Research Article

Evaluation of Target Definition for Radiotherapeutic Management of Recurrent Merkel Cell Carcinoma (MCC)

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

Department of Radiation Oncology; University of Health Sciences, Gulhane Medical Faculty, Ankara, Turkey

Submission: May 24, 2023; Published: June 06, 2023

*Corresponding Address:Dr. Murat Beyzadeoglu, University of Health Sciences, Gulhane Medical Faculty, Department of Radiation Oncology, Gn.Tevfik Saglam Cad. 06018, Etlik, Kecioren, Ankara, Turkey

How to cite this article: Murat B, Selcuk D, Ferrat D, Omer S. Evaluation of Target Definition for Radiotherapeutic Management of Recurrent Merkel Cell Carcinoma (MCC). Canc Therapy & Oncol Int J. 2023; 24(2): 556133. DOI:10.19080/CTOIJ.2023.24.556133

Abstract

_Objective: Merkel cell carcinoma (MCC) is a relatively rare type of skin cancer which typically follows an aggressive disease course. Local recurrence is frequent for patients with MCC. Management of patients should be performed by use of a multidisciplinary approach. Surgery is a principal mode of treatment for MCC, however, radiation therapy (RT) may also be used in certain circumstances. We assessed target definition for radiotherapeutic management of recurrent MCC in this original research article.

_{Materials and methods:} The aim of this study has been to assess target definition for radiotherapeutic management of recurrent MCC based on Computed Tomography (CT) only or fused CT-MRI (Magnetic Resonance Imaging). We conducted a comparative analysis for evaluation of target definition by CT simulation images only or by incorporation of MRI. Main objective of the study has been to assess the integration of multimodality imaging for target definition.

_Results: Ground truth target volume has been used as the reference for comparative analysis, and results revealed that use of fused CT-MRI based target definition was identical with ground truth target volume definition in selected group of patients with recurrent MCC.

_Conclusion: Multimodality imaging with integration of MRI in RT target definition procedure may be used for patients with recurrent MCC despite the need for further supporting evidence.

Keywords:Merkel Cell Carcinoma (MCC); Radiation therapy (RT); Magnetic Resonance Imaging (MRI)

Introduction

Merkel cell carcinoma (MCC) is a relatively rare type of skin cancer which typically follows an aggressive disease course [1-7]. Local recurrence is frequent for patients with MCC [1-7]. Management of patients should be performed by use of a multidisciplinary approach. Surgery is a principal mode of treatment for MCC, however, radiation therapy (RT) may also be used in certain circumstances [1-7]. RT may have a role as supplementary or definitive therapeutic option, recurrent disease may also benefit from irradiation [1-7]. Given the relative rarity of MCC, literature data from case series, retrospective studies, experiences from big treatment centers, and collaborative guidelines have been followed for optimal patient treatment [1-7]. RT has been utilized for MCC management, sometimes for its improved toxicity profile compared to other therapeutic options [1-7]. Treatment of recurrent MCC may even be more challenging. Improved patient management may be observed by better treatment results in the millenium era. In this context, quality of life issues and normal tissue sparing are considered as more critical aspects of current radiotherapeutic management. Integration of contemporary treatment concepts and technologies such as molecular imaging methods, automatic segmentation techniques, Image Guided RT (IGRT), Intensity Modulated RT (IMRT), stereotactic RT, and adaptive RT (ART) may improve RT results [8-49]. However, advances in target definition can be thought as a critical part of modernized RT strategies. Common practice includes the use of Computed Tomography (CT) simulation for acquisition of RT planning images, however, incorporation of other imaging modalities such as Magnetic Resonance Imaging (MRI) may clearly add to the precision of target definition as mentioned in several other studies [50-93]. Herein, we assess target definition for radiotherapeutic management of recurrent MCC.

Materials and Methods

Department of Radiation Oncology at Gulhane Medical Faculty, University of Health Sciences currently serves as a tertiary cancer center with a huge patient population from several places from Turkey and allied countries. In this context, a variety of cancers are treated annually for decades. The aim of this study has been to assess target definition for radiotherapeutic management of recurrent MCC based on CT only or fused CT-MRI. We conducted a comparative analysis for evaluation of target definition by CT simulation images only or by incorporation of MRI. Main objective of the study has been to assess the integration of multimodality imaging for target definition, nevertheless, delineation of normal tissues, interobserver and intraobserver variations have also been evaluated. Ground truth target volume was used for comparative analysis and for comparison purposes, and it has been defined by board certified radiation oncologists after detailed evaluation of all imaging and related data with thorough colleague peer review and consensus. Decision making procedure for optimal treatment has involved multidisciplinary input from experts on surgical oncology, radiation oncology, medical oncology and hematology. Individualized patient evaluation included consideration of patient, disease, and treatment related factors. Patient age, previous treatments, symptomatology, lesion size, performance status, lesion location and association with critical structures, contemplated outcomes of therapies, patient preferences and logistical issues have been all taken into account.

A Linear Accelerator (LINAC) furnished with the capability of contemporary IGRT techniques was used for RT. After rigid patient immobilization, planning CT images were acquired at CT simulator for radiation treatment planning. Then, acquired RT planning images have been transferred to the delineation workstation through the network. Target volumes and normal tissues have been defined on these images and structure sets have been generated. Either CT simulation images only or fused CT-MR images were utilized for evaluation.

Results

We have conducted this study to evaluate the use of multimodality imaging with incorporation of MRI for target delineation in a selected group of patients referred for recurrent MCC RT. Treatment of patients have been performed in our Radiation Oncology Department of Gulhane Medical Faculty at University of Health Sciences, Ankara. Prior to treatment with RT, patients were individually evaluated by a multidisciplinary team of experts from surgical oncology, medical oncology and radiation oncology. Briefly, we have conducted a comparative assessment based on either CT only imaging or by fused CT-MRI to explore the use of this sophisticated strategy. Optimal radiation treatment planning procedure included consideration of lesion sizes, localization and association with surrounding critical structures. Radiation physicists were involved in radiation treatment planning processs with consideration of reports by American Association of Physicists in Medicine (AAPM) and International Commission on Radiation Units and Measurements (ICRU). Accurate radiation treatment planning procedure included critical consideration of electron density, tissue heterogeneity, CT number and HU values in CT images. Main consideration in radiation treatment planning was to achieve optimal coverage of target volume with minimized exposure of surrounding normal tissues. Ground truth target volume has been used as the reference for comparative analysis, and results revealed that use of fused CT-MRI based target definition was identical with ground truth target volume definition in selected group of patients with recurrent MCC.

Discussion

MCC is considered as a relatively seldom type of skin cancers mostly following an aggressive disease course [1-7]. Local recurrence may be encountered after initial management [1- 7]. Treatment of patients should be handled by experienced centers which utilize a multidisciplinary therapeutic strategy. Surgery serves as the main modality of management for patients with MCC, nevertheless, RT may also play a role in treatment [1- 7]. RT may be used as a supplementary or definitive treatment modality, and for management of recurrent disease [1-7]. Taking into account the relative rarity of MCC, literature data from case series, retrospective studies, experiences from big treatment centers, and collaborative guidelines are for exploited for optimal management [1-7]. RT has been used for MCC treatment, sometimes for its improved toxicity profile compared with other treatment modalities [1-7]. Management of recurrent MCC may even be more challenging due to several factors.

Optimal patient management may be achieved and improved treatment results could be obtained through several advances in the millenium era. Within this context, quality of life issues and critical organ protection may be considered as pertinent aspects of contemporary RT strategies. Incorporation of sophisticated therapeutic concepts and technologies such as molecular imaging methods, automatic segmentation techniques, IGRT, IMRT, stereotactic RT, and ART may further improve radiotherapeutic outcomes [8-49]. Nevertheless, improved target definition may also be considered as a critical part of current irradiation approaches. In the meantime, CT simulation is still the widely accepted technique for acquisition of radiation treatment planning images, however, incorporation of other imaging modalities such as MRI may improve the accuracy in target definition as addressed by other studies [50-93].

Conclusion

In conclusion, multimodality imaging with integration of MRI in RT target definition procedure may be used for patients with recurrent MCC despite the need for further supporting evidence.

Conflict of Interest

There are no conflicts of interest and no acknowledgements.

References

1. Hughes MP, Hardee ME, Cornelius LA, Hutchins LF, Becker JC, et al. (2014) Merkel Cell Carcinoma: Epidemiology, Target, and Therapy. Curr Dermatol Rep 3(1): 46-53
2. McEvoy AM, Lachance K, Hippe DS, Cahill K, Moshiri Y, et al. (2022) Recurrence and Mortality Risk of Merkel Cell Carcinoma by Cancer Stage and Time From Diagnosis. JAMA Dermatol 158(4): 382-389.
3. Eng TY, Naguib M, Fuller CD, Jones WE 3rd, Herman TS (2004) Treatment of recurrent Merkel cell carcinoma: an analysis of 46 cases. Am J Clin Oncol 27(6): 576-583.
4. Liang E, Brower JV, Rice SR, Buehler DG, Saha S, et al. (2015) Merkel Cell Carcinoma Analysis of Outcomes: A 30-Year Experience. PLoS One 10(6): e0129476.
5. Cornejo C, Miller CJ (2019) Merkel Cell Carcinoma: Updates on Staging and Management. Dermatol Clin 37(3): 269-277.
6. Green MD, Hayman JA (2018) Radiotherapy in the Multidisciplinary Management of Merkel Cell Carcinoma. J Natl Compr Canc Netw 16(6): 776-781.
7. Hong AM, Stretch JR, Thompson JF (2021) Treatment of primary Merkel cell carcinoma: Radiotherapy can be an effective, less morbid alternative to surgery. Eur J Surg Oncol 47(2): 483-485.
8. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2022) Potential Utility of Radiopharmaceuticals in the Battle Against SARSCov- 2 and COVID-19 Pandemic. Curr Radiopharm 15(2): 93-95.
9. Oktay EA, Zerener T, Dırıcan B, Yıldız S, Sager O, et al. (2022) Dosimetric evaluation of the effect of dental restorative materials in head and neck radiotherapy. Indian J Cancer 59(3): 402-407.
10. 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.
11. Gamsiz H, Sager O, Uysal B, Dincoglan F, Demiral S, et al. (2022) Active breathing control guided stereotactic body ablative radiotherapy for management of liver metastases from colorectal cancer. Acta Gastroenterol Belg 85(3): 1-7.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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.
17. 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.
18. 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.
19. 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.
20. 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.
21. 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.
22. 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.
23. 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.
24. 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.
25. 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.
26. Sager O, Dincoglan F, Uysal B, Demiral S, Gamsiz H, et al. (2017) Splenic Irradiation: A Concise Review of Literature. J App Hem Bl Tran 1: 101.
27. 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.
28. 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.
29. 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.
30. 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.
31. 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.
32. 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.
33. 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.
34. 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.
35. 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.
36. Ozsavas EE, Telatar Z, Dirican B, Sager O, Beyzadeoglu M (2014) Automatic segmentation of anatomical structures from CT scans of thorax for RTP. Comput Math Methods Med 2014: 472890.
37. 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.
38. 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.
39. 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.
40. 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.
41. 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.
42. 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.
43. Demiral S, Beyzadeoglu M, Uysal B, Oysul K, Kaha YE, et al. (2013) Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer. Neoplasma 60(3): 322-327.
44. 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.
45. Sager O, Dincoglan 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.
46. 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.
47. 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.
48. 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.
49. 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.
50. Beyzadeoglu M, Dincoglan F, Demiral S, Sager O (2023) An Original Article Revisiting the Utility of Multimodality Imagıng for Refıned Target Volume Determinatıon of Recurrent Kidney Carcinoma.  Canc Therapy & Oncol Int J 23(5): 556122.
51. Beyzadeoglu M, Demiral S, Dincoglan F, Sager O (2022) Assessment of Target Definition for Extramedullary Soft Tissue Plasmacytoma: Use of Multımodalıty Imaging for Improved Targetıng Accuracy. Canc Therapy & Oncol Int J 22(4): 556095.
52. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2022) Target Volume Determination for Recurrent Uterine Carcinosarcoma: An Original Research Article Revisiting the Utility of Multimodality Imaging. Canc Therapy & Oncol Int J 22(3): 556090.
53. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2022) Reappraisal of Computed Tomography (CT) And Magnetic Resonance Imaging (MRI) Based Target Definition for Radiotherapeutic Management of Recurrent Anal Squamous Cell Carcinoma (ASCC): An Original Article. Canc Therapy & Oncol Int J 22(2): 556085.
54. Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2022) An Original Article for Assessment of Multimodality Imaging Based Precise Radiation Therapy (Rt) in the Management of Recurrent Pancreatic Cancers. Canc Therapy & Oncol Int J 22(1): 556078.
55. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2022) Assessment of Target Volume Definition for Precise Radiotherapeutic Management of Locally Recurrent Biliary Tract Cancers: An Original Research Article. Biomed J Sci & Tech Res 46(1): 37054-37059.
56. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2022) Radiation Therapy (RT) Target Volume Determination for Locally Advanced Pyriform Sinus Carcinoma: An Original Research Article Revisiting the Role of Multimodality Imaging. Biomed J Sci & Tech Res 45(1): 36155-36160.
57. 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.
58. 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.
59. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2022) Multimodality imaging-based treatment volume definition for recurrent Rhabdomyosarcomas of the head and neck region: An original article. J Surg Surgical Res 8(2): 013-018.
60. Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2022) Appraisal of Target Definition for Management of Paraspinal Ewing Tumors with Modern Radiation Therapy (RT): An Original Article. Biomed J Sci & Tech Res 44(4): 35691-35696.
61. Beyzadeoglu M, Sager O, Demiral S, Dincoglan F (2022) Assessment of Target Volume Definition for Contemporary Radiotherapeutic Management of Retroperitoneal Sarcoma: An Original Article. Biomed J Sci & Tech Res 44(5): 35883-35887.
62. 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(2): 001-005.
63. 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.
64. 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): 1-5.
65. 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.  
66. 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.
67. 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.
68. 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.
69. 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.
70. 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.
71. 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.
72. 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.
73. 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: 14-21.
74. 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): 1-6.  
75. 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(4): 555917.
76. 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.
77. 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.
78. 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.
79. 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.
80. 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.
81. 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.
82. 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.
83. 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.
84. 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.
85. 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.
86. 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.
87. 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.
88. 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.
89. 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.
90. 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.
91. 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.
92. 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.
93. 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(5): 555848.