ISSN: 2455-2968
Journal of Surgery and Surgical Research
Research Article       Open Access      Peer-Reviewed

Reappraisal of multimodality imaging for improved Radiation Therapy (RT) target volume determination of recurrent Oral Squamous Cell Carcinoma (OSCC): An original article

Murat Beyzadeoglu*, Omer Sager, Selcuk Demiral and Ferrat Dincoglan

Department of Radiation Oncology, University of Health Sciences, Gulhane Medical Faculty, Ankara, Turkey
*Corresponding author: Dr. Murat Beyzadeoglu, Department of Radiation Oncology, University of Health Sciences, Gulhane Medical Faculty, Gn. Tevfik Saglam Cad. 06018, Etlik, Kecioren, Ankara, Turkey, Tel: +90 312 304 4681, +90 532 3043224; Fax: +90 312 304 4680; E-mail: drmbeyzadeoglu@gmail.com
Received: 01 March, 2022 | Accepted: 17 March, 2022 | Published: 18 March, 2022
Keywords: Recurrent Oral Squamous Cell Carcinoma (OSCC); Radiation Therapy (RT); Magnetic Resonance Imaging (MRI)

Cite this as

Beyzadeoglu M, Sager O, Demiral S, Dincoglan F (2022) Reappraisal of multimodality imaging for improved Radiation Therapy (RT) target volume determination of recurrent Oral Squamous Cell Carcinoma (OSCC): An original article. J Surg Surgical Res 8(1): 004-008. DOI: 10.17352/2455-2968.000146

Copyright

© 2022 Beyzadeoglu M, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Objective: Head and Neck Squamous Cell Carcinoma (HNSCC) is one of the most frequent cancer sites around the globe. Within the heterogeneous group of HNSCC, Oral Squamous Cell Carcinoma (OSCC) deserves the utmost attention as an important subsite. Despite multimodality management, recurrence of OSCC is not uncommon. RT may play an integral role as part of initial management or as adjunctive therapy, or for treatment of recurrent disease. In this study, we evaluate multimodality imaging-based RT treatment volume definition for irradiation of recurrent OSCC.

Materials and methods: Multimodality imaging-based RT treatment volume definition for radiotherapeutic management of recurrent OSCC was assessed. RT target volume determination by incorporation of Magnetic Resonance Imaging (MRI) or by Computed Tomography (CT)-simulation images only has been evaluated and comparative analysis has been performed for patients receiving salvage RT for recurrent OSCC.

Results: Ground truth target volume has been found to be identical with treatment volume definition by CT-MR fusion-based imaging.

Conclusion: Incorporation of MRI in target and treatment volume definition may improve target and treatment volume definition for recurrent OSCC.

Introduction

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancer sites around the globe [1]. Within the heterogeneous group of HNSCC, oral squamous cell carcinoma (OSCC) deserves the utmost attention as an important subsite [1-3]. Incidence of OSCC varies among different geographical regions, and risk factors for OSCC development include exposure to exogenous carcinogens such as tobacco smoke and alcohol consumption. Given the rich lymphatic submucosal plexus, OSCC may have a tendency for involving ipsilateral or bilateral neck lymph nodes. Affected patients may suffer from several symptoms depending on lesion size and association with critical structures. Management options for OSCC include surgery, RT, and systemic therapies which may be utilized either alone or in combination with respect to clinical stage, tumor, and pathological characteristics. Despite multimodality management, recurrence of OSCC is not uncommon [1-3]. RT may play an integral role as part of initial management or as adjunctive therapy, or for treatment of recurrent disease [1-3]. With the introduction of innovatory and contemporary technologies, there has been a rising trend towards improving the toxicity profile of radiation delivery by incorporation of state-of-the-art RT delivery techniques. Image-Guided Radiation Therapy (IGRT), Intensity Modulated Radiation Therapy (IMRT), Adaptive Radiation Therapy (ART), and several other radiotherapeutic strategies have contributed to the increased adoption of contemporary irradiation approaches into clinical practice. In the context of recurrent OSCC management, RT may have utility as a viable salvage therapeutic option [1-3]. However, accuracy and precision in target volume definition are critical for optimal radiotherapeutic management. Herein, we evaluate multimodality imaging-based RT treatment volume definition for irradiation of recurrent OSCC.

Materials and methods

In this study, multimodality imaging-based RT treatment volume definition for radiotherapeutic management of recurrent OSCC was assessed. Written informed consents of all patients were acquired before treatment with institutional tumor board approval at our tertiary cancer center, and the study was performed in compliance with the Declaration of Helsinki principles and its later amendments.

RT target volume determination by incorporation of Magnetic Resonance Imaging (MRI) or by Computed Tomography (CT)-simulation images only has been evaluated and comparative analysis has been performed for 18 patients receiving salvage RT for recurrent OSCC. Ground truth target volume serving as the reference for actual treatment and comparison purposes was determined by an expert group of radiation oncologists following meticulous assessment, colleague peer review, detailed discussion, and consensus. All patients have been thoroughly assessed by a multidisciplinary team with consideration of lesion size, localization, and association with surrounding critical structures, symptomatology, and expected outcomes of reirradiation. CT-simulator (GE Lightspeed RT, GE Healthcare, Chalfont St. Giles, UK) was utilized for RT simulation for treatment planning. Planning CT images were taken and then transferred to the delineation workstation (SimMD, GE, UK) via the network for delineation of treatment volumes and surrounding critical structures. Either CT-simulation images only or fused CT and MR images have been used for treatment volume definition.

Planning CT images were fused with T1 contrast-enhanced volumetric MR images. By incorporating MR images in the target definition process, we primarily aimed to take advantage of 2 imaging modalities. Treatment volume definition with CT only and with the incorporation of CT-MR fusion was comparatively evaluated. Synergy (Elekta, UK) linear accelerator (LINAC) was used for precise RT with routine incorporation of IGRT techniques including electronic digital portal imaging and kilovoltage cone-beam CT for treatment verification.

Results

Out of the 18 patients, 11 patients received reirradiation and 7 patients received were treated with de novo RT for salvage management of recurrent OSCC. At our tertiary cancer center, radiation treatment planning was performed by contemporary RT treatment planning systems. Optimal target volume coverage was prioritized while maintaining minimized exposure of surrounding critical structures. Definition of ground truth target volume was performed by an expert group of radiation oncologists after collaborative detailed collaborative evaluation, colleague peer review, detailed discussion, and consensus to be utilized for actual treatment and for comparative assessment. Synergy (Elekta, UK) LINAC has been utilized for the delivery of treatment with routine incorporation of IGRT techniques such as kilovoltage cone-beam CT and electronic digital portal imaging. Target volume definition by CT-only imaging and by CT-MR fusion-based imaging was evaluated with comparative analysis. Ground truth target volume has been found to be identical with treatment volume definition by CT-MR fusion-based imaging.

Discussion

Tumors of the head and neck region pose a formidable therapeutic challenge to the treating physicians due to their critical location in the vicinity of several critical structures associated with vital functions. Within this context, every effort should be made to avoid injury to normal tissues while treating these tumors. OSCC tends to recur even after multidisciplinary management by surgery, RT, and systemic therapy [1-3]. Salvage treatment of recurrent OSCC with RT is a complex procedure that may be hampered by the delivered radiation dose for initial management. Within this context, accuracy in target volume determination emerged as a critical part of current RT approaches with the inclusion of state-of-the-art irradiation techniques and modalities. Precisely focused RT to well-defined targets may be achieved by the use of radiosurgery with robust stereotactic immobilization and image guidance. Nevertheless, accuracy and precision in target volume determination are critical for avoiding geographic misses, treatment failures, and radiation-induced adverse effects. While the determination of larger than actual treatment volumes may lead to increased radiation doses to surrounding normal tissues with resultant toxicity, outlining of smaller than actual treatment volumes may result in treatment failures. In this regard, there is an emerging requirement for improving target volume determination. IGRT techniques may result in improved target localization and using matched CT and MR images may allow for precise treatment volume determination for RT. There is a growing body of data supporting the utility of multimodality imaging-based treatment volume determination for a variety of indications [4-35]. From this standpoint, our study may add to the accumulating data about the incorporation of multimodality imaging-based target volume determination for recurrent OSCC management with salvage RT.

Indeed, the emergence of novel technologies and therapeutic strategies may lead to achieving an improved toxicity profile of RT. Using ablative doses of RT may improve tumor eradication whilst maintaining optimal critical organ sparing and result in better outcomes for recurrent OSCC management. At this point, precision in treatment volume determination emerged as a critical aspect of recent RT approaches. The Millenium era has come up with unprecedented advances with critical improvements in the radiation oncology discipline through the incorporation of up to date treatment equipment and adaptive RT approaches, Adaptive Radiation Therapy (ART), Breathing Adapted Radiation Therapy (BART), IGRT, IMRT, molecular imaging methods, automatic segmentation techniques, and stereotactic RT [36-73].

This study is not devoid of limitations. Nevertheless, we conclude that the incorporation of MRI in target and treatment volume definition may improve target and treatment volume definition for recurrent OSCC.

  1. Zittel S, Moratin J, Horn D, Metzger K, Ristow O, et al. (2022) Clinical outcome and prognostic factors in recurrent oral squamous cell carcinoma after primary surgical treatment: a retrospective study. Clin Oral Investig 26: 2055-2064. Link: https://bit.ly/34PJoX8
  2. da Silva SD, Hier M, Mlynarek A, Kowalski LP, Alaoui-Jamali MA (2012) Recurrent oral cancer: current and emerging therapeutic approaches. Front Pharmacol 3:149. Link: https://bit.ly/3tkythL   
  3. Koo BS, Lim YC, Lee JS, Choi EC (2006) Recurrence and salvage treatment of squamous cell carcinoma of the oral cavity. Oral Oncol 42: 789-794. Link: https://bit.ly/3IleyDq   
  4. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2021) Assessment of the role of multimodality imaging for treatment volume definition of intracranial ependymal tumors: An original article. Glob J Cancer Ther 7: 043-045. Link: https://bit.ly/3IeNNkc  
  5. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2021) Multimodality Imaging Based Treatment Volume Definition for Reirradiation of Recurrent Small Cell Lung Cancer (SCLC). Arch Can Res 9: 1-5. Link: https://bit.ly/3tl2m1n  
  6. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2021) Radiation Therapy (RT) target determination for irradiation of bone metastases with soft tissue component: Impact of multimodality imaging. J Surg Surgical Res 7: 042-046. Link: https://bit.ly/36d5EuG  
  7. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2021) Evaluation of Changes in Tumor Volume Following Upfront Chemotherapy for Locally Advanced Non Small Cell Lung Cancer (NSCLC). Glob J Cancer Ther 7: 031-034. Link: https://bit.ly/3tiqEco  
  8. Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2021) Evaluation of Target Definition for Management of Myxoid Liposarcoma (MLS) with Neoadjuvant Radiation Therapy (RT). Biomed J Sci Tech Res 33: 26171-26174. Link: https://bit.ly/3KTnd1D  
  9. Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2021) Assessment of Multimodality Imaging for Target Definition of Intracranial Chondrosarcomas. Canc Therapy Oncol Int J 18: 001-005. Link: https://bit.ly/3wp3934  
  10. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2021) Impact of Multimodality Imaging to Improve Radiation Therapy (RT) Target Volume Definition for Malignant Peripheral Nerve Sheath Tumor (MPNST). Biomed J Sci Tech Res 34: 26734-26738. Link: https://bit.ly/3CPJoD4  
  11. Dincoglan F, Beyzadeoglu M, Demiral S, Sager O (2020) Assessment of Treatment Volume Definition for Irradiation of Spinal Ependymomas: an Original Article. ARC J Cancer Sci 6: 1-6. Link: https://bit.ly/2Q387zE
  12. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2021) Radiation Therapy (RT) Target Volume Definition for Peripheral Primitive Neuroectodermal Tumor (PPNET) by Use of Multimodality Imaging: An Original Article. Biomed J Sci Tech Res 34: 26970-26974. Link: https://bit.ly/3KVmWeA  
  13. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2021) Assessment of posterior fossa target definition by multimodality imaging for patients with medulloblastoma. J Surg Surgical Res 7: 037-041. Link: https://bit.ly/3N3yRZC  
  14. Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2020) Multimodality Imaging Based Target Definition of Cervical Lymph Nodes in Precise Limited Field Radiation Therapy (Lfrt) for Nodular Lymphocyte Predominant Hodgkin Lymphoma (Nlphl). ARC J Cancer Sci 6: 06-11. Link: https://bit.ly/3N4gDHt  
  15. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Treatment Volume Determination for Irradiation of chordoma: an Original Article. Int J Res Stud Med Health Sci 5: 3-8. Link: https://bit.ly/3rSbLKE
  16. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Assessment of Target Volume Definition for Irradiation of Hemangiopericytomas: An Original Article. Canc Ther Oncol Int J 17. Link: https://bit.ly/3bMfQub
  17. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2020) Target Definition of orbital Embryonal Rhabdomyosarcoma (Rms) by Multimodality Imaging: An Original Article. ARC J Cancer Sci 6: 12-17. Link: https://bit.ly/3wjdy0w  
  18. Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2020) Utility of Multimodality Imaging Based Target Volume Definition for Radiosurgery of Trigeminal Neuralgia: An Original Article. Biomed J Sci Tech Res 26: 19728-19732. Link: https://bit.ly/2OXKAja
  19. Demiral S, Beyzadeoglu M, Dincoglan F, Sager O (2020) Assessment of Target Volume Definition for Radiosurgery of Atypical Meningiomas with Multimodality Imaging. J Hematol Oncol Res 3: 14-21. Link: https://bit.ly/3eFbEy7
  20. Beyzadeoglu M, Dincoglan F, Sager O, Demiral S (2020) Determination of Radiosurgery Treatment Volume for Intracranial Germ Cell Tumors (GCTS). Asian Journal of Pharmacy, Nursing and Medical Sciences 8: 18-23. Link: https://bit.ly/3toPNzn   
  21. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2020) Target Volume Definition for Stereotactic Radiosurgery (SRS) Of Cerebral Cavernous Malformations (CCMs). Canc Therapy Oncol Int J 15: 555917. Link: https://bit.ly/3ldxev6
  22. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Treatment Volume Determination for Irradiation of Recurrent Nasopharyngeal Carcinoma with Multimodality Imaging: An Original Article. ARC J Cancer Sci 6: 18-23. Link: https://bit.ly/366Gfmw  
  23. Demiral S, Beyzadeoglu M, Dincoglan F, Sager O (2020) Evaluation of Radiosurgery Target Volume Definition for Tectal Gliomas with Incorporation of Magnetic Resonance Imaging (MRI): An Original Article. Biomedical Journal of Scientific & Technical Research (BJSTR) 27: 20543-20547. Link: https://bit.ly/3bNk0lO
  24. Beyzadeoglu M, Dincoglan F, Demiral S, Sager O (2020) Target Volume Determination for Precise Radiation Therapy (RT) of Central Neurocytoma: An Original Article. Int J Res Stud Med Health Sci 5: 29-34. Link: https://bit.ly/3661Yec  
  25. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Target Volume Determination for Irradiatıon of Pilocytic Astrocytomas: An Original Article. ARC J Cancer Sci 6: 1-5. Link: https://bit.ly/3rRdSyc
  26. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Radiosurgery Treatment Volume Determination for Brain Lymphomas with and without Incorporation of Multimodality Imaging. J Med Pharm Allied Sci 9: 2398-2404. Link: https://bit.ly/3eyrkn0
  27. Beyzadeoglu M, Sager O, Dincoglan F, Demiral S (2019) Evaluation of Target Definition for Stereotactic Reirradiation of Recurrent Glioblastoma. Arch Can Res 7: 3. Link: https://bit.ly/2OpxR90
  28. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2019) Incorporation of Multimodality Imaging in Radiosurgery Planning for Craniopharyngiomas: An Original Article. SAJ Cancer Sci 6: 103. Link: https://bit.ly/2NiFkpL
  29. Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2019) Evaluation of the Impact of Magnetic Resonance Imaging (MRI) on Gross Tumor Volume (GTV) Definition for Radiation Treatment Planning (RTP) of Inoperable High Grade Gliomas (HGGs). Concepts in Magnetic Resonance Part A 2019: 4282754. Link: https://bit.ly/3qK77Nn
  30. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2019) Assessment of target definition based on Multimodality imaging for radiosurgical Management of glomus jugulare tumors (GJTs). Canc Therapy Oncol Int J 15: 555909. Link: https://bit.ly/3vp4hB2
  31. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2019) Evaluation of Radiosurgery Target Volume Determination for Meningiomas Based on Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Cancer Sci Res Open Access 5: 1-4. Link: https://bit.ly/3vp4hkw
  32. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2019) Multimodality Imaging for Radiosurgical Management of Arteriovenous Malformations. Asian Journal of Pharmacy, Nursing and Medical Sciences 7: 7-12. Link: https://bit.ly/3cwnFmX
  33. Demiral S, Sager O, Dincoglan F, Uysal B, Gamsiz H, et al. (2018) Evaluation of Target Volume Determination for Single Session Stereotactic Radiosurgery (SRS) of Brain Metastases. Canc Therapy Oncol Int J 12: 555848. Link: https://bit.ly/2MXRS1K
  34. Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2019) Utility of Magnetic Resonance Imaging (Imaging) in Target Volume Definition for Radiosurgery of Acoustic Neuromas. Int J Cancer Clin Res 6: 119. Link: https://bit.ly/3bMhr3j
  35. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2019) Assessment of Computed Tomography (CT) And Magnetic Resonance Imaging (MRI) Based Radiosurgery Treatment Planning for Pituitary Adenomas. Canc Therapy Oncol Int J 13: 555857. Link: https://bit.ly/3qKvfPR
  36. Sager O, Dincoglan F, Demiral S, Gamsiz H, Uysal B, et al. (2022) Optimal timing of thoracic irradiation for limited stage small cell lung cancer: Current evidence and future prospects. World J Clin Oncol 13: 116-124. Link: https://bit.ly/3iiYA2k  
  37. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2021) Concise review of stereotactic irradiation for pediatric glial neoplasms: Current concepts and future directions. World J Methodol 11: 61-74. Link: https://bit.ly/3qfgQ0C  
  38. Demiral S, Sager O, Dincoglan F, Uysal B, Gamsiz H, et al. (2021) Evaluation of breathing-adapted radiation therapy for right-sided early stage breast cancer patients. Indian J Cancer 58: 195-200. Link: https://bit.ly/3wlR8LU  
  39. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2021) Omission of Radiation Therapy (RT) for Metaplastic Breast Cancer (MBC): A Review Article. Int J Res Stud Med Health Sci 6: 10-15. Link: https://bit.ly/3N0M8Cb  
  40. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2020) Adaptive radiation therapy of breast cancer by repeated imaging during irradiation. World J Radiol 12: 68-75. Link: https://bit.ly/3bKVSzT
  41. Sager O, Dincoglan F, Uysal B, Demiral S, Gamsiz H, et al. (2018) Evaluation of adaptive radiotherapy (ART) by use of replanning the tumor bed boost with repeated computed tomography (CT) simulation after whole breast irradiation (WBI) for breast cancer patients having clinically evident seroma. Jpn J Radiol 36: 401-406. Link: https://bit.ly/3bOpQmV  
  42. Sager O, Dincoglan F, Uysal B, Demiral S, Gamsiz H, et al. (2017) Splenic Irradiation: A Concise Review of the Literature. J App Hem Bl Tran 1: 101. Link: https://bit.ly/3eBmtkP   
  43. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2019) Breathing adapted radiation therapy for leukemia relapse in the breast: A case report. World J Clin Oncol 10: 369-374. Link: https://bit.ly/3qNJsLS  
  44. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2019) Utility of Molecular Imaging with 2-Deoxy-2-[Fluorine-18] Fluoro-DGlucose Positron Emission Tomography (18F-FDG PET) for Small Cell Lung Cancer (SCLC): A Radiation Oncology Perspective. Curr Radiopharm 12: 4-10. Link: https://bit.ly/3bKW7eh
  45. Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Uysal B, et al. (2015) Adaptive splenic radiotherapy for symptomatic splenomegaly management in myeloproliferative disorders. Tumori 101: 84-90. Link: https://bit.ly/2OAe0DT
  46. Özsavaş EE, Telatar Z, Dirican B, Sağer Ö, Beyzadeoğlu M  (2014) Automatic segmentation of anatomical structures from CT scans of thorax for RTP. Comput Math Methods Med 2014: 472890. Link: https://bit.ly/3qOsjC3
  47. Dincoglan F, Beyzadeoglu M, Sager O, Oysul K, Kahya YE, et al. (2013) Dosimetric evaluation of critical organs at risk in mastectomized left-sided breast cancer radiotherapy using breath-hold technique. Tumori 99: 76-82. Link: https://bit.ly/2OoOmSM
  48. Sager Ö, Dinçoglan F, Gamsiz H, Demiral S, Uysal B, et al. (2012) Evaluation of the impact of integrated [18f]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography imaging on staging and radiotherapy treatment volume definition of nonsmall cell lung cancer. Gulhane Med J 54: 220-227. Link: https://bit.ly/3htqTt5
  49. Sager O, Beyzadeoglu M, Dincoglan F, Oysul K, Kahya YE, et al. (2012) The Role of Active Breathing Control-Moderate Deep Inspiration Breath-Hold (ABC-mDIBH) Usage in non-Mastectomized Left-sided Breast Cancer Radiotherapy: A Dosimetric Evaluation. UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi 22: 147-155. Link: http://bit.ly/3bMn7dF
  50. Sager O, Beyzadeoglu M, Dincoglan F, Oysul K, Kahya YE, et al. (2012) Evaluation of active breathing control-moderate deep inspiration breath-hold in definitive non-small cell lung cancer radiotherapy. Neoplasma 59: 333-340. Link: http://bit.ly/3cVtnNh
  51. Beyzadeoglu M, Sager O, Dincoglan F, Demiral S, Uysal B, et al. (2020) Single Fraction Stereotactic Radiosurgery (SRS) versus Fractionated Stereotactic Radiotherapy (FSRT) for Vestibular Schwannoma (VS). J Surg Surgical Res 6: 062-066. Link: https://bit.ly/3qVHOs1   
  52. Dincoglan F, Beyzadeoglu M, Sager O, Demiral S, Uysal B, et al. (2020) A Concise Review of Irradiation for Temporal Bone Chemodectomas (TBC). Arch Otolaryngol Rhinol 6: 016-020. Link: https://bit.ly/3cymTWr
  53. Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Gamsiz H, et al. (2020) Multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation: Implications for an improved toxicity profile. J Surg Surgical Res 6: 056-061. Link: https://bit.ly/3toiKvl
  54. Dincoglan F, Sager O, Uysal B, Demiral S, Gamsiz H, et al. (2019) Evaluation of hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity after surgical resection of brain metastases: A single center experience. Indian J Cancer 56: 202-206. Link: https://bit.ly/38EOeVM  
  55. Demiral S, Dincoglan F, Sager O, Uysal B, Gamsiz H, et al. (2018) Contemporary Management of Meningiomas with Radiosurgery. Int J Radiol Imaging Technol 80: 187-190. Link: https://bit.ly/3rJwiRw
  56. Dincoglan F, Sager O, Demiral S, Uysal B, Gamsiz H, et al. (2017) Radiosurgery for recurrent glioblastoma: A review article. Neurol Disord Therap 1: 1-5. Link: Link: https://bit.ly/30JZTOQ
  57. Dincoglan F, Sager O, Demiral S, Gamsiz H, Uysal B, et al. (2019) Fractionated stereotactic radiosurgery for locally recurrent brain metastases after failed stereotactic radiosurgery. Indian J Cancer 56: 151-156. Link: https://bit.ly/3tkGss6
  58. Gamsiz H, Beyzadeoglu M, Sager O, Demiral S, Dincoglan F, et al. (2015) Evaluation of stereotactic body radiation therapy in the management of adrenal metastases from non-small cell lung cancer. Tumori 101: 98-103. Link: https://bit.ly/3tkGpNa
  59. Dincoglan F, Beyzadeoglu M, Sager O, Demiral S, Gamsiz H, et al. (2015) Management of patients with recurrent glioblastoma using hypofractionated stereotactic radiotherapy. Tumori 101: 179-184. Link: https://bit.ly/3eDf4BN
  60. Demiral S, Dincoglan F, Sager O, Gamsiz H, Uysal B, et al. (2016) Hypofractionated stereotactic radiotherapy (HFSRT) for who grade I anterior clinoid meningiomas (ACM). Jpn J Radiol 34: 730-737. Link: https://bit.ly/30FFBpK
  61. Sager O, Dincoglan F, Beyzadeoglu M (2015) Stereotactic radiosurgery of glomus jugulare tumors: Current concepts, recent advances and future perspectives. CNS Oncol 4: 105-114. Link: https://bit.ly/3lh1FjT
  62. Gamsiz H, Beyzadeoglu M, Sager O, Dincoglan F, Demiral S, et al. (2014) Management of pulmonary oligometastases by stereotactic body radiotherapy. Tumori 100: 179-183. Link: https://bit.ly/2Q7uCDH
  63. Sager O, Beyzadeoglu M, Dincoglan F, Gamsiz H, Demiral S, et al. (2014) Evaluation of linear accelerator-based stereotactic radiosurgery in the management of glomus jugulare tumors. Tumori 100: 184-188. Link: https://bit.ly/38F16eL
  64. Demiral S, Beyzadeoglu M, Sager O, Dincoglan F, Gamsiz H, et al. (2014) Evaluation of linear accelerator (linac)-based stereotactic radiosurgery (srs) for the treatment of craniopharyngiomas. UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi 24: 123-129. Link: https://bit.ly/3vr4DqI
  65. Demiral S, Beyzadeoglu M, Sager O, Dincoglan F, Gamsiz H, et al. (2014) Evaluation of linear accelerator (linac)-based stereotactic radiosurgery (srs) for the treatment of craniopharyngiomas. UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi 24: 123-129. Link: https://bit.ly/3vr4DqI
  66. Sager O, Beyzadeoglu M, Dincoglan F, Uysal B, Gamsiz H, et al. (2014) Evaluation of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) for cerebral cavernous malformations: A 15-year single-center experience. Ann Saudi Med 34: 54-58. Link: https://bit.ly/3rPpuBM
  67. Dincoglan F, Sager O, Gamsiz H, Uysal B, Demiral S, et al. (2014) Management of patients with ≥ 4 brain metastases using stereotactic radiosurgery boost after whole brain irradiation. Tumori 100: 302-306. Link: https://bit.ly/3rOh6CN
  68. Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Uysal B, et al. (2013) Management of vestibular schwannomas with linear accelerator-based stereotactic radiosurgery: a single center experience. Tumori 99: 617-622. Link: https://bit.ly/3bMgoAf   
  69. Dincoglan F, Beyzadeoglu M, Sager O, Oysul K, Sirin S et al. (2012) Image-guided positioning in intracranial non-invasive stereotactic radiosurgery for the treatment of brain metastasis. Tumori 98: 630-635. Link: http://bit.ly/2B0tOZA
  70. Dincoglan F, Beyzadeoglu M, Sager O, Uysal B, Demiral S, et al. (2013) Evaluation of linear accelerator-based stereotactic radiosurgery in the management of meningiomas: A single center experience. J Buon 18: 717-722. Link: https://bit.ly/3litoRa
  71. Demiral S, Beyzadeoglu M, Uysal B, Oysul K, Kahya YE, et al. (2013) Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer. Neoplasma 60: 322-327. Link: https://bit.ly/2ORe4iD
  72. Dincoglan F, Sager O, Gamsiz H, Uysal B, Demiral S, et al. (2012) Stereotactic radiosurgery for intracranial tumors: A single center experience. Gulhane Med J 54: 190-198. Link: https://bit.ly/3cYmv1J
  73. Sirin S, Oysul K, Surenkok S, Sager O, Dincoglan F, et al. (2011) Linear accelerator-based stereotactic radiosurgery in recurrent glioblastoma: A single center experience. Vojnosanit Pregl 68: 961-966. Link: http://bit.ly/3hqfBGb