Proposal of thermal imaging application in photodynamic therapy-Preliminary report

- The increase of observed isotherm area may suggest the range of therapy.
- Isotherm areas change their dimensions during therapy.
- It can be connected with heat transport and partly with the range of tumor cell occurrence.
- Thermovision may be helpful in describing the range and effects of therapy however further studies are necessary.

There are many different skin lesions that manifest a skin temperature gradient. Basal cell carcinoma (BCC) is the most frequently occurring type of malignant skin lesion (almost 95% of all skin tumors). BCC is sometimes treated by using photodynamic therapy which is very well tolerated by patients and provides good results, especially in superficial skin layer lesions.The results of our studies showed significant changes in the area of temperature gradient due to photodynamic therapy. It seems that the ability to acquire knowledge of such area changes may provide additional useful information to physicians. The increase of observed isotherm area in comparison to lesion size on the skin was a few times higher. It may suggest the range of areas where the metabolism processes take place. Due to the accumulation of photosensitivity only in tumor cells, we theorize that such a large region of increased metabolism observed during therapy may be connected with a larger range of tumor cells than was previously predicted through diagnosis. However, it should be noted that the region can be much bigger due to the existing heat transfer. The results obtained have a potential meaning in describing the range of chemical and physiological processes occurring during photodynamic therapy.