Browsing by Author "Gungor, Gorkem"

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Artificial Intelligence in magnetic Resonance guided Radiotherapy: Medical and physical considerations on state of art and future perspectives
(ELSEVIER SCI LTD, 2021-01-01) Cusumano, Davide; Boldrini, Luca; Dhont, Jennifer; Fiorino, Claudio; Green, Olga; Gungor, Gorkem; Jornet, Nuria; Klueter, Sebastian; Landry, Guillaume; Mattiucci, Gian Carlo; Placidi, Lorenzo; Reynaert, Nick; Ruggieri, Ruggero; Tanadini-Lang, Stephanie; Thorwarth, Daniela; Yadav, Poonam; Yang, Yingli; Valentini, Vincenzo; Verellen, Dirk; Indovina, Luca
Over the last years, technological innovation in Radiotherapy (RT) led to the introduction of Magnetic Resonance-guided RT (MRgRT) systems. Due to the higher soft tissue contrast compared to on-board CT-based systems, MRgRT is expected to significantly improve the treatment in many situations. MRgRT systems may extend the management of inter- and intra-fraction anatomical changes, offering the possibility of online adaptation of the dose distribution according to daily patient anatomy and to directly monitor tumor motion during treatment delivery by means of a continuous cine MR acquisition. Online adaptive treatments require a multidisciplinary and well-trained team, able to perform a series of operations in a safe, precise and fast manner while the patient is waiting on the treatment couch. Artificial Intelligence (AI) is expected to rapidly contribute to MRgRT, primarily by safely and efficiently automatising the various manual operations characterizing online adaptive treatments. Furthermore, AI is finding relevant applications in MRgRT in the fields of image segmentation, synthetic CT reconstruction, automatic (on-line) planning and the development of predictive models based on daily MRI. This review provides a comprehensive overview of the current AI integration in MRgRT from a medical physicist's perspective. Medical physicists are expected to be major actors in solving new tasks and in taking new responsibilities: their traditional role of guardians of the new technology implementation will change with increasing emphasis on the managing of AI tools, processes and advanced systems for imaging and data analysis, gradually replacing many repetitive manual tasks.
Estimation of secondary cancer risk after radiotherapy in high-risk prostate cancer patients with pelvic irradiation
(WILEY, 2020-01-01) Haciislamoglu, Emel; Gungor, Gorkem; Aydin, Gokhan; Canyilmaz, Emine; Guler, Ozan Cem; Zengin, Ahmet Yasar; Yenice, Kamil Mehmet
We aimed to estimate the risk of secondary cancer after radiotherapy (RT) in high-risk prostate cancer (HRPC) patients with pelvic irradiation. Computed tomography data of five biopsy-proven HRPC patients were selected for this study. Two different planning target volumes (PTV(1)and PTV2) were contoured for each patient. The PTV(1)included the prostate, seminal vesicles, and pelvic lymphatics, while the PTV(2)included only the prostate and seminal vesicles. The prescribed dose was 54 Gy for the PTV(1)with a sequential boost (24 Gy for the PTV2). Intensity-modulated RT (IMRT) and volumetric modulated arc therapy (VMAT) techniques were used to generate treatment plans with 6 and 10 MV photon energies with the flattening filter (FF) or flattening filter-free (FFF) irradiation mode. The excess absolute risks (EARs) were calculated and compared for the bladder, rectum, pelvic bone, and soft tissue based on the linear-exponential, plateau, full mechanistic, and specific mechanistic sarcoma dose-response model. According to the models, all treatment plans resulted in similar risks of secondary bladder or rectal cancer and pelvic bone or soft tissue sarcoma except for the estimated risk of the bladder according to the full mechanistic model using IMRT((6MV
Evaluation of response to stereotactic radiosurgery in patients with radioresistant brain metastases
(KOREAN SOC THERAPEUTIC RADIOLOGY \& ONCOLOGY, 2019-01-01) Sayan, Mutlay; Mustafayev, Teuta Zoto; Sahin, Bilgehan; Kefelioglu, Erva Seyma Sare; Wang, Shang-Jui; Kurup, Varsha; Balmuk, Aykut; Gungor, Gorkem; Ohri, Nisha; Weiner, Joseph; Ozyar, Enis; Atalar, Banu
Purpose: Renal cell carcinoma (RCC) and melanoma have been considered `radioresistant' due to the fact that they do not respond to conventionally fractionated radiation therapy. Stereotactic radiosurgery (SRS) provides high-dose radiation to a defined target volume and a limited number of studies have suggested the potential effectiveness of SRS in radioresistant histologies. We sought to determine the effectiveness of SRS for the treatment of patients with radioresistant brain metastases. Materials and Methods: We performed a retrospective review of our institutional database to identify patients with RCC or melanoma brain metastases treated with SRS. Treatment response were determined in accordance with the Response Evaluation Criteria in Solid Tumors. Results: We identified 53 radioresistant brain metastases (28\% RCC and 72\% melanoma) treated in 18 patients. The mean target volume and coverage was 6.2 +/- 9.5 mL and 95.5\% +/- 2.9\%, respectively. The mean prescription dose was 20 +/- 4.9 Gy. Forty lesions (75\%) demonstrated a complete/partial response and 13 lesions (24\%) with progressive/stable disease. Smaller target volume (p < 0.001), larger SRS dose (p < 0.001), and coverage (p = 0.008) were found to be positive predictors of complete response to SRS. Conclusion: SRS is an effective management option with up to 75\% response rate for radioresistant brain metastases. Tumor volume and radiation dose are predictors of response and can be used to guide the decision-making for patients with radioresistant brain metastases.
First 500 Fractions Delivered with a Magnetic Resonance-guided Radiotherapy System: Initial Experience
(CUREUS INC, 2019-01-01) Sahin, Bilgehan; Mustafayev, Teuta Zoto; Gungor, Gorkem; Aydin, Gokhan; Yapici, Bulent; Atalar, Banu; Ozyar, Enis
Objectives Improved soft-tissue visualization, afforded by magnetic resonance imaging integrated into a radiation therapy linear accelerator-based radiation delivery system (MR-linac) promises improved image-guidance. The availability of MR-imaging can facilitate on-table adaptive radiation planning and enable real-time intra-fraction imaging with beam gating without additional exposure to radiation. However, the novel use of magnetic resonance-guided radiation therapy (MRgRT) in the field of radiation oncology also potentially poses challenges for routine clinical implementation. Herein the early experience of a single institution, implementing the first MRgRT system in the country is reported. We aim to describe the workflow and to characterize the clinical utility and feasibility of routine use of an MR-linac system. Methods The ViewRay MRIdian MR-linac system consists of a split-magnet 0.35 T MR-imaging scanner with a double focused multi-leaf collimator (MLC) equipped 6MV linear accelerator. Unique to the system are the control console integrated on-table adaptive radiation therapy (oART) planning capabilities as well as automated beam gating based on real-time intra-fraction MR imaging. From the first day of clinical implementation, oART was performed according to physicians' discretion when medically indicated. All fractions were delivered under real-time imaging with soft tissue-based automated beam gating with individualized gating boundary settings. Patients actively assisted in breath-hold beam gating with the help of custom designed prismatic glasses allowing sight of a computer monitor mounted on the back wall just behind the MRI system bore. Patient demographics and treatment experience, indications for MRgRT including diagnosis and disease site, radiation dose prescribed and fractionation scheme, utilization of oART, respiratory gating settings, as well as duration of each treatment phase were analyzed. Results Between September 2018 and May 2019, 72 patients with 84 tumor sites were treated with MRgRT in 500 total fractions. Median patient age was 66 years (range: 28-83 years). Among 84 tumor sites, the most frequently treated regions were upper abdominal and pelvic (n = 36, 43\% and n = 29, 34\%, respectively). The most common diagnosis was prostate cancer, with 14 patients treated. In 69 patients (93.2\%) oART was used at least once during a treatment course. Twenty-nine targets (43.1\%) with significant breathing-related motion were treated in breath-hold with patient visual feedback. Median prescribed dose was 36.25 Gy (range: 24-70 Gy) in median five fractions (range: 3-28 fractions). A gating boundary of 3 mm around a gating region of interest (gROI) was most commonly used (range: 3-5 mm) with 95\% of the gROI (range: 93-97\%) required to be within the gating boundary for the beam to automatically engage. Mean total treatment time was 47 min (range: 21-125 min) and mean beam-on time was 16.7 min (range: 6-62 min). Conclusions MRgRT afforded by an MR-linac system has been successfully implemented into routine clinical use at our institution as the first system of its kind in Turkey. While the overall number of patients treated and fractions delivered is still limited, we have demonstrated the feasibility of both on-table adaptive radiation therapy as well as automated real-time beam gating on a daily basis in acceptable time schedules.
Improvement of conformal arc plans by using deformable margin delineation method for stereotactic lung radiotherapy
(WILEY, 2018-01-01) Gungor, Gorkem; Demir, Melek; Aydin, Gokhan; Yapici, Bulent; Atalar, Banu; Ozyar, Enis
Purpose: Stereotactic body radiotherapy (SBRT) is an established treatment technique in the management of medically inoperable early stage non-small cell lung cancer (NSCLC). Different techniques such as volumetric modulated arc (VMAT) and three-dimensional conformal arc (DCA) can be used in SBRT. Previously, it has been shown that VMAT is superior to DCA technique in terms of plan evaluation parameters. However, DCA technique has several advantages such as ease of use and considerable shortening of the treatment time. DCA technique usually results in worse conformity which is not possible to ameliorate by inverse optimization. In this study, we aimed to analyze whether a simple method-deformable margin delineation (DMD)-improves the quality of the DCA technique, reaching similar results to VMAT in terms of plan evaluation parameters. Methods: Twenty stage I-II (T1-2, N0, M0) NSCLC patients were included in this retrospective dosimetric study. Noncoplanar VMAT and conventional DCA plans were generated using 6 MV and 10 MV with flattening filter free (FFF) photon energies. The DCA plan with 6FFF was calculated and 95\% of the PTV was covered by the prescription isodose line. Hot dose regions (receiving dose over 100\% of prescription dose) outside PTV and cold dose regions (receiving dose under 100\% of prescription dose) inside PTV were identified. A new PTV (PTV-DMD) was delineated by deforming PTV margin with respect to hot and cold spot regions obtained from conventional DCA plans. Dynamic multileaf collimators (MLC) were set to PTV-DMD beam eye view (BEV) positions and the new DCA plans (DCA-DMD) with 6FFF were generated. Three-dimensional (3D) dose calculations were computed for PTV-DMD volume. However, the prescription isodose was specified and normalized to cover 95\% volume of original PTV. Several conformity indices and lung doses were compared for different treatment techniques. Results: DCA-DMD method significantly achieved a superior conformity index (CI), conformity number (CIPaddick), gradient index (R-50\%), isodose at 2 cm (D-2 (cm)) and external index (CD) with respect to VMAT and conventional DCA plans (P < 0.05 for all comparisons). CI ranged between 1.00-1.07 (Mean: 1.02)
Intensity modulated radiotherapy (IMRT) in bilateral retinoblastoma
(ASSOC RADIOLOGY \& ONCOLOGY, 2010-01-01) Atalar, Banu; Ozyar, Enis; Gunduz, Kaan; Gungor, Gorkem
Background. External beam radiotherapy (EBRT) for retinoblastoma has traditionally been done with conventional radiotherapy techniques which resulted high doses to the surrounding normal tissues. Case report. A 20 month-old girl with group D bilateral retinoblastoma underwent intensity modulated radiotherapy (IMRT) to both eyes after failing chemoreduction and focal therapies including cryotherapy and transpupillary thermotherapy. In this report, we discuss the use of IMRT as a method for reducing doses to adjacent normal tissues while delivering therapeutic doses to the tumour tissues compared with 3-dimensional conformal radiotherapy (3DCRT). At one year follow-up, the patient remained free of any obvious radiation complications. Conclusions. Image guided IMRT provides better dose distribution than 3DCRT in retinoblastoma eyes, delivering the therapeutic dose to the tumours and minimizing adjacent tissue damage.
Long-term toxicity and survival outcomes after stereotactic ablative radiotherapy for patients with centrally located thoracic tumors
(WALTER DE GRUYTER GMBH, 2020-01-01) Atalar, Banu; Mustafayev, Teuta Zoto; Sio, Terence T.; Sahin, Bilgehan; Gungor, Gorkem; Aydin, Gokhan; Yapici, Bulent; Ozyar, Enis
Background. Stereotactic ablative radiotherapy (SABR) is effective for thoracic cancer and metastases
Magnetic resonance image-guided adaptive stereotactic body radiotherapy for prostate cancer: preliminary results of outcome and toxicity
(BRITISH INST RADIOLOGY, 2021-01-01) Ugurluer, Gamze; Atalar, Banu; Mustafayev, Teuta Zoto; Gungor, Gorkem; Aydin, Gokhan; Sengoz, Meric; Abacioglu, Ufuk; Tuna, Mustafa Bilal; Kural, Ali Riza; Ozyar, Enis
Objective: Using moderate or ultra-hypofractionation, which is also known as stereotactic body radiotherapy (SBRT) for treatment of localized prostate cancer patients has been increased. We present our preliminary results on the clinical utilization of MRI-guided adaptive radiotherapy (MRgRT) for prostate cancer patients with the workflow, dosimetric parameters, toxicities and prostate-specific antigen (PSA) response. Methods: 50 prostate cancer patients treated with ultrahypofractionation were included in the study. Treatment was performed with intensity-modulated radiation therapy (step and shoot) technique and daily plan adaptation using MRgRT. The SBRT consisted of 36.25 Gy in 5 fractions with a 7.25 Gy fraction size. The time for workflow steps was documented. Patients were followed for the acute and late toxicities and PSA response. Results: The median follow-up for our cohort was 10 months (range between 3 and 29 months). The median age was 73.5 years (range between 50 and 84 years). MRgRT was well tolerated by all patients. Acute genitourinary (GU) toxicity rate of Grade 1 and Grade 2 was 28 and 36\%, respectively. Only 6\% of patients had acute Grade 1 gastrointestinal (GI) toxicity and there was no Grade 2G1 toxicity. To date, late Grade 1 GU toxicity was experienced by 24\% of patients, 2\% of patients experienced Grade 2 GU toxicity and 6\% of patients reported Grade 2 GI toxicity. Due to the short follow-up, PSA nadir has not been reached yet in our cohort. Conclusion: In conclusion, MRgRT represents a new method for delivering SBRT with markerless soft tissue visualization, online adaptive planning and real-time tracking. Our study suggests that ultra-hypofractionation has an acceptable acute and very low late toxicity profile. Advances in knowledge: MRgRT represents a new markerless method for delivering SBRT for localized prostate cancer providing online adaptive planning and real-time tracking and acute and late toxicity profile is acceptable.
Magnetic Resonance Image-Guided Hypofractionated Ablative Radiation Therapy for Hepatocellular Carcinoma With Tumor Thrombus Extending to the Right Atrium
(CUREUS INC, 2022-01-01) Dincer, Neris; Ugurluer, Gamze; Mustafayev, Teuta Zoto; Gungor, Gorkem; Atalar, Banu; Guven, Koray; Ozyar, Enis
Hepatocellular carcinoma (HCC) presenting with tumor thrombus and inferior vena cave (IVC)/right atrium (RA) infringement point to an advanced-stage disease that is deemed inoperable. Stereotactic body radiotherapy is an emerging treatment option for this group of patients with promising outcomes in recent studies that are comparable to conventional treatment methods, namely, transarterial chemoembolization and transarterial radioembolization. Here, we report a case of HCC with RA extension through the IVC. The patient was referred to our clinic for treatment options, and he was found suitable for magnetic resonance imaging-guided radiotherapy (MRgRT). We treated the patient with MRgRT in five fractions to a total dose of 40 Gray. The tumor was tracked during the treatment sessions, and adaptive treatment planning was performed before each fraction. The patient tolerated the treatment well with no acute grade 3-4 toxicities. The last follow-up showed that the patient had a complete biochemical response and is now a candidate for an orthotopic liver transplant. To our knowledge, this report is the first to document the MRgRT treatment of an HCC with TT and RA extension. MRgRT is safe and feasible for this patient group and can be an effective bridging therapy for liver transplants.
Magnetic Resonance Imaging-Guided Online Adaptive Lattice Stereotactic Body Radiotherapy in Voluminous Liver Metastasis: Two Case Reports
(CUREUS INC, 2022-01-01) Dincer, Neris; Ugurluer, Gamze; Korkmaz, Latif; Serkizyan, Anatolia; Atalar, Banu; Gungor, Gorkem; Ozyar, Enis
Lattice Radiotherapy (LRT) is a technique in which heterogeneous doses are delivered to the target so large tumors can have optimal doses of radiation without compromising healthy tissue sparing. lb date, case reports and case series documented its application for bulky tumors mainly in the pelvic region. LRT not only provides dosimetric advantages but also promotes tumor control by triggering some radiobiological and immunological pathways. We report two cases of giant liver metastases for whom other treatment options were not suitable. We treated both patients with Magnetic Resonance Image-Guided Radiotherapy (MRgRT) with online adaptive LRT (OALRT) technique. Adaptive plans were generated before each fraction. Tumors were observed to have regressed interfractionally so the location and number of spheres were adapted to tumor size and daily anatomy of the surrounding organs at risk (OAR). Both patients had good treatment compliance without any Grade 3+ side effects. They are both under follow-up and report improvement. By reporting the first application of OALRT by using MRgRT in liver metastases, we show that MRgRT is a promising modality for LRT technique with better target and OAR visualization as well as online adaptive planning before each fraction according to the daily anatomy of the patient.
Magnetic Resonance Imaging-Guided Radiation Therapy for Early-Stage Gastric Mucosa-Associated Lymphoid Tissue Lymphoma
(CUREUS INC, 2022-01-01) Dincer, Neris; Ugurluer, Gamze; Gungor, Gorkem; Mustafayev, Teuta Zoto; Atalar, Banu; Ozyar, Enis
Lymphoid neoplasia derived from mucosa-associated lymphoid tissue (MALT
Management of symptomatic radiation necrosis after stereotactic radiosurgery and clinical factors for treatment response
(KOREAN SOC THERAPEUTIC RADIOLOGY \& ONCOLOGY, 2020-01-01) Sayan, Mutlay; Mustafayev, Teuta Zoto; Balmuk, Aykut; Mamidanna, Swati; Kefelioglu, Erva Seyma Sare; Gungor, Gorkem; Chundury, Anupama; Ohri, Nisha; Karaarslan, Ercan; Ozyar, Enis; Atalar, Banu
Purpose: Approximately 10\% of patients who received brain stereotactic radiosurgery (SRS) develop symptomatic radiation necrosis (RN). We sought to determine the effectiveness of treatment options for symptomatic RN, based on patient-reported outcomes. Materials and Methods: We conducted a retrospective review of 217 patients with 414 brain metastases treated with SRS from 2009 to 2018 at our institution. Symptomatic RN was determined by appearance on serial magnetic resonance images (MRIs), MR spectroscopy, requirement of therapy, and development of new neurological complaints without evidence of disease progression. Therapeutic interventions for symptomatic RN included corticosteroids, bevacizumab and/or surgical resection. Patient-reported therapeutic outcomes were graded as complete response (CR), partial response (PR), and no response. Results: Twenty-six patients experienced symptomatic RN after treatment of 50 separate lesions. The mean prescription dose was 22 Gy (range, 15 to 30 Gy) in 1 to 5 fractions (median, 1 fraction). Of the 12 patients managed with corticosteroids, 6 patients (50\%) reported CR and 4 patients (33\%) PR. Of the 6 patients managed with bevacizumab, 3 patients (50\%) reported CR and 1 patient (18\%) PR. Of the 8 patients treated with surgical resection, all reported CR (100\%). Other than surgical resection, age >= 54 years (median, 54 years
Multi-Institutional Outcomes of Stereotactic Magnetic Resonance Image Guided Adaptive Radiation Therapy With a Median Biologically Effective Dose of 100 Gy(10) for Non-bone Oligometastases
(ELSEVIER INC, 2022-01-01) Kutuk, Tugce; Herrera, Robert; Mustafayev, Teuta Z.; Gungor, Gorkem; Ugurluer, Gamze; Atalar, Banu; Kotecha, Rupesh; Hall, Matthew D.; Rubens, Muni; Mittauer, Kathryn E.; Contreras, Jessika A.; McCulloch, James; Kalman, Noah S.; Alvarez, Diane; Romaguera, Tino; Gutierrez, Alonso N.; Garcia, Jacklyn; Kaiser, Adeel; Mehta, Minesh P.; Ozyar, Enis; Chuong, Michael D.
Purpose: Randomized data show a survival benefit of stereotactic ablative body radiation therapy in selected patients with oligometastases (OM). Stereotactic magnetic resonance guided adaptive radiation therapy (SMART) may facilitate the delivery of ablative dose for OM lesions, especially those adjacent to historically dose-limiting organs at risk, where conventional approaches preclude ablative dosing. Methods and Materials: The RS Search Registry was queried for OM patients (1-5 metastatic lesions) treated with SMART. Freedom from local progression (FFLP), freedom from distant progression (FFDP), progression-free survival (PFS), and overall survival (LS) were estimated using the Kaplan-Meier method. FFLP was evaluated using RECIST 1.1 criteria. Toxicity was evaluated using Common Terminology Criteria for Adverse Events version 4 criteria. Results: Ninety-six patients with 108 OM lesions were treated on a 0.35 T MR Linac at 2 institutions between 2018 and 2020. SMART was delivered to mostly abdominal or pelvic lymph nodes (48.1\%), lung (18.5\%), liver and intrahepatic bile ducts (16.7\%), and adrenal gland (11.1\%). The median prescribed radiation therapy dose was 48.5 Gy (range, 30-60 Gy) in 5 fractions (range, 3-15). The median biologically effective dose corrected using an alpha/beta value of 10 was 100 Gy10 (range, 48-180). No acute or late grade 3+ toxicities were observed with median 10 months (range, 3-25) follow-up. Estimated 1-year FFLP, FFDP, PFS, and OS were 92.3\%, 41.1\%, 39.3\%, and 89.6\%, respectively. Median FFDP and PFS were 8.9 months (95\% confidence interval, 5.2-12.6 months) and 7.6 months (95\% confidence interval, 4.5-10.6 months), respectively. Conclusions: To our knowledge, this represents the largest analysis of SMART using ablative dosing for non-bone OM. A median prescribed biologically effective dose of 100 Gy10 resulted in excellent early FFLP and no significant toxicity, likely facilitated by continuous intrafraction MR visualization, breath hold delivery, and online adaptive replanning. Additional prospective evaluation of dose-escalated SMART for OM is warranted. (C) 2022 The Author(s). Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.
Multichannel Film Dosimetry for Quality Assurance of Intensity Modulated Radiotherapy Treatment Plans Under 0.35 T Magnetic Field
(CUREUS INC, 2020-01-01) Gungor, Gorkem; Korkmaz, Latif; Kayalilar, Namik; Aydin, Gokhan; Yapici, Bulent; Mustafayev, Teuta Zoto; Atalar, Banu; Ozyar, Enis
Purpose To evaluate the intensity modulated radiotherapy (IMRT) quality assurance (OA) results of the multichannel film dosimetry analysis with single scan method by using Gafchromic (TM) EBT3 (Ashland Inc., Covington, KY, USA) film under 0.35 T magnetic field. Methods Between September 2018 and June 2019, 70 patients were treated with ViewRay MRldian (R) (ViewRay Inc., Mountain View, CA) linear accelerator (Linac). Film dosimetry OA plans were generated for all IMRT treatments. Multichannel film dosimetry for red, green and blue (RGB) channels were compared with treatment planning system (TPS) dose maps by gamma evaluation analysis. Results The mean gamma passing rates of RGB channels are 97.3\% +/- 2.26\%, 96.0\% +/- 3.27\% and 96.2\% +/- 3.14\% for gamma evaluation with 2\% DD/2 mm distance to agreement (DTA), respectively. Moreover, the mean gamma passing rates of RGB channels are 99.7\% +/- 0.41\%, 99.6\% +/- 0.59\% and 99.5\% +/- 0.67\% for gamma evaluation with 3\% DD/3 mm DTA, respectively. Conclusion The patient specific QA using Gafchromic (TM) EBT3 film with multichannel film dosimetry seems to he a suitable tool to implement for MR-guided IMRT treatments under 0.35 T magnetic field. Multichannel film dosimetry with Gafchromic (TM) EBT3 is a consistent QA tool for gamma evaluation of the treatment plans even with 2\% DD/2 mm DTA under 0.35 T magnetic field presence.
Non-small Cell Lung Cancer with Multiple Brain Metastases Treated with Radiosurgery and Erlotinib: A Case Report
(CUREUS INC, 2017-01-01) Sahin, Bilgehan; Mustafayev, Teuta; Aydin, Gokhan; Gungor, Gorkem; Yapici, Bulend; Atalar, Banu; Ozyar, Enis
Brain metastases are commonly seen complications in non-small cell lung cancer (NSCLC) patients. The incidence of brain metastases is increasing as a result of more effective systemic targeted therapies with prolonged survival. The prognosis is usually poor, and up to six months of median survivals were reported with different therapeutic options. Here, we present an NSCLC case with multiple brain metastases treated with radiosurgery and systemic erlotinib therapy with prolonged survival. The use of tyrosine kinase inhibitors (TKI) in conjunction with either stereotactic radiosurgery or whole brain radiotherapy is not well established in terms of efficiency and toxicity. This reported case had an excellent response with a tolerable toxicity profile from the combination of either therapies.
Patient-Reported Tolerance of Magnetic Resonance-Guided Radiation Therapy
(FRONTIERS MEDIA SA, 2020-01-01) Sayan, Mutlay; Serbez, Ilkay; Teymur, Bilgehan; Gur, Gokhan; Zoto Mustafayev, Teuta; Gungor, Gorkem; Atalar, Banu; Ozyar, Enis
Purpose Magnetic resonance-guided radiation therapy (MRgRT) has been incorporated into a growing number of clinical practices world-wide, however, there is limited data on patient experiences with MRgRT. The purpose of this study was to prospectively evaluate patient tolerance of MRgRT using patient reported outcome questionnaires (PRO-Q). Methods Ninety patients were enrolled in this prospective observational study and treated with MRgRT (MRIdian Linac System, ViewRay Inc. Oakwood Village, OH, United States) between September 2018 and September 2019. Breath-hold-gated dose delivery with audiovisual feedback was completed as needed. Patients completed an in-house developed PRO-Q after the first and last fraction of MRgRT. Results The most commonly treated anatomic sites were the abdomen (47\%) and pelvis (33\%). Respiratory gating was utilized in 62\% of the patients. Patients rated their experience as positive or at least tolerable with mean scores of 1.0-2.8. The most common complaint was the temperature in the room (61\%) followed by paresthesias (57\%). The degree of anxiety reported by 45\% of the patients significantly decreased at the completion of treatment (mean score 1.54 vs. 1.36,p= 0.01). Forty-three percent of the patients reported some degree of disturbing noise which was improved considerably by use of music. All patients appreciated their active role during the treatment. Conclusion This evaluation of PROs indicates that MRgRT was well-tolerated by our patients. Patients' experience may further improve with adjustment of room temperature and noise reduction.
Re-Irradiation of Non-Small Cell Lung Cell Cancer Recurrences with Stereotactic Body Radiotherapy
(2016-01-01) Atalar, Banu; Sahin, Bilgehan; Gungor, Gorkem; Aydin, Gokhan; Yapici, Bulent; Ozyar, Enis
Secondary cancer risk after whole-breast radiation therapy: field-in-field versus intensity modulated radiation therapy versus volumetric modulated arc therapy
(BRITISH INST RADIOLOGY, 2019-01-01) Haciislamoglu, Emel; Cinar, Yunus; Gurcan, Fatih; Canyilmaz, Emine; Gungor, Gorkem; Yoney, Adnan
Objective: In this study, we used the concept of organ-equivalent dose (OED) to evaluate the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for breast cancer. Methods: Using CT data set of 12 patients, we generated three different whole-breast radiation treatment plans using 50 Gy in 2Gy fractions: three-dimensional conformal radiotherapy with a field-in-field (FinF) technique, intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). The OEDs were calculated from differential dose-volume histograms on the basis of the ``linear-exponential,{''} ``plateau,{''} and `'full mechanistic{''} dose-response models. Secondary cancer risks of the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL) were estimated and compared. Results: The lowest EARs for the CB, CL, and IL were achieved with FinF, which reduced the EARs by 77\%, 88\%. and 56\% relative to those with IMRT, and by 77\%, 84\%, and 58\% relative to those with VMAT, respectively. The secondary cancer risk for FinF was significantly lower than those of IMRT and VMAT. OED-based secondary cancer risks for CB and IL were similar when IMRT and VMAT were used, but the risk for CL was statistically lower when VMAT was used. Conclusion: The overall estimation of EAR indicated that the radiation-induced cancer risk of breast radiation therapy was lower with FinF than with IMRT and VMAT. Therefore, when secondary cancer risk is a major concern, FinF is considered to be the preferred treatment option in irradiation of whole-breast. Advances in knowledge: Secondary malignancy estimation after breast radiotherapy is becoming an important subject for comparative treatment planning.When secondary cancer risk a major concern, FinF technique is considered the preferred treatment option in whole breast patients.
Stereotactic MR-guided online adaptive radiation therapy (SMART) for the treatment of liver metastases in oligometastatic patients: initial clinical experience
(KOREAN SOC THERAPEUTIC RADIOLOGY \& ONCOLOGY, 2021-01-01) Ugurluer, Gamze; Mustafayev, Teuta Zoto; Gungor, Gorkem; Atalar, Banu; Abacioglu, Ufuk; Sengoz, Meric; Agaoglu, Fulya; Demir, Gokhan; Ozyar, Enis
Purpose: We aimed to present our initial clinical experience on the implementation of a stereotactic MR-guided online adaptive radiation therapy (SMART) for the treatment of liver metastases in oligometastatic disease. Materials and Methods: Twenty-one patients (24 lesions) with liver metastasis treated with SMART were included in this retrospective study. Step-and-shoot intensity-modulated radiotherapy technique was used with daily plan adaptation. During delivery, real-time imaging was used by acquiring planar magnetic resonance images in sagittal plane for monitoring and gating. Acute and late toxicities were recorded both during treatment and follow-up visits. Results: The median follow-up time was 11.6 months (range, 2.2 to 24.6 months). The median delivered total dose was 50 Gy (range, 40 to 60 Gy)