PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4810
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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 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.