Evaluation of sequential FDG-PET/CT for monitoring bone metastasis of breast cancer during therapy: correlation between morphological and metabolic changes with tumor markers

Review of imaging techniques for evaluating morphological and functional responses to the treatment of bone metastases in prostate and breast cancer

Bone metastases are very common complications associated with certain types of cancers that frequently negatively impact the quality of life and functional status of patients; thus, early detection is necessary for the implementation of immediate therapeutic measures to reduce the risk of skeletal complications and improve survival and quality of life. There is no consensus or universal standard approach for the detection of bone metastases in cancer patients based on imaging. Endorsed by the Spanish Society of Medical Oncology (SEOM), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM) a group of experts met to discuss and provide an up-to-date review of our current understanding of the biological mechanisms through which tumors spread to the bone and describe the imaging methods available to diagnose bone metastasis and monitor their response to oncological treatment, focusing on patients with breast and prostate cancer. According to current available data, the use of next-generation imaging techniques, including whole-body diffusion-weighted MRI, PET/CT, and PET/MRI with novel radiopharmaceuticals, is recommended instead of the classical combination of CT and bone scan in detection, staging and response assessment of bone metastases from prostate and breast cancer.Clinical trial registration: Not applicable.

Prediction of therapy response in bone-predominant metastatic breast cancer: comparison of [18F] fluorodeoxyglucose and [18F]-fluoride PET/CT with whole-body MRI with diffusion-weighted imaging

PURPOSE

To compare [18F]-fluorodeoxyglucose (FDG) and [18F]-sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) with whole-body magnetic resonance with diffusion-weighted imaging (WB-MRI), for endocrine therapy response prediction at 8 weeks in bone-predominant metastatic breast cancer.

PATIENTS AND METHODS

Thirty-one patients scheduled for endocrine therapy had up to five bone metastases measured [FDG, NaF PET/CT: maximum standardized uptake value (SUVmax); WB-MRI: median apparent diffusion coefficient (ADCmed)] at baseline and 8 weeks. To detect the flare phenomenon, a 12-week NaF PET/CT was also performed if 8-week SUVmax increased. A 25% parameter change differentiated imaging progressive disease (PD) from non-PD and was compared to a 24-week clinical reference standard and progression-free survival (PFS).

RESULTS

Twenty-two patients (median age, 58.6 years, range, 40-79 years) completing baseline and 8-week imaging were included in the final analysis. Per-patient % change in NaF SUVmax predicted 24-week clinical PD with sensitivity, specificity and accuracy of 60, 73.3, and 70%, respectively. For FDG SUVmax the results were 0, 100, and 76.2% and for ADCmed, 0, 100 and 72.2%, respectively. PFS < 24 weeks was associated with % change in SUVmax (NaF: 41.7 vs. 0.7%, p = 0.039; FDG: - 4.8 vs. - 28.6%, p = 0.005) but not ADCmed (- 0.5 vs. 10.1%, p = 0.098). Interlesional response heterogeneity occurred in all modalities and NaF flare occurred in seven patients.

CONCLUSIONS

FDG PET/CT and WB-MRI best predicted clinical non-PD and both FDG and NaF PET/CT predicted PFS < 24 weeks. Lesional response heterogeneity occurs with all modalities and flare is common with NaF PET/CT.

Functional and Hybrid Imaging of Bone Metastases

Bone metastases are common, cause significant morbidity, and impact on healthcare resources. Although radiography, computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy have frequently been used for staging the skeleton, these methods are insensitive and nonspecific for monitoring treatment response in a clinically relevant time frame. We summarize several recent reports on new functional and hybrid imaging methods including single photon emission CT/CT, positron emission tomography/CT, and whole-body MRI with diffusion-weighted imaging. These modalities generally show improvements in diagnostic accuracy for staging and response assessment over standard imaging methods, with the ability to quantify biological processes related to the bone microenvironment as well as tumor cells. As some of these methods are now being adopted into routine clinical practice and clinical trials, further evaluation with comparative studies is required to guide optimal and cost-effective clinical management of patients with skeletal metastases. © 2018 American Society for Bone and Mineral Research.

SEOM Clinical Guideline for bone metastases from solid tumours (2016)

Bone metastases are common in many advanced solid tumours, being breast, prostate, thyroid, lung, and renal cancer the most prevalent. Bone metastases can produce skeletal-related events (SREs), defined as pathological fracture, spinal cord compression, need of bone irradiation or need of bone surgery, and hypercalcaemia. Patients with bone metastases experience pain, functional impairment and have a negative impact on their quality of life. Several imaging techniques are available for diagnosis of this disease. Bone-targeted therapies include zoledronic acid, a potent biphosfonate, and denosumab, an anti-RANKL monoclonal antibody. Both reduce the risk and/or delay the development of SREs in several types of tumours. Radium 233, an alpha-particle emitter, increases overall survival in patients with bone metastases from resistant castration prostate cancer. Multidisciplinary approach is essential and bone surgery and radiotherapy should be integrated in the treatment of bone metastases when necessary. This SEOM Guideline reviews bone metastases pathogenesis, clinical presentations, lab tests, imaging techniques for diagnosis and response assessment, bone-targeted agents, and local therapies, as radiation and surgery, and establishes recommendations for the management of patients with metastases to bone.

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-[(18)F]-fluoro-2-deoxy-d-glucose ((18)F-FDG)-PET is an accurate method for detecting bone metastases. For example, in breast cancer, combined (18)F-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 (18)F-FDG-PET for the assessment of osseous response to treatment. Preliminary data suggest improved diagnostic accuracy of (18)F-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 (18)F-fluoride ((18)F-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, (11)C-choline and (18)F-choline PET-CT have better specificities than (18)F-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.

Effectiveness of 18F-FDG-PET/CT vs Bone Scintigraphy in Treatment Response Assessment of Bone Metastases in Breast Cancer

The aim of the study was to examine the effectiveness of fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) versus bone scintigraphy (BS) in treatment response assessment of bone metastases in breast cancer.The medical records of breast cancer patients with metastatic bone disease were reviewed retrospectively in our hospital from the period of January 2003 until April 2014. We included in our study patients evaluated by BS and/or 18F-FDG-PET/CT. Group 1 included patients who underwent pre- and post-treatment BS. Group 2 included patients who underwent pre- and post-treatment 18F-FDG-PET/CT scans. Group 3 included patients who underwent pretreatment BS and post-treatment both modalities. Functional and structural bone changes were monitored on pre- and post-treatment scans.Group 1 included 71 patients, average age of 49.5 y (range 28-73 y). Post-treatment results were as follows: 34% stable disease, 43% progressed disease, 19% improved disease, 3% resolved disease, and 2% relapsed disease. Group 2 included 32 patients, average age 53.2 y (ranges between 37 and 78 y). Post-treatment results were as follows: 3% stable disease, 15% progressed disease, 15% improved disease, 53% resolved disease, and 14% relapsed disease. After treatment, the total symptomatic/imaging concordance rate was 51% in BS and 83% in 18F-FDG-PET/CT. Structurally, most patients with newly diagnosed metastatic bone disease had predominantly osteolytic lesions, which became mixed or osteoblastic after treatment as noted on CT images of responders. Group 3 included 8 patients, average age 48.9 y (ranges 32-64 y). Five patients had stable disease according to BS. 18F-FDG-PET/CT was concordant in 3/5 patients and discordant in 2/5 patients. Three patients had progressed disease on BS with concordant findings on 18F-FDG-PET/CT.18F-FDG-PET/CT was found a powerful tool in treatment response assessment of bone metastases in breast cancer and consistent with clinical status of the patients as it reflects tumor activity. BS is insufficient for response assessment of bone metastases as it reflects osteoblastic reaction of the bone against metastatic disease which increases as the disease responds to treatment.

Application of positron emission tomography (PET/CT) in diagnosis of breast cancer. Part I. Diagnosis of breast cancer prior to treatment

Positron emission tomography with computed tomography (PET/CT) is gaining popularity as a method for overall staging assessment of breast cancer. Currently, it is not a part of the routine workup before the beginning of treatment, because of insufficient sensitivity for the detection of small tumors (due to its limited spatial resolution), the heterogeneity of radiotracer uptake by the primary tumor, and unsatisfactory sensitivity in detection of lymph node metastases (particularly when they are small). Nevertheless, it should be considered when there is a high risk of metastases, because then initial PET/CT examination allows for accurate staging and may change the treatment algorithm in up to almost 50% of stage III patients, due to detection of distant and lymph node metastases throughout the whole body. Despite the discussed limitations of PET/CT, there is ongoing research concerning the recommendations for the examination prior to treatment. For a particular group of patients with high risk of metastases, PET/CT may be expected to become a part of the routine workup as the most appropriate staging method.

Cadherin-5: a biomarker for metastatic breast cancer with optimum efficacy in oestrogen receptor-positive breast cancers with vascular invasion

BACKGROUND

A glycoproteomic study has previously shown cadherin-5 (CDH5) to be a serological marker of metastatic breast cancer when both protein levels and glycosylation status were assessed. In this study we aimed to further validate the utility of CDH5 as a biomarker for breast cancer progression.

METHODS

A nested case-control study of serum samples from breast cancer patients, of which n=52 had developed a distant metastatic recurrence within 5 years post-diagnosis and n=60 had remained recurrence-free. ELISAs were used to quantify patient serum CDH5 levels and assess glycosylation by Helix pomatia agglutinin (HPA) binding. Clinicopathological, treatment and lifestyle factors associated with metastasis and elevated biomarker levels were identified.

RESULTS

Elevated CDH5 levels (P=0.028) and ratios of CDH5:HPA binding (P=0.007) distinguished patients with metastatic disease from those that remained metastasis-free. Multivariate analysis showed that the association between CDH5:HPA ratio and the formation of distant metastases was driven by patients with oestrogen receptor (ER+) positive cancer with vascular invasion (VI+).

CONCLUSIONS

CDH5 levels and the CDH5 glycosylation represent biomarker tests that distinguish patients with metastatic breast cancer from those that remain metastasis-free. The test reached optimal sensitivity and specificity in ER-positive cancers with vascular invasion.

Imaging Bone Metastases in Breast Cancer: Staging and Response Assessment

Bone metastases are common in patients with advanced breast cancer. Given the significant associated morbidity, the introduction of new, effective systemic therapies, and the improvement in survival time, early detection and response assessment of skeletal metastases have become even more important. Although planar bone scanning has recognized limitations, in particular, poor specificity in staging and response assessment, it continues to be the main method in current clinical practice for staging of the skeleton in patients at risk of bone metastases. However, the accuracy of bone scanning can be improved with the addition of SPECT/CT. There have been reported improvements in sensitivity and specificity for staging of the skeleton with either bone-specific PET/CT tracers, such as (18)F-NaF, or tumor-specific tracers, such as (18)F-FDG, although these methods are less widely available and more costly. There is a paucity of data on the use of (18)F-NaF PET/CT for response assessment in breast cancer, but there is increasing evidence that (18)F-FDG PET/CT may improve on current methods in this regard. At the same time, interest and experience in using whole-body morphologic MRI augmented with diffusion-weighted imaging for both staging and response assessment in the skeleton have been increasing. However, data on comparisons of these methods with PET methods to determine the best technique for current clinical practice or for clinical trials are insufficient. There are early data supporting the use (18)F-FDG PET/MRI to assess malignant disease in the skeleton, with the possibility of taking advantage of the synergies offered by combining morphologic, physiologic, and metabolic imaging.

Contemporary approaches for imaging skeletal metastasis

The skeleton is a common site of cancer metastasis. Notably high incidences of bone lesions are found for breast, prostate, and renal carcinoma. Malignant bone tumors result in significant patient morbidity. Identification of these lesions is a critical step to accurately stratify patients, guide treatment course, monitor disease progression, and evaluate response to therapy. Diagnosis of cancer in the skeleton typically relies on indirect bone-targeted radiotracer uptake at sites of active bone remodeling. In this manuscript, we discuss established and emerging tools and techniques for detection of bone lesions, quantification of skeletal tumor burden, and current clinical challenges.

Monitoring the response of bone metastases to treatment with Magnetic Resonance Imaging and nuclear medicine techniques: a review and position statement by the European Organisation for Research and Treatment of Cancer imaging group

Assessment of the response to treatment of metastases is crucial in daily oncological practice and clinical trials. For soft tissue metastases, this is done using computed tomography (CT), Magnetic Resonance Imaging (MRI) or Positron Emission Tomography (PET) using validated response evaluation criteria. Bone metastases, which frequently represent the only site of metastases, are an exception in response assessment systems, because of the nature of the fixed bony defects, their complexity, which ranges from sclerotic to osteolytic and because of the lack of sensitivity, specificity and spatial resolution of the previously available bone imaging methods, mainly bone scintigraphy. Techniques such as MRI and PET are able to detect the early infiltration of the bone marrow by cancer, and to quantify this infiltration using morphologic images, quantitative parameters and functional approaches. This paper highlights the most recent developments of MRI and PET, showing how they enable early detection of bone lesions and monitoring of their response. It reviews current knowledge, puts the different techniques into perspective, in terms of indications, strengths, weaknesses and complementarity, and finally proposes recommendations for the choice of the most adequate imaging technique.

CA15-3 is a useful serum tumor marker for diagnostic integration of hybrid positron emission tomography with integrated computed tomography during follow-up of breast cancer patients

BACKGROUND

The aim of this study was to evaluate the value of CA15-3 for the diagnostic integration of molecular imaging findings performed with hybrid positron emission tomography and computed tomography (PETCT) technology.

METHODS

We retrospectively selected 45 patients with a median age of 60 years (range 39-85 years) and a previous history of breast cancer (BC) who had already been treated with surgery and other treatments. Three measurements of CA15-3 were collected within 1 year before PETCT examination, at 6-9 months 3-6 months and 0-3 months before PETCT. The prolonged clinical outcome or imaging follow-up was used to define disease relapse. An increase in tumor marker value was compared with PETCT findings and disease relapse. Sensitivity and specificity for both tests were calculated with respect to clinical outcome.

RESULTS

Disease relapse was detected in 16 out of 45 BC patients. CA15-3 and PETCT showed 75% sensitivity with a specificity percentage of 76% for CA15-3 and 79% for PETCT. Serum CA15-3 expression levels were significantly higher in BC patients with multiple metastatic sites with hepatic involvement. Analysis of serial CA15-3 serum levels showed an increase in CA15-3 3-6 months before PETCT could identify BC patients at risk for relapse (AUC = 0.81). Moreover, patients receiving anti-hormonal or chemotherapy medications with negative PETCT and positive CA15-3 relapsed after a median time of 158 days compared to patients who were negative for both tests and who were free from disease for at least 1 year.

CONCLUSIONS

Our results showed that serial increases in CA15-3 can be used to predict positive PETCT results in BC patients during follow-up. Increased levels of CA15-3 may be considered an early warning sign in patients needing accurate molecular imaging investigations, as they are at higher risk of recurrence. In cases of elevated levels, multiple lesions or liver involvement may exist. Also, patients receiving chemotherapeutic or anti-hormonal treatment who have negative PETCT scans and increased CA15-3 serum levels should be considered at risk for relapse, because the CA15-3-linked biochemical signal of the presence of a tumor can predict positive metabolic imaging.

Role of positron emission tomography/computed tomography in breast cancer

Although positron emission tomography (PET) imaging may not be used in the diagnosis of breast cancer, the use of PET/computed tomography is imperative in all aspects of breast cancer staging, treatment, and follow-up. PET will continue to be relevant in personalized medicine because accurate tumor status will be even more critical during and after the transition from a generic metabolic agent to receptor imaging. Positron emission mammography is an imaging proposition that may have benefits in lower doses, but its use is limited without new radiopharmaceuticals.

Usefulness of traditional serum biomarkers for management of breast cancer patients

The measurement of serum tumor markers levels in breast cancer (BC) patients is an economic and noninvasive diagnostic assay frequently requested by clinical oncologists to get information about the presence or absence of disease as well as its evolution. Despite their wide use in clinical practice, there is still an intense debate between scientific organizations about the real usefulness for patient monitoring during followup as well as response to therapy evaluation in case of advanced BC. In this review, we want to highlight the current recommendations published by scientific organizations about the use of “established” BC serum markers (CEA, TPA, TPS, CIFRA-21, CA15-3, and s-HER2) in clinical oncology practice. Moreover, we will focus on recent papers evidencing the usefulness of tumor markers levels measurement as a guide for the prescription and diagnostic integration of molecular imaging exams such as those performed by hybrid 18-fluorofeoxyglucose-positron emission tomography with integrated computed tomography. This technology is nowadays able to detect early cancer lesions undetectable by conventional morphological imaging investigation and most likely responsible for increasing of serum tumor markers levels.