
==== Front
Clin Transl Radiat Oncol
Clin Transl Radiat Oncol
Clinical and Translational Radiation Oncology
2405-6308
Elsevier

S2405-6308(24)00116-2
10.1016/j.ctro.2024.100839
100839
Correspondence
In response to Chuong et al.
Grimbergen Guus g.grimbergen@umcutrecht.nl
⁎
Intven Martijn P.W.
Meijer Gert J.
Department of Radiation Oncology, University Medical Center Utrecht, the Netherlands
⁎ Corresponding author at: Department of Radiation Oncology, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, the Netherlands. g.grimbergen@umcutrecht.nl
20 8 2024
9 2024
20 8 2024
48 1008398 8 2024
12 8 2024
© 2024 The Author(s)
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
==== Body
pmcTo the Editor,

We thank Dr. Chuong and colleagues for their interest in our recent work “Treatment planning for MR-guided SBRT of pancreatic tumors on a 1.5 T MR-Linac: a global consensus protocol” [1]. In their letter, the authors recommend the inclusion of a clinical target volume (CTV) in treatment planning for MR-guided SBRT for locally advanced pancreatic cancer (LAPC), thereby targeting not just the macroscopic disease but also nearby perineural or lymphatic areas highly suspect for microscopic involvement.

The concept of elective irradiation to address potential occult disease is indeed compelling, but it is evident that this is still a controversial practice. There is at present limited evidence from prospective studies demonstrating that a CTV results in improved clinical outcomes. Current literature is largely retrospective, and significant variation exists in CTV definition, patient selection, and the appropriate dose to the elective regions [2], [3], [4], [5], [6].

The main objective of our consensus study was standardization and dosimetric harmonization across multiple centers. The focus within our consortium was on the gross tumor volume (GTV) and most important organs at risk. This approach also aligns with current guidelines, which do not recommend elective nodal irradiation for pancreatic cancer SBRT [7], [8].

We appreciate the dialogue initiated by Dr. Chuong and colleagues, and agree that a collaborative effort towards standardization of CTV definition and dose prescription could be a future endeavor. This could pave the way for solid, prospective clinical evidence demonstrating the benefits of CTV inclusion.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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References

1 Grimbergen G. Eijkelenkamp H. Snoeren L.M.W. Bahij R. Bernchou U. van der Bijl E. Treatment planning for MR-guided SBRT of pancreatic tumors on a 1.5 T MR-Linac: A global consensus protocol Clin Transl Radiat Oncol 47: 100797 2024 10.1016/j.ctro.2024.100797
2 Kharofa J. Mierzwa M. Olowokure O. Sussman J. Latif T. Gupta A. Pattern of marginal local failure in a phase II trial of neoadjuvant chemotherapy and stereotactic body radiation therapy for resectable and borderline resectable pancreas cancer Am J Clin Oncol 42 3 2019 247 252 10.1097/COC.0000000000000518 30724781
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6 Chuong M.D. McAllister N. Carvallo N. Chundru S. Herrera R. Kaiser A. Patterns of locoregional failure after ablative 5-fraction stereotactic MR-guided on-table adaptive radiation therapy for pancreatic cancer Int J Radiat Oncol Biol Phys 117 2 2023 S14 S15 10.1016/j.ijrobp.2023.06.231
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8 Brunner T.B. Haustermans K. Huguet F. Morganti A.G. Mukherjee S. Belka C. ESTRO ACROP guidelines for target volume definition in pancreatic cancer Radiother Oncol 154 2021 60 69 10.1016/j.radonc.2020.07.052 32861703
