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Item 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, LucaOver 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.Item 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, BanuPurpose: 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 yearsItem 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, EnisBackground. Stereotactic ablative radiotherapy (SABR) is effective for thoracic cancer and metastasesItem 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 MehmetWe 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((6MVItem Intensity modulated radiotherapy (IMRT) in bilateral retinoblastoma(ASSOC RADIOLOGY \& ONCOLOGY, 2010-01-01) Atalar, Banu; Ozyar, Enis; Gunduz, Kaan; Gungor, GorkemBackground. 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.Item 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.Item 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, EnisLattice 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.Item 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, EnisPurpose 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.Item 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, EnisPurpose 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.Item 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, AdnanObjective: 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.