Optical vulvar biopsy by optical coherence tomography (OCT)

Optical coherence tomography (OCT) is an emerging biomedical optical imaging
technique that performs high resolution, cross sectional tomographic imaging
generating pictures that resemble histopathological examination1. By this high
resolution OCT functions as a type of *optical biopsy* providing cross
sectional images of tissues in analogy to histopathology but without removal or
staining tissue. Presently, OCT is widely used in ophthalmology where it has
become a key diagnostic tool in the areas of retinal disease and glaucoma.
Vulvar intraepithelial neoplasia (VIN) is a premalignant disease, caused by
HPV16 with often severe and long-lasting complaint. The progression rate to
cancer is about 8% without treatment. The presence of an occult carcinoma at
diagnosis is 3.2%, although in several studies it is as high as 20.5%. The
incidence of VIN is increasing dramatically the last three decades. Standard
management of the patients consisted until recently of taking multiple
*mapping* biopsies to exclude invasion followed by conservative surgical
excisions and/or laser vaporization, however every attempt is made to avoid
vulvar mutilation1. In 2008 the application of imiquimod, an local immune
modulating agent, became the standard treatment, giving a complete remission
rate of VIN of 35% and a partial remission rate of 46%. With this conservative
management, however, there is an urgent need for an effective diagnostic tool
to foresee occult invasion. Optical coherence tomography (OCT) might be such a
test. OCT has been shown to be useful in the qualitative and quantitative
assessment of normal skin. In the cervix uteri it improves the sensitivity and
specificity of coplopscopy for high grade cervical intraepithelial neoplasia
(CIN) to 76% resp 61%. It was never evaluated in vulvar skin or VIN.

To determine the diagnostic value of OCT in patients with (suspicion of) vulvar
intraepithelial neoplasia and in patients with vulvar cancer.

It is a prospective observational study. In total 100 measurements will be made
in 25 patients. The OCT images will be correlated to the histopathological
results. In patients with (suspicion of) vulvar intraepithelial neoplasia, in
whom during the diagnostisc work-up or during follow up a diagnostic biopsy has
to be taken, the vulvar skin at the place of the biopsy will be scanned with
the OCT device. In patients with vulvar cancer the vulvar skin will be scanned
with the OCT device within the resection margins . A maximum of 5 biopsies will
be taken.

OCT is harmless, it uses light that enters the skin several mm. Presently, OCT
is widely used in ophthalmology where it has become a key diagnostic tool in
the areas of retinal disease and glaucoma. Patient's gynaecologic exam is
extended with 15 minutes or the operation is extended with 15 minutes.