Photodynamic
Diagnostic (PDD) is a non-invasive
diagnostic technique for detecting surface and near surface
tumors. After taking the photosensitizer, the body is scanned
with a red laser. Fluorescent radiation from the activated photosensitizer
inside the tumors is detected with a camera fitted with a red
filter and displayed on a TV screen or computer. Cancer shows
up as fluorescent areas of various shapes and sizes.
Although PDD works for a number
of cancers, PDD works best on
Breast and Skin Cancer because
the cancer is near the surface of the body. PDD
has the ability to detect cancer at its earliest stages well
before it become a tumor. At the present time the mammogram
is the accepted diagnostic tool for detecting breast cancer.
From day one through 3 years cancer is undetectable using a
mammogram. Cancer cells could possibly be present 3 years before
they are detectable by a mammogram, and by the time the cancer
is detected by mammogram in the form of a lump/tumor the cancer
as been present from 6 to 10 years. This year over 211,000 women
in the United States will be diagnosed with breast cancer and
over 40,000 will die. The obvious key to surviving breast cancer
is the earliest possible detection. Photodynamic
Diagnostic (PDD), as detailed below, offers the earliest
possible detection of Breast Cancer (see case history
Patient "A" under patient results). Photodynamic
Diagnostic (PDD) becomes less effective on deeper tumors
because:
a. The activating light energy rapidly declines as the
light passes through tissue and bone.
b. The deeper the tumor, the smaller the fraction of emitted
light detected by the camera. |
With the obvious importance of early diagnosis in cancer,
Photodynamic Diagnostic (PDD)
will become the diagnostic tool of the future. This is all
made possible by the unique aspects of our next generation
photosensitizers XyChloro®
(see section under technology comparison)
With appropriate patients, Photodynamic
Diagnostic (PDD) is an excellent diagnostic technique.
We have used PDD to detect
about 80 tumors in a patient with late stage melanoma, and
most of these tumors could not be detected any other way.
With deeper tumors we must rely on more conventional diagnostic
techniques at this time along with changes in patient symptoms
to monitor treatment progress.
An approved diagnostic tool for Cancer
Karl Storz PDD set
Visible example
in patients of how the activating light in XPDT is absorbed
by the
sensitizer and re-emitted as fluorescent radiation for Photodynamic
Diagnostic (PDD).
Tumor Before Agent |
Agent Selectively attaches to Tumor |
|
Squamous cancer on floor of mouth (Before)
|
After agent tumor fluorescence
|
|
Before
|
After agent tumor fluorescence
|
| Squamous cancer right vocal cord |
|
Photodynamic diagnosis of
breast cancer.
The white spots are metastases.
|
 |
 |
|
Accumulation on ovarian
cancer in incision
|
 |
In Photodynamic Diagnostic (PDD)
how do we know that what we are seeing is cancer? Firstly
because when PDD is done before
surgery, the large spots detected by PDD
can be confirmed as cancer by histopathology. Secondly because
after (XPDT) treatment, these spots usually disappear. This
would not occur if the fluorescence were due to scarring or
other artifacts. For surface and near-surface tumors, this
is a very sensitive diagnostic technique, which often detects
metastases not found by other screening techniques.
Additionally we can confirm that XyChloro Photodynamic Therapy
(XPDT) kills metastases by using conventional scanning techniques
such as CT scans, by pathology and by improvements in the
patient's symptoms.
We can often directly observe the tumor destruction process
as our therapy proceeds. We can literally see surface and
near surface tumors using Photodynamic
Diagnosis (PDD). At the start of therapy, a patient may
have six visible tumors. As therapy progresses, these disappear.
The smallest ones go first, then the larger tumors. As stated,
PDD with near surface tumors
is very sensitive and detects tumors much better than other
diagnostic techniques. Being free from cancer as shown by
PDD can be a much stronger
statement then being free from cancer as shown by other diagnostic
techniques.
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