PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4810
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Item Superscan Appearance of Ga-68 PSMA PET/CT in a Patient with Refractory Prostate Cancer(2022) Koc, Zehra Pinar; Ozcan, Pinar Pelin; Ercolak, Vehbi; Reyhan, Mehmet; https://orcid.org/0000-0001-8550-3368; 35114754; AAJ-5242-2021A 64-year-old male patient with metastatic prostate carcinoma diagnosis received lutetium-177 prostate-specific membrane antigen (PSMA) treatment; however, his disease progressed. Herein, presented the final images of the patient that demonstrated a superscan appearance in the Gallium-68 PSMA positron emission tomography/computed tomography, which is a rare phenomenon.Item Clinical parameters and nomograms for predicting lymph node metastasis detected with Ga-68-PSMA-PET/CT in prostate cancer patients candidate to definitive radiotherapy(2021) Onal, Cem; Ozyigit, Gokhan; Oymak, Ezgi; Guler, Ozan Cem; Hurmuz, Pervin; Tilki, Burak; Reyhan, Mehmet; Tuncel, Murat; Akyol, Fadil; 0000-0002-2742-9021; 33949694; D-5195-2014Background Defining the extent of disease spread with imaging modalities is crucial for therapeutic decision-making and definition of treatment. This study aimed to investigate whether clinical parameters and nomograms predict prostate-specific membrane antigen (PSMA)-positive lymph nodes in treatment-naive nonmetastatic prostate cancer (PC) patients. Materials and Methods The clinical data of 443 PC patients (83.3% high-risk and 16.7% intermediate-risk) were retrospectively analyzed. Receiver operating characteristic (ROC) curves with areas under the curve (AUC) were generated to evaluate the accuracy of clinical parameters (prostate-specific antigen [PSA], T stage, Gleason score [GS], International Society of Urological Pathology [ISUP] grade) and nomograms (Roach formula [RF], Yale formula [YF], and a new formula [NF]) in predicting lymph node metastasis. The AUCs of the various parameters and clinical nomograms were compared using ROC and precision-recall (PR) curves. Results A total of 288 lymph node metastases were identified in 121 patients (27.3%) using Ga-68-PSMA-11-positron emission tomography (PET)/computed tomography (CT). Most PSMA-avid lymph node metastases occurred in external or internal iliac lymph nodes (142; 49.3%). Clinical T stage, PSA, GS, and ISUP grade were significantly associated with PSMA-positive lymph nodes according to univariate logistic regression analysis. The PSMA-positive lymph nodes were more frequently detected in patients with PSA >20 ng/ml, GS >= 7 or high risk disease compared to their counterparts. The clinical T stage, serum PSA level, GS, and ISUP grade showed similar accuracy in predicting PSMA-positive metastasis, with AUC values ranging from 0.675 to 0.704. The median risks for PSMA-positive lymph nodes according to the RF, YF, and NF were 31.3% (range: 12.3%-100%), 22.3% (range: 4.7%-100%), and 40.5% (range: 12.3%-100%), respectively. The AUC values generated from ROC and PR curve analyses were similar for all clinical nomograms, although the RF and YF had higher accuracy compared to NF. Conclusion The clinical T stage, PSA, GS, and ISUP grade are independent predictors of PSMA-positive lymph nodes. The RF and YF can be used to identify patients who can benefit from Ga-68-PSMA-11 PET/CT for the detection of lymph node metastasis. Together with nomograms, Ga-68-PSMA-11 PET/CT images help to localize PSMA-positive lymph node metastases and can thus assist in surgery and radiotherapy planning.Item Oligometastatic Bone Disease in Castration-Sensitive Prostate Cancer Patients Treated With Stereotactic Body Radiotherapy Using Ga-68-PSMA PET/CT TROD 09-004 Study(2021) Onal, Cem; Ozyigit, Gokhan; Akgun, Zuleyha; Atalar, Banu; Igdem, Sefik; Oymak, Ezgi; Agaoglu, Fulya; Selek, Ugur; Guler, Ozan Cem; Hurmuz, Pervin; 33661210Purpose To evaluate the outcomes of metastasis-directed treatment (MDT) using stereotactic body radiotherapy (SBRT) for bone-only oligometastasis (OM) detected with gallium prostate-specific membrane antigen (Ga-68-PSMA) PET/CT in castration-sensitive prostate cancer (PC) patients. Methods In this multi-institutional study, clinical data of 74 PC patients with 153 bone lesions who were undergoing MDT were retrospectively evaluated. Twenty-seven patients (36.5%) had synchronous, and 47 (63.5%) had metachronous OM. All patients had PC with 5 metastases or fewer detected by Ga-68-PSMA PET/CT and treated using SBRT with a median dose of 20 Gy. The prognostic factors for PC-specific survival (PCSS) and progression-free survival (PFS) were analyzed. Results The median follow-up was 27.3 months. Patients with synchronous OM were older and received higher rates of androgen deprivation therapy after SBRT compared with patients with metachronous OM. The 2-year PCSS and PFS rates were 92.0% and 72.0%, respectively. A prostate-specific antigen (PSA) decline was observed in 56 patients (75.7%), and 48 (64.9%) had a PSA response defined as at least 25% decrease of PSA after MDT. The 2-year local control rate per lesion was 95.4%. In multivariate analysis, single OM and PSA response after MDT were significant predictors for better PCSS and PFS. In-field recurrence was observed in 4 patients (6.5%) with 10 lesions at a median of 13.1 months after MDT completion. No serious late toxicity was observed. Conclusions We demonstrated that SBRT is an efficient and well-tolerated treatment option for PC patients with 5 bone-only oligometastases or fewer detected with Ga-68-PSMA PET/CT.Item No Tumor Suppressor Role for LKB1 in Prostate Cancer(2021) Koseoglu, Hikmet; Celebi, Asuman; Galamiyeva, Gunay; Dalay, Nejat; Ozkardes, Hakan; Buyru, Nur; 34370601To elucidate the pathogenesis of prostate diseases, following in silico analysis, the LKB1 gene was selected for further investigation. The LKB1 gene has been associated with poor prognosis and is frequently mutated in different types of cancers. In this study, 50 benign prostatic hyperplasia (BPH) and 57 prostate cancer (PCa) tissues, including matched normal tissue for the patients, were analyzed by qRT-PCR and DNA sequencing for LKB1 expression and the mutation profile, respectively. Expression of LKB1 was increased in 60.7% of the PCa tissues compared with noncancerous tissue samples (p <= 0.001). However, LKB1 expression was lower when compared with normal tissues in BPH (p = 0.920). Four coding sequence alterations were detected in BPH. Three silent mutations were located in codons 9, 32, and 275 and a missense mutation was observed in codon 384. Six alterations were identified in the intronic regions of the LKB1 gene in both PCa and BPH. Five mutations were observed in both patient groups. A new alteration in intron 6 was observed in a patient with PCa. The LKB1 gene may be associated with benign transformations rather than the tumors in prostate pathogenesis when its expression and mutation status are considered. However, the mechanism of LKB1 in PCa needs further studies.Item Stereotactic body radiotherapy for oligoprogressive lesions in metastatic castration-resistant prostate cancer patients during abiraterone/enzalutamide treatment(2021) Onal, Cem; Kose, Fatih; Ozyigit, Gokhan; Aksoy, Sercan; Oymak, Ezgi; Muallaoglu, Sadik; Guler, Ozan C.; Tilki, Burak; Hurmuz, Pervin; Akyol, Fadil; 0000-0002-2742-9021; 33905131; D-5195-2014Background Metastasis-directed therapy (MDT) utilizing stereotactic body radiotherapy (SBRT) for oligoprogressive lesions could provide a delay in next-line systemic treatment (NEST) change while undergoing androgen receptor-targeted agents (ARTA) treatment. We evaluated prognostic factors for prostate cancer-specific survival (PCSS) and progression-free survival (PFS) to characterize patients receiving treatment with ARTA who may benefit from MDT for oligoprogressive lesions. The impact of MDT on delaying NEST and the predictive factors for NEST-free survival (NEST-FS) were also assessed. Materials and Methods The clinical data of 54 metastatic castration-resistant prostate cancer patients with 126 oligoprogressive lesions receiving abiraterone (1 g/day) or enzalutamide (160 mg/day) before or after systemic chemotherapy were analyzed. A median of three lesions (range: 1-5) were treated with MDT. The primary endpoints were PCSS and PFS. The secondary endpoints were time to switch to NEST and NEST-FS. Results The median follow-up time was 19.1 months. Univariate analysis showed that the number of oligoprogressive lesions treated with SBRT and the time between the start of ARTA treatment and oligoprogression were significant prognostic factors for PCSS, and the timing of ARTA treatment (before or after chemotherapy) and the prostate-specific antigen (PSA) response after MDT were significant prognostic factors for PFS. Multivariate analysis showed that early MDT for oligoprogressive lesions delivered less than 6 months after the beginning of ARTA and higher PSA levels after MDT were significant predictors of worse PCSS and PFS. The median total duration of ARTA treatment was 13.8 months. The median time between the start of ARTA treatment and the start of MDT for oligoprogressive lesions was 5.2 months, and MDT extended the ARTA treatment by 8.6 months on average. Thirty-two (59.3%) patients continued ARTA treatment after MDT. ARTA treatment after chemotherapy, early oligoprogression requiring MDT, and lower radiation doses for MDT were independent predictors of NEST-FS in multivariate analysis. Conclusions MDT for oligoprogressive lesions is effective and may provide several benefits compared to switching from ARTA treatment to NEST. Patients with early progression while on ARTAs and inadequate PSA responses after MDT have a greater risk of rapid disease progression and poor survival, which necessitates intensified treatment.Item Can Extraprostatic Extension Be Predicted by Tumor-Capsule Contact Length in Prostate Cancer? Relationship With International Society of Urological Pathology Grade Groups(2020) Bakir, Baris; Onay, Aslihan; Vural, Metin; Armutlu, Ayse; Yildiz, Sevda Ozel; Esen, Tarik; 31670596OBJECTIVE. The objective of our study was to evaluate the relationship between the tumor-capsule contact length, defined as tumor contact length (TCL), and extraprostatic extension (EPE) using the MRI-based TCL measurements and the real TCL measurements from pathology and to determine whether the International Society of Urological Pathology (ISUP) grade group of the tumors influenced this relationship. MATERIALS AND METHODS. In this retrospective study, we reviewed prostate multiparametric MRI (mpMRI) studies performed between 2012 and 2018 of 1576 patients and found that 134 patients also underwent radical prostatectomy (RP) after mpMRI. Finally, 86 patients with index lesions in contact with the prostate capsule in RP specimens were enrolled in the study. ROC analysis was used to evaluate the cutoff values of TCLs measured at pathology and TCLs measured on MRI in terms of EPE according to ISUP grade groups. RESULTS. There was no statistically significant cutoff value for pathology-based TCL measurements in individual ISUP grade groups and subgroups. Although not statistically significant, pathology-based TCL cutoff values decreased (from 21.0 to 11.0 mm) as ISUP grade group increased in terms of EPE, positivity. When the relationship between MRI-based TCL measurements and EPE was considered, statistically significant cutoff values (range, 145-16.6 mm) could be determined in many groups and subgroups with low ISUP grades (sensitivity, 66.7-100%; specificity, 52.8-93.0%; p = 0.006-0.042). However, no statistically significant cutoff value was found for high ISUP grades. CONCLUSION. ISUP grade groups may have an effect on the TCL-EPE relationship. When the MRI-based TCL and EPE relationship is evaluated independent of ISUP grade group, a cutoff value around 15-16 mm may be usable to predict EPE.Item Estimation of secondary cancer risk after radiotherapy in high-risk prostate cancer patients with pelvic irradiation(2020) Haciislamoglu, Emel; Gungor, Gorkem; Aydin, Gokhan; Canyilmaz, Emine; Guler, Ozan Cem; Zengin, Ahmet Yasar; Yenice, Kamil Mehmet; 0000-0001-6908-3412; 32671989; AAC-5654-2020We aimed to estimate the risk of secondary cancer after radiotherapy (RT) in high-risk prostate cancer (HRPC) patients with pelvic irradiation. Computed tomography data of five biopsy-proven HRPC patients were selected for this study. Two different planning target volumes (PTV(1)and PTV2) were contoured for each patient. The PTV(1)included the prostate, seminal vesicles, and pelvic lymphatics, while the PTV(2)included only the prostate and seminal vesicles. The prescribed dose was 54 Gy for the PTV(1)with a sequential boost (24 Gy for the PTV2). Intensity-modulated RT (IMRT) and volumetric modulated arc therapy (VMAT) techniques were used to generate treatment plans with 6 and 10 MV photon energies with the flattening filter (FF) or flattening filter-free (FFF) irradiation mode. The excess absolute risks (EARs) were calculated and compared for the bladder, rectum, pelvic bone, and soft tissue based on the linear-exponential, plateau, full mechanistic, and specific mechanistic sarcoma dose-response model. According to the models, all treatment plans resulted in similar risks of secondary bladder or rectal cancer and pelvic bone or soft tissue sarcoma except for the estimated risk of the bladder according to the full mechanistic model using IMRT((6MV;FF))technique compared with VMAT techniques with FFF options. The overall estimation of EAR indicated that the radiation-induced cancer risk due to RT in HRPC was lower for bladder than the rectum. EAR values ranged from 1.47 to 5.82 for bladder and 6.36 to 7.94 for rectum, depending on the dose-response models used. The absolute risks of the secondary pelvic bone and soft tissue sarcoma were small for the plans examined. We theoretically predicted the radiation-induced secondary cancer risk in HRPC patients with pelvic irradiation. Nevertheless, prospective clinical trials, with larger patient cohorts with a long-term follow-up, are needed to validate these model predictions.Item Integration of 68Ga-PSMA-PET/CT in Radiotherapy Planning for Prostate Cancer Patients(2019) Onal, Cem; Torun, Nese; Akyol, Fadil; Guler, Ozan Cem; Hurmuz, Pervin; Yildirim, Berna Akkus; Caglar, Meltem; Reyhan, Mehmet; Ozyigit, Gokhan; 0000-0001-6908-3412; 31283600Purpose To assess the role of (68)Gallium-labeled-prostate-specific membrane antigen PET/CT (Ga-68-PSMA-PET/CT) in risk group definition and radiotherapy planning in the initially planned definitive radiotherapy (RT) for prostate cancer patients. Methods The clinical data of 191 prostate cancer patients treated with definitive intensity-modulated RT were retrospectively analyzed. All patients were initially staged with thoracoabdominal CT and bone scintigraphy, and the second staging was performed using Ga-68-PSMA-PET/CT. Both stages were evaluated for the decision making of RT and any change in RT target volumes. Results After staging with Ga-68-PSMA-PET/CT, 26 patients (13.6%) had risk group changes, 16 patients (8.4%) had an increase in risk group, and 10 patients (5.2%) had a decrease in risk group. Down-staging occurred in 22 patients (11.5%), and upstaging was observed in 30 patients (15.7%). A total of 26 patients (13.6%) had nodal stage changes. After the Ga-68-PSMA-PET/CT scans, the number of metastatic patient increased to 17 (8.9%), with 4 of them moving from oligo- to polymetastatic disease. An additional irradiation of pelvic lymphatics and metastatic site was performed in 13 patients (6.8%) and 6 patients (3.2%), respectively. The RT was aborted in 4 patients (2.1%) because of parenchymal or distant site metastasis observed in the Ga-68-PSMA-PET/CT. Conclusions We found that Ga-68-PSMA-PET/CT causes considerable migration in stage, risk group, and RT field arrangements, especially in high-risk patients regardless of the GS and baseline prostate-specific antigen values alone. Ga-68-PSMA-PET/CT seems to have a great influence on RT decision making in prostate cancer patients.Item The hematologic parameters in metastatic castration-resistant prostate cancer patients treated with abiraterone acetate(2019) Onal, Cem; Sedef, Ali Murat; Kose, Fatih; Oymak, Ezgi; Guler, Ozan Cem; Sumbul, Ahmet Taner; Aksoy, Sercan; Yildirim, Berna Akkus; Besen, Ali Ayberk; Muallaoglu, Sadik; Mertsoylu, Huseyin; Ozyigit, Gokhan; 0000-0001-6908-3412; 0000-0002-5573-906X; 0000-0002-0156-5973; 30977383; D-4793-2014; AAC-5654-2020Currently, there are no predictive markers of response to abiraterone. We calculated neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at baseline and at 4 and 12 weeks after initiation of abiraterone, and we evaluated prostate-specific antigen (PSA) response every 4 weeks in 102 metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone either pre-or postchemotherapy. With a median follow-up was 24.0 months (range: 0.3-54.9), median overall survival (OS) was 20.8 months. High-NLR patients who remained high or who returned to low NLR after 4 and 12 weeks showed significantly worse OS than patients with low baseline NLR. NLR and prostate-specific antigen response to abiraterone was a significant predictor of OS and progression-free survival (PFS) in metastatic castration-resistant prostate cancer patients treated with abiraterone delivered either pre-or postchemotherapy.