Assessment of Blood Vessel Density in Kaposi's Sarcoma Lesions
Condition: Kaposi's Sarcoma
MeSH terms: Sarcoma, Kaposi; Sarcoma
Study type: Observational

Summary: 
      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.

      ...
    

Detailed description: 
      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.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Subject selection will primarily be from patients with Kaposi's Sarcoma enrolled on other
        protocols in the human immunodeficiency virus (HIV) and Acquired immunodeficiency syndrome
        (AIDS) Malignancy Branch. Other sources will be referrals from other institutes and
        physicians.
      
Keywords: Kaposi Sarcoma; Doppler; Infrared; HIV; Imaging; Kaposi's Sarcoma; Laser Imaging; Infrared Imaging