ABSTRACT

Objective: Radiation therapy (RT) may be utilized as part of multidisciplinary Ewing sarcoma management. Every effort is made to avoid radiation induced toxicity in radiotherapeutic management of Ewing sarcoma. Exploitation of image guided RT (IGRT) techniques, adaptive RT, and improved target definition are among the several considerations for contemporary radiotherapeutic management with an improved toxicity profile. Currently, majority of cancer centers utilize Computed Tomography (CT) simulation for RT planning for Ewing sarcoma. While CT is an effective imaging modality, incorporation of other imaging modalities such as Magnetic Resonance Imaging (MRI) may result in improved target definition for radiotherapeutic management. In this study, we assessed RT target definition for paraspinal Ewing sarcoma by use of multimodality imaging.

Materials and Methods: Patients receiving RT for paraspinal Ewing sarcoma were assessed with comparative analysis to explore whether multimodality imaging improves target volume definition, interobserver and intraobserver variations for radiotherapeutic management of Ewing sarcoma. To address this critical issue, we comparatively assessed RT target volume determination by integration of MRI or by CT-simulation images only.

Results: Patients referred for radiotherapeutic management of paraspinal Ewing sarcoma at the Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences have been studied for target volume determination by either CTonly imaging or by CT-MR registration-based imaging in this original study. Ground truth target volume has been found to be identical with CT-MR registration-based imaging in this study for radiotherapeutic management of paraspinal Ewing sarcoma.

Conclusion: Our study suggests improved target volume definition for radiotherapeutic management of paraspinal Ewing sarcoma by incorporation of MRI in RT planning procedure. Admittedly, there is need for further supporting evidence.

Keywords: Paraspinal Ewing Sarcoma; Radiation Therapy (RT); Magnetic Resonance Imaging (MRI)

Abbreviations: AAPM: American Association of Physicists in Medicine; ICRU: International Commission on Radiation Units and Measurements; LINAC: Linear Accelerator; IGRT: Image Guided RT; ART: Adaptive RT; CT: Computed Tomography; RT: Radiation Therapy; MRI: Magnetic Resonance Imaging

Introduction

Ewing sarcoma, initially described by James Ewing in 1921, may be broadly categorized as a high-grade osteolytic bone tumor which may occur at several localizations throughout the skeleton albeit with a tendency to involve the diaphysis of long bones [1- 11]. Children and adolescents are more frequently affected, and multidisciplinary management is required for improved therapeutic outcomes [3-11]. Radiation therapy (RT) plays a major role in treatment of Ewing sarcoma, and there have been improvements in radiotherapeutic management recently [3-11]. Since younger patients are more commonly diagnosed with Ewing sarcoma, adverse effects of irradiation should be thoroughly considered before radiotherapeutic management. While RT is a viable therapeutic option for a variety of cancers, pediatric patients should be more vigilantly considered for irradiation in view of the toxicity and consequences regarding quality of life. Younger patients still in the process of growing may be negatively affected by adverse irradiation effects. Nevertheless, RT may be utilized as part of multidisciplinary Ewing sarcoma management. Every effort is made to avoid radiation induced toxicity in radiotherapeutic management of Ewing sarcoma. Exploitation of image guided RT (IGRT) techniques, adaptive RT (ART), and improved target definition are among the several considerations for contemporary radiotherapeutic management with an improved toxicity profile. Currently, majority of cancer centers utilize Computed Tomography (CT) simulation for RT planning for Ewing sarcoma. While CT is an effective imaging modality, incorporation of other imaging modalities such as Magnetic Resonance Imaging (MRI) may result in improved target definition for radiotherapeutic management. In this study, we assessed RT target definition for Ewing sarcoma by use of multimodality imaging.

Materials and Methods

Patients receiving RT for Ewing sarcoma were assessed with comparative analysis to explore whether multimodality imaging improves target volume definition, interobserver and intraobserver variations for radiotherapeutic management of Ewing sarcoma. To address this critical issue, we comparatively assessed RT target volume determination by integration of MRI or by CT-simulation images only. Ground truth target volume has been determined for every patient on a collaborative basis by board certified radiation oncologists after detailed assessment, colleague peer review, and consensus for actual treatment and comparison purposes. Included patients had paraspinal Ewing sarcoma, and management with RT was decided after close collaboration and detailed multidisciplinary evaluation on an individual basis. We considered optimal therapeutic approaches and protocols by meticulous evaluation of patient, tumor, and treatment characteristics. Decision making procedure included thorough consideration of lesion sizes, localization and association with critical structures, contemplated outcomes of treatment, patient symptomatology and preferences along with logistical issues. RT delivery has been accomplished by use of Synergy (Elekta, UK) linear accelerator (LINAC) available at our tertiary referral institution. CT-simulation has been individually performed for each patient at the CT-simulator (GE Lightspeed RT, GE Healthcare, Chalfont St. Giles, UK) to acquire high quality RT planning images. Following the CT-simulation procedure, acquired RT planning images were sent to the delineation workstation (SimMD, GE, UK) by use of the network. Structure sets including treatment volumes and critical structures have been meticulously determined. Target volume definition was performed by either the CT-simulation images only or by registered CT and MR images. We conducted a comparative analysis for assessment of target definition by CT only and with incorporation of CT-MR registrationbased imaging to investigate the impact of multimodality imaging.

Results

Patients referred for radiotherapeutic management of paraspinal Ewing sarcoma at the Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences have been studied for target volume determination by either CT-only imaging or by CT-MR registration-based imaging in this original study. Evaluated tumor related parameters included lesion size, localization and association with the spinal cord, extent of bony invasion, and other characteristics. Additionally, patient age, symptomatology, performance status, lesion location and association with other critical structures have also been assessed. We considered the reports by American Association of Physicists in Medicine (AAPM) and International Commission on Radiation Units and Measurements (ICRU) in precise RT planning. In view of contemporary guidelines and clinical experience, radiation physicists have generated plans by taking into account relevant critical organ dose constraints. Tissue heterogeneity, electron density, CT number and HU values in CT images have been considered by the radiation physicist in RT planning. A critical objective of RT planning included achieving optimal target volume coverage without violation of critical organ dose constraints. The definition of ground truth target volume has beeen accomplished by board certified radiation oncologists after thorough evaluation, colleague peer review, and consensus. Ground truth target volume has been used for actual treatment and for comparison purposes. Treatment delivery with Synergy (Elekta, UK) LINAC has been performed by incorporation of IGRT techniques including the kilovoltage cone beam CT and electronic digital portal imaging. Ground truth target volume has been found to be identical with CTMR registration-based imaging in this study for radiotherapeutic management of paraspinal Ewing sarcoma.

Discussion

Ewing sarcoma has been initially described by James Ewing in 1921 and may be defined as a high-grade osteolytic bone tumor which may occur at several localizations throughout the skeleton albeit with a tendency to involve the diaphysis of long bones [1-11]. Ewing sarcoma more frequently affects children and adolescents, and improved therapeutic outcomes may be achieved through collaborative multidisciplinary management [3-11]. RT composes a critical weapon in the therapeutic armamentarium for treatment of Ewing sarcoma, and there have been several improvements in radiotherapeutic management lately [3-11]. Given that younger patients are more frequently diagnosed with Ewing sarcoma, thorough consideration of adverse effects is mandatory. RT offers a viable therapeutic option for a variety of cancers, however, pediatric patients should be more vigilantly considered for irradiation in given the risk of toxicity and consequences affecting quality of life. Younger patients still in the process of growing may be more prone to be negatively affected by adverse irradiation effects. Even so, RT may be utilized as part of multidisciplinary Ewing sarcoma management. Every effort should be made to avoid radiation induced toxicity in radiotherapeutic management of Ewing sarcoma. Exploitation of IGRT techniques, ART, and improved target definition are among the several considerations for contemporary radiotherapeutic management with an improved toxicity profile. Multimodality imaging techniques and image fusion methods have clearly contributed to improving target definition for several cancers, and there is now growing body of evidence suggesting the use of multimodality imaging for target definition of several tumors throughout the human body [12-45].

In the meantime, majority of cancer centers utilize CT simulation for RT planning for Ewing sarcoma. CT has been an effective imaging modality, however, incorporation of other imaging modalities such as MRI may result in improved target definition for radiotherapeutic management. In this study, we assessed RT target definition for Ewing sarcoma by use of multimodality imaging and found that target definition is improved by multimodality imaging. Within this context, this study may add to accumulating body of data suggesting improved target volume definition by use of multimodality imaging. Clearly, recent years have witnessed several advances in the spectrum of radiation oncology through the introduction of molecular imaging methods, automatic segmentation techniques, stereotactic RT, intensity modulated RT (IMRT), IGRT, and ART [46-84]. In line with these innovatory advances, accuracy and precision in target volume definition has been a more critical aspect of contemporary radiotherapeutic approaches. From this perspective, we consider that our study may have relevant clinical implications for routinization of multimodality imaging for target volume definition in radiotherapeutic management of paraspinal Ewing sarcoma. In conclusion, this study suggests improved target volume definition for radiotherapeutic management of paraspinal Ewing sarcoma by incorporation of MRI in RT planning procedure. Admittedly, there is need for further supporting evidence.

Conflicts of Interest

There are no conflicts of interest and no acknowledgements.

References

1. Khan S, Abid Z, Haider G, Bukhari N, Zehra D, et al. (2021) Incidence of Ewing's Sarcoma in Different Age Groups, Their Associated Features, and Its Correlation With Primary Care Interval. Cureus 13(3): e13986.
2. Esiashvili N, Goodman M, Marcus RB Jr (2008) Changes in incidence and survival of Ewing sarcoma patients over the past 3 decades: Surveillance Epidemiology and End Results data. J Pediatr Hematol Oncol 30(6): 425-430.
3. Bellan DG, Filho RJ, Garcia JG, de Toledo Petrilli M, Maia Viola DC, et al. (2015) EWING'S SARCOMA: EPIDEMIOLOGY AND PROGNOSIS FOR PATIENTS TREATED AT THE PEDIATRIC ONCOLOGY INSTITUTE, IOP-GRAACC-UNIFESP. Rev Bras Ortop 2015 47(4): 446-450.
4. Eaton BR, Claude L, Indelicato DJ, Vatner R, Yeh B, et al. (2021) Ewing sarcoma. Pediatr Blood Cancer 68(Suppl 2): e28355.
5. Gaspar N, Hawkins DS, Dirksen U, Lewis IJ, Ferrari S, et al. (2015) Ewing Sarcoma: Current Management and Future Approaches Through Collaboration. J Clin Oncol 33(27): 3036-3046.
6. Kridis WB, Toumi N, Chaari H, Khanfir A, Ayadi K, et al. (2017) A Review of Ewing Sarcoma Treatment: Is it Still a Subject of Debate. Rev Recent Clin Trials 12(1): 19-23.
7. Donaldson SS (2004) Ewing sarcoma: radiation dose and target volume. Pediatr Blood Cancer 42(5): 471-476.
8. Uezono H, Indelicato DJ, Rotondo RL, Mailhot Vega RB, Bradfield SM, et al. (2020) Treatment Outcomes After Proton Therapy for Ewing Sarcoma of the Pelvis. Int J Radiat Oncol Biol Phys 107(5): 974-981.
9. Kharod SM, Indelicato DJ, Rotondo RL, Mailhot Vega RB, Uezono H, et al. (2020) Outcomes following proton therapy for Ewing sarcoma of the cranium and skull base. Pediatr Blood Cancer 67(2): e28080.
10. Indelicato DJ, Vega RBM, Viviers E, Morris CG, Bradfield SM, et al. (2022) Modern Therapy for Chest Wall Ewing Sarcoma: An Update of the University of Florida Experience. Int J Radiat Oncol Biol Phys 113(2): 345-354.
11. Indelicato DJ, Vega RBM, Viviers E, Morris CG, Bradfield SM, et al. (2022) Modern Therapy for Spinal and Paraspinal Ewing Sarcoma: An Update of the University of Florida Experience. Int J Radiat Oncol Biol Phys 113(1): 161-165.
12. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2022) Improved Target Volume Definition for Radiotherapeutic Management of Parotid Gland Cancers by use of Multimodality Imaging: An Original Article. Canc Therapy & Oncol Int J 21(3): 556062.
13. 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.
14. 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(1): 042-046.
15. 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(1): 031-034.
16. 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.
17. 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(5): 26171-26174.
18. 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(1): 043-045.
19. 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.
20. 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(3): 26734-26738.
21. 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(4): 26970-26974.
22. 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(1): 037-041.
23. Dincoglan F, Beyzadeoglu M, Demiral S, Sager O (2020) Assessment of Treatment Volume Definition for Irradiation of Spinal Ependymomas: an Original Article. ARC Journal of Cancer Science 6: 1-6.
24. 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 Journal of Cancer Science 6(2): 06-11.
25. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Assessment of Target Volume Definition for Irradiation of Hemangiopericytomas: An Original Article. Canc Therapy & Oncol Int J 17(2): 555959.
26. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Treatment Volume Determination for Irradiation of chordoma: an Original Article. International Journal of Research Studies in Medical and Health Sciences 5(10): 3-8.
27. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2020) Target Definition of orbital Embryonal Rhabdomyosarcoma (Rms) by Multimodality Imaging: An Original Article. ARC Journal of Cancer Science 6(2): 12-17.
28. 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(2): 19728-19732.
29. Demiral S, Beyzadeoglu M, Dincoglan F, Sager O (2020) Assessment of Target Volume Definition for Radiosurgery of Atypical Meningiomas with Multimodality Imaging. Journal of Hematology and Oncology Research 3(4): 14-21.
30. 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(3): 18-23.
31. 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.
32. 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 Journal of Cancer Science 6(2): 18-23.
33. 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.
34. Beyzadeoglu M, Dincoglan F, Demiral S, Sager O (2020) Target Volume Determination for Precise Radiation Therapy (RT) of Central Neurocytoma: An Original Article. International Journal of Research Studies in Medical and Health Sciences 5(3): 29-34.
35. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Evaluation of Target Volume Determination for Irradiatıon of Pilocytic Astrocytomas: An Original Article. ARC Journal of Cancer Science 6(1): 1-5.
36. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2020) Radiosurgery Treatment Volume Determination for Brain Lymphomas with and without Incorporation of Multimodality Imaging. Journal of Medical Pharmaceutical and Allied Sciences 9: 2398-2404.
37. Beyzadeoglu M, Sager O, Dincoglan F, Demiral S (2019) Evaluation of Target Definition for Stereotactic Reirradiation of Recurrent Glioblastoma. Arch Can Res 7(1): 3.
38. 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(1): 103.
39. 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.
40. 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.
41. 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(1): 7-12.
42. 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(2): 1-4.
43. 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(3): 119.
44. 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(2): 555857.
45. 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.
46. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2022) Concise review of radiosurgery for contemporary management of pilocytic astrocytomas in children and adults. World J Exp Med 12(3): 36-43.
47. 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(2): 116-124.
48. 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(2): 195-200.
49. 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(3): 61-74.
50. 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. International Journal of Research Studies in Medical and Health Sciences 6(1): 10-15.
51. 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(5): 68-75.
52. 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(11): 369-374.
53. 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(1): 4-10.
54. 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(6): 401-406.
55. 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.
56. 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(1): 84-90.
57. Ozsavaş EE, Telatar Z, Dirican B, Sager O, Beyzadeoğlu M (2014) Automatic segmentation of anatomical structures from CT scans of thorax for RTP. Comput Math Methods Med.
58. 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(1): 76-82.
59. Saǧer Ö, Dinçoǧlan 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.
60. 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(3): 147-155.
61. 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(3): 333-340.
62. 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(1): 062-066.
63. 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(2): 016-020.
64. 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(1): 056-061.
65. 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(3): 202-206.
66. 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.
67. Dincoglan F, Sager O, Demiral S, Uysal B, Gamsiz H, et al. (2017) Radiosurgery for recurrent glioblastoma: A review article. Neurol Disord Therap 1(4): 1-5.
68. 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(2): 151-156.
69. 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(1): 98-103.
70. 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(2): 179-184.
71. 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(11): 730-737.
72. Sager O, Dincoglan F, Beyzadeoglu M (2015) Stereotactic radiosurgery of glomus jugulare tumors: Current concepts, recent advances and future perspectives. CNS Oncol 4(2): 105-114.
73. Gamsiz H, Beyzadeoglu M, Sager O, Dincoglan F, Demiral S, et al. (2014) Management of pulmonary oligometastases by stereotactic body radiotherapy. Tumori 100(2): 179-183.
74. 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(2): 184-188.
75. 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(2): 123-129.
76. 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(2): 123-129.
77. 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(1): 54-58.
78. 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(3): 302-306.
79. 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(5): 617-622.
80. 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(3): 717-722.
81. 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(3): 322-327.
82. 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(5): 630-635.
83. 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(3): 190-198.
84. 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(11): 961-966.

ABSTRACT

Objective: Radiation therapy (RT) may be utilized as part of multidisciplinary Ewing sarcoma management. Every effort is made to avoid radiation induced toxicity in radiotherapeutic management of Ewing sarcoma. Exploitation of image guided RT (IGRT) techniques, adaptive RT, and improved target definition are among the several considerations for contemporary radiotherapeutic management with an improved toxicity profile. Currently, majority of cancer centers utilize Computed Tomography (CT) simulation for RT planning for Ewing sarcoma. While CT is an effective imaging modality, incorporation of other imaging modalities such as Magnetic Resonance Imaging (MRI) may result in improved target definition for radiotherapeutic management. In this study, we assessed RT target definition for paraspinal Ewing sarcoma by use of multimodality imaging. Materials and Methods: Patients receiving RT for paraspinal Ewing sarcoma were assessed with comparative analysis to explore whether multimodality imaging improves target volume definition, interobserver and intraobserver variations for radiotherapeutic management of Ewing sarcoma. To address this critical issue, we comparatively assessed RT target volume determination by integration of MRI or by CT-simulation images only. Results: Patients referred for radiotherapeutic management of paraspinal Ewing sarcoma at the Department of Radiation Oncology, Gulhane Medical Faculty, University of Health Sciences have been studied for target volume determination by either CTonly imaging or by CT-MR registration-based imaging in this original study. Ground truth target volume has been found to be identical with CT-MR registration-based imaging in this study for radiotherapeutic management of paraspinal Ewing sarcoma. Conclusion: Our study suggests improved target volume definition for radiotherapeutic management of paraspinal Ewing sarcoma by incorporation of MRI in RT planning procedure. Admittedly, there is need for further supporting evidence.

Keywords: Paraspinal Ewing Sarcoma; Radiation Therapy (RT); Magnetic Resonance Imaging (MRI)

Abbreviations: AAPM: American Association of Physicists in Medicine; ICRU: International Commission on Radiation Units and Measurements; LINAC: Linear Accelerator; IGRT: Image Guided RT; ART: Adaptive RT; CT: Computed Tomography; RT: Radiation Therapy; MRI: Magnetic Resonance Imaging