Review of strategies for MRI based reconstruction of endocavitary and interstitial applicators in brachytherapy of cervical cancer
| Autor: | Ana M. Tornero-López, Jose Perez-Calatayud, T. García-Martínez, A. Herreros, V. Carmona-Meseguer, Jose Richart, Santiago Pellejero Pellejero, A Otal |
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| Rok vydání: | 2018 |
| Předmět: |
Cervical cancer
Contouring medicine.medical_specialty Modality (human–computer interaction) medicine.diagnostic_test Brachytherapy Catheters reconstruction Cervix cancer Magnetic resonance Computer science business.industry medicine.medical_treatment Ultrasound Brachytherapy Special issue paper Magnetic resonance imaging medicine.disease 030218 nuclear medicine & medical imaging 03 medical and health sciences Catheter 0302 clinical medicine Oncology 030220 oncology & carcinogenesis medicine Radiology Nuclear Medicine and imaging Radiology Radiation treatment planning business |
| Zdroj: | REPORTS OF PRACTICAL ONCOLOGY AND RADIOTHERAPY r-IIS La Fe. Repositorio Institucional de Producción Científica del Instituto de Investigación Sanitaria La Fe instname |
| ISSN: | 1507-1367 |
| Popis: | Brachytherapy plays an essential role in the curative intent management of locally advanced cervical cancer. The introduction of the magnetic resonance (MR) as a preferred image modality and the development of new type of applicators with interstitial components have further improved its benefits. The aim of this work is to review the current status of one important aspect in the cervix cancer brachytherapy procedure, namely catheter reconstruction. MR compatible intracavitary and interstitial applicators are described. Considerations about the use of MR imaging (MRI) regarding appropriate strategies for applicator reconstruction, technical requirements, MR sequences, patient preparation and applicator commissioning are included. It is recommendable to perform the reconstruction process in the same image study employed by the physician for contouring, that is, T2 weighted (T2W) sequences. Nevertheless, a clear identification of the source path inside the catheters and the applicators is a challenge when using exclusively T2W sequences. For the intracavitary component of the implant, sometimes the catheters may be filled with some substance that produces a high intensity signal on MRI. However, this strategy is not feasible for plastic tubes or titanium needles, which, moreover, induce magnetic susceptibility artifacts. In these situations, the use of applicator libraries available in the treatment planning system (TPS) is useful, since they not only include accurate geometrical models of the intracavitary applicators, but also recent developments have made possible the implementation of the interstitial component. Another strategy to improve the reconstruction process is based on the incorporation of MR markers, such as small pellets, to be used as anchor points. Many institutions employ computed tomography (CT) as a supporting image modality. The registration of CT and MR image sets should be carefully performed, and its uncertainty previously assessed. Besides, an important research work is being carried out regarding the use of ultrasound and electromagnetic tracking technologies. |
| Databáze: | OpenAIRE |
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