Tomotherapy

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Tomotherapy Hi Art

As TomoTherapy one will radiate therapeutic method called, as in the similar in a diagnostic CT scanner , the beams can be directed from all sides to be irradiated site of the patient. For this purpose, the radiation source rotates in a corresponding ring (see figure). A small linear accelerator with an energy of 6 MeV is used as the radiation source .

Precision in the alignment of the radiation is achieved by creating a series of CT images from the linear accelerator before each treatment with low-dose radiation or by using a computer tomograph combined with the tomotherapy device to check the exact positioning of the tumor to be irradiated (so-called image -guided radiotherapy IGRT).

The strip-shaped radiation field of the linear accelerator is divided into 64 rectangular individual fields by a multileaf collimator consisting of 64 separately controllable shutters. At the same time, every rotation of the system is computationally divided into 51 irradiation directions, each with a 7 ° difference. Each individual therapy session consists of tens of thousands of individual fields (so-called beamlets ) that are individually modulated (varied in strength). This enables particularly complicated dose distributions that are optimally adapted to the target volumes, similar to the older intensity-modulated radiotherapy IMRT. Tomotherapy can easily treat concave target volumes and any number of targets in the same session.

The side effects often associated with the irradiation of tumor patients should thereby be reduced.

The treatment method was first used clinically in 2003. It is based on developments at the University of Wisconsin (USA). Manufacturers are, for example, the US companies Accuray Inc. and Varian . Around 300 devices are in use worldwide, including 11 in Germany and 3 in Switzerland (as of 2011).

The main areas of application for tomotherapy are malignant neoplasms such as prostate cancer , lung cancer , breast cancer and head and neck cancer .

Individual evidence

  1. ↑ WA Tomé, HA Jaradat, IA Nelson, MA Ritter, MP Mehta: Helical tomotherapy: image guidance and adaptive dose guidance. In: Frontiers of radiation therapy and oncology Volume 40, 2007, pp. 162-178, ISSN  0071-9676 . doi: 10.1159 / 000106034 . PMID 17641508 . (Review).
  2. ↑ M. Tomsej: [The TomoTherapy Hi.Art System for sophisticated IMRT and IGRT with helical delivery: Recent developments and clinical applications]. In: Cancer Radiotherapy Volume 10, Number 5, September 2006, pp. 288-295, ISSN  1278-3218 . doi: 10.1016 / j.canrad.2006.07.006 . PMID 16935540 .
  3. ↑ JS Welsh, M. Lock, PM Harari, WA Tomé, J. Fowler, TR Mackie, M. Ritter, J. Kapatoes, L. Forrest, R. Chappell, B. Paliwal, MP Mehta: Clinical implementation of adaptive helical tomotherapy : a unique approach to image-guided intensity modulated radiotherapy. In: Technology in cancer research & treatment Volume 5, Number 5, October 2006, pp. 465-479, ISSN  1533-0346 . PMID 16981789 . (Review).

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