Metastatic tumor deposits in bone marrow elicit differential bone responses that vary with the type of malignancy. This results in either sclerotic, lytic, or mixed bone lesions, which can change... Show moreMetastatic tumor deposits in bone marrow elicit differential bone responses that vary with the type of malignancy. This results in either sclerotic, lytic, or mixed bone lesions, which can change in morphology due to treatment effects and/or secondary bone remodeling. Hence, morphological imaging is regarded unsuitable for response assessment of bone metastases and in the current Response Evaluation Criteria In Solid Tumors 1.1 (RECIST1.1) guideline bone metastases are deemed unmeasurable. Nevertheless, the advent of functional and molecular imaging modalities such as whole-body magnetic resonance imaging (WB-MRI) and positron emission tomography (PET) has improved the ability for follow-up of bone metastases, regardless of their morphology. Both these modalities not only have improved sensitivity for visual detection of bone lesions, but also allow for objective measurements of bone lesion characteristics. WB-MRI provides a global assessment of skeletal metastases and for a one-step "all-organ" approach of metastatic disease. Novel MRI techniques include diffusion-weighted imaging (DWI) targeting highly cellular lesions, dynamic contrast-enhanced MRI (DCE-MRI) for quantitative assessment of bone lesion vascularization, and multiparametric MRI (mpMRI) combining anatomical and functional sequences. Recommendations for a homogenization of MRI image acquisitions and generalizable response criteria have been developed. For PET, many metabolic and molecular radiotracers are available, some targeting tumor characteristics not confined to cancer type (e.g. F-18-FDG) while other targeted radiotracers target specific molecular characteristics, such as prostate specific membrane antigen (PSMA) ligands for prostate cancer. Supporting data on quantitative PET analysis regarding repeatability, reproducibility, and harmonization of PET/CT system performance is available. Bone metastases detected on PET and MRI can be quantitatively assessed using validated methodologies, both on a whole-body and individual lesion basis. Both have the advantage of covering not only bone lesions but visceral and nodal lesions as well. Hybrid imaging, combining PET with MRI, may provide complementary parameters on the morphologic, functional, metabolic and molecular level of bone metastases in one examination. For clinical implementation of measuring bone metastases in response assessment using WB-MRI and PET, current RECIST1.1 guidelines need to be adapted. This review summarizes available data and insights into imaging of bone metastases using MRI and PET. Show less
Groenen, K.H.J.; Bitter, T.; Veluwen, T.C.G. van; Linden, Y.M. van der; Verdonschot, N.; Tanck, E.; Janssen, D. 2018
BACKGROUND: Radiotherapy is an effective treatment for painful bone metastases. Whether this applies also in patients with limited survival remains to be investigated. This study analyzed the... Show moreBACKGROUND: Radiotherapy is an effective treatment for painful bone metastases. Whether this applies also in patients with limited survival remains to be investigated. This study analyzed the effect of radiotherapy for painful bone metastases in patients with a survival <= 12 weeks. METHODS: In the Dutch Bone Metastasis Study, 1157 patients with painful bone metastases were randomized to single fraction (1 x 8 grays [Gy]) or multiple fraction (6 x 4 Gy) radiotherapy. Patients who died within 12 weeks after randomization were included in this analysis. Patients were classified as responders or nonresponders, based on their pain response to radiotherapy. This response was calculated considering changes in pain intensity (measured with an 11-point numeric rating scale) and analgesic usage. Cox proportional hazards models were used to analyze pain response and survival. RESULTS: Two hundred seventy-4 patients were included in this analysis. At randomization, the mean pain intensity score (+/- standard deviation) was 7 (+/- 2). The proportion showing a pain response did not differ between the single fraction and multiple fraction groups. Toward death, pain intensity score decreased to 5 (+/- 3) in responders (45%), whereas in nonresponders (55%) no change was observed. Despite the benefit in responders, in 60% of all patients pain intensity remained 5 after randomization. CONCLUSIONS: Pain responded in about half of the patients who survived <= 12 weeks after randomization into the Dutch Bone Metastasis Study. When considering radiotherapy, single fraction should be preferred. Additional palliative measures remain essential for adequate pain control. Cancer 2010;116:2716-25. (C) 2070 American Cancer Society. Show less
