Tıp Fakültesi / Faculty of Medicine
Permanent URI for this collectionhttps://hdl.handle.net/11727/1403
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Item Prostate Mucinous Carcinoma Treated with Definitive Radiotherapy and Hormonal Therapy: Case Report and Review of the Literature(2014) Guler, Ozan Cem; Onal, Cem; Erbay, Gurcan; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0002-1706-8680; 24365124; AAC-5654-2020; HOC-5611-2023; AAK-5370-2021Prostate mucinous carcinoma (MC) is a rare variant of prostate adenocarcinoma that is characterized by large pools of extracellular mucin, which by definition compose at least 25% of the tumor volume. Prostate MC has 3 subtypes. The most common variant is pure MC; primary signet ring cell carcinoma and MC with signet ring cell are less common variants and are more aggressive than pure MC. Because of the rarity of prostate MC and conflicting reports regarding the behavior of the disease, the optimal treatment strategy is not clear. Most series report the efficacy of surgery. We report a rare case of a patient with a large prostate MC that was treated successfully with hormone therapy (HT) and radiotherapy (RT). Treatment response was assessed by dynamic contrast-enhanced magnetic resonance imaging (MRI). (C) 2014 Elsevier Inc. All rights reserved.Item Treatment Outcomes of Patients with Cervical Cancer with Complete Metabolic Responses After Definitive Chemoradiotherapy(2014) Onal, Cem; Reyhan, Mehmet; Guler, Ozan C.; Yapar, Ali Fuat; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0001-8550-3368; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0003-1715-4180; 24562649; HOC-5611-2023; AAJ-5242-2021; AAC-5654-2020; AAI-8973-2021Purpose We sought to evaluate failure patterns and prognostic factors predictive of recurrences and survival in cervical cancer patients who are treated with definitive chemoradiotherapy (ChRT), who have a subsequent complete metabolic response (CMR) with (18) F-fluorodeoxyglucose positron-emission tomography (FDG-PET) after treatment. Methods The records of 152 cervical cancer patients who were treated with definitive chemoradiotherapy were evaluated. All patients underwent pre-treatment positron emission tomography (PET-CT), and post-treatment PET-CT was performed within a median of 3.9 months (range, 3.0-9.8 months) after the completion of ChRT. The prognoses of partial response/progressive disease (PR/PD) cases (30 patients, 18 %) and CMR cases (122 patients, %82) were evaluated. Univariate and multivariate analysis effecting the treatment outcome was performed in CMR cases. Results The median follow-ups for all patients and surviving patients were 28.7 (range, 3.3-78.7 months) and 33.2 months (range, 6.23-78.7 months), respectively. Four-year overall survival (OS) rate was significantly better in patients with CMR compared to patients with PR/PD (66.9 % vs. 12.4 %, p < 0.001, respectively). Patients with PR/PD had higher maximum standardized uptake value (SUVmax) of primary cervical tumor (26.4 +/- 10.1 vs. 15.9 +/- 6.3; p < 0.001) and larger tumor (6.4 cm +/- 2.3 cm vs. 5.0 cm +/- 1.4 cm; p < 0.001) compared to patients with CMR. Of the 122 patients with post-treatment CMRs, 25 (21 %) developed local, locoregional, or distant failure. In univariate analysis, tumor size a parts per thousand yen 5 cm, 'International Federation of Obstetricians and Gynecologists' (FIGO) stage a parts per thousand yenaEuro parts per thousand IIB, and pelvic and/or para-aortic lymph node metastasis were predictive of both overall survival (OS) and disease-free survival (DFS), while histology was predictive of only OS. In multivariate analysis, tumor size, stage and lymph node metastasis were predictive of OS and DFS. Conclusion Although CMR is associated with better outcomes, relapses remain problematic, especially in patients with bulky tumors (a parts per thousand yen 5 cm), extensive stage (a parts per thousand yen IIB) or pelvic and/or para-aortic lymph node metastasis. These findings could support the need for more aggressive treatment or adjuvant chemotherapy regimens.Item Multifocal Soft Tissue Langerhans' Cell Histiocytosis Treated with PET-CT Based Conformal Radiotherapy(2015) Onal, Cem; Oymak, Ezgi; Reyhan, Mehmet; Canpolat, Tuba; Ozyilkan, Ozgur; 0000-0002-2742-9021; 0000-0001-8550-3368; 0000-0001-8825-4918; 26211006; AGG-9214-2022; HOC-5611-2023; D-5195-2014; AAJ-5242-2021; AAD-2817-2021; AAK-8107-2021Langerhans' cell histiocytosis (LCH) is a proliferative disorder of Langerhans cells, which is seen extremely rarely in adults. Conventional imaging modalities, such as skeletal surveys and bone scans, were accepted to be standard methods for diagnosis; however, 18-fluorodeoxyglucose positron emission tomography (PET-CT) has been increasingly used. We report on a 33-year-old female patient with disseminated LCH treated with radiotherapy and systemic chemotherapy where PET-CT has been used for defining the extent of the disease, RT planning and assessment of treatment response during follow-up. The patient was treated with 24 Gy 3-dimensional conformal radiotherapy (RT), given as 2 Gy a day, 5 days a week. The patient was also treated with systemic prednisolone 20 mg/m(2), concurrently. The chemotherapeutic regimen switched to cytosine-arabinoside with a dose of 100 mg/m(2) subcutaneously daily for 4 days, vincristine 1.5 mg/m(2) given on the 1st day and prednisolone 20 mg/m(2) for 4 cycles. After local RT with adjuvant chemotherapy, the patient was alive for 54 months and remained disease-free at last visit. RT is a treatment choice in multi-system LCH as well as solitary lesions. Low-dose RT is adequate to control large masses of LCH including soft tissue and lymph nodes.Item Daily Workflow and Workload of Radiation Oncology Specialists in Turkey(2015) Akman, Fadime; Kamer, Serra; Onal, Cem; Agaoglu, Fulya; Guney, Yildiz; Hicsonmez, Ayse; Koc, Mehmet; Colpan Oksuz, Didem; Ozyigit, Gokhan; Ozkok, Serdar; 0000-0002-2742-9021; D-5195-2014OBJECTIVES This study aimed to research the effort required by patient evaluation, radiotherapy planning and treatment processes in the daily applications of radiation oncology in terms of time, and to use this effort as the primary source for human power and infrastructure planning required in radiotherapy. METHODS The surveys carried out by Turkish Radiation Oncology Association Proficiency Board, Curriculum Preparation and Evaluation Commission on Education Institutions, Surveys delivered to the officers of the center via electronic mail, were answered and evaluated in accordance with the data of 2012. RESULTS 26 University and 8 Ministry of Health Hospitals participated in the study. The total number of specialists employed in the participant centers, were 227. For per specialist, 383 hours in a year were spent for the patients at follow-up, 334 hours were spent for the patients that were in treatment, and 950 hours were spent for planning and treatment set-ups. It was determined that the time spent for per patient in intensity modulated radiotherapy technique, was 2-3 times more when compared to the location of tumor, which is a conformal technique. It was observed that this duration was much longer in special radiotherapy applications such as brachytherapy, total body irradiation and radiosurgery. CONCLUSION Technological advancements in radiotherapy, require more effort and working time for new job descriptions and in daily practice.Item Stereotactic Ablative Body Radiotherapy as a Bridge to Liver Transplant for Hepatocellular Carcinoma: Preliminary Results of Baskent University Experience(2022) Yavas, Guler; Soy, Ebru Hatice Ayvazoglu; Coskun, Mehmet; Onal, Cem; Boyvat, Fatih; Haberal, Mehmet; https://orcid.org/0000-0002-3462-7632; 35384806; HOC-5611-2023; AAJ-8097-2021Objectives: Hepatocellular carcinoma is the most common primary liver tumor, with curative treatment options being liver transplant and resection. However, approximately 20% to 30% of patients have substantial disease progression while awaiting transplant. Here, we report our initial experience on stereotactic ablative body radiotherapy as a bridge to liver transplant for patients with hepatocellular carcinoma. Materials and Methods: Seven patients with 9 lesions received stereotactic ablative body radiotherapy as a bridge treatment to transplant. All patients underwent radiofrequency ablation, transcatheter arterial chemoembolization, or hepatic resection before stereotactic ablative body radiotherapy. Magnetic resonance imaging was used to evaluate radiographic responses 1 month later. Results: Median age of patients was 65 years (range, 63-71 years), median stereotactic ablative body radiotherapy dose was 45 Gy (range, 30-54 Gy; delivered in 3-5 fractions), and median tumor diameter was 17 mm (range, 12-30 mm). Before stereotactic ablative body radiotherapy, all patients underwent liver-directed therapies, including transcatheter arterial chemoembolization for 3 lesions, transcatheter arterial chemoembolization and radiofrequency ablation for 4 lesions, surgical resection for 1 lesion, and surgical resection plus transcatheter arterial chemoembolization for the remaining lesion. Patients showed no evidence of gastrointestinal toxicity or radiation-induced liver disease. Acute toxicity was negligible; all patients completed the treatment course. One month after stereotactic ablative body radiotherapy administration, response rates were assessed with magnetic resonance imaging, with complete responses obtained in 5 lesions (55.5%), partial responses for 2 lesions, and stable disease for 2 lesions. No disease progression was shown following stereotactic ablative body radiotherapy application. Conclusions: Stereotactic ablative body radiotherapy is an effective, safe, and tolerable bridging therapy option. Although we observed an early response after treatment, exact response rates will not be known for at least 3 months following stereotactic ablative body radiotherapy. Thus, our findings should be confirmed through additional prospective studies with longer follow-up.Item Treatment Outcomes of Breast Cancer Liver Metastasis Treated with Stereotactic Body Radiotherapy(2018) Onal, Cem; Guler, Ozan Cem; Yildirim, Berna Akkus; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0001-6661-4185; 30296648; HOC-5611-2023; AAC-5654-2020; V-5717-2017Background: To assess the outcomes of breast cancer liver metastasis (BCLM) treated with stereotactic body radiotherapy (SBRT) and systemic treatment. Materials and methods: Patients with oligometastasis at the time of liver metastasis (LM) or who became oligometastatic (<= 5 metastases) after systemic treatment were assessed. Twenty-nine liver metastatic lesions were treated with a total of 54 Gy delivered in 3 fractions. The local control (LC), overall survival (OS), and progression-free survival (PFS) rates were calculated using Kaplan-Meier analyses. Results: A total of 22 patients with 29 liver metastatic lesions treated with liver SBRT between April 2013 and September 2017 were retrospectively analyzed. After a median follow-up time of 16.0 months (range 4.4-59.4 months), 18 patients (82%) had disease recurrence, median of 7.4 months (range 1.0-27.9 months) after completion of liver SBRT. The 1- and 2-year OS rates were 85% and 57%, and the 1- and 2-year PFS rates were 38% and 8%, respectively. The 1- and 2-year LC rates were 100% and 88%, respectively. No significant prognostic factors, including disease extension, size of metastasis, number of liver metastasis and timing of liver metastasis, hormonal status affecting OS, PFS and LC were found. No patients experienced Grade 4 or 5 toxicity; furthermore, only one patient experienced rib fracture 6 months after completion of treatment, and one patient had a duodenal ulcer. Conclusion: This study is the first to evaluate the feasibility of SBRT to BCLM patients. Liver SBRT is a conservative approach with excellent LC and limited toxicities. (C) 2018 Elsevier Ltd. All rights reserved.Item The İmpact of Androgen Deprivation Therapy on Setup Errors During External Beam Radiation Therapy for Prostate Cancer(2017) Onal, Cem; Dolek, Yemliha; Ozdemir, Yurday; 0000-0002-2742-9021; 0000-0002-2218-2074; 28409246; HOC-5611-2023; AAG-5629-2021Purpose To determine whether setup errors during external beam radiation therapy (RT) for prostate cancer are influenced by the combination of androgen deprivation treatment (ADT) and RT. Materials and methods Data from 175 patients treated for prostate cancer were retrospectively analyzed. Treatment was as follows: concurrent ADT plus RT, 33 patients (19%); neoadjuvant and concurrent ADT plus RT, 91 patients (52%); RT only, 51 patients (29%). Required couch shifts without rotations were recorded for each megavoltage (MV) cone beam computed tomography (CBCT) scan, and corresponding alignment shifts were recorded as left-right (x), superior-inferior (y), and anterior-posterior (z). The nonparametric Mann-Whitney test was used to compare shifts by group. Pearson's correlation coefficient was used to measure the correlation of couch shifts between groups. Mean prostate shifts and standard deviations (SD) were calculated and pooled to obtain mean or group systematic error (M), SD of systematic error (Sigma), and SD of random error (sigma). Results No significant differences were observed in prostate shifts in any direction between the groups. Shifts on CBCT were all less than setup margins. A significant positive correlation was observed between prostate volume and the z-direction prostate shift (r = 0.19, p = 0.04), regardless of ADT group, but not between volume and x- or y-direction shifts (r = 0.04, p = 0.7; r = 0.03, p = 0.7). Random and systematic errors for all patient cohorts and ADT groups were similar. Conclusion Hormone therapy given concurrently with RT was not found to significantly impact setup errors. Prostate volume was significantly correlated with shifts in the anterior-posterior direction only.Item Graves' Ophthalmopathy Treated with Protracted Hypofractionated Low-Dose Adaptive Radiotherapy: Case Report and Review of The Literature(2016) Guler, Ozan Cem; Onal, Cem; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-2742-9021; 26466836; AAC-5654-2020; HOC-5611-2023Graves' ophthalmopathy (GO) is the most common extra-thyroidal manifestation of Graves' disease. The treatment options for GO are high-dose glucocorticoids, selenium, rituximab, cyclosporine, orbital radiotherapy (RT), and surgery. A 43-year-old male patient was referred to our clinic with complaints of severe bilateral proptosis, diplopia, and orbital pain at both globes for 1 year. Pretreatment magnetic resonance imaging revealed bilateral proptosis, the expansion of bilateral optic nerves sheath, the increase of right medial muscle thickness, and a mass at the right eyehole. Patient was treated with 1 Gy per fraction per week with a total dose of 10 Gy over 10 weeks with adoptive intensity-modulated radiotherapy technique. During RT at 3rd and 6th weeks, a moderate shrinkage of the lesions was observed. The patient has been disease free, has had no complaints for 36 months, and has not required any surgical intervention. No late side effects such as retinopathy or cataract were observed. Orbital RT with innovative techniques may be considered as an initial local treatment for GO. With adoptive protracted low dose RT, a good clinical and radiological response could be seen without increasing early and late reactions.Item Metachronous Prostate Metastasis of Renal Cell Carcinoma: Case Report and Review of the Literature(2016) Guler, Ozan Cem; Bal, Nebil; Onal, Cem; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-2742-9021; 26739102; AAC-5654-2020; HOC-5611-2023Secondary tumors of the prostate are very rare, and only a few reports of prostate metastasis originating from renal cell carcinoma (RCC) have been published. The reported 5-year survival rate has been approximately 35% for patients who underwent nephrectomy and surgical resection of a solitary metastasis. Immunohistochemical analysis showed that CD10 and vimentin positivity were helpful for distinguishing clear cell RCC from other renal tumors. We report a case with delayed metachronous metastasis of RCC to the prostate, which clinically mimicked benign prostatic hyperplasia or prostate cancer, treated with transurethral resection and palliative radiotherapy. (C) 2016 Elsevier Inc. All rights reserved.Item Prognostic Use of Pretreatment Hematologic Parameters in Patients Receiving Definitive Chemoradiotherapy for Cervical Cancer(2016) Onal, Cem; Guler, Ozan C.; Yildirim, Berna A.; 0000-0002-2742-9021; 0000-0001-6661-4185; 0000-0001-6908-3412; 27206286; D-5195-2014; V-5717-2017; AAC-5654-2020Objectives: The aim of this work was to evaluate the prognostic role of pretreatment neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in recipients of definitive chemoradiotherapy (ChRT) for cervical cancer. Methods: In 235 patients given definitive ChRT for histologically confirmed cervical cancer, clinical data and pretreatment complete blood cell counts were analyzed. Prognostic and therapeutic ramifications of NLR and PLR were assessed. Results: Median pretreatment NLR and PLR were 3.03 (range, 1.04-13.03) and 133.02 (range, 36.3-518.16), respectively. Both NLR and PLR correlated significantly with tumor size, lymph node metastasis, and treatment response. In addition to NLR and PLR, tumor stage, size, and nodal metastasis were identified by univariate analysis as significant predictors of overall survival (OS) and progression-free survival (PFS). By multivariate analysis, independent predictors of OS and PFS were NLR (OS: hazard ratio [HR], 3.322; 95% confidence interval [CI], 1.905-5.790; PFS: HR, 3.579; 95% CI, 2.106-6.082; both P < 0.001) and lymph node metastasis (OS: HR, 2.620; 95% CI, 1.706-4.023; PFS: HR, 2.989; 95% CI, 1.918-4.378; both P < 0.001), although patients' age (HR, 1.019; 95% CI, 1.003-1.035; P = 0.02) was also significantly predictive of OS. Conclusions: Pretreatment NLR and PLR were associated with larger tumors, lymph node metastasis, and poorer therapeutic responses to definitive ChRT. By multivariate analysis, pretreatment NLR and lymph node metastasis were found independently predictive of OS and PFS, whereas patients' age was significantly predictive of OS only. In patients with advanced cervical cancer, NLR is a potential biomarker, serving to guide systemic therapy and predict treatment outcomes.
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