Browsing by Author "Yavas, Cagdas"

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Bone Only Oligometastatic Renal Cell Carcinoma Patients Treated with Stereotactic Body Radiotherapy: A Multi Institutional Study
(2022) Onal, Cem; Guler, Ozan Cem; Hurmuz, Pervin; Yavas, Guler; Tilki, Burak; Oymak, Ezgi; Yavas, Cagdas; Ozyigit, Gokhan; 0000-0002-2742-9021; 35695908; D-5195-2014
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 undergoing SBRT treated between 2013 and 2020 with a dose of at least 5 Gy per fraction and a biologically effective dose (BED) of at least 90 Gy were retrospectively evaluated. Results The majority of lesions were located in the spine (57.4%) and had only one metastasis (64.8%). After a median follow-up of 22.4 months, the 1- and 2-year OS rates were 84.6% and 67.3%, respectively, and median OS was 43.1 months. The 1- and 2-year PFS rates and median PFS were 63.0%, 38.9%, and 15.3 months, respectively. In SBRT-treated lesions, the 1-year local control (LC) rate was 94.9%. Age, metastasis localization, and number of fractions of SBRT were significant prognostic factors for OS in univariate analysis. In multivariate analysis, patients with spinal metastasis had better OS compared to their counterparts, and patients who received single-fraction SBRT had better PFS than those who did not. No patient experienced acute or late toxicities of grade 3 or greater. Conclusion Despite excellent LC at the oligometastatic site treated with SBRT, disease progression was observed in nearly half of patients 13 months after metastasis-directed local therapy, particularly as distant disease progression other than the treated lesion, necessitating an effective systemic treatment to improve treatment outcomes.
Cardiac angiosarcoma treated with 1.5 Tesla MR-guided adaptive stereotactic body radiotherapy-Case report and review of the literature
(2022) Noyan, Asli; Yavas, Guler; Arslan, Gungor; Yavas, Cagdas; Onal, Cem; 0000-0002-2742-9021; 36027835; D-5195-2014
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 radiation doses to the target volume.Presentation of case: The case of a 16-year-old boy with cardiac angiosarcoma that recurred one year after surgery and was treated with chemotherapy is presented. The patient received high field 1.5-Tesla (magnetic resonance) MR-Linac treatment in 5 fractions with a dosage of 25 Gy to the tumor bed and 30 Gy to the recurrent nodules using the simultaneous integrated boost technique. The patient tolerated the treatment well and had stable disease two months later. Discussion: MR-guided radiotherapy, particularly in the case of cardiac malignancies, allows for direct tumor visualization with high soft tissue image resolution capacity. Furthermore, modern RT techniques allow for the full therapeutic window to be used by achieving superior dose distributions, allowing for dose escalation stra-tegies with tolerable toxicity rates.Conclusion: Magnetic resonance guided RT allows direct visualization of the target during treatment delivery, allowing for higher-dose administration with less damage to healthy tissue near the tumor. This treatment strategy is a viable option in selected patients with cardiac angiosarcoma.
Comment on Hunt et al, "Feasibility of magnetic resonance guided radiotherapy for the treatment of bladder cancer"
(2021) Yavas, Guler; Yavas, Cagdas; Arslan, Gungor; Onal, Cem; 33912694
Prediction of treatment response in patients with locally advanced cervical cancer using midtreatment PET/MRI during concurrent chemoradiotherapy. In regard to Vojtisek et al.
(2021) Onal, Cem; Yavas, Guler; Yavas, Cagdas; 0000-0002-2742-9021; 34341837; D-5195-2014
Prognostic Significance of Serum Human Epididymis Protein 4 Level in Patients with Locally Advanced Non-Small Cell Lung Cancer who Underwent Definitive Chemo-Radiotherapy
(2022) Yavas, Guler; Birgi, Sumerya Duru; Unlu, Ali; Yavas, Cagdas; Duzova, Mursel; Akyurek, Serap
We aimed to investigate the prognostic significance of serum human epididymis protein 4 (HE4) level in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who underwent definitive chemo-radiotherapy (CRT). A hundred seventeen patients with the diagnosis of LA-NSCLC were enrolled. The serum concentrations of HE4 were measured at the beginning of CRT, at the end of CRT, and 3 months after the completion of CRT. The median follow-up period was 21.7 months (range, 5.4-39.8 months). The mean serum HE4 levels prior to CRT, at the end of the CRT, and 3rd month after the completion of CRT were 159.2, 130.2, and 127.5, respectively (p= 0.023). The median progression free survival (PFS) was 15.4 months. One, and two-year PFS rates were 58.1%, and 22.2%, respectively. One, and two-year expected survival rates were 81.2%, and 62%, respectively. In multivariate analysis, stage (p= 0.002), HE4 levels after 3 months of CRT (p= 0.037) were predictive of OS. Stage IIIC patients had 10.2 times likely to death when compared to stage IIIA patients (95%CI: 2.3-45.7; p= 0.037). The increase of 1 HE4 levels after 3 months of CRT increased the mortality rate 1.002 (95%CI: 1.000-1.0004; p= 0.037). In multivariate analysis stage was predictive of PFS. When compared to stage IIIA patients, stage IIIC patients have 2.5 times risk for progression (95% CI: 1.2-5.2; p= 0.014). Our findings suggested that serum HE4 may be an important prognostic biomarker for LA-NSCLC patients. This issue warrants further prospective studies with more patient populations.
Radiation-Induced Myocardial Fibrosis in Long-Term Esophageal Cancer Survivors
(2021) Yavas, Guler; Yavas, Cagdas; Onal, Cem; 34793738
Role of Consolidative Thoracic Radiotherapy for Extensive-stage Small Cell Lung Cancer: Trod Thoracic Oncology Study Group 08-006 Multi-institutional Study
(2022) Yavas, Guler; Kirakli, Esra Korkmaz; Dagdelen, Meltem; Topkan, Erkan; Saynak, Mert; Dincbas, Fazilet Oner; OzdemIr, Yurday; Yavas, Cagdas; Birgi, Sumerya Duru; Akyurek, Serap
OBJECTIVE We aimed to evaluate the role of consolidative thoracic radiotherapy (TRT) in patients with extensive-stage small cell lung cancer (ES-SCLC). METHODS The clinical data for 151 patients with the diagnosis of ES-SCLC treated with consolidative TRT from six different hospitals from Turkey analyzed. RESULTS The median age of the patients was 61 years (range 36-83 years). The median dose of radiotherapy (RT) was 45 Gy (range: 30-66 Gy) applied in median 25 fractions (range 10-34 fractions). For 151 assessable patients, the median survival time (MST) was 14 months (range: 12.6-15.3). The patients who has complete response and partial response had 16 months, and 14 months of MST. In multivariate analyses prophylactic cranial irradiation (PCI) (p=0.011), female gender (p=0.017), and comorbidity (p=0.006) were found as significant parameters associated with survival. The MSTs were 12 months in patients without comorbidity, and 16 months for the patients with at least one comorbid disease. The patients who received PCI had improved MSTs when compared the ones without PCI (16 months vs. 12 months). There was a trend towards improved overall survival times in patients who received EQD2 >= 47 Gy RT doses (p=0.08). CONCLUSION Female gender, use of PCI, and unavailability of comorbid disease were associated with improved survival in ES-SLCL patients. There was a trend towards overall survival times in patients who received >= 47 Gy EQD2 doses; however, we believe that this statistical insignificance was related to our limited patient numbers.
The Role Of Stereotactic Body Radiotherapy In Switching Systemic Therapy For Patients With Extracranial Oligometastatic Renal Cell Carcinoma
(2022) Onal, Cem; Hurmuz, Pervin; Guler, Ozan Cem; Yavas, Guler; Tilki, Burak; Oymak, Ezgi; Yavas, Cagdas; Ozyigit, Gokhan; https://orcid.org/0000-0002-2742-9021; 35119653; D-5195-2014
Background Targeting oligometastatic lesions with metastasis-directed therapy (MDT) using stereotactic-body radiotherapy (SBRT) may improve treatment outcomes and postpone the need for second-line systemic therapy (NEST). We looked at the results of oligometastatic renal cell carcinoma (RCC) patients who had five or fewer lesions and were treated with SBRT. Methods We examined the treatment outcomes of 70 extracranial metastatic RCC (mRCC) patients treated at two oncology centers between 2011 and 2020. The clinical parameters of patients with and without NEST changes were compared. The prognostic factors for overall survival (OS), progression-free survival (PFS), and NEST-free survival were evaluated. Results Median age was 67 years (range 31-83 years). Lung and bone metastasis were found in 78.4% and 12.6% of patients, respectively. With a median follow-up of 21.1 months, median OS was 49.1 months and the median PFS was 18.3 months. Histology was a prognostic factor for OS, BED, and treatment switch for PFS in univariate analysis. In multivariate analysis, the significant predictor of poor OS was clear cell histology, and a lower BED for PFS. Following SBRT for oligometastatic lesions, 19 patients (27.2%) had a median NEST change of 15.2 months after MDT completion. There were no significant differences in median OS or PFS between patients who had NEST changes and those who did not. No patient experienced grade >= 3 acute and late toxicities. Conclusions The SBRT to oligometastatic sites is an effective and safe treatment option for <= 5 metastases in RCC patients by providing favorable survival and delaying NEST change.
Stereotactic Body Radiotherapy and Tyrosine Kinase Inhibitors in Patients with Oligometastatic Renal Cell Carcinoma: A Multi-Institutional Study
(2023) Onal, Cem; Oymak, Ezgi; Guler, Ozan Cem; Tilki, Burak; Yavas, Guler; Hurmuz, Pervin; Yavas, Cagdas; Ozyigit, Gokhan; https://orcid.org/0000-0002-2742-9021; 36450836; HOC-5611-2023
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 metastases treated between 2011 and 2020 were retrospectively evaluated. The prognostic factors predicting overall survival (OS) and progression-free survival (PFS) were assessed in uni-and multivariable analyses.Results Median follow-up and time between TKI therapy and SBRT were 62.3 and 3.7 months, respectively. The 2-year OS and PFS rates were 58.0% and 51.3%, respectively, and 2-year local control rate was 94.1% per SBRT-treated lesion. In univariable analysis, the time between TKI therapy and SBRT and treatment response were significant prognostic factors for OS and PFS. In multivariable analysis, a time between TKI therapy and SBRT of less than 3 months and complete response were significant predictors of better OS and PFS. Only 12 patients (28.6%) had a systemic treatment change at a median of 18.2 months after SBRT, mostly in patients with a non-complete treatment response after this therapy. Two patients (4.8%) experienced grade III toxicity, and all side effects observed during metastasis-directed therapy subsided over time.Conclusion We demonstrated that SBRT in combination with TKIs is an effective and safe treatment option for RCC patients with <= 5 metastases. However, distant metastasis was observed in 60% of the patients, indicating that distant disease control still has room for improvement.
Treatment Outcomes of Stereotactic Body Radiotherapy in Patients with Synchronous and Metachronous Oligometastatic Renal Cell Carcinoma
(2023) Guler, Ozan Cem; Oymak, Ezgi; Hurmuz, Pervin; Yavas, Guler; Tilki, Burak; Yavas, Cagdas; Ozyigit, Gokhan; Onal, Cem; 0000-0002-2742-9021; 36455527; D-5195-2014
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 and January 2019 were retrospectively analyzed. All patients had <= 5 metastasis at diagnosis (synchronous) or during progression (metachronous) and were treated with SBRT for their metastasis. The primary endpoints were local control (LC) and progression-free survival (PFS). The secondary endpoint was overall survival (OS). Results: Median follow-up was 20.4 months for entire cohort and 27.2 months for survivors. Synchronous oligometastatic disease was observed in 35 patients (40.2%), and 52 patients (59.8%) had metachronous disease. Seventy-two patients (82.8%) received systemic treatment synchronously or after MDT, while 15 patients (17.2%) did not receive any systemic treatment. The 1- and 2-year OS rates were 79.4% and 58.1%, respectively, and the 1- and 2-year PFS rates were 58.6% and 15.1%, respectively. The 1- and 2-year LC rates per lesion were 96.6% and 91.4%, respectively. There were no significant differences in survival between patients with synchronous oligometastasis and those with metachronous oligometastasis. All disease progressions were observed at a median time of 31.6 months (range: 1.9-196.9 months) after the completion of SBRT. Patients with solitary oligometastasis had significantly better OS compared to patients with >1 metastasis (p = 0.04). No patients experienced grade 3 or higher acute or late toxicities. Conclusion: SBRT is a successful treatment for oligometastatic RCC patients due to its excellent LC and minimal toxicity profile. There were no statistically significant survival differences between patients with synchronous and metachronous oligometastasis. Patients with solitary oligometastasis outlived their counterparts.
The utility of 1.5 tesla MR-guided adaptive stereotactic body radiotherapy for recurrent ovarian tumor - Case reports and review of the literature
(2022) Yavas, Guler; Kuscu, Ulku Esra; Ayhan, Ali; Yavas, Cagdas; Onal, Cem; 36261943
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 recurrent disease.Presentation of case: After surgery and chemotherapy, two patients, aged 57 and 70, presented with recurrent lesions in the parailiac region. The recurrent lesions were treated with high field 1.5-Tesla MR-Linac treatment in 5 fractions at a dose of 30 Gy. The patients tolerated the treatment well and were disease free after 12 and 20 months of magnetic resonance guided radiotherapy (MRgRT), respectively.Discussion: MRgRT is a novel and rapidly evolving technology that allows for the highly precise treatment of even mobile targets through direct visualization of the tumor. The majority of patients with EOC frequently present with abdominal-pelvic recurrences. It has been demonstrated that EOC requires high radiation doses for curative treatment. MR-Linac enables monitoring of organ motion during treatment, which is necessary for delivering higher doses to target volumes while sparing surrounding organs.Conclusion: To reduce radiation doses to nearby normal tissues, MRgRT allows for the delivery of hypofractio-nated RT with tight safety margins. Regardless of initial resistance or gradual development of intolerance to standard chemotherapy regimens, the role of RT in patients with persistent or recurrent EOC should be reconsidered.