Assessment of Blood Vessel Density in Kaposi's Sarcoma Lesions

The purpose of this study is to develop imaging techniques to determine the density of blood vessels and the amount of blood flow in Kaposi s sarcoma (KS) tumors. KS tumors depend on the formation of new blood vessels for their growth. Some experimental therapies for KS are directed at reducing the amount of blood vessels and blood flow in these lesions. Measurement of blood vessel density and blood flow in these lesions could be useful in evaluating the effectiveness of both standard and experimental treatments for this disease.

Patients 18 years of age or older with Kaposi's sarcoma involving the skin may be eligible for this study. Participants will have photographs taken of their lesions and will undergo three imaging procedures (described below) at the beginning of the study (baseline) and then about once every 3 months or so while on the study (up to 2 years) to compare the test results over time. (Imaging may be done at more or less frequent intervals depending on the findings.) A small amount of blood (less than a tablespoon) will be drawn the day of each imaging procedure.

Laser Doppler imaging This technique measures the amount of blood flow in KS lesions by scanning the lesions with a low-power laser beam. Each lesion takes about 3 minutes to scan. The imaging may be done before and after a blood pressure cuff around the arm is inflated for a short time (usually less than 30 seconds).

Multi-spectral imaging This technique uses light to measure the total blood volume in each lesion and how much oxygen is in the blood. Oxygen is carried to the body s cells by a protein in red blood cells called hemoglobin. The light on the multi-spectral imaging instrument is absorbed differently depending on whether the hemoglobin has oxygen attached to it or not. It takes about 2 minutes to scan each lesion.

Infrared thermal imaging This test uses a special camera to take digital infrared pictures of the skin. Images formed of the temperature of the KS lesions are used to assess blood flow in the lesions. This imaging takes about 1 minute per lesion.

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Background:

Kaposi's sarcoma is a highly vascular tumor. As such, it may provide a good model for the study of angiogenesis-based therapy in cancer. However, there are no standardized techniques now available to assess the effects of anti-angiogenesis therapy on blood flow in KS tissues. The present protocol was written to allow us to explore and gain experience with four promising techniques to examine tumor vasculature in cutaneous KS lesions: a) laser Doppler imaging; b) multi-spectral imaging; c) infrared thermal imaging; and d) optical coherence tomography.

Objectives:

The main objective is to assess, in preliminary fashion, non-invasive methods for studying tumor vascularity and vascular changes in patients with Kaposi's sarcoma using four different imaging techniques. Other objectives are to correlate these techniques to each other and to conventional KS tumor assessment, and to assess the response of these techniques in patients receiving therapy for Kaposi s sarcoma.

Eligibility:

Patients 18 of more years of age with biopsy-proven cutaneous Kaposi's sarcoma involving the skin or mucosa are eligible. They must be willing and able to give informed consent.

Design:

This will be a preliminary study to explore these techniques in Kaposi's sarcoma. Selected Kaposi's sarcoma lesions of patients will be assessed using laser Doppler imaging, multi-spectral imaging, infrared thermal imaging, and optical coherence tomography at entry and then additional time points for up to 4 years. Lesions will also be assessed by conventional measurement and photographs with conventional cameras. In selected patients in which there are Kaposi's sarcoma lesions on the arm, the effects of stopping venous flow for up to 10 seconds will be assessed on the measurements. A complete blood count will be done the day of the measurements. The results of the imaging techniques will be compared with each other, and with conventional tumor assessments. Changes over time will be assessed.

Eligibility Criteria:
* INCLUSION CRITERIA:

Biopsy proven Kaposi's sarcoma involving the skin or mucosa.

Age greater than or equal to 18 years.

EXCLUSION CRITERIA:

Unable or unwilling to give informed consent.