Multi-technique imaging of bone metastases: spotlight on PET-CT

There is growing evidence that molecular imaging of bone metastases with positron-emission tomography (PET) can improve diagnosis and treatment response assessment over current conventional standard imaging methods, although cost-effectiveness has not been assessed. In most cancer types, 2-[F-18]-fluoro-2-deoxy-p-glucose (F-18-FDG)-PET is an accurate method for detecting bone metastases. For example, in breast cancer, combined F-18-FDG-PET and computed tomography (CT) is more sensitive at detecting bone metastases than (99m)technetium (Tc)-labelled diphosphonate planar bone scintigraphy (BS) and there is increasing evidence to support the use of serial F-18-FDG-PET for the assessment of osseous response to treatment. Preliminary data suggest improved diagnostic accuracy of F-18-FDG-PET-CT in a number of other malignancies including lung, thyroid, head and neck, gastro-oesophageal cancers, and osteosarcoma. As a bone-specific tracer, there is accumulating evidence to support the use of sodium F-18-fluoride (F-18-NaF) PET-CT in the diagnosis of skeletal metastases in breast and prostate cancer, although relatively little data are available to support its use for assessment of treatment response. In prostate cancer, C-11-choline and F-18-choline PET-CT have better specificities than F-18-NaF-PET-CT, but equivalent sensitivities in the detection of bone metastases. We review the current literature for staging and response assessment of bone metastases in different cancers. (C) 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.