Bone imaging in metastatic breast cancer

Fluorine-18 deoxyglucose positron emission tomography, magnetic resonance imaging and bone scintigraphy for the diagnosis of bone metastases in patients with lung cancer: which one is the best?--a meta-analysis

AIMS

To carry out a meta-analysis to compare fluorine-18 deoxyglucose ((18)FDG) positron emission tomography (PET), magnetic resonance imaging (MRI) and bone scintigraphy imaging for the diagnosis of bone metastases in patients with lung cancer.

MATERIALS AND METHODS

MEDLINE, EMBASE, Scopus and other databases were searched for relevant original articles published between January 1995 and January 2010. Inclusion criteria were as follows: (18)FDG PET, MRI or (99m)Tc-MDP bone scintigraphy was carried out to detect bone metastases in patients with lung cancer; sufficient data were presented to construct a 2×2 contingency table; histopathological analysis and/or close clinical and imaging follow-up and/or radiographic confirmation by multiple imaging modalities were used as the reference standard. Two reviewers independently extracted data. META-DiSc was used to obtain pooled estimates of sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curves and the *Q index.

RESULTS

In total, 14 articles that consisted of 34 studies fulfilled all inclusion criteria. On a per-patient basis, the pooled sensitivity estimates for PET, MRI and bone scintigraphy were 91.9, 80.0 and 91.8%, respectively. The sensitivity for PET and bone scintigraphy were significantly higher than for MRI (P<0.05). There was no significant difference between PET and bone scintigraphy (P>0.05). The pooled specificity estimates for PET, MRI and bone scintigraphy were 96.8, 90.6 and 68.8%, respectively. The specificity for PET was significantly higher than for MRI and bone scintigraphy (P<0.05), and the specificity for MRI was significantly higher than for bone scintigraphy (P<0.05). The pooled DOR estimates for PET, MRI and bone scintigraphy were 365.5, 53.8 and 34.4, respectively. The DOR for PET was significantly higher than for MRI and bone scintigraphy (P<0.05). There was no significant difference between MRI and bone scintigraphy (P>0.05). The SROC curve for PET showed better diagnostic accuracy than for MRI and bone scintigraphy. The SROC curve for MRI was better than for bone scintigraphy. The *Q index estimates for PET, MRI and bone scintigraphy were 0.933, 0.903 and 0.857, respectively. The *Q index for PET and MRI were significantly higher than for bone scintigraphy (P<0.05). There was no significant difference between PET and MRI (P>0.05). On a per-lesion basis, the pooled sensitivity estimates for PET, MRI and bone scintigraphy were 95.0, 83.8 and 71.5%, respectively. The sensitivity for PET was significantly higher than for MRI and bone scintigraphy (P<0.05), and the sensitivity for MRI was significantly higher than for bone scintigraphy (P<0.05). The pooled specificity estimates for PET, MRI and bone scintigraphy were 94.6, 96.3 and 91.0%, respectively. The specificity for MRI was significantly higher than for PET and bone scintigraphy (P<0.05), and the specificity for PET was significantly higher than for bone scintigraphy (P<0.05). The pooled DOR estimates for PET, MRI and bone scintigraphy were 431.9, 158.1 and 9.0, respectively. The DOR for PET was significantly higher than for MRI and bone scintigraphy (P<0.05) and the DOR for MRI was significantly higher than for bone scintigraphy (P<0.05). The SROC curve for PET and MRI showed better diagnostic accuracy than for bone scintigraphy. There was no significant difference between PET and MRI. The *Q index estimates for PET, MRI and bone scintigraphy were 0.953, 0.962 and 0.778, respectively. The *Q index for PET and MRI were significantly higher than for bone scintigraphy (P<0.05). There was no significant difference between PET and MRI (P>0.05).

CONCLUSION

(18)FDG PET was found to be the best modality to detect bone metastasis in patients with lung cancer, both on a per-patient basis and a per-lesion basis; MRI had the highest specificity on a per-lesion basis. For the subgroup analysis of (18)FDG PET, PET/computed tomography was shown to be better than PET and there were no significant differences between using (68)Ge and computed tomography for attenuation correction on a per-patient basis.

Bone scans, bisphosphonates, and a lack of acute changes within the mandible

PURPOSE

The etiology of osteonecrosis of the jaw is poorly understood, but preferential mandibular uptake of intravenous bisphosphonates (IVBPs) has been implicated. We examined this association within a prospective study assessing the effect of IVBPs on radionuclide bone scanning.

PATIENTS AND METHODS

Women with at least 3 osseous breast metastases on bone scanning and previous IVBP use within 8 weeks were eligible for the present study. After the first clinically indicated bone scan, the patients received zoledronic acid within 72 hours and underwent a second bone scan within another 72 hours. The regions of interest on the bone scan were read in triplicate, and the mean count per pixel was calculated for the mandible (C(M)), left femur (C(FL)), right femur (C(FR)), and thigh (C(B)). The mandibular bone turnover (MBT) was quantified as the ratio of (C(M) - C(B))/(C(F) - C(B)), where C(F) = (C(FL) + C(FR)/2). The MBT was compared before and after IVBP use.

RESULTS

A total of 10 patients were enrolled (median age 51 years, range 40 to 71); none had known osteonecrosis of the jaw. Of the 10 patients, 8 had paired bone scans available for analysis. The previous zoledronic acid exposure was 48.6 mg (range 24 to 148) for a median of 13 months (range 6 to 35). The baseline mean MBT ratio was 2.33 (range 0.88 to 4.22). After IVBP administration, the mean MBT ratio was statistically unchanged at 2.23 (range 1.05 to 3.09). The MBT had declined in 4 patients and increased in 4. Only 1 patient had had an MBT of less than 1.0 before IVBP use, and no patient had an MBT ratio of less than 1.0 after IVBP use.

CONCLUSIONS

The mandibular region appears to be a site of increased uptake of technetium-99m bound to methylene diphosphonate-technetium. Acute changes in bisphosphonate binding in the mandible were not observed in our patients receiving chronic IVBP therapy.

Bone metastases from prostate cancer: assessing treatment response by using diffusion-weighted imaging and functional diffusion maps--initial observations

PURPOSE

To prospectively investigate and monitor the response to antiandrogen treatment of bone metastases in patients with prostate cancer by using diffusion-weighted (DW) magnetic resonance (MR) imaging with the apparent diffusion coefficient (ADC) and functional diffusion maps (DMs).

MATERIALS AND METHODS

This study had institutional review board approval; informed consent was obtained from all patients. Nine treatment-naive men (mean age, 73 years; range, 66-86 years) with 20 pelvic bone metastases were included. Imaging was performed before antiandrogen treatment and at 1, 2, and 3 months afterward. Imaging included a DW MR imaging sequence with five b factors (0-800 sec/mm²). Serum prostate-specific antigen (PSA) levels and mean ADCs of each metastasis were measured over time and analyzed by using the general linear model. Pairwise comparisons (paired-samples t tests) of PSA levels and ADCs before and after therapy were performed with the significance level set at P < .017 (Bonferroni correction). To determine the relationship between serum PSA level and the averaged mean ADCs in each patient, the two parameters were correlated across time. In addition, an analysis with functional DMs was performed to evaluate ADC response to treatment on a per-voxel basis.

RESULTS

Serum PSA levels decreased by more than 90% during therapy. The mean ADCs of metastases were increased significantly at 1 (P < .001), 2 (P = .002), and 3 (P = .011) months after therapy compared with pretreatment values. Heterogeneous response was revealed at functional DM analysis. After 1 month of therapy, 47.3% of all analyzed tumor voxels showed significantly increased ADCs, while 46.5% were unchanged and 6.2% exhibited decreased ADCs in comparison to the pretreatment values. At 3 months after therapy, the proportion of voxels showing ADC decrease was higher (13.7%) than that at 1 month.

CONCLUSION

DW MR imaging allows monitoring of antiandrogen therapy in bone metastases. PSA level decrease corresponded well with an increase in mean tumor ADC. Heterogeneity of tumor response to therapy was demonstrated by functional DM analysis.

Future directions of bone-targeted therapy for metastatic breast cancer

Bone is the most common metastatic site for breast cancer, and bone metastases can cause pain as well as risk of pathological fractures. Emerging treatments for metastatic bone disease have arisen from advances in our understanding of the unique cellular and molecular mechanisms that contribute to bone metastasis. The interaction between tumor cells and the bone microenvironment results in a 'vicious cycle' that increases both bone destruction and tumor burden. The tumor secretes factors, such as parathyroid hormone-related peptide, that stimulate osteoclastogenesis. Similarly, the bone stroma produces growth factors, such as transforming growth factor β, that promote tumor growth in bone. Therapeutic targeting of these microenvironmental factors is under intensive investigation. Other attractive therapeutic targets include signaling molecules, such as receptor activator of nuclear factor κB ligand, Src kinase, and cathepsin K, all of which regulate osteoclast function, and chemokine receptor 4, which is involved in the homing of tumor cells to bone. In this Review, we describe the progress and future directions of novel bone-targeted therapies that may reduce or prevent destructive bone metastasis from breast cancer. Novel modalities for predicting and monitoring treatment response will also be described.

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.

Assessment of Response to Therapy for Bone Metastases: Is it Still a Challenge in Oncology?

Bone is one of the most common sites of metastases from cancer. Most anticancer treatments are highly toxic but only a fraction of all patients respond to them. Guidelines are needed to evaluate the response in the routine practice of oncology as well as in clinical trials in which new treatment options are evaluated. All current imaging procedures have major limitations. This article reviews old and new criteria for response evaluation. The major problem of accurate response evaluation in bone disease is discussed in detail. Some examples from our daily practice illustrate the difficulties. The indications for bone biopsy are also reviewed.

Cancer Response Criteria and Bone Metastases: RECIST 1.1, MDA and PERCIST

Response criteria represent the standard by which the efficacy of therapeutic agents is determined in cancer trials. The most widely used criteria are based on the anatomic measurement of solid tumors. Because bone metastases are typically located in irregularly shaped bones and are difficult to measure with rulers, they have been previously considered unmeasurable disease. New developments in cancer response criteria have increased awareness of the importance of the response of bone metastases to therapy. The recently updated Response Evaluation Criteria in Solid Tumors (RECIST 1.1) now consider bone metastases with soft tissue masses > 10 mm to be measurable disease. Response criteria specific to bone metastases have been developed at The University of Texas MD Anderson Cancer Center (MDA criteria) and can be used to assess therapeutic response in numerous types of bone metastases. Functional imaging criteria, such as the recently developed Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) allow response to be measured in the absence of anatomic change through assessment of metabolic activity. As monitoring tumor response of bone metastases becomes more important in the management of cancer, so does the demand on radiologists and nuclear medicine physicians for accurate interpretation of the behavior of these lesions. This article reviews anatomic, bone, and metabolic response criteria, providing illustrations for the interpretation of therapy-induced change in bone metastases.

Heterogeneity of metabolic response to systemic therapy in metastatic breast cancer patients

AIM

The aim of this retrospective study was to describe the intra-individual heterogeneity of the ¹⁸F-labelled fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) response among lesions in bone-dominant metastatic breast cancer patients treated with systemic therapies.

PATIENTS AND METHODS

The metabolic response was analysed by comparing PET/CT scans carried out before and during a new treatment phase (n=46) in 25 bone-dominant metastatic breast cancer patients. Patients presented both bone and extra-bone metastases in 48% treatment phases. The metabolic response was analysed according to European Organization for Research and Treatment of Cancer (EORTC) criteria. A heterogeneous response was defined as the coexistence of responding and non-responding lesions within the same patient.

RESULTS

The lesion-based response analysis showed a heterogeneous metabolic response in 48% of treatment phases. In the subset with both bone and extra-bone metastases (n=20), PET/CT showed discordant responses between bone and extra-bone metastases in 6/20 (30%) treatment phases. Considering all the cases included in the study, the time to progression (TTP) was longer in cases with a metabolic response compared with the cases with a metabolic non-response (P=0.02). In cases with a PET/CT non-response, TTP seemed to be lower in those with a homogeneous non-response compared with those with a heterogeneous metabolic response (P=0.07).

CONCLUSION

Whole-body FDG-PET allows frequent heterogeneous responses after systemic therapy to be identified in bone-dominant metastatic breast cancer patients.

Drug-induced vessel remodeling in bone metastases as assessed by dynamic contrast enhanced magnetic resonance imaging and vessel size imaging: a longitudinal in vivo study

PURPOSE

The aim of this study was to assess the antiangiogenic treatment effects of zoledronic acid (ZA) and sunitinib malate (SM) noninvasively in experimental breast cancer bone metastases by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and vessel size imaging.

EXPERIMENTAL DESIGN

Nude rats bearing bone metastases after inoculation of MDA-MB-231 breast cancer cells were treated with ZA (40 microg/kg weekly; n = 8 rats), SM (20 mg/kg daily; n = 8 rats), or their combination (ZA and SM; n = 8 rats) and compared with sham-treated controls (n = 10 rats). Vascular changes in bone metastases were longitudinally imaged in vivo using DCE-MRI [amplitude (A) and exchange rate coefficient (k(ep))] and vessel size imaging [blood volume (BV) and vessel size index (VI)]. In addition, antiresorptive and antitumor changes were assessed in these lesions by flat-panel volumetric computed tomography as well as morphologic MRI and diffusion-weighted imaging.

RESULTS

In bone metastases, significant changes in A, k(ep), BV, and VI in accordance with decreased blood volume and vessel permeability as well as with increased mean vessel diameters were observed after application of ZA and SM as compared with controls. In this longitudinal study, antiangiogenic changes preceded the inhibition of osteolysis and antitumor effects after treatment.

CONCLUSIONS

These results indicate vessel remodeling in breast cancer bone metastases on ZA and SM treatment and implicate substantial effects on imaging and treatment of malignant bone lesions.

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.

Positron emission tomography with computed tomography (PET-CT) to evaluate the response of bone metastases to non-surgical treatment

A case of solitary bone metastasis from breast cancer, where MRI assessment of treatment response was inaccurate and whole-body fluorodeoxyglucose ((18)FDG) positron emission tomography with computed tomography (PET-CT) proved more reliable and objective, is presented.

Kinetic analysis of 18F-fluoride PET images of breast cancer bone metastases

The most common site of metastasis for breast cancer is bone. Quantitative (18)F-fluoride PET can estimate the kinetics of fluoride incorporation into bone as a measure of fluoride transport, bone formation, and turnover. The purpose of this analysis was to evaluate the accuracy and precision of (18)F-fluoride model parameter estimates for characterizing regional kinetics in metastases and normal bone in breast cancer patients.

METHODS

Twenty metastatic breast cancer patients underwent dynamic (18)F-fluoride PET. Mean activity concentrations were measured from serial blood samples and regions of interest placed over bone metastases, normal vertebrae, and cardiac blood pools. This study examined parameter identifiability, model sensitivity, error, and accuracy using parametric values from the patient cohort.

RESULTS

Representative time-activity curves and model parameter ranges were obtained from the patient cohort. Model behavior analyses of these data indicated (18)F-fluoride transport and flux (K(1) and Ki, respectively) into metastatic and normal osseous tissue could be independently estimated with a reasonable bias of 9% or less and reasonable precision (coefficients of variation

CONCLUSION

Fluoride transport and flux can be accurately and independently estimated for bone metastases and normal vertebrae. Reasonable bias and precision for estimates of K(1) and Ki from simulations and significant differences in values from patient modeling results in metastases and normal bone suggest that (18)F-fluoride PET images may be useful for assessing changes in bone turnover in response to therapy. Future studies will examine the correlation of parameters to biologic features of bone metastases and to response to therapy.

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Key Words

• pet
• ¹⁸f-fluoride
• radiotracer tissue kinetics
• bone metastases
• breast cancer

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MESH Headings

• Adult
• Aged
• Analysis of Variance
• Biological Transport
• Biomarkers, Tumor/metabolism
• Bone Neoplasms/metabolism
• Bone Neoplasms/pathology
• Bone Neoplasms/secondary
• Bone Neoplasms/therapy
• Breast Neoplasms/pathology
• Female
• Fluorides/chemistry
• Fluorides/metabolism
• Fluorine Radioisotopes
• Humans
• Kinetics
• Male
• Middle Aged
• Positron-Emission Tomography
• Sensitivity and Specificity
• Spine/cytology
• Spine/diagnostic imaging
• Spine/metabolism
• Treatment Outcome

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Grants

• R01 CA124573 NCI NIH HHS
• CA124573 NCI NIH HHS
• CA72064 NCI NIH HHS
• R01 CA072064 NCI NIH HHS
• S10 RR017229 NCRR NIH HHS
• RR17229 NCRR NIH HHS
• P01 CA042045 NCI NIH HHS

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Affiliation(s)

Robert K Doot Division of Nuclear Medicine, University of Washington and Seattle Cancer Care Alliance, Seattle, Washington 98195-7987, USA.
Mark Muzi
Lanell M Peterson
Erin K Schubert
Julie R Gralow
Jennifer M Specht
David A Mankoff

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Collaborators Collapse

Diagnosis of bone metastases in urological malignancies--an update

The spread of urological malignancies to bone is a poor prognostic factor. Early detection of metastatic bony lesions assists with tailoring patient management and potentially improving quality of life. Newer therapies such as zolderonic acid for prostate cancer have reinvigorated the importance of clinicians treating bony disease. An array of biochemical and imaging options are available and the order, sensitivity and cost of such investigations need to be understood to maximise clinical benefit. Furthermore, the ideal time to investigate for bony metastases has often been controversial. Although simple history and examination, serum calcium and alkaline phosphatase and plain radiography with bone scintigraphy remain at the forefront of diagnosing bony disease, evolving diagnostic modalities, such as positron emission tomography and newer bone markers need to be considered. The aim of this review is to clarify the role of various investigations and to give clinicians a current analysis of the timing of such investigations in the context of evolving diagnostic modalities and accepted guidelines for urological malignancy.

Intravenous bisphosphonate therapy does not acutely alter nuclear bone scan results

INTRODUCTION

Theoretically, the bisphosphonates used to treat metastatic bone disease could influence the results of nuclear bone scans which use the structurally similar technetium 99m methylene diphosphonate (99mTc MDP). A prospective clinical study was designed to explore this hypothesis.

PATIENTS AND METHODS

Patients with metastatic breast cancer receiving intravenous bisphosphonate (IVBP) therapy who had > or =3 osseous lesions on nuclear bone scan were eligible. A baseline bone scan (number 1) was performed as clinically indicated and IVBP with zoledronic acid was administered within 72 hours. A second bone scan (number 2) was performed within 72 hours of zoledronic acid dosing. Both bone scans were reviewed in a blinded fashion and assessed for changes in the number and intensity of osseous lesions. Ten patients were planned to yield at least 30 lesions.

RESULTS

Ten patients were enrolled. One patient withdrew consent and 1 was excluded due to protocol deviation. Among the 8 patients were 163 assessable osseous lesions. The median time from bone scan number 1 to IVBP was 1 day (range, 1-2 days). The median time from IVBP to bone scan number 2 was 2 days (range, 1-3 days). The paired imaging showed no changes in the total number of bone metastases. One hundred sixty-one lesions were identical in both scans; in 1 patient there were 2 lesions that were discordant, one more intense, the other less intense.

CONCLUSION

These data do not support the hypothesis that IVBP therapy interferes with bone scan results.

Tumour response interpretation with new tumour response criteria vs the World Health Organisation criteria in patients with bone-only metastatic breast cancer

BACKGROUND

We compared the utility of a new response classification (MDA; based on computed tomography (CT), magnetic resonance imaging (MRI), plain radiography (XR), and skeletal scintigraphy (SS)) and the World Health Organisation response classification (WHO; based on XR and SS) in stratifying breast cancer patients with bone-only metastases with respect to progression-free survival (PFS), overall survival (OS), and clinical response.

METHODS

We retrospectively reviewed 41 patients with bone-only metastatic breast cancer and assigned responses according to the MDA and WHO criteria. We analysed whether the MDA or WHO response classifications correlated with PFS and OS.

RESULTS

With the MDA criteria, there were significant differences in PFS between patients classified as responders and those classified as nonresponders (P=0.025), but with the WHO criteria, there were not. Neither criteria distinguished responders from nonresponders in terms of OS. MDA response criteria correlated better than WHO response criteria with clinical response assessment.

CONCLUSIONS

The MDA classification is superior to the WHO classification in differentiating between responders and nonresponders among breast cancer patients with bone-only metastases. Application of the MDA classification may allow bone lesions to be considered measurable disease. Prospective study is needed to test the MDA classification among patients with bone metastasis.

Imaging pharmacodynamics in oncology: the potential significance of "flares"

The clinical use of (18)F-fluorodeoxyglucose (FDG) positron emission tomography in monitoring anticancer treatment is expanding. At the same time a number of radiotracers aiming to image different aspects of tumour biology such as proliferation and apoptosis are being developed. However, the factors determining changes of radiotracer uptake parameters in response to treatment are not well understood. In many cases, cellularity may be the primary determinant of changes of FDG uptake and may confound the interpretation of metabolic changes. Early imaging assessments have in some cases showed transient increases of uptake parameters, commonly termed "flares", which are likely to be unaffected by cellularity and directly reflect pharmacodynamics at a cellular level. In this review a number of settings where molecular imaging "flares" have been described are discussed. Such changes may often be clinically informative and warrant careful study as potential predictive biomarkers.

Detection of hematogenous bone metastasis in cervical cancer: 18F-fluorodeoxyglucose-positron emission tomography versus computed tomography and magnetic resonance imaging

BACKGROUND

In this large-scale, retrospective study, the authors evaluated the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET) in detecting hematogenous bone metastasis in patients with cervical cancer. The associated risk factors also were analyzed.

METHODS

Patients with invasive cervical cancer who had both (18)F-FDG-PET studies and CT or MR imaging studies were selected. Patients who had either International Federation of Gynecology and Obstetrics (FIGO) stage III/IV disease or positive lymph node metastasis at the time of primary staging and patients who had suspected recurrent disease were included in the analyses. The diagnostic performances of PET was compared with the performance of CT and MR imaging by using the area under the receiver-operating-characteristic curve (AUC). Both univariate and multivariate analyses were applied to assess the risk factors for hematogenous bone metastasis at primary staging.

RESULTS

PET was more sensitive than CT (P = .004) and was more specific than MR imaging (P = .04). The diagnostic performance of PET was significantly superior to the performance CT (AUC, 0.964 vs 0.662; P < .001) and MR (AUC, 0.966 vs 0.833; P = .033). Both FIGO stage and the extent of lymph node metastases were associated with hematogenous bone metastasis in univariate analysis. However, the extent of lymph node metastases was the only significant risk factor in multivariate analysis (P = .025).

CONCLUSIONS

The current study demonstrated the superiority of (18)F-FDG-PET over CT and MR imaging for detecting hematogenous bone metastasis in patients with advanced cervical cancer. Hematogenous bone metastasis in cervical cancer was associated with the extent of lymph node metastases rather than with FIGO stage.

Magnetic resonance imaging and bone scintigraphy in bone metastasis detection: A comparative study

Background/Aim. Bone scintigraphy is well-known method for the detection of neoplastic lesions with a high sensitivity and, at the same time, a lower specificity. On the other hand magnetic resonance imaging (MRI) is previously established noninvasive imaging method regarding its diagnostic specificity. The aim of this study was to determine the possibilities and to correlate two different diagnostic methods - bone scintigraphy and MRI in the detection of bone metastasis in the spine and pelvic bones. Methods. A total of 123 patients who underwent both bone scintigraphy and spine and pelvic MRI on 1.5 T MR imager were enrolled in this study. Scans were subsequently analyzed in total and divided in regions of interest (cervical, upper, middle and lower thoracic, upper and lower lumbar and pelvic region, which includes sacral spinal segment); afterwards the total number of 585 matching regions were compared and statistically analyzed. Results. The statistical analysis demonstrated significant correlation between the findings of both methods in total. Divided by regions of interest, significant degrees of correlation were demonstrated in all of them, except in the cervical spine region where the r-value was in the range of low correlation. Conclusion. Having a high mutual correlation, bone scintigraphy and MRI are to be considered as the complementary diagnostic methods in the detection of bone metastases. Still, increased diagnostic potential of MRI may highlights negative bone scintigraphy findings in the patients with solitary metastatic lesions or diffuse vertebral infiltration. Advances in the bone scintigraphy (single photon emission tomography - SPECT, SPECTcomputed tomography - SPECT-CT) and MRI (whole body MRI, diffusion MRI), make it possible the diagnostic potential of both methods will result in a further improvement in bone metastasis detection.

Death receptor 5 agonist TRA8 in combination with the bisphosphonate zoledronic acid attenuated the growth of breast cancer metastasis

INTRODUCTION

Bone metastasis affects the majority of patients with advanced breast cancer and no adequate therapy exists. Bisphosphonates, like zoledronic acid, inhibit the osteolytic component of tumor growth in osseous tissues, but these drugs are not curative. The current study evaluated the combination of zoledronic acid with death receptor 5 agonists in an animal model of breast cancer bone metastasis.

MATERIALS AND METHODS

Female athymic nude mice (age 4-6 weeks, n=35) were inoculated with 200,000 luciferase-positive MDA- MB-435 cells by injection into the left ventricle. Animals were immediately imaged by bioluminescence technique and placed into one of the following therapy groups: Saline, hTRA8, hTRA8 + zoledronic acid, mTRA8, mTRA8 + zoledronic acid, or zoledronic acid monotherapy. DR5 agonists were given at 200 microg/dose and zoledronic acid 5 microg/dose, with mice treated biweekly for 4.5 weeks and imaged weekly.

RESULTS

Combination therapy containing either hTRA8 or mTRA8 with zoledronic acid significantly reduced the number of secondary lesions (7.67+2.2 and 7.5+1.7 lesions/mouse, respectively) compared to saline treated controls (12.1+/-1.56 lesions/mouse) as assessed by bioluminescence imaging (p<0.05). Additionally, monotherapy with hTRA8 resulted in a significant reduction in tumor number (8.3 +/- 2.9) compared to control animals. Total body tumor burden over time were significantly less in groups treated with hTRA8+zoledronic and mTRA8 + Zoledronic acid combination as compared with the saline control group. At day 33, both combination therapies and zoledronic acid monotherapy provided significant reduction in total tumor burden and tumor infiltration of hindlimbs by histomorphometry (p<0.05).

CONCLUSION

DR5 agonists in combination with bisphosphonates may be an acceptable combination therapy to reduce breast cancer growth in bone.

Targeting the alphavbeta3 integrin for small-animal PET/CT of osteolytic bone metastases

This article describes the evaluation of the radiopharmaceutical (64)Cu-CB-TE2A-c(RGDyK) ((64)Cu-RGD) as an imaging agent for osteolytic bone metastases and their associated inflammation by targeting of the alpha(v)beta(3) integrin on osteoclasts and the proinflammatory cells involved at the bone metastatic site.

METHODS

The (64)Cu-RGD radiotracer was evaluated in the transgenic mouse expressing Tax (Tax(+)), which spontaneously develops osteolytic tumors throughout the vertebrae and hind limbs, using biodistribution studies and small-animal PET/CT. Histologic analysis was also performed on Tax(+) mouse tails, using hematoxylin and eosin and tartrate-resistant acid phosphatase to confirm the presence of osteolytic bone lesions and the presence of osteoclasts, respectively. Additionally, a proof-of-principle study was conducted with a small group of Tax(+) animals presenting with osteolytic lesions. These animals were treated with the bisphosphonate zoledronic acid and imaged with (64)Cu-RGD to determine whether this radiopharmaceutical was sensitive enough to detect a response to the bisphosphonate therapy.

RESULTS

Biodistribution studies using (64)Cu-RGD demonstrated that Tax(+) mice between the ages of 6 and 12 mo had a greater accumulation of activity in their tail vertebrae than did the wild-type (WT) cohort (P = 0.013). Additionally, Tax(+) mice between the ages of 6 and 12 mo had significantly more tracer activity associated with their tail vertebrae than did Tax(+) mice older than 12 mo (P = 0.003), suggesting that earlier bone metastases cause an increased recruitment of alpha(v)beta(3)-expressing cells. Small-animal PET/CT with (64)Cu-RGD was conducted on Tax(+) and WT mice. On the basis of standardized uptake value analysis, Tax(+) mice had approximately 2-fold more tail-associated activity than did WT animals (P = 0.0157). Additionally, decreases in uptake were observed in the tails of Tax(+) mice after treatment with the osteoclast inhibitor zoledronic acid, and histologic analysis of Tax(+) mouse-tail vertebrae revealed the presence of Tax(+) tumor cells, osteoclasts, and proinflammatory cells within the bone microenvironment.

CONCLUSION

Together, these data suggest that (64)Cu-RGD has the potential to effectively image osteolytic bone metastases and monitor the physiologic changes in the bone metastatic microenvironment after osteoclast-inhibiting bisphosphonate therapy.

PET and PET-CT Imaging in Treatment Monitoring of Breast Cancer

Breast cancer is one of the more responsive solid tumors with a wide range of systemic therapy options. The treatment of newly diagnosed breast cancer is primarily determined by the extent of disease and generally includes surgery, radiation, and chemotherapy. This article discusses the PET and PET-CT modalities for evaluating treatment response in breast cancer.

Progressive osteoblastic bone metastases in breast cancer negative on FDG-PET

Positron emission tomography using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is increasingly used in breast cancer. The new generation cameras integrate PET and CT within the same camera, allowing the simultaneous assessment of the structural and metabolic aspects of disease. There is presently a controversy on the clinical significance of osteoblastic bone metastases in breast cancer which are not detected on FDG-PET. It has been suggested that these radiologically dense lesions represent the result of successful treatment of initially osteolytic lesions. We report a case of a 65-year-old woman with a suspicion of recurrent breast cancer based on an increasing serum tumor marker. Serial PET/CT showed progressive blastic bone metastases on the CT without FDG uptake. These lesions were confirmed by bone single photon emission computed tomography. This case report shows: first, that progressive osteoblastic lesions can lack FDG-avidity, leading to a false-negative PET; and secondly, that bone scintigraphy should not be replaced by FDG-PET/CT for the detection of bone metastases in breast cancer.

[SPECT-CT in sentinel node detection in patients with melanoma]

INTRODUCTION

The prognosis of patients with cutaneous melanoma is greatly influenced by the presence of lymph node metastases. One of the most innovative and fascinating concepts to emerge in the field of oncology in recent years is the use of sentinel lymph node biopsy (SLNB).

AIM

The aim of this study was to determine what SPECT-CT images contribute to the search for sentinel nodes in patients with melanoma.

METHODS

From March 2007 to October 2008, 18 patients were examined for sentinel nodes using dynamic scintigraphy, planar images, and SPECT-CT in the Nuclear Medicine Department of San Carlos University Hospital. The group contained 10 women and 8 men, age range 14-83 years, mean age 57 years (57+/-20.1).

RESULTS

The sentinel node was located by conventional imaging techniques (dynamic scintigraphy and planar images) in 16 of 18 patients (88.88%). SPECT-CT identified the sentinel node in 18 of 18 patients (100%) and detected clinically relevant findings in 6 of 18 patients (33.33%)

CONCLUSIONS

SPECT-CT imaging contributed clinically relevant information on sentinel nodes of melanoma, which is particularly important in patients with melanoma of the trunk or head and neck.

Lower-dose vs high-dose oral estradiol therapy of hormone receptor-positive, aromatase inhibitor-resistant advanced breast cancer: a phase 2 randomized study

CONTEXT

Estrogen deprivation therapy with aromatase inhibitors has been hypothesized to paradoxically sensitize hormone-receptor-positive breast cancer tumor cells to low-dose estradiol therapy.

OBJECTIVE

To determine whether 6 mg of estradiol (daily) is a viable therapy for postmenopausal women with advanced aromatase inhibitor-resistant hormone receptor-positive breast cancer.

DESIGN, SETTING, AND PATIENTS

A phase 2 randomized trial of 6 mg vs 30 mg of oral estradiol used daily (April 2004-February 2008 [enrollment closed]). Eligible patients (66 randomized) had metastatic breast cancer treated with an aromatase inhibitor with progression-free survival (> or = 24 wk) or relapse (after > or = 2 y) of adjuvant aromatase inhibitor use. Patients at high risk of estradiol-related adverse events were excluded. Patients were examined after 1 and 2 weeks for clinical and laboratory toxicities and flare reactions and thereafter every 4 weeks. Tumor radiological assessment occurred every 12 weeks. At least 1 measurable lesion or 4 measurable lesions (bone-only disease) were evaluated for tumor response.

INTERVENTION

Randomization to receive 1 oral 2-mg generic estradiol tablet 3 times daily or five 2-mg tablets 3 times daily.

MAIN OUTCOME MEASURES

Primary end point: clinical benefit rate (response plus stable disease at 24 weeks).

SECONDARY OUTCOMES

toxicity, progression-free survival, time to treatment failure, quality of life, and the predictive properties of the metabolic flare reaction detected by positron emission tomography/computed tomography with fluorodeoxyglucose F 18.

RESULTS

The adverse event rate (> or = grade 3) in the 30-mg group (11/32 [34%]; 95% confidence interval [CI], 23%-47%) was higher than in the 6-mg group (4/34 [18%]; 95% CI, 5%-22%; P = .03). Clinical benefit rates were 9 of 32 (28%; 95% CI, 18%-41%) in the 30-mg group and 10 of 34 (29%; 95% CI, 19%-42%) in the 6-mg group. An estradiol-stimulated increase in fluorodeoxyglucose F 18 uptake (> or = 12% prospectively defined) was predictive of response (positive predictive value, 80%; 95% CI, 61%-92%). Seven patients with estradiol-sensitive disease were re-treated with aromatase inhibitors at estradiol progression, among which 2 had partial response and 1 had stable disease, suggesting resensitization to estrogen deprivation.

CONCLUSIONS

In women with advanced breast cancer and acquired resistance to aromatase inhibitors, a daily dose of 6 mg of estradiol provided a similar clinical benefit rate as 30 mg, with fewer serious adverse events. The efficacy of treatment with the lower dose should be further examined in phase 3 clinical trials.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00324259.

Pilot study of targeted skeletal radiation therapy for bone-only metastatic breast cancer

PURPOSE

Bone-targeted radiation therapy is an attractive strategy for addressing bone disease with minimal systemic toxicity. This pilot study was designed to determine the safety and efficacy of (166)Holmium (Ho)-DOTMP for irradiating malignant cells and adjacent marrow in women with bone-only metastatic breast cancer.

PATIENTS AND METHODS

Subjects included 6 women aged < or = 65 years with breast cancer and bone-only metastases at M. D. Anderson Cancer Center. The activity of (166)Ho-DOTMP was calculated to deliver a therapeutic absorbed dose of 22 Gy (n = 3) or 28 Gy (n = 3) to the marrow. Treatment was followed by autologous stem cell transplantation to circumvent the anticipated myelosuppresion. Median follow-up time was 40 months.

RESULTS

All subjects showed prompt hematologic recovery. No patient experienced grade 3/4 acute toxicity aside from myelosuppression. Two patients developed hemorrhagic cystitis 2 years after therapy. One patient developed myelodysplastic syndrome but was found to have had pre-existing trisomy 8. Two patients remained progression free without evidence of disease for more than 6 years. Five women experienced disease relapse (4 at extraosseous sites) and died of progressive disease. Median time to progression was 10.4 months.

CONCLUSION

The approach of bone-targeted radiation therapy with (166)Ho-DOTMP had an acceptable toxicity profile, and sustained complete response was obtained in 2 of 6 patients. We are conducting a phase II study to evaluate the efficacy of targeted skeletal radiation therapy for treating bone-only metastases.

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.

Imaging response to systemic therapy for bone metastases

In patients with osteotropic primary tumours such as breast and prostate cancer, imaging treatment response of bone metastases is essential for the clinical management. After treatment of skeletal metastases, morphological changes, in particular of bone structure, occur relatively late and are difficult to quantify using conventional X-rays, CT or MRI. Early treatment response in these lesions can be assessed from functional imaging techniques such as dynamic contrast-enhanced techniques by MRI or CT and by diffusion-weighted MRI, which are quantifiable. Among the techniques within nuclear medicine, PET offers the acquisition of quantifiable parameters for response evaluation. PET, therefore, especially in combination with CT and MRI using hybrid techniques, holds great promise for early and quantifiable assessment of treatment response in bone metastases. This review summarises the classification systems and the use of imaging techniques for evaluation of treatment response and suggests parameters for the early detection and quantification of response to systemic therapy.

Synergy between anti-CCL2 and docetaxel as determined by DW-MRI in a metastatic bone cancer model

Metastatic prostate cancer continues to be the second leading cause of cancer death in American men with an estimated 28,660 deaths in 2008. Recently, monocyte chemoattractant protein-1 (MCP-1, CCL2) has been identified as an important factor in the regulation of prostate metastasis. CCL2, shown to attract macrophages to the tumor site, has a direct promotional effect on tumor cell proliferation, migration, and survival. Previous studies have shown that anti-CCL2 antibodies given in combination with docetaxel were able to induce tumor regression in a pre-clinical prostate cancer model. A limitation for evaluating new treatments for metastatic prostate cancer to bone is the inability of imaging to objectively assess response to treatment. Diffusion-weighted MRI (DW-MRI) assesses response to anticancer therapies by quantifying the random (i.e., Brownian) motion of water molecules within the tumor mass, thus identifying cells undergoing apoptosis. We sought to measure the treatment response of prostate cancer in an osseous site to docetaxel, an anti-CCL2 agent, and combination treatments using DW-MRI. Measurements of tumor apparent diffusion coefficient (ADC) values were accomplished over time during a 14-day treatment period and compared to response as measured by bioluminescence imaging and survival studies. The diffusion data provided early predictive evidence of the most effective therapy, with survival data results correlating with the DW-MRI findings. DW-MRI is under active investigation in the pre-clinical and clinical settings to provide a sensitive and quantifiable means for early assessment of cancer treatment outcome.

Treatment Options for Breast Cancer and Bone Metastases

The most common destination for breast cancer metastases is bone. If bone metastases are detected, treatment algorithms should include the continuation of cytoreductive therapy with the addition of treatment to counter skeletal-related events, including bone pain. The range of current treatment options includes bisphosphonates, surgical intervention to improve structural integrity and palliative focal radiotherapy. This article focuses on the role of bisphosphonate therapy in metastatic breast cancer. Bisphosphonate therapy significantly reduces the impact of skeletal-related events, reduces bone pain and increases patient quality of life. Our current understanding is that bisphosphonates may also disrupt the metastatic process and reduce the development of bone lesions. Ultimately, this may lead to further expansion of bisphosphonate-based therapy in the future.

Imaging anti-angiogenic treatment response with DCE-VCT, DCE-MRI and DWI in an animal model of breast cancer bone metastasis

As current classification systems for the assessment of treatment response in bone metastasis do not meet the needs of oncologists, new imaging biomarkers are desirable. Therefore, the diagnostic impact of dynamic contrast enhanced (DCE)-volumetric computed tomography (VCT) (descriptive analysis), DCE-MRI (two-compartment model) and diffusion weighted imaging (DWI) for monitoring anti-angiogenic therapy effects of the VEGF antibody bevacizumab in breast cancer bone metastases in rats was studied. Nude rats (n=8 animals treated with bevacizumab and n=9 untreated control rats) with site-specific osteolytic bone metastasis of the hind leg were imaged with a 1.5T clinical MRI-scanner in an animal coil as well as in a volumetric CT-scanner at days 30, 40, 50 and 60 after inoculation of MDA-MB-231 human breast cancer cells. From these data, osteolytic lesion size (OLS), peak enhancement (PE), area under the curve (AUC), amplitude (A), exchange rate constant (k(ep)) and apparent diffusion coefficient (ADC) were determined in bone metastases. Prior to changes in OLS (p< or =0.05 at days 50 and 60) there was already a significant decrease in PE, AUC and A (p< or =0.05 at days 40-60) in treated animals compared to controls. However, for k(ep) and ADC there were no significant differences between the groups at any time point (p>0.05 at days 40-60). In conclusion, anti-angiogenic treatment response in osteolytic breast cancer bone metastases can be assessed early with surrogate markers of vascularization, while DWI appears to be insensitive.

Diffusion-weighted imaging with apparent diffusion coefficient mapping and spectroscopy in prostate cancer

Prostate cancer is a major health problem, and the exploration of noninvasive imaging methods that have the potential to improve specificity while maintaining high sensitivity is still critically needed. Tissue changes induced by tumor growth can be visualized by magnetic resonance imaging (MRI) methods. Current MRI methods include conventional T2-weighted imaging, diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping and magnetic resonance spectroscopy (MRS). Techniques such as DWI/ADC provide functional information about the behavior of water molecules in tissue; MRS can provide biochemical information about the presence or absence of certain metabolites, such as choline, creatine, and citrate. Finally, vascular parameters can be investigated using dynamic contrast-enhanced MRI. Moreover, with whole-body MRI and DWI, metastatic disease can be evaluated in 1 session and may provide a way to monitor treatment. Therefore, when combining these various methods, a multiparametric data set can be built to assist in the detection, localization, assessment of prostate cancer aggressiveness, and tumor staging. Such a comprehensive approach offers more power to evaluate prostate disease than any single measure alone. In this article, we focus on the role of DWI/ADC and MRS in the detection and characterization using both in vivo and ex vivo imaging of prostate pathology.

Blood flow and glucose metabolism in stage IV breast cancer: heterogeneity of response during chemotherapy

Objective

The purpose of the study was to compare early changes in blood flow (BF) and glucose metabolism (MR_glu) in metastatic breast cancer lesions of patients treated with chemotherapy.

Methods

Eleven women with stage IV cancer and lesions in breast, lymph nodes, liver, and bone were scanned before treatment and after the first course of chemotherapy. BF, distribution volume of water (V_d), MR_glu/BF ratio, MR_glu and its corresponding rate constants K₁ and k₃ were compared per tumor lesion before and during therapy.

Results

At baseline, mean BF and MR_glu varied among different tumor lesions, but mean V_d was comparable in all lesions. After one course of chemotherapy, mean MR_glu decreased in all lesions. Mean BF decreased in breast and node lesions and increased in bone lesions. V_d decreased in breast and nodes, but did not change in bone lesions. The MR_glu/BF ratio decreased in breast and bone lesions and increased in node lesions. In patients with multiple tumor lesions BF and MR_glu response could be very heterogeneous, even within similar types of metastases. BF and MR_glu increased in lesions of patients who experienced early disease progression or showed no response during clinical follow-up.

Conclusion

BF and MR_glu changes separately give unique information on different aspects of tumor response to chemotherapy. Changes in BF and MR_glu parameters can be remarkably heterogeneous in patients with multiple lesions.

Metastatic bone pain: treatment options with an emphasis on bisphosphonates

INTRODUCTION

One of the key targets for metastatic cancer cells is the skeleton. Once metastatic cells are established within the bone matrix, skeletal integrity becomes increasingly compromised. Bone lesions lead to various complications, including bone pain, fractures and spinal cord compression.

MECHANISMS OF BONE PAIN

Bone pain is debilitating and affects quality of life of the patient. In addition, it increases the use of health care resources. Many patients with metastatic bone disease experience substantial bone pain despite state-of-the-art systemic analgesic treatment. Incident pain is the predominant pain syndrome.

TREATMENT OPTIONS FOR BONE PAIN

Typically, this syndrome requires moderate baseline analgesia with increased on-demand doses. Other techniques for treating bone pain, including radiation therapy, neuraxial application of analgesics, nerve blocks and local stabilisation procedures, should be considered. In addition, therapy with bisphosphonates targeting bone-specific pain is an important strategy. This review discusses the various management options for bone pain arising from metastatic bone disease.