Dosimetric performance of cone beam CT-guided adaptive carbon-ion radiotherapy with daily replanning for pancreatic cancer
Purpose - We investigated whether an ultra-hypofractionated carbon-ion radiotherapy (CIRT) protocol for pancreatic cancer (PC) could produce satisfactory dosimetric results with or without cone-beam CT-guided adaptive replanning and explored the potential dosimetric advantages of the adapted protoco...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 May 2025
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| In: |
Physica medica
Year: 2025, Volume: 134, Pages: 1-7 |
| ISSN: | 1724-191X |
| DOI: | 10.1016/j.ejmp.2025.104991 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1016/j.ejmp.2025.104991 Verlag, kostenfrei, Volltext: https://www.sciencedirect.com/science/article/pii/S1120179725001012 
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| Author Notes: | Lukas Fabrizio Klassen, Hideaki Hirashima, Hiraku Iramina, Takahiro Iwai, Michio Yoshimura, Hiroki Tanaka, Takashi Mizowaki, Mitsuhiro Nakamura |
| Summary: | Purpose - We investigated whether an ultra-hypofractionated carbon-ion radiotherapy (CIRT) protocol for pancreatic cancer (PC) could produce satisfactory dosimetric results with or without cone-beam CT-guided adaptive replanning and explored the potential dosimetric advantages of the adapted protocol. - Methods - Eleven PC patients who underwent CBCT-guided online adaptive photon radiotherapy were selected. Data were imported into a CIRT treatment planning software to develop new plans for an ultra-hypofractionated CIRT protocol. Prescriptions and constraints were recalculated for a five-fraction schedule using a linear quadratic model for organs-at-risk (OARs) and targets, respectively. The biologically effective dose-equivalent prescribed dose was set at 43.2 Gy (relative biological effectiveness [RBE]). Each day, a synthetic CT (SCT) was generated from the planning CT (PCT) with the daily CBCT. A reference plan based on the PCT was compared to an adapted plan based on the SCT. Deformable image registration was used to allow summation of the daily doses. - Results - The adapted plans met the clinical goals, whereas the reference plans exceeded the constraints in 27 % (stomach), 53 % (duodenum), and 31 % (small bowel) of the fractions. The adapted plans notably decreased V35.5 Gy[RBE] for all gastrointestinal OARs, while significantly enhancing the gross tumor volume (GTV) D95% and planning target volume (PTV) D90%. The accumulated doses showed significant improvements in the duodenum V35.5 Gy[RBE], GTV D95%, and PTV D90%. - Conclusion - CBCT-guided adaptive CIRT for PC demonstrated favorable dosimetric results, notably enhancing the sparing of OARs and ensuring superior target coverage compared with non-adaptive CIRT protocols. |
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| Item Description: | Gesehen am 28.10.2025 |
| Physical Description: | Online Resource |
| ISSN: | 1724-191X |
| DOI: | 10.1016/j.ejmp.2025.104991 |