The Value of FDG Positron Emission Tomography in the Management of Patients with Breast Cancer

A brief insight to the role of glyconanotechnology in modern day diagnostics and therapeutics

Carbohydrate-protein and carbohydrate-carbohydrate interactions are very important for various biological processes. Although the magnitude of these interactions is low compared to that of protein-protein interaction, the magnitude can be boosted by multivalent approach known as glycocluster effect. Nanoparticle platform is one of the best ways to present diverse glycoforms in multivalent manner and thus, the field of glyconanotechnology has emerged as an important field of research considering their potential applications in diagnostics and therapeutics. Considerable advances in the field have been achieved through development of novel techniques, use of diverse metallic and non-metallic cores for better efficacy and application of ever-increasing number of carbohydrate ligands for site-specific interaction. The present review encompasses the recent developments in the area of glyconanotechnology and their future promise as diagnostic and therapeutic tools.

Pretherapeutic Imaging for Axillary Staging in Breast Cancer: A Systematic Review and Meta-Analysis of Ultrasound, MRI and FDG PET

BACKGROUND

This systematic review aimed at comparing performances of ultrasonography (US), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (PET) for axillary staging, with a focus on micro- or micrometastases.

METHODS

A search for relevant studies published between January 2002 and March 2018 was conducted in MEDLINE database. Study quality was assessed using the QUality Assessment of Diagnostic Accuracy Studies checklist. Sensitivity and specificity were meta-analyzed using a bivariate random effects approach; Results: Across 62 studies (n = 10,374 patients), sensitivity and specificity to detect metastatic ALN were, respectively, 51% (95% CI: 43-59%) and 100% (95% CI: 99-100%) for US, 83% (95% CI: 72-91%) and 85% (95% CI: 72-92%) for MRI, and 49% (95% CI: 39-59%) and 94% (95% CI: 91-96%) for PET. Interestingly, US detects a significant proportion of macrometastases (false negative rate was 0.28 (0.22, 0.34) for more than 2 metastatic ALN and 0.96 (0.86, 0.99) for micrometastases). In contrast, PET tends to detect a significant proportion of micrometastases (true positive rate = 0.41 (0.29, 0.54)). Data are not available for MRI.

CONCLUSIONS

In comparison with MRI and PET Fluorodeoxyglucose (FDG), US is an effective technique for axillary triage, especially to detect high metastatic burden without upstaging majority of micrometastases.

Lipid-weighted intraoperative photoacoustic tomography of breast tumors: Volumetric comparison to preoperative MRI

With a lifetime risk of 1 in 8, breast cancer continues to be a major concern for women and their physicians. The optimal treatment of the disease depends on the stage of the cancer at diagnosis, which is typically assessed using medical imaging. However, currently employed imaging systems for breast tumor measurement rarely agree perfectly. Our group developed an Intraoperative Photoacoustic Screening (iPAS) soft tissue scanner featuring high bulk tissue sensitivity, a clinically compatible scan-time of 6 min, imaging depths greater than 2 cm and the capability to visualize whole breast tumors based on their lipid, rather than hemoglobin, profile. Here, we report on the first clinical experience with breast cancer patients by comparing tumor-measurement using iPAS, preoperative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and gold-standard pathology. Tumor size was measured volumetrically for iPAS and DCE-MRI, and separately using maximum diameters for pathology, DCE-MRI and iPAS. Comparisons were performed using Pearson's correlation coefficients, and the non-parametric Wilcoxon signed-rank test. Twelve consecutive patients were included in the study, contingent on pathologically documented invasive carcinoma. iPAS volumetric tumor size was positively correlated to DCE-MRI (Pearson's r = 0.78, p = 0.003) and not significantly different (Wilcoxon, p = 0.97). In comparison to pathology, tumor diameters given by iPAS were positively correlated (Pearson's r = 0.87, p = 0.0002) and significantly different (Wilcoxon, p = 0.0015). The results indicated that volumetric-measurement of invasive breast tumors with iPAS is similar to that of DCE-MRI. On the other hand, tumor diameter measurements were less reliable. Beyond enhancing surgical specimen examination, an extension of this technology to diagnostic imaging promises a new perspective on tumor assessment, potentially improving our current understanding and treatment of breast cancer.

Automatic segmentation of lesion from breast DCE-MR image using artificial fish swarm optimization algorithm

Interpreting Dynamic Contrast-Enhanced (DCE) MR images for signs of breast cancer is time consuming and complex, since the amount of data that needs to be examined by a radiologist in breast DCE-MRI to locate suspicious lesions is huge. Misclassifications can arise from either overlooking a suspicious region or from incorrectly interpreting a suspicious region. The segmentation of breast DCE-MRI for suspicious lesions in detection is thus attractive, because it drastically decreases the amount of data that needs to be examined. The new segmentation method for detection of suspicious lesions in DCE-MRI of the breast tissues is based on artificial fishes swarm clustering algorithm is presented in this paper. Artificial fish swarm optimization algorithm is a swarm intelligence algorithm, which performs a search based on population and neighborhood search combined with random search. The major criteria for segmentation are based on the image voxel values and the parameters of an empirical parametric model of segmentation algorithms. The experimental results show considerable impact on the performance of the segmentation algorithm, which can assist the physician with the task of locating suspicious regions at minimal time.

Potential Clinical Applications of 18F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance Mammography in Breast Cancer

The whole-body positron emission tomography (PET)/magnetic resonance (MR) scan is a cutting edge technology providing comprehensive structural information from MR imaging and functional features from PET in a single session. Recent research findings and clinical experience have shown that ¹⁸F-fluorodeoxyglucose (FDG) whole-body PET/MR imaging has a diagnostic performance comparable with or superior to that of PET/CT in the field of oncology, including for breast cancer. In particular, FDG PET/MR mammography in the prone position with the breast hanging in a pendant manner can provide more comprehensive information about the metabolism, anatomy, and functional features of a breast lesion than a whole-body PET/MR scan. This article reports on current state-of-the-art PET/MR mammography in patients with breast cancer and the prospects for potential application in the future.

Diagnostic performance of 18F-FDG PET/CT, ultrasonography and MRI. Detection of axillary lymph node metastasis in breast cancer patients

The aim of this study was to evaluate the diagnostic abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography(PET/CT) compared with those of ultrasonography and magnetic resonance imaging (MRI) for axillary lymph node staging in breast cancer patients.

PATIENTS, METHODS

Preoperative 18F-FDG PET/non-contrast CT, ultrasonography and MRI were performed in 215 women with breast cancer. Axillary lymph node dissection was performed in all patients and the diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. ROC curves were compared to evaluate the diagnostic ability of several imaging modalities (i. e., ultrasonography, MRI and 18F-FDG PET/CT).

RESULTS

In total, 132 patients (61.4%) had axillary lymph node metastasis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of axillary lymph node metastasis were 72.3%, 77.3%, 66.7%, 81.6%, 75.3% for ultrasonography, 67.5%, 78.0%, 65.9%, 79.2%, 74.0% for MRI, and 62.7%, 88.6%, 77.6%, 79.1%, 78.6% for 18F-FDG PET/CT, respectively. There was no significant difference in diagnostic ability among the imaging modalities (i.e., ultrasonography, MRI and 18F-FDG PET/CT). The diagnostic ability of 18F-FDG PET/CT was significantly improved by combination with MRI (p = 0.0002) or ultrasonography (p < 0.0001). The combination of 18F-FDG PET/CT with ultrasonography had a similar diagnostic ability to that of all three modalities combined (18F-FDG PET/CT+ultrasonography+MRI, p = 0.05).

CONCLUSION

The diagnostic performance of 18F-FDG PET/CT for detection of axillary node metastasis was not significantly different from that of ultrasonography or MRI in breast cancer patients. Combining 18F-FDG PET/CT with ultrasonography or MRI could improve the diagnostic performance compared to 18F-FDG PET/CT alone.

Should a routine metastatic workup be performed for all patients with pathologic N2/N3 breast cancer?

BACKGROUND

Node-positive breast cancer patients are at risk for metastatic disease. A routine metastatic workup might or might not be necessary for all patients with N2 or N3 diseases. The National Comprehensive Cancer Network guidelines recommend a metastatic workup for patients with T3N1 disease, yet no definitive recommendations are made for N2/N3 diseases. We hypothesized that for patients with operable pathologic N2/N3 diseases, a metastatic workup should only be considered for patients with T3/T4 lesions.

STUDY DESIGN

Two hundred and fifty-six patients with pathologic N2/N3 diseases were identified from a prospective breast cancer database of 1,329 patients with stage 0 to III breast cancer. A metastatic workup included chest x-rays, bone scans, CT scans, and PET scans. Primary end point was incidence of stage IV disease at the time of diagnosis or within 1 month of definitive surgery. Statistical analysis included chi-square test, independent t-test, Kaplan-Meier Survival method, log-rank test, and Cox proportional hazard model. A p value ≤ 0.05 was considered statistically significant.

RESULTS

There were 158 patients with N2 disease (62%) and 98 with N3 disease (38%). Overall, 16% had stage IV disease (N2 = 15%, N3 = 16%). There was no significant difference in age (p = 0.37), tumor size (p = 0.89), tumor grade (p = 0.09), estrogen-receptor status (p = 0.23), or progesterone-receptor status (p = 0.35) between the N2 and N3 groups. Incidences of stage IV disease were T0/T1, 0%; T2, 6%; T3, 22%; and T4, 36%. Multivariate analysis demonstrated that only T stage (p = 0.0006) and grade (p = 0.026) were independent predictors of overall survival.

CONCLUSIONS

A metastatic workup is only indicated for N2/N3 patients with T3 or T4 primary lesions.

Evaluation of the evidence on staging imaging for detection of asymptomatic distant metastases in newly diagnosed breast cancer

While guidelines recommend against routine use of staging imaging to detect asymptomatic distant metastases (DM) in newly diagnosed breast cancer (BC), modern imaging technologies may have improved detection capability and may have a role in some cases. We performed a systematic review of studies (1995-2011) evaluating the prevalence of DM and the accuracy of staging imaging for detection of asymptomatic DM. Twenty-two studies reporting on 14,824 BC subjects (median age 53 years) undergoing staging imaging were eligible. Median prevalence of DM was 7.0% (range 1.2-48.8%); prevalence increased with increasing BC stage. Conventional imaging studies had lower DM prevalence than studies of PET(PET/CT). Imaging median sensitivity/specificity respectively were: combined conventional imaging 78.0%/91.4%; bone scintigraphy 98.0%/93.5%; chest X-ray 100%/97.9%; liver ultrasound 100%/96.7%; CT chest/abdomen 100%/93.1%; FDG-PET 100.0%/96.5%; FDG-PET/CT 100%/98.1%. Low prevalence of DM was seen in Stage I-II BC with much higher prevalence in more advanced disease. Accuracy of PET modalities was very high however the high proportion of detected asymptomatic DM partly reflects selection bias.

FDG-PET/CT in the staging of local/regional metastases in breast cancer

Breast cancer is the commonest female malignancy in the Western world and the most reliable predictor for survival is axillary lymph node metastases. Conventional staging techniques employed in breast cancer include mammography, ultrasonography, isotope bone scanning, sentinel lymph node biopsy, axillary lymph node dissection and magnetic resonance imaging. More recently FDG-PET and FDG-PET/CT have been used to complement the above methods. This review assesses the role of FDG-PET/CT in axillary staging in patients with primary breast cancer. A PubMed search was conducted and all articles containing relevant or new information were included. Relevant studies examined identified that FDG-PET/CT has a sensitivity of 60% and a specificity of 97% in detecting lymphatic metastasis. Although positive axillary FDG-PET/CT is a good predictor of axillary disease and correlates well with SLNB, the relatively poor sensitivity (60%) must be considered for treatment planning.

Radiopharmacological evaluation of 6-deoxy-6-[18F]fluoro-D-fructose as a radiotracer for PET imaging of GLUT5 in breast cancer

INTRODUCTION

Several clinical studies have shown low or no expression of GLUT1 in breast cancer patients, which may account for the low clinical specificity and sensitivity of 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) used in positron emission tomography (PET). Therefore, it has been proposed that other tumor characteristics such as the high expression of GLUT2 and GLUT5 in many breast tumors could be used to develop alternative strategies to detect breast cancer. Here we have studied the in vitro and in vivo radiopharmacological profile of 6-deoxy-6-[(18)F]fluoro-D-fructose (6-[(18)F]FDF) as a potential PET radiotracer to image GLUT5 expression in breast cancers.

METHODS

Uptake of 6-[(18)F]FDF was studied in murine EMT-6 and human MCF-7 breast cancer cells over 60 min and compared to [(18)F]FDG. Biodistribution of 6-[(18)F]FDF was determined in BALB/c mice. Tumor uptake was studied with dynamic small animal PET in EMT-6 tumor-bearing BALB/c mice and human xenograft MCF-7 tumor-bearing NIH-III mice in comparison to [(18)F]FDG. 6-[(18)F]FDF metabolism was investigated in mouse blood and urine.

RESULTS

6-[(18)F]FDF is taken up by EMT-6 and MCF-7 breast tumor cells independent of extracellular glucose levels but dependent on the extracellular concentration of fructose. After 60 min, 30±4% (n=9) and 12±1% (n=7) ID/mg protein 6-[(18)F]FDF was found in EMT-6 and MCF-7 cells, respectively. 6-deoxy-6-fluoro-d-fructose had a 10-fold higher potency than fructose to inhibit 6-[(18)F]FDF uptake into EMT-6 cells. Biodistribution in normal mice revealed radioactivity uptake in bone and brain. Radioactivity was accumulated in EMT-6 tumors reaching 3.65±0.30% ID/g (n=3) at 5 min post injection and decreasing to 1.75±0.03% ID/g (n=3) at 120 min post injection. Dynamic small animal PET showed significantly lower radioactivity uptake after 15 min post injection in MCF-7 tumors [standard uptake value (SUV)=0.76±0.05; n=3] compared to EMT-6 tumors (SUV=1.23±0.09; n=3). Interestingly, [(18)F]FDG uptake was significantly different in MCF-7 tumors (SUV(15 min) 0.74±0.12 to SUV(120 min) 0.80±0.15; n=3) versus EMT-6 tumors (SUV(15 min) 1.01±0.33 to SUV(120 min) 1.80±0.25; n=3). 6-[(18)F]FDF was shown to be a substrate for recombinant human ketohexokinase, and it was metabolized rapidly in vivo.

CONCLUSION

Based on the GLUT5 specific transport and phosphorylation by ketohexokinase, 6-[(18)F]FDF may represent a novel radiotracer for PET imaging of GLUT5 and ketohexokinase-expressing tumors.

Positron emission tomography (PET) for assessment of axillary lymph node status in early breast cancer: A systematic review and meta-analysis

PURPOSE

Sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) are used to assess axillary nodal status in breast cancer, but are invasive procedures associated with morbidity, including lymphoedema. This systematic review evaluates the diagnostic accuracy of positron emission tomography (PET), with or without computed tomography (CT), for assessment of axillary nodes in early breast cancer.

METHODS

Eleven databases including MEDLINE, EMBASE and the Cochrane Library, plus research registers and conference proceedings, were searched in April 2009. Study quality was assessed using the QUality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. Sensitivity and specificity were meta-analysed using a bivariate random effects approach.

RESULTS

Across 26 studies evaluating PET or PET/CT (n = 2591 patients), mean sensitivity was 63% (95% CI: 52-74%; range 20-100%) and mean specificity 94% (95% CI: 91-96%; range 75-100%). Across 7 studies of PET/CT (n = 862), mean sensitivity was 56% (95% CI: 44-67%) and mean specificity 96% (90-99%). Across 19 studies of PET-only (n = 1729), mean sensitivity was 66% (50-79%) and mean specificity 93% (89-96%). Mean sensitivity was 11% (5-22%) for micrometastases (≤2 mm; five studies; n = 63), and 57% (47-66%) for macrometastases (>2 mm; four studies; n = 111).

CONCLUSIONS

PET had lower sensitivity and specificity than SLNB. Therefore, replacing SLNB with PET would avoid the adverse effects of SLNB, but lead to more false negative patients at risk of recurrence and more false positive patients undergoing unnecessary ALND. The present evidence does not support the routine use of PET or PET-CT for the assessment of the clinically negative axilla.

(18)F-FDG PET/CT with Contrast Enhancement for Evaluation of Axillary Lymph Node Involvement in T1 Breast Cancer

BACKGROUND

(18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography ((PET) safely predicts axillary status in patients with breast cancer, but is not sufficiently accurate in early breast cancer patients. This study analyzed the value of (18)F-FDG PET/computed tomography (CT) with contrast enhancement in detecting axillary lymph node involvement in T1 breast cancer patients.

METHODS

Contrast-enhanced (18)F-FDG PET/CT was performed within 20 days of surgery in 143 breast cancer patients with tumors ≤2 cm in size. The patients underwent either axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB), and histopathology reports were used to provide the definitive diagnosis against which the contrast-enhanced (18)F-FDG PET/CT study results were compared.

RESULTS

The sensitivity, specificity, and negative and positive predictive values of contrast-enhanced (18)F-FDG PET/CT in detecting axillary involvement were 70.0%, 92.2%, 88.8%, and 77.8%, respectively, in the entire series of 143 patients, with eight false-positive and 12 false negative results. The false-negative results were associated with the number of metastatic lymph nodes and the rate of FDG uptake.

CONCLUSION

Contrast-enhanced (18)F-FDG PET/CT cannot replace histologic staging using SLNB in patients with breast cancer, but (18)F-FDG PET/CT increases the sensitivity for predicting axillary node metastasis, and allows for a selective approach to either ALND or SLNB, even in patients with T1 breast cancer.

FDG-PET and other imaging modalities for the evaluation of breast cancer recurrence and metastases: a meta-analysis

Background and purpose

Breast carcinoma is the most common cancer in female patients with a propensity for recurrence and metastases. The accuracy of ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), scintimammography (SMM) and positron emission tomography (PET) in diagnosing the recurrent and/or breast cancer has never been systematically assessed, and present systematic review was aimed at this issue.

Methods

MEDLINE and EMBASE were searched for articles dealt with detection of recurrent and/or metastatic breast cancer by US, CT, MRI, SMM or PET whether interpreted with or without the use of CT. Histopathologic analysis and/or close clinical and imaging follow-up for at least 6 months were used as golden reference. We extracted data to calculate sensitivity, specificity, summary receiver operating characteristic curves and area under the curve and to test for heterogeneity.

Result

In 42 included studies, US and MRI had highest pooled specificity (0.962 and 0.929, respectively); MRI and PET had highest pooled sensitivity (0.9500 and 0.9530, respectively). The AUC of US, CT, MRI, SMM and PET was 0.9251, 0.8596, 0.9718, 0.9386 and 0.9604, respectively. Results of pairwise comparison between each modality demonstrated that AUC of MRI and PET was higher than that of US or CT, p < 0.05. No statistical significance was found between MRI and PET. There was heterogeneity among studies and evidence of publication bias.

Conclusion

In conclusion, MRI seemed to be a more useful supplement to current surveillance techniques to assess patients with suspected recurrent and/or metastatic breast cancer. If MRI shows an indeterminate or benign lesion or MRI was not applicable, FDG-PET could be performed in addition.

Practical applications of nuclear medicine in imaging breast cancer

The rise in incidence, morbidity, and mortality of breast cancer has triggered multiple imaging efforts to detect this malignancy early, stage it accurately, and monitor it with precision in the posttherapeutic course. Among different imaging modalities, nuclear medicine provides an important contribution to the clinical management of breast cancer. This article discusses four practical applications based on the use of radionuclides in the evaluation of breast malignancy, focusing on scintimammography, preoperative tumor localization procedure using radioactive seeds, sentinel nodal scintigraphy, and F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Diagnostic value of full-dose FDG PET/CT for axillary lymph node staging in breast cancer patients

PURPOSE

The aims of this study were (1) to evaluate FDG PET/CT and CT for the detection of axillary lymph node metastases in breast cancer (BC) patients and (2) to evaluate FDG PET/CT as a pre-test for the triage to sentinel lymph node biopsy (SLNB) versus axillary lymph node dissection (ALND).

METHODS

The sensitivity, specificity, positive and negative predictive value (PPV, NPV), and accuracy of FDG PET/CT and CT for axillary lymph node metastases were determined in 61 patients (gold standard: histopathology). According to the equation "NPV = specificity (1-prevalence) / [specificity (1-prevalence) + (1-sensitivity) prevalence]" FDG PET/CT was evaluated as a triage tool for SLNB versus ALND.

RESULTS

The sensitivity, specificity, PPV, NPV and accuracy of FDG PET/CT was 58, 92, 82, 77 and 79% and of CT 46, 89, 72, 71 and 72%, respectively. Patients with an up to approximately 60% risk for axillary lymph node metastases appear to be candidates for SLNB provided that the axilla is unremarkable on FDG PET/CT.

CONCLUSION

FDG PET/CT cannot replace invasive approaches for axillary staging but may extend the indication for SLNB.

The impact of functional imaging on radiation medicine

Radiation medicine has previously utilized planning methods based primarily on anatomic and volumetric imaging technologies such as CT (Computerized Tomography), ultrasound, and MRI (Magnetic Resonance Imaging). In recent years, it has become apparent that a new dimension of non-invasive imaging studies may hold great promise for expanding the utility and effectiveness of the treatment planning process. Functional imaging such as PET (Positron Emission Tomography) studies and other nuclear medicine based assays are beginning to occupy a larger place in the oncology imaging world. Unlike the previously mentioned anatomic imaging methodologies, functional imaging allows differentiation between metabolically dead and dying cells and those which are actively metabolizing. The ability of functional imaging to reproducibly select viable and active cell populations in a non-invasive manner is now undergoing validation for many types of tumor cells. Many histologic subtypes appear amenable to this approach, with impressive sensitivity and selectivity reported.

For clinical radiation medicine, the ability to differentiate between different levels and types of metabolic activity allows the possibility of risk based focal treatments in which the radiation doses and fields are more tightly connected to the perceived risk of recurrence or progression at each location.

This review will summarize many of the basic principles involved in the field of functional PET imaging for radiation oncology planning and describe some of the major relevant published data behind this expanding trend.

Is there a role for positron emission tomography in breast cancer staging?

Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) is a radiotracer imaging method that is used in the care of patients with cancer. We conducted a nonsystematic review of the literature regarding the applicability of this technique in patients with breast cancer, encompassing the impact of FDG-PET on surgical management, including axillary node staging and sentinel lymph node biopsy; the use of FDG-PET in the evaluation of the primary tumor; the role of FDG-PET in the evaluation of distant metastases both at diagnosis and in the investigation of suspected recurrence; and the ability of FDG-PET to predict treatment response. FDG-PET is not sufficiently sensitive to replace histologic surgical staging of the axilla. Although FDG avidity of the primary tumor has been shown to be an unfavorable indicator, there is insufficient information to recommend its routine use for this indication. FDG-PET is more sensitive than conventional imaging in the detection of metastatic or recurrent disease, but the impact of increased sensitivity on patient care and outcome has not been demonstrated. The data regarding prediction of treatment response are insufficient to reach any conclusion. There are a number of prospective, adequately powered clinical trials currently in progress that should provide more definitive answers regarding the role, if any, of this technique in the management of patients with breast cancer.

Standardized Uptake Values for Breast Carcinomas Assessed by Fluorodeoxyglucose-Positron Emission Tomography Correlate with Prognostic Factors

Several studies have revealed the diagnostic value of fluorodeoxyglucose-positron emission tomography for breast carcinomas. However, breast carcinomas display considerable variation in 18F-labeled 2-fluoro-2-deoxy-D-glucose uptake, and few papers have reported the clinical utility of the standardized uptake values (SUV). The purpose of this study is to investigate the relationship between SUV assessed by positron emission tomography (PET) and the clinicopathological characteristics of breast carcinoma. We reviewed 52 breast carcinomas of 45 patients presented at our department between January 2004 and July 2005. We compared the histopathological findings of the breast carcinomas with the preoperative SUV. Of the 52 breast carcinomas, 49 (94%) were detected by preoperative PET. A positive correlation was found between the SUV and tumor size ( P < 0.01), histological grade ( P < 0.01), the expression of the estrogen receptor ( P < 0.001), progesterone receptor ( P < 0.01), and p53 ( P < 0.01). The number of metastatic axillary lymph nodes (r = 0.73; P < 0.0001) and the MIB-1 labeling rates (r = 0.5; P < 0.01) correlated with the SUV of the breast carcinomas. No relationship existed between the SUV and the following: histological tumor types ( P = 0.07), human epidermal growth factor receptor-2 status ( P = 0.10), and the presence of metastatic lymph nodes ( P = 0.10). The SUV of the breast carcinomas correlate with several histopathological and immunohistochemical prognostic factors. We can obtain information on the degree of malignancy of the carcinoma and prognostic factors by preoperative PET examination.

PET/CT in oncology: for which tumours is it the reference standard?

Positron emission tomography (PET)/computed tomography (CT) has a growing role in the imaging of many cancers. As our experience has grown over the past number of years so has our understanding for which cancers it is particularly useful. The value of PET/CT at each stage of the cancer journey is different for each cancer. This review attempts to tease out the role of PET/CT in the common cancers with particular emphasis on where it is the imaging investigation of choice.

Alternative Breast-Imaging Approaches

Although conventional breast-imaging techniques routinely include mammography and ultrasound, growing interest in other approaches, perhaps most notably MR imaging, has drawn increasing attention to exploiting the anatomic and physiologic basis for understanding breast cancer. Nuclear medicine techniques have been applied in several circumstances with the intent of approaching or defining a role for molecular imaging, exemplified by the use of F-18 fluorodeoxyglucose and positron emission tomography. Other techniques, including exploitation of additional components of the electromagnetic spectrum, have provided novel concepts that may ripen into clinical use.

Therapeutic impact of 2-[fluorine-18]fluoro-2-deoxy-D-glucose positron emission tomography in the pre- and postoperative staging of patients with clinically intermediate or high-risk breast cancer

BACKGROUND

Positron emission tomography with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG-PET) is an accurate imaging modality for the staging of breast cancer. The aim of this study was to determine the potential therapeutic impact of pre- and postoperative FDG-PET in patients with clinically intermediate or high-risk breast cancer.

PATIENTS AND METHODS

One hundred and fourteen patients with newly diagnosed breast cancer were examined before (73) or after (41) surgery. Patient data were translated into three scoring sheets corresponding to information available before positron emission tomography (PET), after PET and after further diagnostic tests. Three medical oncologists independently reviewed the retrospectively acquired patient data and prospectively made decisions on the theoretically planed treatment for each time point, according to the recommendations of St Gallen Consensus Guidelines 2005.

RESULTS

FDG-PET changed the planed treatment in 32% of 114 patients. In 20% of cases, therapeutic intention (curative versus palliative) was modified. Radiation treatment planning was changed in 27%, surgical planning in 9%, chemotherapy in 11% and intended therapy with bisphosphonates in 13% of all patients.

CONCLUSION

Based on current treatment guidelines, FDG-PET, as a staging procedure in patients with newly diagnosed clinically intermediate or high-risk breast cancer examined pre- and postoperatively, may have a substantial therapeutic impact on treatment planning.

PET/CT: form and function

Functional imaging with positron emission tomography (PET) is playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. PET with the labeled glucose analogue fluorine 18 fluorodeoxyglucose (FDG) is a relatively recent addition to the medical technology for imaging of cancer, and FDG PET complements the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance imaging. CT is complementary in the sense that it provides accurate localization of organs and lesions, while PET maps both normal and abnormal tissue function. When combined, the two modalities can help both identify and localize functional abnormalities. Attempts to align CT and PET data sets with fusion software are generally successful in the brain; other areas of the body is more challenging, owing to the increased number of degrees of freedom between the two data sets. These challenges have recently been addressed by the introduction of the combined PET/CT scanner, a hardware-oriented approach to image fusion. With such a device, accurately registered anatomic and functional images can be acquired for each patient in a single scanning session. Currently, over 800 combined PET/CT scanners are installed in medical institutions worldwide, many of them for the diagnosis and staging of malignant disease and increasingly for monitoring of the response to therapy. This review will describe some of the most recent technologic developments in PET/CT instrumentation and the clinical indications for which combined PET/CT has been shown to be more useful than PET and CT performed separately.

Digital documentation of the physical examination: moving the clinical breast exam to the electronic medical record

BACKGROUND

Documentation of the clinical breast examination (CBE) has consisted of simple hand-drawings and stick figures without a common lexicon. There is a need for a device that can accurately depict the CBE in digital format while being objective, reproducible over time, and useable in the electronic medical record. This new device is called palpation imaging (PI).

METHODS

We examined 110 patients with a complaint of a breast mass using PI. This laptop-sized device creates a real-time digital display of the palpable area in both video and still formats. The size, hardness, shape, homogeneity, and mass location may be extracted from the image.

RESULTS

Of those with a true mass, PI identified the mass in 94% while physical examination identified 86%. The positive predictive value (PPV) for breast cancer using PI was 94% and 78% for physical examination. A survey of primary care physicians revealed the inclusion of the PI record in a consultation note implied competence, experience, and skill by the surgeon.

CONCLUSIONS

PI documented the CBE in a timely, efficient, and accurate manner. A reproducible record allows objective review by multiple examiners at varied times. Continued work will optimize examination methods.

Physics and imaging for targeting of oligometastases

Oligometastases refer to metastases that are limited in number and location and are amenable to regional treatment. The majority of these metastases appear in the brain, lung, liver, and bone. Although the focus of interest in the past within radiation oncology has been on the treatment of intracranial metastases, there has been growing interest in extracranial sites such as the liver and lung. This is largely because of the rapid development of targeting techniques for oligometastases such as intensity-modulated and image-guided radiation therapy, which has made it possible to deliver single or a few fractions of high-dose radiation treatments, highly conformal to the target. The clinical decision to use radiation to treat oligometastases is based on both radiobiological and physics considerations. The radiobiological considerations involve improvement of treatment schema for time, dose, and volume. Areas of interests are hypofractionation, tumor and normal tissue tolerance, and hypoxia. The physics considerations for oligometastases treatment are focused mainly on ensuring treatment accuracy and precision. This article discusses the physics and imaging aspects involved in each step of the radiation treatment process for oligometastases, including target definition, treatment simulation, treatment planning, pretreatment target localization, radiation delivery, treatment verification, and treatment evaluation.

The role of FDG-PET/CT in suspected recurrence of breast cancer

BACKGROUND

Early diagnosis of recurrent breast cancer is crucial to selection of the most appropriate therapy. The current study evaluated the role of FDG-PET/CT in the assessment of suspected recurrent breast cancer in patients who presented with elevated serum tumor markers.

METHODS

Forty-seven consecutive FDG-PET/CT studies of 46 women (aged 32-79 years; mean, 59.9 years) with a history of breast cancer presented with elevated serum tumor markers 1-21 years (mean = 6.2 years) after their initial diagnosis and were retrospectively evaluated. PET/CT results were confirmed by pathology (n = 11), further imaging, and follow-up (mean = 17.2 months; n = 36). Changes in further management based on PET/CT were recorded.

RESULTS

Thirty (65%) patients had tumor recurrence, and 16 (35%) patients showed no further evidence of disease. Thirty-one patients had 32 abnormal PET/CT studies, and 15 patients had normal studies with an overall sensitivity, specificity, and accuracy of 90%, 71%, and 83%, respectively. In 37 patients, PET/CT was compared with contrast-enhanced CT and had a higher sensitivity (85% vs 70%), specificity (76% vs 47%), and accuracy (81% vs 59%). PET/CT had an impact on the management of 24 (5l%) patients. Of these, chemotherapy or radiotherapy was started in 16 patients, treatment was modified in 2 patients, and 6 patients were referred to biopsy, followed by referral to surgery for 2 patients.

CONCLUSIONS

In patients with breast cancer and rising tumor markers, FDG-PET/CT had high performance indices and was superior to CT for diagnosis of tumor recurrence, which led to changes in the subsequent clinical management of 51% of these patients.