Whole body PET for the evaluation of bony metastases in patients with breast cancer: comparison with 99Tcm-MDP bone scintigraphy

How has the field of metastatic breast cancer in bones evolved over the past 22 years?

Background

Although knowledge on metastatic breast cancer in bones (MBCB) has increased rapidly over the past 22 years, a comprehensive and objective bibliometric analysis is still lacking.

Materials and methods

We used R, VOSviewer, and Citespace software to conduct a bibliometric analysis of 5,497 papers on MBCB from the Web of Science Core Collection (WOSCC) using author, institution, country/region, citation, and keyword indicators.

Results

A general strong sense of scholarly collaboration was noted in the MBCB field at the author, research institution, and country/region levels. We discovered some outstanding authors and highly productive institutions, but with less collaboration with other academic groups. Unbalanced and uncoordinated developments were observed among countries/regions in the field of MBCB research. We also found that by using various indicators and applying different analysis methods to them, we were able to broadly identify primary clinical practices, relevant clinical experiments, and directions for bioinformatics regarding MBCB, changes over the past 22 years, and current challenges in the field. The development of knowledge on MBCB is progressing greatly; however, MBCB is still incurable.

Conclusion

This study is the first to use bibliometrics to provide an overall analysis of the scientific output of MBCB studies. Palliative therapies for MBCB are mostly in a mature state. However, research on the molecular mechanisms and immune response to tumors related to the development of treatments to cure MBCB remains relatively immature. Therefore, further research should be undertaken in this area.

An Iterative Algorithm for Semisupervised Classification of Hotspots on Bone Scintigraphies of Patients with Prostate Cancer

Prostate cancer (PCa) is the second most diagnosed cancer in men. Patients with PCa often develop metastases, with more than 80% of this metastases occurring in bone. The most common imaging technique used for screening, diagnosis and follow-up of disease evolution is bone scintigraphy, due to its high sensitivity and widespread availability at nuclear medicine facilities. To date, the assessment of bone scans relies solely on the interpretation of an expert physician who visually assesses the scan. Besides this being a time consuming task, it is also subjective, as there is no absolute criteria neither to identify bone metastases neither to quantify them by a straightforward and universally accepted procedure. In this paper, a new algorithm for the false positives reduction of automatically detected hotspots in bone scintigraphy images is proposed. The motivation relies in the difficulty of building a fully annotated database. In this way, our algorithm is a semisupervised method that works in an iterative way. The ultimate goal is to provide the physician with a fast, precise and reliable tool to quantify bone scans and evaluate disease progression and response to treatment. The algorithm is tested in a set of bone scans manually labeled according to the patient's medical record. The achieved classification sensitivity, specificity and false negative rate were 63%, 58% and 37%, respectively. Comparison with other state-of-the-art classification algorithms shows superiority of the proposed method.

Clinicopathological and prognostic characteristics of acral metastases in patients with malignant disease: A retrospective study

OBJECTIVE

This study aimed to investigate the clinical, pathological, and prognostic characteristics of acral metastases in patients with malignant disease and to determine the impact of different types of acral metastasis treatment on patient survival.

METHODS

In this retrospective study, 64 acral metastatic lesions in 46 patients (17 women, 29 men; mean age, 61.5 years; age range, 35-82 years) who were evaluated by the Bone and Soft Tissue Tumors Council of our institute from 2015 to 2019 were included. The patients' primary tumor site, tumor type, localization of acral metastases, main symptom, duration from the diagnosis of the primary tumor to the diagnosis of acral metastasis, duration from the diagnosis of acral metastasis to death, and survival data were analyzed. The diagnosis of acral metastasis was confirmed by histopathological evaluation in 38 patients and clinical and radiological assessment of the lesions in 8 patients. The treatment type for each acral metastasis was individualized by the institutional Bone and Soft Tissue Tumors Council and categorized into 3 groups: excisional surgery (amputations and resections), palliative surgery (prophylactic fixation, intralesional curettage, and bone cement augmentation), and non-surgical treatment (chemotherapy, radiotherapy, and hormone therapy).

RESULTS

A total of 16 acral metastases (25%) were identified in the upper extremity and 48 (75%) in the lower extremity. The most common primary tumor site was the lungs (32.6%), and the most common tumor type was adenocarcinoma (43.2%). The most frequent symptom and the primary reason for admission was pain (58.7%). The mean duration between the diagnosis of primary tumor and the diagnosis of acral metastasis was 19.1 (range, 0-124) months. No significant correlation was determined between the primary tumor types and duration from the diagnosis of primary tumor to the diagnosis of acral metastasis (p=0.278). Acral metastases were treated by excisional surgery in 15 (32.6%) patients, palliative surgery combined with non-surgical treatment in 10 (21.7%) patients, and only non-surgical treatment modalities in 21 (45.7%) patients. No significant correlation existed between the treatment types and patient survival (p=0.058). At the final follow-up, 30 (65.2%) patients were dead owing to the disease. The mean overall survival of the entire study group was 24.9 (range, 3-55) months. The mean duration between the diagnosis of acral metastasis and death was 7.6 (range, 3-24) months in patients who were dead owing to the disease (p=0.012).

CONCLUSION

When the diagnosis of acral metastasis is established, it should be borne in mind that the most common primary tumor site and type are most likely the lungs and adenocarcinoma, respectively. The treatment type for acral metastasis may have no significant impact on patient survival, but the extensiveness of the disease may be a critical factor for survival.

LEVEL OF EVIDENCE

Level IV, Prognostic study.

Bone Metastases: Mechanisms of the Metastatic Process, Imaging and Therapy

The mechanisms by which tumors metastasize to bone are complex. Upon the successful establishment of metastatic deposits in the skeleton, detection of the disease becomes essential for therapeutic planning. The roles of CT, skeletal scintigraphy, SPECT/CT, MRI, PET/CT and PET/MRI will be reviewed. Therapeutic response criteria specifically designed to evaluate bone metastases (MD Anderson/MDA criteria) can guide image interpretation. Knowledge of therapeutic strategies such as systemic therapy with bisphosphonates or radiopharmaceuticals, radiation therapy, surgery, and percutaneous interventions such as vertebroplasty and radiofrequency ablation can help the radiologist produce reports that will provide maximum benefit to clinicians and patients.

Machine learning in quantitative PET: A review of attenuation correction and low-count image reconstruction methods

The rapid expansion of machine learning is offering a new wave of opportunities for nuclear medicine. This paper reviews applications of machine learning for the study of attenuation correction (AC) and low-count image reconstruction in quantitative positron emission tomography (PET). Specifically, we present the developments of machine learning methodology, ranging from random forest and dictionary learning to the latest convolutional neural network-based architectures. For application in PET attenuation correction, two general strategies are reviewed: 1) generating synthetic CT from MR or non-AC PET for the purposes of PET AC, and 2) direct conversion from non-AC PET to AC PET. For low-count PET reconstruction, recent deep learning-based studies and the potential advantages over conventional machine learning-based methods are presented and discussed. In each application, the proposed methods, study designs and performance of published studies are listed and compared with a brief discussion. Finally, the overall contributions and remaining challenges are summarized.

Distribution and predictive value of initial presenting symptoms in spinal metastases from primary cancer patients

PURPOSE

Primary cancer patients may have some symptoms and develop spinal metastases in their disease progression. This study was to report the distribution and predictive value of specific initial presenting symptoms in patients with spine metastatic disease.

METHODS

The clinical information about patients with primary cancers was retrospectively collected and analyzed at their initial diagnosis from January 2008 to December 2017. The distribution and specific value of initial presenting symptoms were analyzed in predicting spinal metastases.

RESULTS

A total of 14,603 cancer patients were finally included, of whom 1665 (11.4%) cases were confirmed with spinal metastases. 41.55% (6067/14,603) patients had initial presenting symptoms, while 92.19% (1535/1665) patients with spinal metastases presented at least one initial presenting symptoms. Among 6269 patients with symptoms, 1535 (24.49%) were diagnosed with spinal metastases. Factors including primary tumor type, local pain, night-aggravating pain, limb numbness, limb weakness, unstable gait, claudication, loss of sphincter control, and weight loss are associated with the distribution of spinal metastases. The pooled sensitivity, specificity, positive predictive value, and negative predictive value were 90.9% (89.4-92.2%), 64.9% (64.0-65.7%), 24.99% (23.91-26.11%), and 98.23% (97.92-98.50%), respectively. Positive likelihood ratio of "night-aggravating pain" was 33.25 (12.65-87.36) and 17.26 (12.25-24.32) in patients < 45 and 45-64 years old, respectively.

CONCLUSIONS

The distribution of spinal metastases is associated with primary tumor type and initial presenting symptoms. The predictive value of initial presenting symptoms differs in age groups, but resembles in cancer types. The presence of night-aggravating pain had relative high value in predicting metastases in cancer patients under 65 years old.

Nuclear Medicine Imaging Techniques for Detection of Skeletal Metastases in Breast Cancer

Bone is the most common site of metastases from advanced breast cancer. Whole-body bone scintigraphy has been most frequently used in the process of managing cancer patients; its advantage is that it provides rapid whole-body imaging for screening of osteoblastic or sclerotic/mixed bone metastases at reasonable cost. Recent advanced techniques, such as single-photon emission computed tomography (SPECT)/CT, quantitative analysis, and bone scan index, contribute to better understanding of the disease state. More recent advances in machines and PET drugs improve the staging of the skeleton with higher sensitivity and specificity.

Prognostic utility of FDG PET/CT and bone scintigraphy in breast cancer patients with bone-only metastasis

We performed this retrospective clinical study to examine the prognostic power of bone scintigraphy (BS) and F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in terms of overall survival (OS) of breast cancer with bone-only metastasis.We retrospectively evaluated 100 female invasive ductal breast cancer patients (mean age 48.1 years) with bone-only metastasis. Twenty-five patients had human epidermal growth factor receptor 2 (HER2)-positive tumors, 65 were estrogen receptor (ER) and/or progesterone receptor (PR)-positive, HER2-negative tumors, and 10 were triple negative tumors. The patients were treated properly with various treatments, including chemotherapy, radiotherapy, hormone, and bisphosphonate therapy, based on their clinical status. All patients underwent BS and FDG PET/CT at baseline and 1 year after treatment. The baseline and follow images were visually compared, and the patients were grouped as responders or nonresponders based on their images. OS was compared between the groups.The mean OS after the diagnosis of bone-only metastasis was 57.6 months. Fifty-one patients (51%) died within 5 years after diagnosis of metastasis. No difference in survival was evident between responders and nonresponders based on BS imaging data (P = .090). The response status based on PET imaging data waste only significant independent prognostic factor on multivariate analysis (P = .001). Survival was lower in nonresponders than in responders based on PET imaging (32.7% vs 66.4%; P < .001).Our findings suggest that the response status according to FDG PET imaging can be used to predict OS in breast cancer patients with bone-only metastasis.

Bone metastases from breast cancer: associations between morphologic CT patterns and glycolytic activity on PET and bone scintigraphy as well as explorative search for influential factors

Background

This study aimed to compare the detection of bone metastases from breast cancer on F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and bone scintigraphy (BS). An explorative search for factors influencing the sensitivity or uptake of BS and FDG-PET was also performed.

Methods

Eighty-eight patients with bone metastases from breast cancer were eligible for this study. Histological confirmation of bone metastases was obtained in 31 patients. The bone metastases were visually classified into four types based on their computed tomography (CT) appearance: osteoblastic, osteolytic, mixed, and negative. The sensitivity of BS and FDG-PET were obtained regarding CT type, adjuvant therapy, and the primary tumor characteristics. The FDG maximum standardized uptake value (SUV_max) was analyzed.

Results

The sensitivities of the three modalities (CT, BS, and FDG-PET) were 77, 89, and 94%, respectively. The sensitivity of FDG-PET for the osteoblastic type (69%) was significantly lower than that for the other types (P < 0.001), and the sensitivity of BS for the negative type (70%) was significantly lower than that for the others. Regarding tumor characteristics, the sensitivity of FDG-PET significantly differed between nuclear grade (NG)1 and NG2–3 (P = 0.032). The SUV_max of the osteoblastic type was significantly lower than that of the other types (P = 0.009). The SUV_max of NG1 was also significantly lower than that of NG2–3 (P = 0.011). No significant difference in FDG uptake (SUV_max) was detected between different histological types.

Conclusion

Although FDG-PET is superior to BS for the detection of bone metastases from breast cancer, this technique has limitations in depicting osteoblastic bone metastases and NG1.

Comparative diagnostic accuracy of 18F-FDG PET/CT for breast cancer recurrence

In the last decades, in addition to conventional imaging techniques and magnetic resonance imaging (MRI), ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has been shown to be relevant in the detection and management of breast cancer recurrence in doubtful cases in selected groups of patients. While there are no conclusive data indicating that imaging tests, including FDG PET/CT, produce a survival benefit in asymptomatic patients, FDG PET/CT can be useful for identifying the site of relapse when traditional imaging methods are equivocal or conflicting and for identifying or confirming isolated loco-regional relapse or isolated metastatic lesions. The present narrative review deals with the potential role of FDG PET in these clinical settings by comparing its accuracy and impact with conventional imaging modalities such as CT, ultrasound, bone scan, ¹⁸F-sodium fluoride PET/CT (¹⁸F-NaF PET/CT) as well as MRI. Patient-focused perspectives in terms of patients' satisfaction and acceptability are also discussed.

Implications of Cancer Staging Uncertainties in Radiation Therapy Decisions

Introduction . Radiation therapy (RT) for cancer is a critical medical procedure that occurs in a complex environment involving numerous health professionals, hardware, software, and equipment. Uncertainties and potential incidents can lead to inappropriate administration of radiation to patients, with sometimes catastrophic consequences such as premature death or appreciably impaired quality of life. The authors evaluate the impact of incorrectly staging (i.e., estimation of extent of cancer) breast cancer patients and resulting inappropriate treatment decisions. Methods . The authors employ analytic and simulation methods in an influence-diagram framework to estimate the probability of incorrect staging and treatment decisions. As inputs, they use a combination of literature information on the accuracy and precision of pathology and tests as well as expert judgment. Sensitivity and value-of-information analyses are conducted to identify important uncertainties. Results and conclusions . The authors find a small but nontrivial probability that breast cancer patients will be incorrectly staged and thus may be subjected to inappropriate treatment. Results are sensitive to a number of variables, and some routinely used tests for metastasis have very limited information value. This work has implications for the methods used in cancer staging, and the methods are generalizable for quantitative risk assessment of treatment errors.

The EANM practice guidelines for bone scintigraphy

PURPOSE

The radionuclide bone scan is the cornerstone of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive diagnostic nuclear medicine imaging technique that uses a radiotracer to evaluate the distribution of active bone formation in the skeleton related to malignant and benign disease, as well as physiological processes.

METHODS

The European Association of Nuclear Medicine (EANM) has written and approved these guidelines to promote the use of nuclear medicine procedures of high quality.

CONCLUSION

The present guidelines offer assistance to nuclear medicine practitioners in optimizing the diagnostic procedure and interpreting bone scintigraphy. These guidelines describe the protocols that are currently accepted and used routinely, but do not include all existing procedures. They should therefore not be taken as exclusive of other nuclear medicine modalities that can be used to obtain comparable results. It is important to remember that the resources and facilities available for patient care may vary.

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.

Efficiency of fluorodeoxyglucose positron emission tomography/computed tomography to predict prognosis in breast cancer patients received neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) has become a standard therapy for patients with advanced breast cancer. Pathological complete response (pCR) after NAC is an important prognostic indicator, but some patients with pCR continue to experience recurrence. So new predictive and prognostic markers in addition to pCR are needed following NAC for breast cancer. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can evaluate metastases in the entire body simultaneously, and has several potential advantages over conventional imaging modalities. The purpose of this study was to evaluate whether FDG-PET/CT can determine NAC response and whether FDG-PET/CT can be a new prognostic marker. We imaged 83 breast cancer tumors with FDG-PET/CT, ultrasound (US), and magnetic resonance imaging (MRI) to evaluate NAC efficacy. As we previously analyzed 110 breast cancers with FDG PET/CT, we defined a threshold of >1.7 maximum standardized uptake value (SUV_max) as abnormal fluorodeoxyglucose (FDG) uptake. After NAC, 16 (19.3 %) tumors had a complete response, 54 (65.1 %) had a partial response, 11 (13.3 %) showed stable disease, and 2 (2.4 %) showed progressive disease. One of the two patients with progressive disease had bone metastasis detected by FDG-PET/CT and was not operated on. Remote metastases were evident in 2.4 % of patients after NAC as determined by FDG-PET/CT. Overall, 17 patients had pathological complete response (pCR). The sensitivity of abnormal FDG uptake after NAC for non-pCR was 20.3 % and the specificity was 94.7 %. Patients with abnormal FDG uptake after NAC experienced significantly more recurrences (P = 0.004) and more of them died (P = 0.010). Moreover, the difference in disease-free survival was more significant in the estrogen receptor (ER)-negative group. FDG-PET after NAC may be more effective for predicting prognosis than for evaluating treatment response. This tendency was particularly remarkable in ER-negative breast cancer tumors. FDG-PET/CT is useful for reevaluating surgical applicability after NAC.

Skeletal metastases from breast cancer: pathogenesis of bone tropism and treatment strategy

Breast cancer (BC) is the most common female cancer worldwide with approximately 10 % of new cases metastatic at diagnosis and 20-50 % of patients with early BC who will eventually develop metastatic disease. Bone is the most frequent site of colonisation and the development of skeletal metastases depends on a complex multistep process, from dissemination and survival of malignant cells into circulation to the actual homing and metastases formation inside bone. Disseminated tumor cells (DTCs) can be detected in bone marrow in approximately 30 % of BC patients, likely reflecting the presence of minimal residual disease that would eventually account for subsequent metastatic disease. Patients with bone marrow DTCs have poorer overall survival compared with patients without them. Although bone-only metastatic disease seems to have a rather indolent behavior compared to visceral disease, bone metastases can cause severe and debilitating effects, including pain, spinal cord compression, hypercalcemia and pathologic fractures. Delivering an appropriate treatment is therefore paramount and ideally it should require interdisciplinary care. Multiple options are currently available, from bisphosphonates to new drugs targeting RANK ligand and radiotherapy. In this review we describe the mechanisms underlying bone colonization and provide an update on existing systemic and locoregional treatments for bone metastases.

Significance of hormone receptor status in comparison of 18F -FDG-PET/CT and 99mTc-MDP bone scintigraphy for evaluating bone metastases in patients with breast cancer: single center experience

BACKGROUND

Fluorine-18 deoxyglucose positron emission tomography computed tomography (18F-FDG-PET/ CT) and bone scintigraphy (BS) are widely used for the detection of bone involvement. The optimal imaging modality for the detection of bone metastases in hormone receptor positive (+) and negative (-) groups of breast cancer remains ambiguous.

MATERIALS AND METHODS

Sixty-two patients with breast cancer, who had undergone both 18F-FDG-PET/CT and BS, being eventually diagnosed as having bone metastases, were enrolled in this study.

RESULTS

18F-FDG-PET/CT had higher sensitivity and specificity than BS. Our data showed that 18F-FDG- PET/CT had a sensitivity of 93.4% and a specificity of 99.4%, whiel for BS they were 84.5%, and 89.6% in the diagnosis of bone metastases. κ statistics were calculated for 18F-FDGPET/CT and BS. The κ-value was 0.65 between 18F-FDG-PET/CT and BS in all patients. On the other hand, the κ-values were 0.70 in the hormone receptor (+) group, and 0.51 in hormone receptor (-) group. The κ-values suggested excellent agreement between all patient and hormone receptor (+) groups, while the κ-values suggested good agreement in the hormone receptor (-) group.

CONCLUSIONS

The sensitivity and specificity for 18F-FDG-PET/CT were higher than BS in the screening of metastatic bone lesions in all patients. Similarly 18F-FDG-PET/CT had higher sensitivity and specificity in hormone receptor (+) and (-) groups.

Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients

BACKGROUND

Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40-75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 ((99)Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) imaging is an innovative technique still under investigation. We compared the capability of PET-MR to that of same-day PET-CT to assess osseous metastases in patients with breast cancer.

METHODS

One hundred and nine patients with breast cancer, who underwent same-day contrast enhanced (CE)-PET-CT and CE-PET-MR, were evaluated. CE-PET-CT and CE-PET-MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Binomial confidence intervals and a χ(2) test were used for categorical data, and paired t-test was used for the SUVmax data; a non-informative prior Bayesian approach was used to estimate and compare the specificities.

RESULTS

Osseous metastases affected 25 out 109 patients. Metastases were demonstrated by CE-PET-CT in 22 out of 25 patients (88%±7%), and by CE-PET-MR in 25 out of 25 patients (100%). CE-PET-CT revealed 90 osseous metastases and CE-PET-MR revealed 141 osseous metastases (P<0.001). The estimated sensitivity of CE-PET-CT and CE-PET-MR were 0.8519 and 0.9630, respectively. The estimated specificity for CE-FDG-PET-MR was 0.9884. The specificity of CE-PET-CT cannot be determined from patient-level data, because CE-PET-CT yielded a false-positive lesion in a patient who also had other, true metastases.

CONCLUSIONS

CE-PET-MR detected a higher number of osseous metastases than did same-day CE-PET-CT, and was positive for 12% of the patients deemed osseous metastasis-negative on the basis of CE-PET-CT.

Clinical significance of FDG-PET/CT at the postoperative surveillance in the breast cancer patients

AIM

We evaluated the clinical role of [(18)F]-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) compared with conventional imaging (CI) to detect locoregional recurrence or distant metastasis during postoperative surveillance of patients with breast cancer.

MATERIALS AND METHODS

We included 1,819 examinations of 1,161 patients, who underwent FDG-PET/CT and CI, including mammography, breast ultrasound, whole-body bone scintigraphy, and chest radiography for postoperative surveillance. All patients had a history of surgery with or without adjuvant treatment due to more than stage II breast cancer between November 2003 and November 2009. We evaluated the diagnostic performance of CI, FDG-PET/CT, and combined CI and FDG-PET/CT for detecting locoregional recurrence, distant metastasis, and incidental cancer. We also analyzed false-positive and false-negative results in both FDG-PET/CT and CI.

RESULTS

Sensitivity, specificity, positive predictive value, and negative predictive value of CI were 75.4, 98.7, 93.4, and 94.3 %. Those of FDG-PET/CT were 97.5, 98.8, 95.4, and 99.4 %. Those of the combined results were 98.6, 98.2, 96.7, and 99.7 %. Sensitivity of FDG-PET/CT was significantly higher than that of CI (P < 0.05). Sensitivity of combined CI and FDG-PET/CT results improved, but they were not significantly different from those of FDG-PET/CT alone (P = 0.43). Seventeen false-positive and nine false-negative cases were detected with FDG-PET/CT, and 19 false-positive and 88 false-negative cases were detected with CI.

CONCLUSION

FDG-PET/CT is considered as an acceptable diagnostic imaging modality for postoperative surveillance of patients with breast cancer.

The Effects of Preoperative (18)F-FDG PET/CT in Breast Cancer Patients in Comparison to the Conventional Imaging Study

PURPOSE

There have been recent studies of the (18)F-fluorodeoxyglucose positron emission tomography and computed tomography ((18)F-FDG PET/CT) in the staging, detection, and follow-up of the breast cancer occurrence and recurrence. There was controversy concerning the use of (18)F-FDG PET/CT for staging primary breast cancer. In this study, we investigated the potential effects of (18)F-FDG PET/CT in the initial assessment of patients with primary breast cancer.

METHODS

From January 2008 to December 2009, 154 consecutive biopsy-proven invasive breast cancer patients were enrolled in this study. Patients underwent conventional imaging studies including mammography, breast ultrasonography (USG), and magnetic resonance imaging for local assessment, and plain chest X-ray, liver USG, and bone scan to rule out distant metastasis. All 154 patients underwent (18)F-FDG PET/CT in the initial assessment.

RESULTS

(18)F-FDG PET/CT did not detect primary breast lesions in 16 patients with a sensitivity of 89.6% and detected only 5 multiple lesions (12.5%) out of 40 cases. Histologically confirmed axillary lymph node (LN) metastases were in 51 patients, and the sensitivity and specificity of (18)F-FDG PET/CT to detect metastatic axilla were 37.3% and 95.8%, respectively; whereas the corresponding estimates of USG were 41.2% and 93.7%, respectively. Eleven extra-axillary LN metastases were found in eight patients, and seven lesions were detected by (18)F-FDG PET/CT only. The sensitivity and specificity of (18)F-FDG PET/CT in detecting distant metastasis were 100% and 96.4%, respectively; whereas the sensitivity and specificity of the conventional imaging were 61.5% and 99.2%, respectively.

CONCLUSION

(18)F-FDG PET/CT cannot be recommended as a primary diagnostic procedure in breast cancer, but it has the potential to be used as an additional imaging tool for the detection of axillary metastasis, distant metastasis, and extra-axillary LN metastasis. (18)F-FDG PET/CT cannot solely replace the conventional diagnostic procedure in primary breast cancer. The best approach may be the combination of different imaging modalities.

Clinical utility of (18)F-fluoride PET/CT in benign and malignant bone diseases

(18)F labeled sodium fluoride is a positron-emitting, bone seeking agent with more favorable skeletal kinetics than conventional phosphate and diphosphonate compounds. With the expanding clinical usage of PET/CT, there is renewed interest in using (18)F-fluoride PET/CT for imaging bone diseases. Growing evidence indicates that (18)F fluoride PET/CT offers increased sensitivity, specificity, and diagnostic accuracy in evaluating metastatic bone disease compared to (99m)Tc based bone scintigraphy. National Oncologic PET Registry (NOPR) has expanded coverage for (18)F sodium fluoride PET scans since February 2011 for the evaluation of osseous metastatic disease. In this article, we reviewed the pharmacological characteristics of sodium fluoride, as well as the clinical utility of PET/CT using (18)F-fluoride in both benign and malignant bone disorders.

Imaging bone metastases in breast cancer: evidence on comparative test accuracy

BACKGROUND

Numerous imaging modalities may be used to detect bone metastases (BM) in women with breast cancer.

METHODS

Systematic evidence review, including quality appraisal, of studies reporting on comparative imaging accuracy for detection of BM from breast cancer.

RESULTS

Eligible studies (N = 16) included breast cancer subjects who had imaging evaluation for suspected BM or for staging/restaging in suspected local or distant relapse. Median prevalence of BM was 34.0% (range 10.0%-66.7%). There was substantial heterogeneity in the quality of reference standards and in the prevalence of BM, which could account for some of the differences in reported comparative accuracy. Most frequently, bone scan (BS) was compared with newer imaging modalities in subjects selected to both tests; therefore, results could be affected by selection bias. There was some evidence that positron emission tomography (PET), and limited evidence that PET/computed tomography (CT), CT, and magnetic resonance imaging (MRI), may provide small increments in accuracy relative to BS as add-on tests; there was little evidence regarding single photon emission computed tomography or whole-body MRI.

CONCLUSIONS

There is some evidence of enhanced incremental accuracy for some of the above-mentioned tests where used as add-on in subjects selected to more than one imaging modality, with little evidence to support their application as a replacement to BS in first-line imaging of BM. PET/CT appears to have high accuracy and is recommended for further evaluation.

Diagnosis of bone metastases: a meta-analysis comparing ¹⁸FDG PET, CT, MRI and bone scintigraphy

OBJECTIVE

To perform a meta-analysis to compare (18)FDG PET, CT, MRI and bone scintigraphy (BS) for the diagnosis of bone metastases.

METHODS

Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 1995 to January 2010. Software was used to obtain pooled estimates of sensitivity, specificity and summary receiver operating characteristic curves (SROC).

RESULTS

67 articles consisting of 145 studies fulfilled all inclusion criteria. On per-patient basis, the pooled sensitivity estimates for PET, CT, MRI and BS were 89.7%, 72.9%, 90.6% and 86.0% respectively. PET=MRI>BS>CT. ("="indicated no significant difference, P > 0.05; ">" indicated significantly higher, P < 0.05). The pooled specificity estimates for PET, CT, MRI and BS were 96.8%, 94.8%, 95.4% and 81.4% respectively. PET = CT = MRI>BS. On per-lesion basis, the pooled sensitivity estimates for PET, CT, MRI and BS were 86.9%, 77.1%, 90.4% and 75.1% respectively. PET = MRI>BS>CT. The pooled specificity estimates for PET, CT, MRI and BS were 97.0%, 83.2%, 96.0% and 93.6% respectively. PET>MRI>BS>CT.

CONCLUSION

PET and MRI were found to be comparable and both significantly more accurate than CT and BS for the diagnosis of bone metastases.

FDG-PET/CT compared with conventional imaging in the detection of distant metastases of primary breast cancer

PURPOSE

Evidence from studies with small numbers of patients indicates that (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) accurately detects distant metastases in the staging of primary breast cancer. We compared the sensitivity and specificity of PET/CT and conventional imaging (CT, ultrasonography, radiography, and skeletal scintigraphy) for the detection of distant metastases in patients with primary breast cancer.

PATIENTS AND METHODS

We performed a retrospective review that identified 225 patients with primary breast cancer seen from January 2000 to September 2009 for whom PET/CT data were available for review. Imaging findings were compared with findings on biopsy, subsequent imaging, or clinical follow-up. Sensitivity and specificity in the detection of distant metastases were calculated for PET/CT and conventional imaging. Fisher's exact tests were used to test the differences in sensitivity and specificity between PET/CT and conventional imaging.

RESULTS

The mean patient age at diagnosis was 53.4 years (range, 23-84 years). The sensitivity and specificity in the detection of distant metastases were 97.4% and 91.2%, respectively, for PET/CT and 85.9% and 67.3%, respectively, for conventional imaging. The sensitivity and specificity of PET/CT were significantly higher than those of conventional imaging (p = .009 and p < .001, respectively). Eleven cases of distant metastases detected by PET/CT were clinically occult and not evident on conventional imaging.

CONCLUSION

PET/CT has higher sensitivity and specificity than conventional imaging in the detection of distant metastases of breast cancer. A prospective study is needed to determine whether PET/CT could replace conventional imaging to detect distant metastases in patients with primary breast cancer.

A meta-analysis of 18FDG-PET, MRI and bone scintigraphy for diagnosis of bone metastases in patients with breast cancer

OBJECTIVE

To perform a meta-analysis comparing the diagnostic value of (18)FDG-PET, MRI, and bone scintigraphy (BS) in detecting bone metastases in patients with breast cancer.

MATERIALS AND METHODS

MEDLINE, EMBASE, Scopus, ScienceDirect, SpringerLink, Web of Knowledge, EBSCO, and the Cochrane Database of Systematic Review databases were searched for relevant original articles published from January 1995 to January 2010. Inclusion criteria was as follows: (18)FDG-PET, MRI or (99m)Tc-MDP BS was performed to detect bone metastases (the number of published CT studies was inadequate for meta-analysis and therefore could not be included in this study); sufficient data were presented to construct a 2 × 2 contingency table; histopathological analysis and/or close clinical and imaging follow-up for at least 6 months were used as the reference standard. Two reviewers independently assessed potentially eligible studies and extracted relevant data. A software program called "META-DiSc" was used to obtain the pooled estimates for sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curves, and the *Q index for each modality.

RESULTS

Thirteen articles consisting of 23 studies fulfilled all inclusion criteria. On a per-patient basis, the pooled sensitivity estimates for MRI (97.1%) were significantly higher than those for PET (83.3%) and BS (87.0%; P <0.05). There was no significant difference between PET and BS (P <0.05). The pooled specificity estimates for PET (94.5%) and MRI (97.0%) were both significantly higher than those for BS (88.1%; P <0.05). There was no significant difference between PET and MRI (P >0.05). The pooled DOR estimates for MRI (298.5) were significantly higher than those for PET (82.1%) and BS (49.3%; P <0.05). There was no significant difference between PET and BS (P >0.05). The SROC curve for MRI showed better diagnostic accuracy than those for PET and BS. The SROC curve for PET was better than that for BS. The*Q index for MRI (0.935), PET (0.922), and BS (0.872) showed no significant difference (P ≥0.05). On a per-lesion basis, the pooled sensitivity estimates for BS (87.8%) were significantly higher than those for PET (52.7%; P <0.05). The pooled specificity estimates for PET (99.6%) were significantly higher than those for BS (96.1%; P <0.05).The pooled DOR estimates for PET (283.3) were significantly higher than those for BS (66.8%; P <0.05). The SROC curve for PET showed better diagnostic accuracy than that for BS. The*Q index for PET (0.941) was significantly higher than that for BS (0.893; P <0.05).

CONCLUSION

Magnetic resonance imaging was found to be better than (18)FDG-PET and BS for diagnosis of bone metastases in patients with breast cancer on a per-patient basis. On a per-lesion basis, (18)FDG-PET had lower sensitivity, higher specificity, a higher DOR, and a higher *Q index than BS.

Bone metastases: assessment of therapeutic response through radiological and nuclear medicine imaging modalities

Radiological and nuclear medicine imaging modalities used for assessing bone metastases treatment response include plain and digitalised radiography (XR), skeletal scintigraphy (SS), dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), magnetic resonance imaging (MRI), [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET) and PET/CT. Here we discuss the advantages and disadvantages of these assessment modalities as evident through different clinical trials. Additionally, we present the more established response criteria of the International Union Against Cancer and the World Health Organization and compare them with newer MD Anderson criteria. Even though serial XR and SS have been used to assess the therapeutic response for decades, several months are required before changes are evident. Newer techniques, such as MRI or PET, may allow an earlier evaluation of response that may be quantified through monitoring changes in signal intensity and standard uptake value, respectively. Moreover, the application of PET/CT, which can follow both morphological and metabolic changes, has yielded interesting and promising results that give a new insight into the natural history of metastatic bone disease. However, only a few studies have investigated the application of these newer techniques and further clinical trials are needed to corroborate their promising results and establish the most suitable imaging parameters and evaluation time points. Last, but not least, there is an absolute need to adopt uniform response criteria for bone metastases through an international consensus in order to better assess treatment response in terms of accuracy and objectivity.

FDG PET for the Detection of Bone Metastases: Sensitivity, Specificity and Comparison with Other Imaging Modalities

A literature review was performed of studies reporting sensitivity and specificity of [18F]fluorodeoxyglucose (FDG) PET from January 1, 2000 to January 1, 2010. PET was found to have higher sensitivity for the detection of osseous metastases when compared to CT, skeletal scintigraphy, whole body MRI and combined conventional imaging modalities. A potential exception is when comparing PET with bone scan in the setting of blastic metastases. PET may be a better indicator of active bony metastases. The efficacy of PET can be increased with fused anatomic imaging.

PET and PET/CT imaging of skeletal metastases

Bone scintigraphy augmented with radiographs or cross-sectional imaging, such as computed tomography (CT) or magnetic resonance imaging (MRI), has remained the commonest method to diagnose and follow up skeletal metastases. However, bone scintigraphy is associated with relatively poor spatial resolution, limited diagnostic specificity and reduced sensitivity for bone marrow disease. It also shows limited diagnostic accuracy in assessing response to therapy in a clinically useful time period. With the advent of hybrid positron emission tomography (PET)/CT scanners there has been an increasing interest in using various PET tracers to evaluate skeletal disease including [(18)F]fluoride (NaF) as a bone-specific tracer and [(18)F]fluorodeoxyglucose and [(18)F]choline as tumour-specific tracers. There is also early work exploring the receptor status of skeletal metastases with somatostatin receptor analogues. This review describes the potential utility of these tracers in the assessment of skeletal metastases.

Spine metastases: current treatments and future directions

Spinal metastases are the most frequently encountered spinal tumour and can affect up to 50% of cancer patients. Both the incidence and prevalence of metastases are thought to be rising due to better detection and treatment options of the systemic malignancy resulting in increased patient survival. Further, the development and access to newer imaging modalities have resulted in easier screening and diagnosis of spine metastases. Current evidence suggests that pain, neurological symptoms and quality of life are all improved if patients with spine metastases are treated early and aggressively. However, selection of the appropriate therapy depends on several factors including primary histology, extent of the systemic disease, existing co-morbidities, prior treatment modalities, patient age and performance status, predicted life expectancy and available resources. This article reviews the currently available therapeutic options for spinal metastases including conventional external beam radiation therapy, open surgical decompression and stabilisation, vertebral augmentation and other minimally invasive surgery (MIS) options, stereotactic spine radiosurgery, bisphosphonates, systemic radioisotopes and chemotherapy. An algorithm for the management of spine metastases is also proposed. It outlines a multidisciplinary and integrated approach to these patients and it is hoped that this along with future advances and research will result in improved patient care and outcomes.

Integrated positron emission tomography/computed tomography may render bone scintigraphy unnecessary to investigate suspected metastatic breast cancer

PURPOSE

Although the accurate detection of osseous metastases in the evaluation of patients with suspected metastatic breast cancer (MBC) has significant prognostic and therapeutic implications, the ideal diagnostic approach is uncertain. In this retrospective, single-institution study, we compare the diagnostic performance of integrated positron emission tomography/computed tomography (PET/CT) and bone scintigraphy (BSc) in women with suspected MBC.

PATIENTS AND METHODS

Women with suspected MBC evaluated with PET/CT and BSc (within 30 days) between January 1, 2003 and June 30, 2008, were identified through institutional databases. Electronic medical records were reviewed, and radiology reports were classified as positive/negative/equivocal for osseous metastases. A nuclear medicine radiologist (blinded to correlative and clinical end points) reviewed all equivocal PET/CT and BSc images and reclassified some reports. Final PET/CT and BSc classifications were compared. Baseline patient/tumor characteristics and bone pathology were recorded and compared to the final imaging results.

RESULTS

We identified 163 women who had a median age of 52 years (range, 30 to 90 years); 32% had locally advanced breast cancer, 42% had been diagnosed with breast cancer less than 12 weeks before identification. Twenty studies were originally deemed equivocal (five with PET/CT, and 15 with BSc), and 13 (65%) of these studies were reclassified after radiology review. Overall, PET/CT and BSc were highly concordant for reporting osseous metastases with 132 paired studies (81%); 32 (20%) were positive, and 100 (61%) were negative. Thirty-one occurrences (19%) were discordant. Twelve of these (39%) had pathology confirming osseous metastases: nine (of 18) were PET/CT positive and BSc negative; one (of three) was PET/CT positive and BSc equivocal; and two (of two) were PET/CT equivocal and BSc negative.

CONCLUSION

This study supports the use of PET/CT in detecting osseous metastases for suspected MBC. Whether PET/CT may supplant BSc in this setting is unknown.

Breast cancer: role of SPECT and PET in imaging bone metastases

Breast cancer is the most common cause of bone metastases in women. Imaging studies are useful to identify bone involvement and associated complications, for follow-up of disease spread and for the assessment of response to therapy. Bone scintigraphy with (99m)technetium-labeled diphosphonates is most widely used, due to its availability, high sensitivity, and low cost, despite the relatively low specificity. The addition of single-photon emission computed tomography and recently single-photon emission computed tomography/computed tomography improves the diagnostic accuracy of this modality. Serial follow-up scans can demonstrate disease progression, but this method is less accurate in determining response to treatment. Positron emission tomography (PET), a tomographic modality with improved resolution shows improved sensitivity and specificity. (18)F-fluorodeoxyglucose (FDG)-PET is the most common clinically used procedure. FDG is taken up by the tumor cells and has therefore the advantage of demonstrating the presence of disease in both bone and soft tissues. FDG-PET is highly sensitive mainly in diagnosis of early metastatic disease, which may still be confined to the bone marrow, as well as for the detection of lytic bone metastases and can be also reliably used to monitor response to therapy. For the detection of sclerotic lesions, however, imaging with a bone-seeking tracer such as (18)F-fluoride, may have a complementary role. As a nonspecific skeletal imaging tracer, (18)F-fluoride has great potential, being more sensitive than bone scintigraphy and when PET/computed tomography is performed it is highly accurate for detection of both lytic and sclerotic lesions and to distinguish benign from malignant skeletal findings.

NCCN Task Force Report: Bone Health in Cancer Care

Bone health and maintenance of bone integrity are important components of comprehensive cancer care in both early and late stages of disease. Risk factors for osteoporosis are increased in patients with cancer, including women with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors for breast cancer, men receiving androgen-deprivation therapy for prostate cancer, and patients undergoing glucocorticoid therapy. The skeleton is a common site of metastatic cancer recurrence, and skeletal-related events are the cause of significant morbidity. The National Comprehensive Cancer Network (NCCN) convened a multidisciplinary task force on Bone Health in Cancer Care to discuss the progress made in identifying effective screening and therapeutic options for management of treatment-related bone loss; understanding the factors that result in bone metastases; managing skeletal metastases; and evolving strategies to reduce bone recurrences. This report summarizes presentations made at the meeting.

Imaging bone metastases in breast cancer: techniques and recommendations for diagnosis

Bone is the most common site of distant metastases from breast carcinoma. The presence of bone metastases affects a patient's prognosis, quality of life, and the planning of their treatment. We discuss recent innovations in bone imaging and present algorithms, based on the strengths and weaknesses of each technique, to facilitate the most successful and cost-effective choice of imaging studies for the detection of osseous metastases. Skeletal scintigraphy (bone scan) is very sensitive in the detection of osseous metastases and is recommended as the first imaging study in patients who are asymptomatic. Radiographs are recommended for the assessment of abnormal radionuclide uptake or the risk of pathological fracture and as initial imaging studies in patients with bone pain. MRI or PET-CT can be considered for cases of abnormal radionuclide uptake that are not addressed by radiography. Osseous metastases can lead to emergent situations, such as spinal-cord compression or impending fracture of a weight-bearing bone, and imaging guidelines are essential for early detection and initiation of appropriate therapy. The imaging method used in non-emergent situations, such as assessment of the ribs, sternum, pelvis, hips, and joints, should be guided by the strengths and limitations of each technique.