Primary and metastatic breast carcinoma: initial clinical evaluation with PET with the radiolabeled glucose analogue 2-[F-18]-fluoro-2-deoxy-D-glucose

Overexpression of Glut-1 glucose transporter in human breast cancer. An immunohistochemical study

BACKGROUND

Breast cancers have higher than normal glucose metabolism, but the mechanism of glucose entry into these tumors is not well understood.

METHODS

The expression of five facilitative glucose transporters, Glut-1 (erythrocyte type), Glut-2 (liver type), Glut-3 (brain type), Glut-4 (muscle/fat type), and Glut-5 (small intestine type), was studied by immunohistochemistry of paraffin sections from 12 primary human breast cancers and 8 lymph node metastases from 2 patients. Rat tissues known to express these glucose transporters were used as controls.

RESULTS

All the primary breast cancers and the lymph node metastases were positive for Glut-1. This transporter was expressed on the cell membrane and in the cytoplasm of the tumor cells, but exhibited marked intratumoral and intertumoral variability in the proportions of positive cells and the intensity of staining. Staining of the normal mammary epithelium, if present, was much lower than observed in tumor cells from the same patient. Glut-2 was expressed in all of the tumors, but the intensity of staining was not consistently stronger than that seen in healthy breast. Clusters of Glut-4-positive granule were observed in cells in six of the tumors. None of the tumors or the healthy breast in the tissues studied expressed Glut-3 or Glut-5.

CONCLUSIONS

Higher expression of the glucose transporter Glut-1 by breast cancer cells compared with the healthy breast tissue is common. Increased glucose transporter protein expression may contribute to the increased uptake of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) by these tumors observed by positron emission tomography (PET) imaging.

Imaging of pulmonary mass lesions with whole-body positron emission tomography and fluorodeoxyglucose

BACKGROUND

The clinical staging and management of both primary and metastatic lung lesions depends on accurate imaging techniques. Biochemical imaging with positron emission tomography, (PET), and the glucose analog 2-[18F]-fluoro-2-deoxy-D-glucose, (FDG), complements anatomic imaging with conventional radiologic methods.

METHODS

A new "whole-body" PET FDG technique that produces two-dimensional, nontomographic and tomographic longitudinal images of the entire body has been developed at UCLA. Sixteen patients with known pulmonary nodules who had undergone thoracic computed tomography (CT) were studied with whole-body PET FDG imaging at the UCLA Medical Center.

RESULTS

This PET FDG imaging method identified metabolically active tumor foci in all eight patients with bronchogenic carcinomas, four patients with metastatic lesions to the thorax, and two patients with Hodgkin disease. All diagnoses were confirmed histologically. Additionally, the PET FDG technique detected extrathoracic metastases in 4 of 16 patients. Thoracic CT was not diagnostic of neoplasm in two of the eight patients with bronchogenic carcinomas. In one patient with an ACTH-producing bronchial carcinoid, the lesion ultimately was detected on high-resolution CT but was not metabolically active on PET FDG imaging.

CONCLUSIONS

This is the first report of whole-body PET FDG imaging in patients with thoracic lesions. PET FDG imaging accurately detected metabolically active tumor (both intrathoracic and extrathoracic) in patients with bronchogenic carcinoma, pulmonary metastatic disease, and Hodgkin lymphoma. Because lung cancer is characteristically a multisystem disease, this whole-body PET FDG technique has significant implications for treatment planning.

Positron emission tomography with fluorine-18-deoxyglucose in the detection and staging of breast cancer

BACKGROUND

An increasing number of patients with breast cancer is being treated with preoperative chemotherapy. Evaluation of treatment response may be facilitated by positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG). This noninvasive technique may allow prediction of the chemotherapy outcome in an early phase of the treatment.

METHODS

Prerequisites for treatment monitoring with PET are good FDG uptake in the tumor, high specificity, and a reliable quantification technique. These factors were studied in 20 patients with primary breast cancer, lymph node metastases, benign breast lesions, a combination of these abnormalities, or no abnormality.

RESULTS

In 10 of 11 patients with primary breast cancer, the tumor was visualized. The median tumor-to-normal-tissue-uptake ratio was 4.9. In all five patients with increased uptake in the lymph node basin, pathologic proof of metastatic cancer was found. Of the patients with benign or no disease of the breast, slightly increased uptake was seen in one patient with fibrocystic disease.

CONCLUSION

It is concluded that PET with FDG can be used for breast cancer imaging and staging.

An animal model for in vivo evaluation of tumor glycolytic rates with positron emission tomography

We developed a method for evaluating tumor glycolytic rates in vivo with nude mice injected with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) and a dedicated animal positron emission tomography (PET) scanner. Animals were injected with NR-6 mouse fibroblast tumor cell lines. When tumors achieved a large enough size to be macroscopically visible, quantitative measurements of FDG uptake in vivo were obtained, using both standard nonlinear regression with the FDG tracer kinetic model to generate estimates of model parameters, including KNLR, the rate constant for net phosphorylation of FDG. Additionally, we determined the values of KPAT, the rate constant for net phosphorylation of FDG measured with a non-iterative graphical method. Estimates of K were highly correlated (r = 0.95) with both methods, and parametric images of KPAT demonstrate both the tumor location and size, but are also scaled in units of phosphorylation of FDG. The method is suitable for serial studies of tumor glucose metabolism during and after therapeutic interventions, such as chemotherapeutic trials.

Glucose effects in an ovarian cancer protocol of exceptional activity

A French multidrug protocol for stage III ovarian cancer has achieved 77% pathologic complete response, 100% total response, and 81% actuarial 4-year survival. Our analysis indicates that these rates exceed typical with very high statistical significance. Yet neither the drugs, the combined intravenous and intraperitoneal mode of delivery, nor potential bias in the predominantly suboptimal patient population appear to explain the protocol's exceptional results. Here we propose that the atypical administration of intraperitoneal glucose prior to drugs underlies the unusual activity of this protocol. We review studies demonstrating that high-dose glucose has pronounced effects on cancer cells, most notably, substantial potentiation of certain antineoplastic agents. We consider possible mechanisms of such glucose potentiation, including hypothesized osmotic effects that would be especially strong under intraperitoneal administration. We conclude that the French ovarian cancer protocol may represent a significant advance and that glucose potentiation may be more widely applicable as an adjunct to cancer chemotherapy.

Genitourinary tract nuclear oncology

Currently available routine radionuclide procedures and on-going investigational scintigraphic studies of genitourinary tract tumors were reviewed. Emphasis was focused on the most commonly encountered tumors located in the kidneys, bladder, and prostate. Other imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), and sonography have replaced many of the routine radionuclide imaging procedures providing high-resolution images and anatomic details. The advantages of radionuclide procedures with their simple, uninvasive, and functioning nature will continue play important role in our management of tumors of the genitourinary tract.

The role of positron emission tomography in oncology and other whole-body applications

Imaging and quantifying biochemical and physiological processes with PET clearly has major potential significance for all organ systems and many disease states. Although the full utility and potential of emerging new applications of PET in organs other than the heart and brain must be demonstrated in basic and clinical research studies, the rapidly accumulating aggregate experience in oncology in particular, and in other organ systems and disease states as well, indicates that PET is now truly becoming a modality of both clinical and investigative use for the body as a whole as well as for specific organ systems. Whole-body PET FDG imaging (Fig 9) illustrates the potential of biochemical imaging to map the distribution of cancer throughout the body. With the growing list of radiopharmaceutical and quantitative techniques applicable to cancer studies with PET, this field will continue to realize significant growth.

The application of positron emission tomographic imaging with fluorodeoxyglucose to the evaluation of breast disease

Positron emission tomography (PET) is a computer-aided tomographic imaging technique that uses positron-emitting compounds to trace biochemical processes of tissue, and construct images based on them. The authors applied a whole-body PET imaging technique to patients with breast masses or mammographic abnormalities using the isotope 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG), in a clinical trial to evaluate the feasibility of using PET to identify primary breast cancer, axillary lymph node involvement, and systemic metastases, before surgical resection. Fourteen patients have been entered on this study, 10 of whom proved to have breast cancer. Positron emission tomography correctly predicted the nature of 12 of the 14 primary breast lesions, and correctly determined the lymph node status of 11 of the 14 patients. The authors conclude that PET with FDG has potential as a diagnostic modality for detection of primary breast cancer, particularly in the patient with radiodense breasts by conventional mammography, and that it has potential for the preoperative identification of axillary lymph node metastases.

Cyclotrons and positron emission tomography radiopharmaceuticals for clinical imaging

Positron emission tomography (PET) requires positron-emitting radionuclides that emit 511-keV photons detectable by PET imagers. Positron-emitting radionuclides are commonly produced in charged particle accelerators, eg, linear accelerators or cyclotrons. The most widely available radiopharmaceuticals for PET imaging are carbon-11-, nitrogen-13-, and oxygen-15-labeled compounds, many of which, either in their normal state or incorporated in other compounds, serve as physiological tracers. Other useful PET radiopharmaceuticals include fluorine-18-, bromine-75-, gallium-68 (68Ga)-, rubidium-82 (82Rb)-, and copper-62 (62Cu)-labeled compounds. Many positron emitters have short half-lives and thus require on-site cyclotrons for application, and others (68Ga, 82Rb, and 62Cu) are available from radionuclides generators using relatively long-lived parent radionuclides. This review is divided into two sections: cyclotrons and PET radiopharmaceuticals for clinical imaging. In the cyclotron section, the principle of operation of the cyclotron, types of cyclotrons, medical cyclotrons, and production of radionuclides are discussed. In the section on PET radiopharmaceuticals, the synthesis and clinical use of PET radiopharmaceuticals are described.