Cem Onal

Cem Onal
Baskent University Adana Dr Turgut Noyan Research and Treatment Center · Department of Radiation Oncology

Professor & Chair

About

348
Publications
23,317
Reads
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2,259
Citations
Additional affiliations
June 2000 - June 2004
Hacettepe University
Position
  • Consultant
October 2004 - May 2005
Ankara University
Position
  • Medical Doctor
June 2006 - present
Başkent University
Position
  • Professor

Publications

Publications (348)
Article
Background To investigate the utility of diffusion‐weighted magnetic resonance imaging (DW‐MRI) in evaluating Gleason score (GS) 7 tumors before definitive radiotherapy (RT) and to explore its association with clinicopathological factors and treatment outcomes. Materials and Methods Clinical data of 266 prostate cancer (PCa) patients with biopsy‐c...
Article
Full-text available
Background This study assessed the biochemical disease-free survival (bDFS), prostate cancer-specific survival (PCSS), overall survival (OS), and side effects in patients aged < 70 and ≥ 70 years following definitive radiotherapy (RT). It also analysed the correlation between age at diagnosis and clinicopathological characteristics of prostate canc...
Article
Full-text available
Purpose To investigate the treatment outcomes of extracranial oligometastatic colorectal cancer (CRC) patients treated with stereotactic body radiotherapy (SBRT). Materials and methods The clinical data of 388 extra-cranial oligometastatic CRC (≤ 5 lesions) patients and 463 lesions treated with SBRT at 19 cancer institutions were retrospectively a...
Article
Purpose To assess the early metabolic response of the primary tumor using Gallium‐68 ( ⁶⁸ Ga)‐labeled‐prostate‐specific membrane antigen positron emission tomography ( ⁶⁸ Ga‐PSMA‐PET/CT), as well as the relationship between PSMA change in the primary tumor and PSA response after definitive radiotherapy (RT), either alone or in combination with andr...
Article
Full-text available
Purpose This study sought to determine the predictive and prognostic value of clinicopathological parameters and neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and hemoglobin (Hgb) level in predicting recurrence patterns and locoregional relapse-free survival (LRFS) and distant metastasis-free survival (DMFS) in cervical...
Article
Background: Alterations in the PIK3/Akt/mTOR pathway are commonly seen in metastatic castration-sensitive prostate cancer (mCSPC), however their role in outcomes is unknown. We aim to evaluate the prognostic significance as well as the genetic landscape of PIK3/Akt/mTOR pathway alteration in mCSPC. Methods: Fourhundred and seventy-two patients w...
Preprint
Full-text available
Objective To investigate the utility of diffusion-weighted magnetic resonance imaging (DW-MRI) in evaluating Gleason score (GS) 7 tumors before definitive radiotherapy (RT) and to explore its association with clinicopathological factors and treatment outcomes. Methods Clinical data of 266 prostate cancer (PCa) patients with biopsy-confirmed GS 7 w...
Article
Purpose We investigated the impact of prostate-specific membrane antigen (PSMA) PET/CT compared with conventional imaging on treatment outcomes for node-positive prostate cancer (PCa) patients who underwent androgen deprivation therapy (ADT) and external radiotherapy (RT). Patients and Methods A multicentric, retrospective study recruited patients...
Article
Background/aim: To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR). Patients and methods: The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fracti...
Article
Full-text available
Purpose Emerging data suggest that metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can detect occult metastatic disease, and PSMA response has been proposed as a biomarker for treatment respo...
Article
Purpose To compare the biochemical failure (FFBF) and prostate cancer specific survival (PCSS) rates of patients with intermediate‐risk prostate cancer (IR‐PC) who were treated with 6 months of androgen deprivation therapy (ADT) with 78 Gy to the prostate, those treated with ADT and focal boost (FB) of 86 Gy to intraprostatic lesion (IPL) using the...
Article
Objective The objective of this study was to assess the prognostic value of clinical factors and metabolic parameters measured using fluorodeoxyglucose PET (FDG-PET/CT) in predicting disease recurrence, as well as distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and overall survival (OS) in patients with uterine cervi...
Article
Background We examined the effects of reducing the planning target volume (PTV) margin in MR‐guided radiotherapy (MRgRT) on the distribution of radiation dose to target volumes and organs‐at‐risk (OARs). Thus, we compared MR‐Linac (MRL) plans with and without reduced margin and intensity‐modulated radiotherapy (IMRT) plan with conventional linac fo...
Article
Full-text available
Background 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,...
Article
Full-text available
PurposeWe examined the prognostic significance of early changes in primary tumor SUV measured with Gallium-68-labeled prostate-specific membrane antigen positron emission tomography ([68Ga]Ga-PSMA-11-PET/CT) and serum PSA values after neoadjuvant androgen deprivation treatment (nADT) in high-risk prostate cancer (PCa) patients treated with definiti...
Article
The aim of this study was to examine the prognostic factors and treatment outcomes of cervical esophageal carcinoma (CEC) patients who underwent definitive chemoradiotherapy (CRT). The clinical data of 175 biopsy-confirmed CEC patients treated with definitive CRT between April 2005 and September 2021 were retrospectively analyzed. The prognostic fa...
Article
Background: To evaluate the treatment outcomes and toxicity of definitive radiotherapy (RT) for prostate cancer (PC) patients using the simultaneous integrated boost (SIB) technique, which delivered 78 Gy to the entire prostate and 86 Gy to the intraprostatic lesion (IPL) in 39 fractions. Materials and methods: Univariable and multivariable anal...
Article
Purpose: We assessed early changes in apparent diffusion coefficient (ADC) and serum prostate specific antigen (PSA) values after definitive radiotherapy (RT) without androgen deprivation treatment in low- and intermediate-risk prostate cancer (PC) patients. Materials and methods: The clinical data and ADC parameters of 229 PC patients were retr...
Article
Full-text available
Objective To establish a prognostic model for endometrial cancer (EC) that individualizes a risk and management plan per patient and disease characteristics. Methods A multicenter retrospective study conducted in nine European gynecologic cancer centers. Women with confirmed EC between January 2008 to December 2015 were included. Demographics, dis...
Article
Objective To investigate the prognostic factors for survival and toxicities in elderly (≥65 years) patients with endometrial cancer who underwent post-operative radiotherapy. Additionally, to compare the treatment outcomes between the older elderly (≥75 years) and younger elderly (65–74 years) patients. Methods Medical records of patients with eno...
Article
Background: This study aimed to evaluate the safety and efficacy of ultra-hypofractionated stereotactic body radiation therapy (SBRT) to prostate bed. Methods: Sixty-six prostate cancer patients treated with postoperative ultra-hypofractionated SBRT between 2018 and 2020 were retrospectively reviewed. All patients received a total dose of 35 Gy...
Article
Full-text available
OBJECTIVE The objective of this study was to compare Federation of Gynecology and Obstetrics (FIGO) 2009 and 2018 staging systems in patients with uterine cervical cancer. METHODS Medical records of 571 patients who were treated with adjuvant radiotherapy or radiochemotherapy between 2001 and 2018 were retrospectively reviewed. Differences in overa...
Chapter
Radiation therapy (RT) is an essential component of gynecological cancer management. Advanced RT techniques including intensity-modulated radiotherapy, image-guided radiotherapy, and stereotactic body radiotherapy allow for highly conformal radiation dose delivery, which can improve treatment results and ensure fewer radiation-related toxicities. M...
Article
Introduction: The aim of this study was to investigate the clinical outcomes of metastasis-directed therapy (MDT) using stereotactic body radiotherapy (SBRT) in patients with synchronous or metachronous oligometastatic renal cell carcinoma (RCC). Methods: The clinical data of 87 patients with 138 lesions who received MDT between February 2008 an...
Article
We aimed to evaluate contralateral breast doses calculated with a Treatment Planning System (TPS) and verified with metal oxide semiconductor field effect transistor (MOSFET) detectors in patients with early-stage breast cancer (BC) who received helical tomotherapy (HT) after breast-conserving surgery. The dosimetric data of 30 patients (15 left-si...
Article
Full-text available
Purpose Few studies have determined the viability of stereotactic body radiotherapy (SBRT) and tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell carcinoma (mRCC). We examined the results of RCC patients who had five or fewer lesions and were treated with TKI and SBRT. Methods The clinical data of 42 patients with 96 metas...
Article
Objective Albumin-globulin ratio or albumin-globulin score predict survival in many cancers, but there are few data on cervical cancer patients. This study examined whether pre-treatment albumin and globulin levels, as well as the albumin-globulin ratio and albumin-globulin score, can predict treatment outcomes in cervical cancer patients undergoin...
Article
Full-text available
Purpose/Objective(s) To investigate the clinical outcomes of cervical esophageal carcinoma patients treated with definitive chemoradiotherapy (CRT). Materials/Methods The clinical data of 180 patients received concurrent CRT between April 2005 and September 2021 at 17 institutions were retrospectively analyzed. All patients were treated with curat...
Article
Purpose/Objective(s) Previous studies had shown a dose-response relationship in prostate cancer during radiotherapy (RT). The clinical outcomes of prostate cancer patients treated with definitive RT using the simultaneous-integrated boost (SIB) technique were investigated in this study. Materials/Methods The clinical data of 556 prostate cancer pa...
Article
Full-text available
Purpose/Objective(s) Prospective randomized phase 3 trials have shown that hypofractionated radiotherapy (RT) regimens are safe and effective for definitive prostate RT. There is, however, a scarcity of data describing the outcomes of ultra-hypofractionation in the postoperative setting. The purpose of this study was to assess the safety of ultra-h...
Article
Purpose/Objective(s) The standard of care for high grade glioma (HGG) treatment consists of postoperative radiotherapy and temozolamide (TMZ). The effect of time between TMZ administration and RT on treatment outcomes is not well defined. The purpose of this study was to examine the interval between oral administration of TMZ and RT, and its effect...
Article
Purpose/Objective(s) By providing more objective measurements, quantitative magnetic resonance imaging (MRI) has the potential to further improve prediction of treatment outcomes for prostate cancer patients. The purpose of this study was to determine whether quantitative multiparametric MRI performed prior to treatment can accurately predict the b...
Article
Purpose/Objective(s) Previous studies demonstrated the efficacy of stereotactic-body radiotherapy (SBRT) for oligometastatic renal cell carcinoma (RCC) patients. However, it has not been well-studied in patients with bone-only metastatic RCC. This study aimed to analyze the prognostic factors associated with overall survival (OS) and progression-fr...
Article
Full-text available
Purpose/Objective(s) Stereotactic body radiotherapy (SBRT) is increasingly being used to treat oligometastatic cancers, but high-level evidence to support policy decisions is lacking in patients with colorectal carcinoma (CRC). The purpose of this study was to determine the prognostic factors for survival in oligometastatic colorectal cancer patien...
Article
Purpose/Objective(s) Emerging data suggest metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET/CT) can detect occult metastatic disease and has been proposed as a biomarker for treatment response....
Article
Introduction: This study aims to report the outcomes of SBRT for adrenal metastasis in a retrospective multi-institutional cohort. Methods: The outcomes of 124 patients with 146 adrenal metastases who underwent SBRT within 11 years (2008-2019) were retrospectively evaluated. Survival outcomes were analyzed by the Kaplan-Meier method. Patient, tu...
Article
Full-text available
Background: Tyrosine kinase inhibitors (TKIs) are the standard of care for resectable and metastatic non-small-cell lung cancer (NSCLC) harbouring epidermal growth factor receptor (EGFR) mutations (EGFRm). We describe the real-world practice of EGFRm testing, prevalence, treatment and outcomes in EGFRm stage III NSCLC from a multi-country, observa...
Article
Full-text available
Introduction Although epithelioid ovarian cancer (EOC) is a radiosensitive tumor and radiotherapy (RT) played a significant role in adjuvant treatment management in the past, the role of RT has evolved with the advent of platinum-based chemotherapy regimens. Nonetheless, modern RT techniques may be useful in certain patients particularly those with...
Article
Full-text available
Introduction Cardiac angiosarcoma is a very rare disease. As a result of their nonspecific presentation symptoms, and the lack of consensus in treatment, caution should be taken in both diagnosis and treatment. The role of radiotherapy (RT) is debatable due to the continuous movement of the heart, which makes it difficult to safely deliver high rad...
Article
Full-text available
Cancer patients often face malnutrition, which negatively affects their response to cancer treatment. This study aims to analyze the effects of the COVID-19 pandemic on nutritional status and anxiety in cancer patients with different types and stages of cancer. This is a cross-sectional cohort study that includes 1,252 patients with varying cancer...
Article
Purpose: 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 progression-free survival (PFS) in this patient coh...
Article
Full-text available
Purpose This study aimed to analyze the prognostic factors associated with overall survival (OS) and progression-free survival (PFS) in patients with bone-only metastatic renal cell carcinoma (RCC) who have five or fewer lesions treated with stereotactic body radiotherapy (SBRT). Methods The clinical data of 54 patients with 70 bone metastases und...
Article
This is a significant study that shows that definitive chemo-radiotherapy is an effective treatment option for cervical esophageal squamous cell carcinoma. We are curious, though, whether local control has any effect on survival.
Article
We retrospectively analysed the prognostic significance of serum albumin, alkaline phosphatase (ALP) and albumin to ALP ratio (AAPR) and other prognostic factors affecting the overall survival (OS) and progression-free survival (PFS) in 200 cervical cancer patients treated with definitive chemoradiotherapy (CRT). The prognostic factors for OS and D...
Article
5011 Background: Emerging data suggest metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET/CT) can detect occult metastatic disease and has been proposed as a biomarker for treatment response. Her...