*Source: Rasch et al. IJROBP 1999;43:57-66
Image courtesy: Radiologische Allianz, Hamburg, Germany
State-of-the-art radiation therapy allows to target dose to a tumor and spare out tissues at risk. This requires excellent image information for therapy planning. Currently, CT is used for RT planning in 90%** of all procedures.
CT provides:
Utilization of MRI in RT planning is a rapidly evolving field. This is due to the fact that MRI’s excellent, soft-tissue contrast, precise information on the tumor extent and information about tumor activity can add substantial clinical value to the therapy process.
From 2006 to 2012, the proportion of treatment plans using MR images has increased from:
MRI provides excellent soft-tissue contrast to clearly depict the margins of the prostate, intra-prostatic structures, and surrounding tissues.
Combined with CT, the strengths of both modalities can be unleashed and a new level of confidence in RT can be entered.
Excellent soft-tissue contrast with T2-weighted imaging
Valuable information about tissue cellularity with diffusion-weighted imaging
Valuable knowledge about metabolic tumor activity with MR spectroscopy
MRI provides great accuracy in defining target structures and helps to spare out organs at risk during treatment.
CT*
MRI
MRIs excellent soft-tissue contrast allows to clearly depict the margins of the prostate, intraprostatic structures, and surrounding tissues. Therefore, extra margins to be added to account for delineation uncertainties may be reduced, less normal tissue is irradiated, thus reducing treatment toxicity. Greer P et al. Med J Aust 2011;194:24.
Furthermore, it has been shown that MRI is useful to predict regions of local recurrence in patients with prostate cancer. Fuchsjäger MH, IJROBP 2010;78:743-50
MRI can be used to select these regions [intraprostatic lesions] for dose escalation without increasing the severity or incidence of acute toxicity. Fonteyne et al, IJROBP 2008; 72 : 799–807
SOMATOM RT Pro edition
MAGNETOM RT Pro edition
Dose calculation and treatment delivery*