PubMed İndeksli Açık & Kapalı Erişimli Yayınlar
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Item The prognostic value of mean apparent diffusion coefficient measured with diffusion-weighted magnetic resonance image in patients with prostate cancer treated with definitive radiotherapy(2022) Onal, Cem; Erbay, Gurcan; Guler, Ozan Cem; Oymak, Ezgi; 35753556Purpose: To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progressionfree survival (PFS) in this patient cohort were analyzed. Materials and methods: The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS. Results: The median follow-up was 72.9 months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737 x 10-3 mm2/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712 +/- 0.158 vs. 1.365 +/- 0. 227 x 10-3 mm2/sec; p < 0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p < 0.001) and PFS rates (83.8% vs. 73.5%; p = 0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS. Conclusions: Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients. (c) 2022 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 173 (2022) 285-291Item Stereotactic radiotherapy to oligoprogressive lesions detected with Ga-68-PSMA-PET/CT in castration-resistant prostate cancer patients(2021) Onal, Cem; Ozyigit, Gokhan; Oymak, Ezgi; Guler, Ozan Cem; Tilki, Burak; Hurmuz, Pervin; Akyol, Fadil; 0000-0002-2742-9021; 33693965; D-5195-2014Purpose We assessed the outcomes of stereotactic body radiotherapy (SBRT) to treat oligoprogressive castration-resistant prostate cancer (CRPC) patients with <= 5 lesions using gallium prostate-specific membrane antigen-positron emission tomography (Ga-68-PSMA-PET/CT). Methods The clinical data of 67 CRPC patients with 133 lesions treated with Ga-68-PSMA-PET/CT-based SBRT were retrospectively analyzed. All of the patients had oligoprogressive disease during androgen-deprivation therapy (ADT). The prognostic factors for overall- (OS) and progression-free survival (PFS) and the predictive factors for switching to next-line systemic treatment (NEST) and NEST-free survival (NEST-FS) were analyzed. Results With a median follow-up of 17.5 months, the 2-year overall survival (OS) and PFS rates were 86.9% and 34.4%, respectively. The PSA response was observed in 49 patients (73.1%). Progression was observed in 37 patients (55.2%) at a median of 11.0 months following SBRT. A total of 45 patients (67.2%) remained on ADT after SBRT, and 22 patients (32.8%) had a NEST change at a median of 16.4 months after metastasis-directed treatment (MDT). Patients with a NEST change had higher post-SBRT PSA values and fewer PSA nadirs after MDT than their counterparts. In multivariate analysis, higher pre-SBRT PSA values were the only significant predictor for worse OS and NEST-FS, and no significant factor was found for PFS. No serious acute or late toxicities were observed. Conclusion This study demonstrated the feasibility of MDT using SBRT to treat oligoprogressive lesions by Ga-68-PSMA-PET/CT in CRPC patients is efficient and well-tolerated, prolonging the effectiveness of ADT by delaying NEST.Item Retrospective correlation of (68)ga-psma uptake with clinical parameters in prostate cancer patients undergoing definitive radiotherapy(2020) Onal, Cem; Torun, Nese; Oymak, Ezgi; Guler, Ozan C.; Reyhan, Mehmet; Yapar, Ali F.; 0000-0001-6908-3412; 0000-0001-8550-3368; 0000-0003-1715-4180; 0000-0002-2742-9021; 0000-0002-5597-676X; 32221791; AAC-5654-2020; AAJ-5242-2021; AAI-8973-2021; D-5195-2014; AAE-2718-2021Objective The aim of the study is to investigate the correlation between the intensity of prostate-specific membrane antigen (PSMA) uptake in primary tumor and clinico-pathological characteristics of non-metastatic prostate cancer patients treated with definitive radiotherapy (RT). Methods Using the clinical data of 201 prostate cancer patients who were referred for (68) Ga-PSMA-positron emission tomography (PET/CT) for staging and RT planning, we analyzed the correlations among intermediate- or high-risk disease based on Gleason score (GS), prostate-specific antigen (PSA) level, D'Amico risk group classification, and maximum standardized uptake (SUVmax) of primary tumor. Results Primary tumor was visualized via (68) Ga-PSMA-PET/CT scan in 192 patients (95.5%). The median SUVmax of primary tumor and metastatic lymph node were 13.2 (range 3.3-83.7) and 11.4 (range 3.6-64.5), respectively. A significant moderate correlation was observed between PSA level and median tumor SUVmax as measured by (68) Ga-PSMA-PET/CT (Spearman = 0.425; p < 0.001). Patients with serum PSA > 10 ng/mL, GS > 7, D'Amico high-risk group classification, and pelvic lymph node metastasis had significantly higher tracer uptake in primary tumor than their counterparts. The median SUVmax of primary tumor was highest in patients with GS 9. The primary tumor detection rates of (68) Ga-PSMA-PET/CT were 83%, 92%, and 99% for patients with serum PSA <= 5.0 ng/mL (14 patients, 7%), PSA 5.1-10.0 ng/mL (45 patients, 22%), and PSA > 10 ng/mL (142 patients, 71%), respectively. Conclusions We demonstrated a correlation between prostate tumor characteristics and PSMA tracer uptake. Patients with serum PSA > 10 ng/mL, GS > 7, D'Amico high-risk group classification, and pelvic lymph node metastasis had significantly higher SUV than their counterparts. In addition, the primary tumor detection rate was higher in patients with serum PSA > 10 ng/mL and GS > 7.Item Role of 68-Ga-PSMA-PET/CT in pelvic radiotherapy field definitions for lymph node coverage in prostate cancer patients(2020) Onal, Cem; Ozyigit, Gokhan; Guler, Ozan Cem; Hurmuz, Pervin; Torun, Nese; Tuncel, Murat; Dolek, Yemliha; Yedekci, Yagiz; Oymak, Ezgi; Tilki, Burak; Akyol, Fadil; 0000-0002-2742-9021; 0000-0001-6908-3412; 32861704; AAE-2718-2021; D-5195-2014; AAC-5654-2020Purpose: To evaluate the distribution of metastatic lymph nodes (LN) detected on Ga-68-PSMA-positron emission tomography/computed tomography (PET/CT) in treatment-naive prostate cancer (PC) patients and to analyze the LN coverage rates of the pelvic fields defined in the GETUG trial and RTOG guidelines and a pelvic field extending superiorly from the L4/L5 interspace. Materials and methods: Ga-68-PSMA-PET/CT images obtained at diagnosis of 138 PC patients were retro-spectively analyzed. The number and locations of Ga-68-PSMA-positive LNs were co-registered with one single-planning CT. The numbers, locations, and sizes of LNs located outside the three pelvic volumes were investigated for the entire cohort and for patients with LN metastasis in the pelvic area only. Results: A total of 441 PSMA-PET-positive LN metastases were identified. The most frequent metastatic LNs were internal iliac LNs (25.2%). Para-aortic and presacral LNs outside the three pelvic fields were present in 20 (14.5%) and 22 patients (15.9%), respectively. The LN coverage rates according to the GETUG trial, the RTOG guidelines, and the pelvic field extending superiorly from L4/L5 were 44.2%, 52.2%, and 71, respectively, in the entire cohort and 51.7%, 61 and 83.1%, respectively, in patients with only pelvic LN metastasis. The number of metastatic LNs was a predictive factor for LNs located outside the three pelvic fields. Conclusions: Extending the cranial margin of the pelvic field from L5/S1 to L4/L5 increases the accuracy of pelvic field irradiation in approximately 20% of patients, highlighting the importance of proximal common iliac irradiation, particularly in patients with multiple LN metastasis. (C) 2020 Elsevier B.V. All rights reserved.