Abstract

Objective: Magnetic Resonance Imaging (MRI), with its superior soft tissue contrast, provides critical supplemental information that enhances target delineation. Particularly in the periportal region, MRI improves the differentiation of lymph nodes from the bile ducts, hepatic vessels, and duodenum-structures that are notoriously difficult to separate on Computed Tomography (CT). This study explores the value of integrating MRI into the radiotherapy planning workflow for stereotactic reirradiation of periportal lymph nodes.
Materials and Methods: Patients with solitary periportal lymph node recurrence, previously treated with radiotherapy were assessed. CT-based simulation was performed with patients immobilized in the supine position using individualized positioning devices. High-resolution axial images were acquired. MRI sequences were also obtained and co-registered to the planning CT dataset. Target definition was initially based on CT images, followed by refinement with MRI input. Treatment planning was conducted using a dedicated radiotherapy planning system, with Stereotactic Body Radiotherapy (SBRT) delivered via LINAC equipped with cone-beam CT for image-guided radiotherapy (IGRT).
Results: MRI integration led to substantial refinements in target definition, particularly in cases involving nodes adjacent to the porta hepatis, bile ducts, or major vasculature. In multiple instances, CT-based contours overestimated the target by including vessels or underrepresented nodal boundaries due to poor soft tissue contrast. MRI-guided contours exhibited more accurate exclusion of non-target structures, resulting in reduced target volume and improved dose gradients.
Conclusion: MRI-enhanced target delineation improves the safety and efficacy of stereotactic reirradiation for periportal lymph node metastases. Further studies are warranted to validate these findings and assess their impact on long-term outcomes.

Keywords:Periportal lymph nodes, SBRT, reirradiation, CT-MRI fusion, target delineation, multimodal imaging

Abbreviations: ACTH: Adrenocorticotropic Hormone; ART: Adaptive Radiotherapy; IGRT: Image-Guided Radiotherapy; IMRT: Intensity-Modulated Radiotherapy

Introduction

Periportal lymph node metastases represent a uniquely challenging target for local therapies due to the dense clustering of critical gastrointestinal and vascular structures in the upper abdomen. As systemic therapies extend survival in patients with advanced malignancies, reirradiation using stereotactic techniques is increasingly being pursued [1-7]. Stereotactic body radiotherapy (SBRT) offers high-dose, image-guided, conformal treatment with potential for long-term local control and minimal toxicity. However, the success of SBRT in periportal locations is highly dependent on the accuracy of target definition.

Traditional Computed Tomography (CT)-based planning often fails to clearly distinguish nodal tissue from adjacent vessels or fibrotic tissues, leading to risks of geographic miss or overtreatment. Magnetic Resonance Imaging (MRI), with its superior soft tissue contrast, provides critical supplemental information that enhances target delineation. Particularly in the periportal region, MRI improves the differentiation of lymph nodes from the bile ducts, hepatic vessels, and duodenum— structures that are notoriously difficult to separate on CT. This study explores the value of integrating MRI into the radiotherapy planning workflow for stereotactic reirradiation in this high-risk anatomical zone.

Materials and Methods

Our study was conducted in the Department of Radiation Oncology at the University of Health Sciences, Gulhane Medical Faculty. Patients with periportal lymph node recurrence, confirmed radiographically or histologically, and previously treated with radiation were studied. All patients were selected for SBRT based on oligometastatic disease status, controlled primary malignancy, and satisfactory performance status (ECOG 0–2). Simulation consisted of contrast-enhanced CT imaging with patients immobilized in the supine position.

MRI was obtained using standard and contrast-enhanced sequences. Image registration was performed to align CT and MRI datasets. Contouring was initially performed using CT images alone and subsequently refined using MRI input by experienced radiation oncologists. SBRT plans were generated using departmental treatment planning systems and delivered via LINAC with cone-beam CT for daily image guidance. Prescription doses aimed for ≥95% coverage while respecting organ-at-risk (OAR) constraints per QUANTEC and AAPM recommendations.

Results

Patients included in this study had periportal lymph node recurrence, confirmed either radiographically or histologically, and had previously undergone radiotherapy. Eligibility for SBRT was based on the presence of oligometastatic disease, a controlled primary tumor, and an ECOG performance status of 0–2. Simulation involved contrast-enhanced CT imaging with patients immobilized in the supine position. MRI, including standard and contrastenhanced sequences, was acquired and co-registered with CT scans for multimodal image alignment. Initial target delineation was performed using CT alone, followed by refinement with MRI guidance by experienced radiation oncologists. SBRT treatment plans were developed using institutional planning software and delivered via a LINAC system with daily image guidance using cone-beam CT.

Dose prescriptions were designed to achieve at least 95% target coverage while adhering to organ-at-risk (OAR) constraints in accordance with QUANTEC and AAPM guidelines. MRI-based refinement significantly impacted target definition in most cases. CT-alone contours commonly overestimated target volume due to inclusion of adjacent hepatic arteries or portal vein segments or underestimated nodal spread obscured by bowel gas or postoperative changes. MRI fusion allowed for precise retraction of contours from non-target tissues and better delineation of true nodal margins. Incorporating MRI data reduced the average target volume and improved dose conformity. MRI-guided plans demonstrated tighter dose falloffs and enhanced treatment plan quality.

Discussion

Periportal lymph node metastases pose a distinct challenge for local therapies due to the proximity of critical gastrointestinal and vascular structures densely clustered in the upper abdomen. With systemic therapies extending survival in patients with advanced cancers, stereotactic reirradiation is increasingly being explored as a viable option for achieving durable local control [1-7]. SBRT enables precise, high-dose, image-guided treatment delivery with the potential for long-term control and acceptable toxicity. However, the success of SBRT in the periportal region relies heavily on accurate target delineation. Conventional CTbased planning often struggles to differentiate lymphatic tissue from adjacent vascular or fibrotic structures, increasing the risk of geographic misses or unnecessary exposure to surrounding organs.

MRI, with its superior soft tissue contrast, provides critical complementary data that enhances target identification. In the periportal region specifically, MRI facilitates improved distinction between lymph nodes and nearby structures such as the bile ducts, hepatic vasculature, and duodenum—anatomical features that are often poorly visualized on CT. Our study evaluated the integration of MRI into the SBRT planning workflow for reirradiation in this anatomically complex and high-risk site. Eligible patients had periportal lymph node recurrence confirmed via imaging or biopsy and had previously received radiotherapy. Selection for SBRT was based on oligometastatic disease status, control of the primary malignancy, and an ECOG performance status of 0–2.

Treatment simulation included contrast-enhanced CT with patients immobilized in the supine position. MRI, acquired with standard and contrast-enhanced sequences, was co-registered with CT to enable multimodal image alignment. Initial target delineation was performed on CT alone and subsequently refined using MRI input by experienced radiation oncologists. SBRT plans were generated using institutional treatment planning systems and delivered on a LINAC platform with daily cone-beam CT guidance. Dose prescriptions aimed to cover at least 95% of the planning target volume while adhering to organ-at-risk (OAR) constraints based on QUANTEC and AAPM guidelines.

MRI-based refinement had a substantial impact on target definition in most cases. CT-alone contours frequently overestimated target volume by inadvertently including portions of the hepatic artery or portal vein or underestimated the extent of nodal disease masked by bowel gas or surgical changes. MRI fusion enabled more accurate exclusion of non-target tissues and clearer delineation of true nodal boundaries. The incorporation of MRI data resulted in reduced target volumes, improved dose conformity, and more favorable dose gradients. MRI-guided planning led to enhanced plan quality, supporting its utility in reirradiation of periportal lymph node metastases. Reirradiation in the periportal region poses a formidable challenge due to the cumulative dose burden and the complexity of surrounding anatomy. Accurate target definition is essential to minimize toxicity and maximize local control.

Our findings underscore the importance of incorporating MRI into SBRT planning, especially in previously irradiated patients, where small deviations in contouring can translate into significant toxicity or treatment failure. These results align with existing literature advocating multimodal imaging in radiotherapy planning for abdominal and pelvic malignancies, including rectal, hepatobiliary, pancreatic cancers and several other disease sites [8-112]. While implementation requires access to high-quality MRI and robust registration workflows, the dosimetric and clinical advantages justify the additional resource investment in high-risk cases. In summary, MRI-enhanced target delineation improves the safety and efficacy of stereotactic reirradiation for periportal lymph node metastases. Further studies are warranted to validate these findings and assess their impact on long-term outcomes.

References

1. Mantel F, Flentje M, Guckenberger M (2013) Stereotactic body radiation therapy in the re-irradiation situation--a review. Radiat Oncol 8: 7.
2. Yeung R, Hamm J, Liu M, Schellenberg D (2017) Institutional analysis of stereotactic body radiotherapy (SBRT) for oligometastatic lymph node metastases. Radiat Oncol 12(1): 105.
3. Høyer M (2017) Re-irradiation with stereotactic body radiation therapy (SBRT). Chin Clin Oncol 6(Suppl 2): S15.
4. Weichselbaum RR, Hellman S (2011) Oligometastases revisited. Nat Rev Clin Oncol 8(6): 378-382.
5. Burkon P, Selingerova I, Slavik M, Pospisil P, Bobek L, et al. (2021) Stereotactic Body Radiotherapy for Lymph Node Oligometastases: Real-World Evidence From 90 Consecutive Patients. Front Oncol 10: 616494.
6. Mohamed Yoosuf AB, Ajmal Khan M, Abdul Aziz MZ, Mansor S, Appalanaido GK, et al. (2023) Re-irradiation Using Stereotactic Radiotherapy: A Bibliometric Analysis of Research Trends. Cureus 15(5): e39600.
7. Mohamed Yoosuf AB, Alshehri S, Abdul Aziz MZ, Mansor S, Appalanaido GK, Alqathami M (2023) Effectiveness of Robotic Stereotactic Radiotherapy in Patients Undergoing Re-irradiation: A Review. Cureus 15(8): e43500.
8. Sager O, Dincoglan F, Demiral S, Uysal B, Gamsiz H, et al. (2023) Adaptive radiation therapy (art) for patients with limited-stage small cell lung cancer (LS-SCLC): A dosimetric evaluation. Indian J Cancer 60(1):140-147.
9. Gamsiz H, Sager O, Uysal B, Dincoglan F, Demiral S, et al. (2023) Outcomes of Sterotactic Body Radiotherapy (SBRT) for pelvic lymph node recurrences after adjuvant or primary radiotherapy for prostate cancer. J Cancer Res Ther 19(Suppl 2): S851-S856.
10. 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): 469-475.
11. 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.
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: 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: 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: 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: 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: 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: 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: 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: 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 the 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: 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. Ozsavaş 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(2): 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, Kahya 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(3): 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. 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.
51. 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.
52. 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, Article ID 4282754.
53. 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.
54. 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.
55. 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.
56. 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.
57. 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(2): 555909.
58. 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.
59. 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.
60. 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.
61. 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.
62. 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.
63. 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.
64. 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.
65. 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.
66. 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.
67. 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.
68. 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(1): 2398-2404.
69. 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.
70. 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.
71. 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.
72. 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(2): 20543-20547.
73. 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.
74. 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.
75. 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.
76. 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.   
77. 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.
78. 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.
79. 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.
80. 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.
81. 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.  
82. 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.
83. 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.
84. 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.
85. 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.  
86. 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.
87. 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.
88. 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.
89. 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: 004-008.
90. 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.
91. 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.
92. 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.
93. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2023) Appraisal of Target Definition for Anaplastic Thyroid Carcinoma (ATC): An Original Article Addressing the Utility of Multimodality Imaging. Canc Therapy & Oncol Int J 24(4): 556143.
94. Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2023) Reappraisal of Treatment Volume Determination for Parametrial Boosting in Patients with Locally Advanced Cervical Cancer. Canc Therapy & Oncol Int J 24(5): 556148.
95. Demiral S, Sager O, Dincoglan F, Beyzadeoglu M (2023) Tumor Size Changes after Neoadjuvant Systemic Therapy for Advanced Oropharyngeal Squamous Cell Carcinoma. Canc Therapy & Oncol Int J 24(5): 556147.
96. Demiral S, Dincoglan F, Sager O, Beyzadeoglu M (2023) Assessment of Changes in Tumor Volume Following Chemotherapy for Nodular Sclerosıng Hodgkin Lymphoma (NSHL). Canc Therapy & Oncol Int J 24(5): 556146.
97. Sager O, Demiral S, Dincoglan F, Beyzadeoglu M (2023) Evaluation of Volumetric Changes in Transglottic Laryngeal Cancers After Induction Chemotherapy. Biomed J Sci & Tech Res 51(4): 43026-43031.
98. Dincoglan F, Sager O, Demiral S, Beyzadeoglu M (2023) An Original Research Article for Evaluation of Changes in Tumor Size After Neoadjuvant Chemotherapy in Borderline Resectable Pancreatic Ductal Adenocarcinoma. Biomed J Sci & Tech Res 52(1): 43253-43255.
99. Sager O, Dincoglan F, Demiral S, Beyzadeoglu M (2023) Assessment of Tumor Size Changes After Neoadjuvant Chemotherapy in Locally Advanced Esophageal Cancer: An Original Article. Biomed J Sci & Tech Res 52(2): 43491-43493.
100. Beyzadeoglu M, Demiral S, Dincoglan F, Sager O (2023) Evaluation of Target Definition for Radiotherapeutic Management of Recurrent Merkel Cell Carcinoma (MCC). Canc Therapy & Oncol Int J 24(2): 556133.
101. Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2023) Reappraisal of Treatment Volume Determination for Recurrent Gastroesophageal Junction Carcinoma (GJC). Biomed J Sci & Tech Res 50 (5): 42061-42066.
102. 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.
103. Beyzadeoglu M, Demiral S, Dincoglan F, Sager O (2023) Appraisal of Target Definition for Recurrent Cancers of the Supralottic Larynx. Biomed J Sci & Tech Res 50(5): 42131-42136.
104. Beyzadeoglu M, Demiral S, Dincoglan F, Sager O (2024) Reappraisal of Target Definition for Sacrococcygeal Chordoma: Comparative Assessment with Computed Tomography (CT) and Magnetic Resonance Imaging (MRI. Biomed J Sci & Tech Res 55(1): 46686-46692.
105. Dincoglan F, Demiral S, Sager O, Beyzadeoglu M (2024) Assessment of Changes in Tumor Size After Induction Systemic Therapy for Locally Advanced Cervical Squamous Cell Carcinoma Running title: Tumor size changes in cervical carcinoma. Cancer Ther Oncol Int J 26(1): 001-007.
106. Dincoglan F, Beyzadeoglu M, Demiral S, Sager O (2024) Appraisal of Changes in Tumor Volume After Neoadjuvant Systemic Therapy for Hepatocellular Carcinoma (HCC). Cancer Ther Oncol Int J 26(2): 001-004.
107. Akin M, Duzova M (2022) Single fraction image guided radiation therapy for management of bone metastases during the COVID-19 pandemic. Journal of Health Sciences and Medicine 5(4): 961-965.
108. Cinar D, Karadakovan A, Akin M (2022). Effects of Paper Marbling Art in the Cancer Rehabilitation Process: Descriptive Research. Journal of Traditional Medical Complementary Therapies 5: 132-142.
109. Akin M, Duzova M (2022) Evaluatin of Treatment Volume Determination for Anaplastic Oligodendrogliomas Based on Multimodality Imaging: An Original Article. Celal Bayar Universitesi Saglik Bilimleri Enstitusu Dergisi 9(3): 414-417.
110. Cinkaya A, Akin M, Sengul A (2016) Evaluation of treatment outcomes of triple negative breast cancer. Journal of Cancer Research and Therapeutics 12(1): 150-154.
111. Duzova M, Akin M (2022) Evaluation of survival outcomes and prognostic factors in acinic cell carcinomas of the parotid gland receiving adjuvant radiotherapy. Anatolian Current Medical Journal 4(3): 290-294.
112. Akin M (2022) Tobacco and lung cancer in elderly patients located in southern marmara: epidemiological study. Celal Bayar Universitesi Saglik Bilimleri Enstitusu Dergisi 9(2): 310-313.