Tıp Fakültesi / Faculty of Medicine
Permanent URI for this collectionhttps://hdl.handle.net/11727/1403
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Item Impact of adjuvant radiotherapy and mitotane on survival in localized adrenocortical carcinoma: A retrospective cohort study(Başkent Üniversitesi Tıp Fakültesi, 2025) Elmali, Aysenur; Guler, Ozan Cem; Ozyigit, Gokhan; Hurmuz, Pervin; Onal, Cem; 41399138Objectives: Adrenocortical carcinoma (ACC) is a rare, aggressive tumor with high recurrence rates after surgery. Although radiotherapy (RT) has historically been underutilized in ACC, modern RT techniques have renewed interest in its potential role for improving local control (LC). This study evaluated long-term outcomes and prognostic factors in high-risk localized ACC treated with adjuvant RT and mitotane. Methods: In this multicenter retrospective study, 23 patients with localized, high-risk ACC who underwent complete surgical resection followed by adjuvant RT between 2003 and 2023 were analyzed. All received mitotane, and 21.6% also received platinum-based chemotherapy. RT was delivered using image-guided IMRT or VMAT to a median dose of 50.4 Gy, targeting the tumor bed with or without regional lymphatics. Survival was estimated using the Kaplan-Meier method, and prognostic factors were assessed with Cox regression analyses. Results : At a median follow-up of 84.7 months, the 5-year LC, overall survival (OS), and disease-free survival (DFS) rates were 85.5%, 58.6%, and 45.6%. Locoregional recurrence occurred in two patients (8.6%), with isolated local failure in one (4.3%). Distant metastasis (DM) developed in 47.8% and was the predominant failure pattern. On univariable analysis, age > 55 years predicted worse OS and DFS, while female sex independently predicted inferior DFS. Treatment was well tolerated, with no grade >= 3 RT-related toxicities. Conclusions: Adjuvant RT achieves excellent LC with minimal toxicity in high-risk localized ACC. These exploratory findings, limited by small cohort size, retrospective design, and absence of a comparator group, warrant confirmation in larger prospective multicenter studies.Item Comparison of Helical and TomoDirect Techniques with Simultaneous Integrated Boost in Early Breast Cancer Patients(REPORTS OF PRACTICAL ONCOLOGY AND RADIOTHERAPY, 2023) Onal, Cem; Bozca, Recep; Oymak, Ezgi; Guler, Ozan CemBackground: The aim of the study was to perform dosimetric comparisons of helical (H) and TomoDirect (TD) plans for whole-breast irradiation (WBI) with simultaneous integrated boost (SIB) in early-stage breast cancer patients undergoing breast conserving surgery.Materials and methods: Fifty patients, 25 with left-side and 25 with right-side tumors, were determined for a treatment planning system for a total dose of 50.4Gy in 1.8Gy per fraction to WBI, with a SIB of 2.3Gy per fraction delivered to the tumor bed. The planning target volume (PTV) doses and the conformity (CI) and homogeneity indices (HI) for PTV(breast )and PTVboost, as well as organ-at-risk (OAR) doses and treatment times, were compared between the H and TD plans.Results: All plans met the PTV coverage criteria for the H plan, except for mean V107 of PTVbreast for TD plan. The H plan yielded better homogeneity and conformity of dose distribution compared to the TD plan. The ipsilateral mean lung doses were not significantly different between the two plans. The TD plans is advantageous for mean doses to the heart, contralateral breast and lung, spinal cord, and esophagus than the H plans. In both the H and TD plans, the right-sided breast patients had lower heart dose parameters than the left-sided breast patients. The TD plan is superior to the H plan in sparing the contralateral breast and lung by decreasing low-dose volumes.Conclusions: While the OAR dose advantages of TD are appealing, shorter treatment times or improved dose homogeneity and conformity for target volume may be advantageous for H plan.Item Innovations in Cervical Cancer Treatment-There is Still Room for Improvement(2023) Onal, Cem; Yavas, Guler; HOC-5611-2023; AAE-2822-2020Item Untitled Reply(2023) Onal, Cem; Sezen, Duygu; Oymak, Ezgi; Bolukbasi, YaseminItem In Regard to Boeri et al. 'Oligorecurrent Prostate Cancer Treated with Metastases-Directed Therapy or Standard of Care: A Single-Center Experience'(2023) Bolukbasi, Yasemin; Oymak, Ezgi; Durankus, Nilufer Kilic; Onal, Cem; https://orcid.org/0000-0002-2742-9021; 35027691; HOC-5611-2023Item Definitive Chemoradiation Therapy Following Surgical Resection or Radiosurgery Plus Whole-Brain Radiation Therapy in Non-Small Cell Lung Cancer Patients With Synchronous Solitary Brain Metastasis: A Curative Approach(2014) Parlak, Cem; Mertsoylu, Huseyin; Guler, Ozan Cem; Onal, Cem; Topkan, Erkan; https://orcid.org/0000-0001-6170-0383; https://orcid.org/0000-0002-1932-9784; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0001-8120-7123; 24495594; B-3671-2014; M-9530-2014; AAC-5654-2020; HOC-5611-2023; AAG-2213-2021Purpose/Objectives: The aim of this study was to evaluate the impact of definitive thoracic chemoradiation therapy following surgery or stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT) on the outcomes of patients with non-small cell lung cancer (NSCLC) with synchronous solitary brain metastasis (SSBM). Methods and Materials: A total of 63 NSCLC patients with SSBM were retrospectively evaluated. Patients were staged using positron emission tomography-computed tomography in addition to conventional staging tools. Thoracic radiation therapy (TRT) with a total dose of 66 Gy in 2 Gy fractions was delivered along with 2 cycles of cisplatin-based chemotherapy following either surgery plus 30 Gy of WBRT (n = 33) or SRS plus 30 Gy of WBRT (n = 30) for BM. Results: Overall, the treatment was well tolerated. All patients received planned TRT, and 57 patients (90.5%) were also able to receive 2 cycles of chemotherapy. At a median follow-up of 25.3 months (7.1-52.1 months), the median months of overall, locoregional progression-free, neurological progression-free, and progression-free survival were 28.6, 17.7, 26.4, and 14.6, respectively. Both univariate and multivariate analyses revealed that patients with a T1-T2 thoracic disease burden (P = .001), a nodal stage of N0-N1 (P = .003), and no weight loss (P = .008) exhibited superior survival. Conclusions: In the present series, surgical and radiosurgical treatments directed toward SSBM in NSCLC patients were equally effective. The similarities between the present survival outcomes and those reported in other studies for locally advanced NSCLC patients indicate the potentially curative role of definitive chemoradiation therapy for highly selected patients with SSBM. (C) 2014 Elsevier Inc.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 Uterine Perforation During 3-Dimensional Image-Guided Brachytherapy in Patients With Cervical Cancer Baskent University Experience(2014) Onal, Cem; Guler, Ozan Cem; Dolek, Yemliha; Erbay, Gurcan; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-1706-8680; 24407583; HOC-5611-2023; AAC-5654-2020; AAK-5370-2021Objectives This study aimed to determine the incidence and characteristics of uterine perforation at our department using 3-dimensional computed tomography (CT)-based brachytherapy (BRT). The characteristics of the patients presenting with perforation and impact of the perforation on the treatment course were also analyzed. Materials and Methods The clinical and radiologic data of 200 patients with biopsy-proven cervical cancer treated using CT-based BRT were retrospectively evaluated. All patients had undergone tandem-based intracavitary BRT, and 67 patients had undergone magnetic resonance imaging (MRI) before BRT. Results Of the 200 patients, 17 (8.5%) had uterine perforation. Of the 626 applications with CT images, 30 (4.8%) resulted in uterine perforation. The median age of patients with perforation was higher (68 years; range, 44-89 years) than that of the patients without perforation (59 years; range, 21-87 years), and the mean (SD) tumor size at diagnosis was larger in patients with perforation (7.0 [1.5] cm) than in patients without perforation (5.0 [1.5] cm). The most frequent perforation site was the posterior uterine wall (8 patients), followed by the fundus (5 patients) and anterior wall (4 patients). Of the 7 patients with a retroverted uterus, 4 had uterine perforation during BRT. In 67 patients with MRI delivered before BRT, only 3 (4%) had uterine perforation, and 2 of the 3 patients with uterine perforation had a retroverted uterus. However, of the 133 patients with no MRI evaluation before BRT, 14 (11%) had uterine perforation. No life-threatening complications or signs of intraperitoneal tumor cell seeding were observed. Conclusions Older age, larger tumors, a retroverted uterus, and a stenotic cervical os were all predisposing factors for uterine perforation during BRT. Preoperative MRI is a feasible and safe method to decrease the risks of uterine perforation and could be used preoperatively in centers where intraoperative ultrasonography is not used in routine practice.Item Prognostic Value of 18F-Fluorodeoxyglucose Uptake in Pelvic Lymph Nodes in Patients with Cervical Cancer Treated with Definitive Chemoradiotherapy(2015) Onal, Cem; Guler, Ozan C.; Reyhan, Mehmet; Yapar, Ali Fuat; 0000-0001-6908-3412; 0000-0003-1715-4180; 0000-0002-2742-9021; 0000-0001-8550-3368; 25641567; AAC-5654-2020; AAI-8973-2021; D-5195-2014; AAJ-5242-2021; HOC-5611-2023Purpose. To evaluate the prognostic significance of the maximum standardized uptake (SUVmax) value for pelvic lymph nodes in patients with cervical cancer and its impact on treatment response, disease control, and survival. Methods. Ninety-three patients with pelvic or para-aortic metastasis detected by PET/CT and treated with definitive chemoradiotherapy were evaluated. The impact of pelvic lymph node SUVmax on prognostic factors and treatment outcomes was assessed. Results. The size and SUVmax of pelvic lymph nodes were significantly correlated (r = 0.859; p < 0.001). Patients with pelvic and para-aortic lymph node metastases had significantly higher SUVmax values for both primary tumor (23.4 +/- 9.2 vs. 18.5 +/- 73; p = 0.01) and pelvic lymph nodes (11.4 +/- 4.6 vs. 7.4 +/- 3.8; p = 0.001). Patients with pelvic lymph node SUVmax >= 7.5 had significantly higher primary tumor SUVmax, larger pelvic lymph nodes, higher rates of para-aortic lymph node metastasis, and lower post-therapy complete response rates. Overall survival (OS) and disease-free survival (DFS) rates were significantly higher in patients with SUVmax < 7.5 compared to patients with SUVmax >= 7.5. In a multivariate analysis, pelvic lymph node SUVmax and post-therapy metabolic response were significant prognostic factors for both OS and DFS for all patients, but no significant prognostic factors were found in pelvic lymph node metastasis only. Conclusions. Patients with highly FDG-avid pelvic lymph nodes have a higher risk of disease recurrence with worse survival. Identification of these patients may assist in the evaluation of the clinical benefits of additional treatments. (C) 2015 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.