MRI and PET Used with Solid Tumor Response Evaluation Criteria to Track Treatment in Bone Metastases

Imaging technologies are very useful in evaluating a patient’s response to cancer treatment, and this can be done quite effectively for most tumors using solid tumor response evaluation criteria.

RECIST (Response Evaluation Criteria in Solid Tumors), however, works well for tumors located in soft tissue, but not so well for cancers that spread to the bone, such as is the case for prostate and breast cancers. More effort, therefore, is needed to improve the determination of how to monitor the response of bone metastases to treatment using magnetic resonance imaging (MRI) and positron emission tomography (PET). A recent European Organization for Research and Treatment of Cancer (EORTC; Brussels, Belgium) Imaging Group review and position statement published online August 16, 2014, in the European Journal of Cancer addresses the situation.

The article published by these EORTC Imaging Group investigators emphasized the most recent developments in MRI and PET and elucidates how these techniques can be used to identify bone metastases at an early stage as well as monitor the response of these to treatments. They described the current state of the art in PET and MRI, the strengths, weaknesses and complementarity of various imaging techniques with respect to specific indications, and recommendations for choosing the most appropriate imaging technique.

Prof. Frederic Lecouvet, from the Cliniques Universitaires Saint Luc (Brussels, Belgium), and lead author of this review and position statement, said, “Assessing the response of metastases to treatment is something we do on a day to day basis, both in our oncology practice as well as for clinical trials. If the metastases occur in soft tissues, then we already have validated criteria, such as RECIST, that enable us to evaluate the response. A host of problems, however, limits our ability to measure the response to treatment of metastases found in bone. These range from the characteristics of bone metastatic disease, the structure of bone itself, to the sensitivity, specificity, and resolution of imaging methods available until now. We hope to resolve these issues, and our review is a step in the right direction.”

Techniques such as MRI and PET have the potential to detect the metastasizing of a cancer into the bone marrow at an earlier stage and also determine the extent of this spread, and the efforts of the EORTC researchers should help towards making these techniques a routine part of oncology practice.

Related Links:
European Organization for Research and Treatment of Cancer
Cliniques Universitaires Saint Luc