|
1
|
Borm KJ, Oechsner M, Wiegandt M, Hofmeister A, Combs SE, Duma MN. Moving targets in 4D-CTs versus MIP and AIP: comparison of patients data to phantom data. BMC Cancer 2018; 18:760. [PMID: 30041618 PMCID: PMC6056919 DOI: 10.1186/s12885-018-4647-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/28/2018] [Indexed: 11/23/2022] Open
Abstract
Purpose Maximum (MIP) and average intensity projection (AIP) CTs allow rapid definition of internal target volumes in a 4D-CT. The purpose of this study was to assess the accuracy of these techniques in a large patient cohort in combination with simulations on a lung phantom. Methods 4DCT data from a self-developed 3D lung phantom and from 50 patients with lung tumors were analyzed. ITVs were contoured in maximum (ITVMIP) and average intensity projection (ITVAIP) and subsequently compared to ITVs contoured in 10 phases of a 4D-CT (ITV10). In the phantom study additionally a theoretical target volume was calculated for each motion and compared to the contoured volumes. Results ITV10 overestimated the actual target volume by 9.5% whereas ITVMIP and ITVAIP lead to an underestimation of − 1.8% and − 11.4% in the phantom study. The ITVMIP (ITVAIP) was in average − 10.0% (− 18.7%) smaller compared to the ITV10. In the patient CTs deviations between ITV10 and MIP/AIP were significantly larger (MIP: – 20.2% AIP: -33.7%) compared to this. Tumors adjacent to the chestwall, the mediastinum or the diaphragm showed lower conformity between ITV10 and ITVMIP (ITVAIP) compared to tumors solely surrounded by lung tissue. Large tumor diameters (> 3.5 cm) and large motion amplitudes (> 1 cm) were associated with lower conformity between intensity projection CTs and ITV10−. Conclusion The application of MIP and AIP in the clinical practice should not be a standard procedure for every patient, since relevant underestimation of tumor volumes may occur. This is especially true if the tumor borders the mediastinum, the chest wall or the diaphragm and if tumors show a large motion amplitude.
Collapse
Affiliation(s)
- Kai Joachim Borm
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Markus Oechsner
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Moritz Wiegandt
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany.,Medical School Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Andreas Hofmeister
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany.,Medical School Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany.,Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany
| | - Marciana Nona Duma
- Department of Radiation Oncology, Klinikum rechts der Isar, TU München, Ismaninger Str. 22, 81675, Munich, Germany. .,Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany.
| |
Collapse
|
|
2
|
Borm K, Wiegandt M, Hofmeister A, Oechsner M, Combs S, Duma M. EP-2138: Contouring of moving targets in maximum and average intensity projection. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32447-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|