Molecular Imaging: Changing the Care Paradigm
Diagnostic imaging modalities utilized in the care of cancer patients must fulfill several requirements: they must diagnose and characterize tumors with a high accuracy, must reliably stage and restage the disease and should allow for monitoring the effects of therapeutic interventions on the course of the disease. Ideally, imaging enables physicians to predict treatment responses before therapies are initiated. They should impact patient management by guiding treating physicians to appropriate, individualized treatment strategies. There is ample evidence that positron emission tomography (PET) and PET/CT imaging meet these requirements.
Several studies have documented that FDG-PET imaging has a substantial impact on patient management. This was reported already in the late 1990s for lung cancer, colorectal cancer, melanoma, breast cancer, lymphoma and others.
The recently published National Oncologic PET Registry (NOPR) data further underscore the important role of glucose metabolic PET imaging for patient management decisions.
Over the last years, the limitations of RECIST (Response Criteria in Solid Tumors) have become increasingly evident. Early response predictions by anatomic imaging are not possible. In contrast, glucose metabolic PET/CT imaging with FDG permits reliable response predictions as early as after a single cycle of chemotherapy. Approaches to standardizing response assessments are now underway and FDG-PET imaging is rapidly emerging as the standard of care for treatment response assessments.
At the same time, cancer phenotyping by PET, together with a variety of novel imaging probes is an emerging new approach to individualizing cancer treatments and for predicting treatment responses before therapy is initiated. Novel imaging probes include tumor proliferation markers such as 18-F-fluorothymidine, fluorinated aminoacid analogues, radiolabeled peptides or antibodies that bind to cell surface receptors and others.
PET/CT imaging is still under-utilized and sometimes not used to its best capabilities. However, there is no doubt that the utilization of PET/CT imaging as a one-stop shop will continue to increase at a high pace.
Clearly, PET/CT imaging has evolved into a routinely available clinical molecular imaging tool that helps to better characterize cancers and that should be used much more frequently to improve the management of cancer patients.
Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology
Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography
David Geffen School of Medicine at UCLA, Los Angeles, Calif.
Several studies have documented that FDG-PET imaging has a substantial impact on patient management. This was reported already in the late 1990s for lung cancer, colorectal cancer, melanoma, breast cancer, lymphoma and others.
The recently published National Oncologic PET Registry (NOPR) data further underscore the important role of glucose metabolic PET imaging for patient management decisions.
Over the last years, the limitations of RECIST (Response Criteria in Solid Tumors) have become increasingly evident. Early response predictions by anatomic imaging are not possible. In contrast, glucose metabolic PET/CT imaging with FDG permits reliable response predictions as early as after a single cycle of chemotherapy. Approaches to standardizing response assessments are now underway and FDG-PET imaging is rapidly emerging as the standard of care for treatment response assessments.
At the same time, cancer phenotyping by PET, together with a variety of novel imaging probes is an emerging new approach to individualizing cancer treatments and for predicting treatment responses before therapy is initiated. Novel imaging probes include tumor proliferation markers such as 18-F-fluorothymidine, fluorinated aminoacid analogues, radiolabeled peptides or antibodies that bind to cell surface receptors and others.
PET/CT imaging is still under-utilized and sometimes not used to its best capabilities. However, there is no doubt that the utilization of PET/CT imaging as a one-stop shop will continue to increase at a high pace.
Clearly, PET/CT imaging has evolved into a routinely available clinical molecular imaging tool that helps to better characterize cancers and that should be used much more frequently to improve the management of cancer patients.
Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology
Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography
David Geffen School of Medicine at UCLA, Los Angeles, Calif.