PET CT guidelines in RTP
EANM-ESTRO Guidelines for the use of PET-CT in radiotherapy planning*
Vincent Gregoire1, MD, PhD, FRCR and Arturo Chiti 2, MD, FEBNM
The clinical use of PET-CT is now a reality. While 10 years ago we were still wondering if molecular imaging with positron emission radiopharmaceuticals would have ever been a reality, nowadays we can affirm that imaging without PET would not be as effective as it is in many fields.
Fluoro-deoxy-glucose (FDG) PET is assessed as an accurate tool to monitor viability of cancer. There is now evidence that in many tumors PET is useful for diagnosis, staging, detection of relapse, restaging and follow-up. In the last years, the most interesting applications ended up to be the assessment of therapy response and the radiation treatment planning. Key factors for this achievements can be linked to the great advances in the technology of radiopharmaceutical synthesis, scanners, imaging management and accelerators. Thanks to these factors, molecular imaging is now able to improve tailoring of therapy by guiding radiation therapy planning and improving definition of tumor target volumes. If CT still stands as the gold standard for target volume definition and dose calculation, PET-CT is of help in dose constraining with potential sparing of organs at risk.
Radiotherapy planning using molecular imaging is a multiple step process which involves different medical specialists, but also physicists, technologists and radio-pharmacists. Physicians meets in multidisciplinary tumor boards, in order to help the Radiation Oncologist to prescribe a treatment plan comprising a dose prescription, a set of dose distribution together with a set of technical parameters that will be transferred to the accelerator for the execution of the therapy plan.
PET radiopharmaceuticals are used as probes for specific metabolic pathways: i.e. hexokinase activity, apoptosis, hypoxia, etc. In this view, different radiopharmaceuticals can be used to specifically localize different tumor entities. The use of molecular imaging in the definition of radiation treatment target is an example of personalized treatment, as the radiation dose is shaped on the tumor of each single patient. The advantage of functional imaging with PET is related to the possibility of further increasing the accuracy of target delineation including only metabolically active tissue. Using different radiopharmaceuticals for different tumors further increases the accuracy of the treatment.
We hope that this first structured contribution on the use of PET-CT in radiation treatment planning will help physicians to improve their knowledge in this fast growing field, with the ultimate goal of providing a better care for their patients.
GE Healthcare has provided an unrestricted educational grant to EANM and ESTRO to support development and publication of European guidelines on the use of PET in radiotherapy planning.
As such, GE Healthcare is delighted to offer you a complimentary copy of these guidelines, and hope that these guidelines aid continued improvement in patient care. Click here to order it.
You can also download the Abstracts and Conclusions of these Guidelines here.
1 Radiation Oncology Department and Laboratory of Molecular Imaging and Experimental Radiotherapy, Université Catholique de Louvain and St-Luc University Hospital, Brussels, Belgium.
2 Nuclear Medicine Department, IRCCS Humanitas, Milan, Italy
*These claims have not been reviewed by FDA. Not for use in USA.