DeLong p = 0.010; IDI = 0.061, p = 0.002). The optimism-corrected AUC was calculated as 0.827, and calibration was found to be adequate (Hosmer–Lemeshow p = 0.342). A threshold value of ≥4 points yielded a sensitivity of 85.3% and a specificity of 65.0% (OR = 10.79, 95% CI 5.12–22.70); no patients scoring 0–1 points (n = 37) underwent nephrostomy. Conclusions: The AP-Score—which combines a structural parameter (degree of hydronephrosis) with two systemic markers (CRP and creatinine)—is a simple and well-calibrated score that performs significantly better than the degree of hydronephrosis alone. The AP-Score was also associated with additional clinical outcomes, suggesting that it captures aspects of the underlying clinical course in addition to local treatment patterns. However, because the primary endpoint reflects the drainage modality selected under a single-center institutional protocol, the score should be considered hypothesis-generating until externally validated in independent, preferably multicenter cohorts with different drainage practices.

  • Analysis of external patient referrals from a tertiary care center: a hyperbaric medicine perspective

    by Recep Özkan, Mehmet Tatlı, Osman Türkmen, Gamze Aydın, Muhammed Tosun

    Introduction: The aim of this study was to analyze the demographic, clinical, and specialty-based distribution of patient referrals from a tertiary hospital to other provinces during 2024, with particular emphasis on referrals related to hyperbaric medicine.Methods: This retrospective descriptive study included all patient referrals made from our hospital 2024. Data were obtained from the hospital information management system and evaluated according to age, sex, specialty of referral, type of institution (public/private), and reason for referral. This retrospective descriptive study was conducted using all 2024 patient referral records from Van Training and Research Hospital.Results: Most referrals (67.3%, n=1,511) were made to public hospitals. Pediatric cardiology (10.6%) and nephrology (5.7%) were the leading specialties for referrals, with pediatric patients representing the majority of the sample (0–19 years: 42.1%). In addition, a small number of patients requiring hyperbaric oxygen therapy (HBOT) were referred to other provinces (0.3%), and all HBOT-related referrals occurred because the hospital’s hyperbaric chamber was undergoing maintenance and revision during the study period.Conclusion: The findings of this study indicate that inter-provincial referrals were predominantly driven by shortages in pediatric subspecialty services and temporary interruptions in hyperbaric oxygen therapy (HBOT) availability. The increase in HBOT related referrals during the chamber maintenance period highlights the importance of ensuring uninterrupted access to hyperbaric services through effective maintenance planning and coordination with alternative centers. Furthermore, enhancing physicians awareness of HBOT indications and referral criteria may reduce unnecessary transfers and improve the efficiency of referral pathways.

  • Open Access

    Erkek Hipogonadizmi: Tanı, Tedavi ve Multidisipliner Yönetim

    by Muhammed Tosun

    Erkek hipogonadizmi, testosteron eksikliği ve buna eşlik eden semptom ve bulgularla karakterize önemli bir klinik sendromdur. Prevalansı yaşla birlikte artmakta olup, obezite, tip 2 diyabet ve metabolik sendrom gibi komorbiditelerle yakından ilişkilidir. Bu durum, cinsel fonksiyon bozuklukları, kas kütlesinde azalma, kemik yoğunluğunda düşüş, bilişsel fonksiyonlarda bozulma ve genel yaşam kalitesinde azalma gibi çok sayıda sistemi etkileyen sonuçlara yol açabilir. Ürolojik pratikte sıkça karşılaşılan bu sendromun yönetimi, sadece testosteron seviyelerinin düzeltilmesini değil, aynı zamanda altta yatan nedenlerin araştırılmasını, hasta beklentilerinin yönetilmesini ve potansiyel risklerin dikkatle değerlendirilmesini gerektirir. Tanı süreci, spesifik semptomların varlığında, sabah saatlerinde ve en az iki ayrı ölçümde total testosteron seviyesinin düşük olduğunun doğrulanmasına dayanır. Tedavide temel yaklaşım testosteron replasman tedavisi (TRT) olmakla birlikte, tedavi kararı hastanın yaşına, komorbiditelerine, fertilite beklentisine ve potansiyel kontrendikasyonlara göre bireyselleştirilmelidir. Özellikle fertilite planlayan erkeklerde veya prostat ve meme kanseri gibi durumlarda TRT'nin riskleri ve alternatif tedavi seçenekleri dikkatle ele alınmalıdır. Erkek hipogonadizminin etkin yönetimi, ürologların merkezde yer aldığı, endokrinoloji, kardiyoloji, androloji ve birinci basamak hekimlerinin dahil olduğu multidisipliner bir yaklaşım gerektirir. Bu bölüm, erkek hipogonadizmine ürolojik perspektiften güncel tanı, tedavi ve yönetim stratejilerini uluslararası kılavuzlar ışığında özetlemektedir.

  • Removal of a retroperitoneal foreign body through single port laparoscopy using nephroscope

    by İsmail Başıbüyük, Muhammed Tosun, Senad Kalkan, Abdulkadir Tepeler

    Foreign bodies are rare and challenging issues leading to symptoms according to the location. Laparoscopy is a popular and minimally invasive method used for removal of foreign bodies in the abdominal cavity or retroperitoneum. We herein report a case with retroperitoneal foreign body that was removed through retroperitoneal single- port laparoscopy using nephroscope. To our knowledge this is the first case of removal of a retroperitoneal foreign body through single- port laparoscopy using nephroscope. Cite this article as: Başıbüyük İ, Tosun M, Kalkan S, Tepeler A. Removal of a retroperitoneal foreign body through single port laparoscopy using nephroscope. Turk J Urol 2017; 43: 386-9


  • Open Access

    Radikal nefrektomi sonrası kontralateral soliter adrenal metastaz: Olgu sunumu

    by Muhammed Tosun, Ramazan Topaktaş, Fatih Elbir, İsmail Başıbüyük, Abdullah Armağan

    Böbreğin en sık görülen malign parankimal tümörü renal hücreli karsinomdur. Renal hücreli karsinom sıklıkla akciğer, karaciğer, lenf nodu ve kemiğe metastaz yapmaktadır fakat bu tümörün cerrahi sonrası karşı taraf soliter adrenal bez metastazı çok nadir saptanan bir durumdur. Tedavide sıklıkla metastaza yönelik agresif cerrahi primer yaklaşım olarak kabul görmektedir. Olgu sunumumuzda sol renal hücreli karsinom nedeniyle radikal cerrahi uygulanan 46 yaşındaki erkek hastanın dördüncü yıl kontrolünde saptananan karşı taraf soliter adrenal metastazı ve tedavisi literatür ışığında sunulmaktadır. Anahtar kelimeler: Adrenal, metastaz, nefrektomi