An Evaluation of Total Internal Motions of Locally Advanced Pancreatic Cancer during SABR Using Calypso<sup>®</sup> Extracranial Tracking, and Its Possible Clinical Impact on Motion Management
(1) Background: the aims of this study were to determine the total extent of pancreatic cancer’s internal motions, using Calypso<sup>®</sup> extracranial tracking, and to indicate possible clinical advantages of continuous intrafractional fiducial-based tumor motion tracking during SABR....
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
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| Series: | Current Oncology |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1718-7729/28/6/389 |
| Summary: | (1) Background: the aims of this study were to determine the total extent of pancreatic cancer’s internal motions, using Calypso<sup>®</sup> extracranial tracking, and to indicate possible clinical advantages of continuous intrafractional fiducial-based tumor motion tracking during SABR. (2) Methods: thirty-four patients were treated with SABR for LAPC using Calypso<sup>®</sup> for motion management. Planning MSCTs in FB and DBH, and 4D-CTs were performed. Using data from Calypso<sup>®</sup> and 4D-CTs, the movements of the lesions in the CC, AP and LR directions, as well as the volumes of the 4D-CT-based ITV and the volumes of the Calypso<sup>®</sup>-based ITV were compared. (3) Results: significantly larger medians of tumor excursions were found with Calypso<sup>®</sup> than with 4D-CT: CC: 29 mm (<i>p</i> < 0.001); AP: 14 mm (<i>p</i> < 0.001) and LR: 11 mm (<i>p</i> < 0.039). The median volume of the Calypso<sup>®</sup>-based ITV was significantly larger than that of the 4D-CT based ITV (<i>p</i> < 0.001). (4) Conclusion: beside known respiratory-induced internal motions, pancreatic cancer seems to have significant additional motions which should be considered during respiratory motion management. Only direct and continuous intrafractional fiducial-based motion tracking seems to provide complete coverage of the target lesion with the prescribed isodose, which could allow for safe tumor dose escalation. |
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| ISSN: | 1198-0052 1718-7729 |