Publications by authors named "Mehmet Onur Demirkol"

Background: To investigate the predictable parameters associated with downgrading in patients with a Gleason score (GS) 8 (4+4) in prostate biopsy after radical prostatectomy.

Methods: We retrospectively analyzed 62 patients with a GS of 4+4 on prostate biopsy who underwent robotic radical prostatectomy between 2017 and 2022.

Results: 38 of 62 (61.

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Introduction: This study aimed to investigate the oncological outcomes and toxicity profile of 177 Lu-PSMA-I&T radioligand therapy (RLT) in patients with metastatic castration-resistant prostate cancer (mCRPC), as well as our initial experience in metastatic hormone-sensitive prostate cancer (mHSPC).

Patients And Methods: A total of 38 consecutive patients with metastatic prostate cancer (33 mCRPC and 5 mHSPC) received 177 Lu-PSMA-I&T RLT, with a median of 2 cycles per patient (range, 1-7). Response to RLT was evaluated based on prostate-specific antigen (PSA) changes and imaging response.

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Introduction And Objectives: To investigate the additive role of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) independent from multiparametric magnetic resonance imaging (mpMRI) and clinical-pathological parameters to predict pathological upgrading in patients with ISUP grade group (GG) 1 prostate cancer (PCa) at prostate biopsy.

Materials And Methods: A total of 41 patients who underwent robotic radical prostatectomy (RP) for GG1 disease at prostate biopsy with preoperative PSMA PET/CT and mpMRI images available for central review were included in the study. Univariate and multivariate logistic regression analyses were performed to determine the independent predictors of pathological upgrading (GG ≥ 2).

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Introduction: Our aims were to explore the relationship between primary hyperparathyroidism (pHPT) and malignant tumour development, to determine the frequency and the time of occurrence of malignant tumours in patients with pHPT, and to evaluate the characteristics of pHPT in these patients.

Material And Methods: This retrospective cohort study included consecutive individuals who were diagnosed with pHPT aged 18 years or older in a university hospital during a 7-year period. A total of 198 patients with pHPT were reviewed retrospectively.

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Background: We aimed to analyze the effect of preoperative risk assessment including Ga-68 PSMA PET and multiparametric magnetic resonance imaging (mpMRI) on nerve sparing practices, positive surgical margin (PSM) rates and oncological outcomes based on a comparison between patients underwent RARP with and without Neurosafe (NS).

Methods: Patients underwent RARP with NS (RARP-NS) or without (RARP-only) NS retrospectively evaluated. Suspicion for extracapsular extension on mpMRI and/or Ga-68 PSMA PET was recorded as i(imaging)T3.

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Aim: The aims of the study are to evaluate the predictive value of early post-operative stimulated thyroglobulin (sTg) analysis on the recurrence risk, and to define a cut-off value that is related to recurrence risk in low to intermediate risk papillary thyroid cancer (PTC).

Methods: This retrospective cohort study included individuals who were diagnosed with PTC aged 18 years or older and had been operated by experienced surgeons of a tertiary university hospital between the years 2011 and 2021. The American Thyroid Association thyroid cancer guidelines version 2015 was used as the risk stratification system.

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Background: Treatment response is traditionally monitored using prostate-specific antigen (PSA) and conventional imaging in patients with metastatic prostate cancer (mPCa).

Objective: To assess the diagnostic performance of prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) when monitoring mPCa patients receiving systemic treatment and also to investigate the concordance between PSMA PET response according to the PSMA PET progression (PPP) criteria and biochemical response.

Design, Setting, And Participants: A total of 96 patients with Ga-PSMA-11 PET/CT-detected mPCa at baseline PSMA PET/CT (bPSMA) who underwent at least one follow-up scan after receiving systemic treatment were included in the study.

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Objective: Lymph node metastasis is the most important factor both in the selection of treatment since many alternatives have been created in recent years, and in the evaluation of prognosis in lung cancer. The most unpredictable cause of lymph node false positivity in fluorine-18-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) is anthracosis. The aim of this study is to compare F-FDG PET/CT texture information of anthracotic (ALN) and metastatic (MLN) lymph nodes, after re-evaluation of the cytological samples obtained from anthracotic lymph nodes by EBUS-TBNA.

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We created our first national clinical protocol of 177Lu-CXCR4 therapy for patient who have failed to respond to current therapy options. We also calculated the kidney, liver, and tumor dosimetry. The kidney's mean absorbed dose was calculated to be 0.

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Background: Results from prospective trials have shown higher accuracy of prostate-specific membrane antigen (PSMA)-based positron emission tomography (PET)/computed tomography (CT) in detection of lymph node metastasis (LNM) compared to conventional imaging.

Objective: To evaluate the accuracy of Ga-PSMA-11 PET/CT for LNM detection in patients undergoing radical prostatectomy (RP) and extended pelvic lymph node dissection (PLND).

Design, Setting, And Participants: Between June 2014 and November 2020, 96 patients with Ga-PSMA PET/CT for primary staging underwent RP and extended PLND.

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Objective: Geriatric patients are often reluctant to undergo parathyroid surgery under general anesthesia because of the major comorbidities. The use of minimally invasive techniques for parathyroid lesions under local anesthesia have been published. Radioguided lesion localization has been known to decrease operative time and reduce the occurrence of positive margins in breast cancer surgery.

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It is very crucial to determine Tg accurately and precisely in thyroid cancer cases. Although there are many studies on the detection of Tg in thyroid cases in the literature, there are no sufficient clinical studies examining many cases with different features by using RIA methodology. Here, a radiometric and chromatographic method has been studied for the first time to eliminate the interference from anti-Tg positive patients.

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Objective: Lymph node metastasis occurs in a subset of papillary microcarcinoma patients. We aimed to analyze the differences between metastatic and non-metastatic papillary microcarcinomas in order to identify a high-risk subgroup that is likely to require more aggressive treatment.

Materials And Methods: 126 thyroidectomies with lymph node dissections (central ± lateral), diagnosed as papillary microcarcinoma, were reviewed.

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Background: To evaluate the additive role of Ga-68 PSMA PET as a primary staging tool in patients bearing prostate cancer in single PIRADS 4 or 5 index lesions.

Methods: Eighty-one biopsy-naive patients with preoperative mpMRI and Ga-68 PSMA PET who underwent radical prostatectomy (RP) were evaluated retrospectively. Forty-nine patients had PIRADS 4 and 32 had PIRADS 5 index lesions.

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Purpose: Morbidity due to papillary thyroid carcinoma (PTC) is increased mostly due to lymph node (LN) metastases, which lead to reoperations and complications associated with these operations. The aim is to compare the outcomes of PTC having total thyroidectomy and prophylactic central lymph node dissection (TT + PCND) with patients having total thyroidectomy (TT) alone.

Methods: This study is a retrospective cohort analysis of 358 PTC patients that were operated by a single surgeon in a single center.

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Purpose: Lu-PSMA inhibitor peptide receptor radioligand therapy (RLT) is playing an increasing role in metastatic castration-resistant prostate cancer. We aimed to estimate the absorbed radiation doses for critical organs (eg, kidneys, parotid glands, submandibular glands, and lacrimal glands) of patients treated with 4 to 6 cycles by Lu-PSMA inhibitor RLT, retrospectively, and to evaluate the findings extensively in order to determine the critical organ radiation-absorbed limitations and the number of prospective RLT.

Materials And Methods: A total of 51 cycles Lu-PSMA inhibitor RLT in 10 patients was analyzed.

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Background/aim: The aim of this study is to investigate clinicopathologic features of familial papillary thyroid carcinoma (fPTC) and compare them with sporadic papillary thyroid carcinoma (sPTC) in Turkish patients. A retrospective analysis of the papillary thyroid carcinoma (PTC) cases, with or without family history with a follow-up around 10 years was performed.

Materials And Methods: A series of patients with fPTC (82 fPTC families with 146 affected individuals) were compared with patients with sPTC (n = 112).

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Imaging is critical for primary staging of prostate cancer. Traditional imaging modalities (computerized tomography scan and nuclear medicine bone scans) are limited by their suboptimal diagnostic performance. Recent meta-analyses have demonstrated that nuclear imaging with Ga-labeled prostate-specific membrane antigen ligand (Ga-PSMA) using positron emission tomography/computed tomography (PET/CT) has higher sensitivity and specificity in this setting compared to conventional imaging techniques.

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A 72-year-old man underwent Ga-PSMA PET/CT because of an elevated prostate-specific antigen level despite prior prostatectomy. Besides low-intensity prostatic PSMA reactivities, a faintly PSMA-positive lesion in the pancreatic corpus drew attention, which seemed suggestive of a primary pancreatic cancer on the subsequent MRI and therefore had to be excised. The final diagnosis was pT3 low-grade neuroendocrine tumor.

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We aimed to emphasize how useful PSMA PET/CT findings can be while trying to restage prostate cancer after radical prostatectomy in the presence of low prostate-specific antigen values. A 64-year-old man with pT3b N1 M0 Gleason 7 adenocarcinoma of the prostate presented 5 years postoperatively with a palpable axillary mass, whereas his prostate-specific antigen was 0.08 ng/mL.

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Background: There is an ongoing need for an accurate imaging modality which can be used for staging purposes, metastatic evaluation, predicting biologic aggresiveness and investigating recurrent disease in prostate cancer. Prostate specific membrane antigen, given its favorable molecular characteristics, holds a promise as an ideal target for prostate cancer-specific nuclear imaging. In this study, we evaluated our initial results of PSMA based PET/CT imaging in prostate cancer.

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Cardiac angiosarcomas are a rare form of malignancy. The majority of cases arise from the right atrium as mural masses. These tumors have extremely aggressive behavior, with early clinical symptoms that vary depending on location, size, and extent of the tumor.

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Unlabelled: Hyper-functioning parathyroid glands with autonomous overproduction of PTH is the most frequent cause of hypercalcemia in outpatient populations with primary hyper-parathyroidism. It is generally caused by a solitary adenoma in 80%-90% of patients. Despite the various methodologies that are available for preoperative localization of parathyroid lesions, there is still no certain preoperative imaging algorithm to guide a surgical approach prior to the management of primary hyper-parathyroidism (P-HPT).

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