Browsing by Author "Topkan, Erkan"

Filter results by typing the first few letters
Now showing 1 - 20 of 105
  • No Thumbnail Available
    Item
    Baseline hemoglobin <11.0 g/dL has stronger prognostic value than anemia status in nasopharynx cancers treated with chemoradiotherapy
    (2019) Topkan, Erkan; Ekici, Nur Yucel; Ozdemir, Yurday; Besen, Ali Ayberk; Yildirim, Berna Akkus; Mertsoylu, Huseyin; Sezen, Duygu; Selek, Ugur; 30864463
    Background: To retrospectively investigate the influence of pretreatment anemia and hemoglobin levels on the survival of nasopharyngeal carcinoma patients treated with concurrent chemoradiotherapy (C-CRT). Methods: A total of 149 nasopharyngeal carcinoma patients who received C-CRT were included. All patients had received 70 Gy to the primary tumor plus the involved lymph nodes, and 59.4 Gy and 54 Gy to the intermediate- and low-risk neck regions concurrent with 1-3 cycles of cisplatin. Patients were dichotomized into non-anemic and anemic (hemoglobin <12 g/dL (women) or <13 g/dL (men)) groups according to their pre-treatment hemoglobin measures. Receiver operating characteristic (ROC) curve analysis was utilized for accessibility of a pre-treatment hemoglobin cut-off that impacts outcomes. Potential interactions between baseline anemia status and hemoglobin measures and overall survival, locoregional progression-free survival (LRPFS), and progression-free survival were assessed. Results: Anemia was evident in 36 patients (24.1%), which was related to significantly shorter overall survival (P=0.007), LRPFS (P<0.021), and progression-free survival (P=0.003) times; all three endpoints retained significance in multivariate analyses (P<0.05, for each). A baseline hemoglobin value of 11.0 g/dL exhibited significant association with outcomes in ROC curve analysis: hemoglobin <11.0 g/dL (N=26) was linked with shorter median overall survival (P<0.001), LRPFS (P=0.004), and progression-free survival (P<0.001) times, which also retained significance for all three endpoints in multivariate analyses and suggested a stronger prognostic worth for the hemoglobin Conclusion: Pre-C-CRT hemoglobin <11.0 g/dL has a stronger prognostic worth than the anemia status with regard to LRPFS, progression-free survival, and overall survival for nasopharyngeal carcinoma patients.
  • No Thumbnail Available
    Item
    Baseline Low Prognostic Nutritional Index Predicts Poor Survival in Locally Advanced Nasopharyngeal Carcinomas Treated With Radical Concurrent Chemoradiotherapy
    (2019) Topkan, Erkan; Yucel Ekici, Nur; Ozdemir, Yurday; Besen, Ali Ayberk; Mertsoylu, Huseyin; Sezer, Ahmet; Selek, Ugur; 31184210
    Background: To retrospectively assess the impact of prognostic nutritional index (PNI) on survival outcomes of patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC) treated with concurrent chemoradiotherapy (CCRT). Methods: This study incorporated 154 patients with LA-NPC who received exclusive cisplatinum-based CCRT. Receiver operating characteristic (ROC) curve analysis was utilized for accessibility of pretreatment PNI cutoffs influencing survival results. The primary end point was the interaction between the overall survival (OS) and PNI values, while cancer-specific survival (CSS) locoregional progression-free survival (LR-PFS), distant metastasis-free survival (DMFS), and PFS were the secondary end points. Results: A rounded PNI cutoff value of 51 was identified in ROC curve analyses to exhibit significant link with CSS, OS, DMFS, and PFS outcomes, but not LR-PFS. Patients grouping per PNI value (>= 51 [N = 95] vs <51 [N = 49]) revealed that PNI < 51 group had significantly shorter median CSS (P< .001), OS (P< .001), DMFS (P< .001), and PFS (P< .001) times than the PNI >= 51 group, and the multivariate results confirmed the PNI < 51 as an independent predictor of poor outcomes for each end point (P< .05 for each). The unfavorable impact of the low PNI was also continued at 10-year time point with survival rates of 77.9% versus 42.4%, 73.6% versus 33.9%, 57.9% versus 27.1%, and 52.6% versus 23.7% for CSS, OS, DMFS, and PFS, respectively. Additionally, we found that PNI < 51 was significantly associated with higher rates of weight loss >5% over past 6 months (49.2% versus 11.6%;P= .002) compared to PNI < 51 group. Conclusion: Low pre-CCRT PNI levels were independently associated with significantly reduced CSS, OS, DMFS, and PFS outcomes in patients with LA-NPC treated with definitive CCRT.
  • No Thumbnail Available
    Item
    Chemoradiotherapy-İnduced Hemoglobin Nadir Values And Survival in Patients With Stage III Non-Small Cell Lung Cancer
    (2018) Topkan, Erkan; Selek, Ugur; Ozdemir, Yurday; Yildirim, Berna A.; Guler, Ozan C.; Mertsoylu, Huseyin; Hahn, Stephen M.; https://orcid.org/0000-0001-8120-7123; https://orcid.org/0000-0002-2218-2074; https://orcid.org/0000-0001-6661-4185; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0002-1932-9784; 29858023; AAG-2213-2021; AAG-5629-2021; V-5717-2017; AAC-5654-2020; M-9530-2014
    Purpose: We investigated the influence of change in hemoglobin (Hgb) levels during concurrent chemoradiotherapy (C-CRT) on outcomes of non-anemic patients with stage IIIA/B non-small cell lung cancer (NSCLC). Methods: We identified 722 patients with stage IIIA/B NSCLC without anemia at baseline [hemoglobin (Hgb) < 12 g/dL for women or < 13 g/dL for men], either nonsmokers or ex-smokers, who received C-CRT between 2007 and 2012. All patients had received 1 - 3 cycles of platinum-based doublet chemotherapy during radiotherapy to 60 - 66 Gy and had documented Hgb measurements before treatment and at weekly intervals for 6 weeks during the C-CRT. Potential associations were assessed between baseline, nadir, extent of change in Hgb level, and anemia and overall survival (OS), locoregional progression-free survival (LRPFS), and PFS. Results: The median baseline Hgb level was 13.9 g/dL (range 12.0-16.8) and declined to a median 12.4 g/dL (range 7.9-16.1) during treatment. Anemia appeared in 237 patients (32.8%) and was more common among women (44.8% vs. 26.5%, P < 0.001). Neither baseline Hgb level nor change during treatment nor anemia emergence influenced any survival endpoint. Receiver operating curve analysis revealed an Hgb nadir of 11.1 g/dL to be associated with outcomes, in that a nadir Hgb < 11.1 g/dL (in 156 patients) was linked with shorter median OS time (P < 0.001), LRPFS time (P < 0.001), and PFS time (P < 0.001); retained significance for all three endpoints in multivariate analyses; and was more strongly associated with OS in squamous cell carcinoma (P < 0.001) than in adenocarcinoma (P = 0.009). Conclusion: Nadir Hgb < 11.1 g/dL levels during C-CRT were associated with significantly poorer survival times in initially non-anemic patients presenting with locally advanced NSCLC.
  • No Thumbnail Available
    Item
    Comment on "Predictors of Prolonged Teatment Time Intervals in Oral Cavity Cancer"
    (ORAL ONCOLOGY, 2024-01) Topkan, Erkan; Somay, Efsun; Selek, Ugur
  • No Thumbnail Available
    Item
    Comment on: Intensity Modulated Radiotherapy in Head and Neck Cancer: Initial Experience of the First Treated Cases from North-East India
    (2023) Topkan, Erkan; Somay, Efsun; Selek, Ugur; 0000-0001-8251-6913; 38187854; AAG-2213-2021; O-5474-2014
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Comment on: Osteoradionecrosis after postoperative radiotherapy for oral cavity cancer: A retrospective cohort study
    (2022) Topkan, Erkan; Somay, Efsun; Yilmaz, Busra; Kucuk, Ahmet; 0000-0003-0633-5648; 36041356
  • No Thumbnail Available
    Item
    Comment on: Quality of Life After Segmental Mandibulectomy and Free Flap for Mandibular Osteonecrosis: Systematic Review
    (2023) Topkan, Erkan; Somay, Efsun; 0000-0001-8251-6913; 37459741; AAG-2213-2021
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Comment on: Required Time for Pre-Oncological Dental Management-A Rapid Review of the Literature
    (2022) Topkan, Erkan; Somay, Efsun; Yilmaz, Busra; Kucuk, Ahmet; 0000-0001-8120-7123; 0000-0003-0633-5648; 36183502; AAG-2213-2021; AAR-6904-2020
  • No Thumbnail Available
    Item
    Comment On: Risk Prediction Of Complicated Course In Patients Undergoing Major Head And Neck Surgery With Free Fl Ap Reconstruction
    (BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY, 2024-12) Topkan, Erkan; Somay, Efsun; Ozturk, Duriye; Senyurek, Sukran
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Comparison of Involved Field Radiotherapy versus Elective Nodal Irradiation in Stage IIIB/C Non-Small-Cell Lung Carcinoma Patients Treated with Concurrent Chemoradiotherapy: A Propensity Score Matching Study
    (2020) Topkan, Erkan; Ozdemir, Yurday; Guler, Ozan Cem; Kucuk, Ahmet; Besen, Ali Ayberk; Mertsoylu, Huseyin; Sezen, Duygu; Akdemir, Eyub Yasar; Sezer, Ahmet; Bolukbasi, Yasemin; Pehlivan, Berrin; Selek, Ugur; 0000-0002-1932-9784; 0000-0001-6908-3412; 0000-0002-2218-2074; 0000-0002-6445-1439; 0000-0001-8120-7123; 0000-0002-7862-0192; 32952557; M-9530-2014; AAC-5654-2020; AAG-5629-2021; AAD-2667-2020; AAG-2213-2021; AAD-6910-2021
    Background. We retrospectively compared the incidence of isolated elective nodal failure (IENF) and toxicity rates and survival outcomes after elective nodal irradiation (ENI) versus involved-field RT (IFRT) by employing the propensity score matching (PSM) methodology in stage IIIB/C inoperable non-small-cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (C-CRT).Methods. Our PSM examination included 1048 stage IIIB/C NSCLC patients treated with C-CRT from January 2007 to December 2016: a total dose of 66 Gy (2 Gy/fraction) radiotherapy and 1-3 cycles of platinum-based doublet chemotherapy concurrently. The primary and secondary endpoints were the IENF and toxicity rates and survival outcomes after ENI versus IFRT, respectively. Propensity scores were calculated for each group to adjust for confounding variables and facilitate well-balanced comparability by creating 1 : 1 matched study groups.Results. The median follow-up was 26.4 months for the whole study accomplice. The PSM analysis unveiled 1 : 1 matched 646 patients for the ENI (N = 323) and IFRT (N = 323) cohorts. Intergroup comparisons discovered that the 5-year isolated ENF incidence rates (3.4% versus 4.3%;P=0.52) and median overall survival (25.2 versus 24.6 months;P=0.69), locoregional progression-free survival (15.3 versus 15.1 months;P=0.52), and progression-free survival (11.7 versus 11.2 months;P=0.57) durations were similar between the ENI and IFRT cohorts, separately. However, acute grade 3-4 leukopenia (P=0.0012), grade 3 nausea-vomiting (P=0.006), esophagitis (P=0.003), pneumonitis (P=0.002), late grade 3-4 esophageal toxicity (P=0.038), and the need for hospitalization (P<0.001) were all significantly higher in the ENI than in the IFRT group, respectively.Conclusion. Results of the present large-scale PSM cohort established the absence of meaningful IENF or survival differences between the IFRT and ENI cohorts and, consequently, counseled the IFRT as the elected RT technique for such patients since ENI increased the toxicity rates.
  • No Thumbnail Available
    Item
    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-2213-2021
    Purpose/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.
  • No Thumbnail Available
    Item
    Definitive concurrent chemoradiotherapy outcomes in Stage IIIB nonsmall cell lung cancer patients younger than 45 years: A retrospective analysis of 145 patients
    (2020) Topkan, Erkan; Guler, Ozan Cem; Ozdemir, Yurday; 0000-0001-6908-3412; 0000-0002-2218-2074; 0000-0001-8120-7123; 32930115; AAC-5654-2020; AAG-5629-2021; AAG-2213-2021
    Purpose: To assess the survival outcomes and prognostic factors of young (<= 45 years) Stage IIIB nonsmall cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (C-CRT). Materials and Methods: Medical records of 145 Stage IIIB NSCLC patients (<= 45 years) who received 60-66 Gy thoracic radiotherapy and concurrent 1-3 cycles of cisplatin-based doublet chemotherapy were retrospectively evaluated. The primary endpoint was overall survival (OS), while locoregional progression-free survival (LRPFS), progression-free survival (PFS), and evaluation of potential prognostic factors constituted the secondary endpoints. Results: At median 21.6 months (range: 7.3-62.5) of follow-up, the median and 4-year survival estimates were 24.8 months and 24.2% for OS, 15.7 months and 18.9%, for LRPFS and 12.0 months and 11.2% for PFS, respectively. On univariate analyses, among all factors, the smaller tumor size (<= 7.0 cm; P = 0.03), lower T-stage (T1-T2; P = 0.02), lower N-stage (N2; P = 0.01), absence of anemia before C-CRT (hemoglobin [Hb] >= 12 g/dL; P < 0.001), and lower/no pretreatment weight loss (WL 5%; P < 0.001) were found to be associated significantly with longer median OS durations, which also retained their independent significance on multivariate analyses, except for tumor size category. Conclusions: The encouraging median 24.8 months OS duration observed here in young NSCLC patients accords well with the results of recent landmark locally advanced NSCLC series without age stratification. Other than the well-established T and N stages, extra exhibit of superior OS in patients with initial Hb 12 g/dL and <= 5% WL levels suggests a noteworthy prognostic role for these two latter variables in the stratification of such patients.
  • No Thumbnail Available
    Item
    Effect of Adjuvant Extended Temozolamide Treatment in Survival of Patients with Glioblastoma Multiforme
    (2018) Yildirim, Berna Akkus; Sumbul, Ahmet Taner; Topkan, Erkan; Ozdemir, Yurday; Besen, Ali Ayberk; Guler, Ozan Cem; Sedef, Ali Murat; Onal, Cem; https://orcid.org/0000-0001-6661-4185; https://orcid.org/0000-0002-5573-906X; https://orcid.org/0000-0001-8120-7123; https://orcid.org/0000-0002-2218-2074; https://orcid.org/0000-0002-7862-0192; V-5717-2017; D-4793-2014; AAG-2213-2021; AAG-5629-2021; AAD-6910-2021; HOC-5611-2023
    Purpose: The aim of this retrospective cohort study was to evaluate the prognostic effect extended temozolamide on survival outcomes of glioblastoma multiforme patients who were underwent surgery/biopsy followed treated with definitive chemo-radiotherapy. Materials and Methods: We retrospectively analyzed the datas of 225 patients with gliablastoma multiforme whom admitted to our clinic All patients were completed concomitant chemoradiotherapy with temozolamide and adjuvant temozolamide therapy at least for six months or more. Patients were divided into two groups as standart and extended temozolamid therapy group as using temozolamide therapy for at least 6 months or more. Results: The median follow-up of the whole patients18 (range 2-125) months, 65 patients (56%) were alive. Extended temozolamide (>6) was associated with longer survival, but was not significantly with survival outcomes in the univariate analysis (49.0 vs 68.33 months; p=0.082). However, progression free survival analysis demonstrated that the patient in extended temozolamide group had paramount extended progression free survival (14 vs 9 months) than other group in standart cycle temozolamide. Conclusion: Our study show that extended temozolamide is good tolerated and leads to a significantly increase in progression free survival and overall survival in newly diagnosed patients with glioblastoma multiforme.
  • No Thumbnail Available
    Item
    Effective Resolution of Lung Cancer Related Tracheal and/or Bronchial Obstruction with External Beam Radiotherapy
    (2015) Topkan, Erkan; Yildirim, Berna Akkus; Ozdemir, Yurday; Guler, Ozan C.; Kose, Fatih; 0000-0001-6908-3412; 0000-0001-8120-7123; 0000-0002-2218-2074; 0000-0001-6661-4185; AAC-5654-2020; AAG-2213-2021; AAG-5629-2021; V-5717-2017
  • Thumbnail Image
    Item
    Effects of Setup Errors on Dose Distribution for Tangential Wedge Field and Field-in-Field Techniques During Breast Irradiation
    (2014) Sonmez, Aydan; Onal, Cem; Sonmez, Serhat; Arslan, Gungor; Parlak, Cem; Topkan, Erkan; Yavuz, Melek
    This study is aimed to evaluate the effects of setup errors on dose distribution for target volume and healthy tissue within the irradiated volume and also critical surrounding organs for breast radiotherapy (RT) using both the tangential field and the field-in-field (FIF) technique. Ten patients with breast cancer were enrolled. For each patients two plans were generated; tangential field plan and FIF-plan. The setup errors were simulated for a series of displacements of +/- 5 mm and +/- 10 mm in superior-inferior (x-axis), medial-lateral (y-axis), and anterior-posterior (z-axis) directions and dose volume comparisons were made both between and within groups. The most prominent changes were observed in setup errors at z-axis. In wedge plan, 10-mm setup error at the +z axis caused a significant decrease in tumor coverage compared with the plan with no setup error (96.5% vs. 99.2%; p= 0.01). The 5 and 10 mm setup errors at the +z-axis resulted in significantly higher healthy tissue doses in wedge plans compared with FIF plans. The setup errors along z-axis had a significant effect on the dose distribution for target volume and also to the lungs. The setup error in the isocenter should be kept strictly below 5 mm.
  • No Thumbnail Available
    Item
    Elective Nodal Irradiation Does Not Alter Isolated Nodal Failure and Survival Outcomes in Stage III NSCLC Patients Undergoing Chemoradiotherapy
    (2015) Topkan, Erkan; Yildirim, Berna Akkus; Guler, Ozanc; Ozdemir, Yurday; 0000-0002-2218-2074; 0000-0001-8120-7123; 0000-0001-6661-4185; AAG-5629-2021; AAG-2213-2021; V-5717-2017
  • No Thumbnail Available
    Item
    Epoetin receptor status may alter the outcomes in head and neck cancers treated with radiotherapy and darbepoetin-alpha
    (2019) Topkan, Erkan; Yildirim, Berna Akkus; 0000-0001-8120-7123; 30414758; AAG-2213-2021