North West Sydney Dermatology & Laser
Ph. (02) 9629 7341
Pigmented nodular BCC 1.1mm depth.
Following biphasic PDT - 2 treatments. Clear on high res imaging (OCT) (scar is pre-existing & unrelated)
after treatment
Pigmented nodular BCC 1.1mm depth.
please note that you can click on the pictures above to freeze the transitioning
Biphasic Photodynamic Treatment (Biphasic PDT)
Photodynamic treatment (PDT) is a non-invasive treatment where skin cancer cells are selectively destroyed and normal skin cells are spared. It is a truly remarkable treatment which has very little risk and excellent cosmetic results. The protocol involves application of a porphyrin cream - the porphyrin is sensitive to light and selectively accumulates in cancer cells as they lack an enzyme involved in its metabolism. The cream is left on for a few hours (the "incubation" period) and the area is then exposed to intense light ("activation").
Of all treatments for basal cell skin cancer (BCC), it is PDT that has the least likelihood of scarring.
The problem with the standard photodynamic protocol (i.e. activation using red light alone) is that incomplete clearance rates run at around 20-30%. This protocol has not been updated since its inception over 25 years ago.
Biphasic PDT is a new, enhanced protocol that was developed to overcome this problem.
Biphasic PDT was peer-reviewed and our preliminary results were published in 2020 in the Journal of the European Academy of Dermatology & Venereology (1).
A more recent paper with more extensive data was published in July 2025 (2). We demonstrated a 98% clearance rate for BCCs up to 1 mm thickness. This paper is in open access format and can be viewed here. The published graphical abstract is shown below.
We now consider that biphasic PDT, when performed under guidance with OCT imaging, is the treatment of choice for superficial BCCs and for many thin nodular tumours.
This is particularly so when an excellent aesthetic outcome is important.
1. Stephens R, Holmes J, Eadie E. Lesion compression during light activation may improve efficacy of photodynamic treatment of basal cell carcinoma: preliminary results and rationale. J Eur Acad Dermatol Venereol. 2020 Oct;34(10):e628-e630. doi: 10.1111/jdv.16503. Epub 2020 May 19. PMID: 32311807.
2. Stephens, Robert & Anderson, Chris & Saager, Rolf & Johnston, Antony & Adybeik, Dariush. (2025). Photodynamic Treatment of 206 Thin (≤ 1 mm) Basal Cell Carcinomas Using a Biphasic Activation Protocol: The Outcomes Over a 7‐Year Period and the Rationale Behind the Treatment. JEADV Clinical Practice. 10.1002/jvc2.70115.
The Protocol
Photodynamic treatment of skin cancer at our clinic is a 3 stage process. Having the imaging technology means that diagnosis and curative treatment can potentially be completed on the same day for very thin BCCs. This is without any needles, without any cutting, without any stitches and with minimal (if any) scarring. The stages are summarised below:
1. ASSESSMENT
An OCT scan is performed to confirm a diagnosis of skin cancer - a biopsy is generally not required. The scan will show the precise depth of the cancer down to 1/100th of a millimetre* (see the image above). Other aspects of the tumour (that are recognisable on OCT) will determine if biphasic photodynamic treatment is suitable.
2. INCUBATION WITH PHOTOSENSITISER
A special photosensitising cream is applied to the tumour and this is left under a dressing for a few hours. The ingredient in the cream will be converted to a light-activated molecule which selectively accumulates in skin cancer cells.
3. ACTIVATION WITH LIGHT
Two types of intense light will then be used to illuminate the area ("biphasic activation"):
The first illumination is with red light (wavelength: 630nm), delivered by a bright LED lamp.
After 8 minutes of red light, or, at the point when flushing is noticeable, the light source is switched to an intense pulsed light device (IPL). High irradiance white light is then delivered with mechanical pressure onto the skin. The mechanical pressure is in order to drain the skin of blood whilst light is being delivered. This optimises delivery of light and enhances penetration. The technique is demonstrated in the video further below.
It is during the illumination process that a chemical reaction occurs within the tumour cells. They are destroyed. The normal healthy cells are spared. This means tumour removal with faster healing and less scarring.
* OCT is extremely high resolution but image quality generally detiorates at depths over 1 mm.
If the tumour is too thick for biphasic PDT, we can excise it in our rooms.
Some tumours are best treated by having biphasic PDT prior to surgery. This is appropriate for tumours which have a broad superficial component and a smaller, deeper component. This can result in a much smaller cut and a simpler repair. It will often mean having a simple side-to-side closure rather than more complicated / more expensive or disfiguring surgery like a skin graft.
Sometimes only some spot cautery is needed for deeper tumour following biphasic treatment.
