Quantification of narrow band UVB radiation doses in phototherapy using diacetylene based film dosimeters.

Narrow band ultraviolet B (NB UVB) radiation doses are administered during phototherapy for various dermatological ailments. Precise quantification of these doses is vital because the absorbed irradiation can cause adverse photochemical reactions which can lead to potential phototherapeutic side effects. The paper presents development of diacetylene based dosimeter for the determination of therapeutic NB UVB doses during phototherapy. The amide terminated diacetylene analogues have been synthesized by tailoring them with different functional groups. The synthesized diacetylene monomers have been introduced in a polyvinyl alcohol binder solution to obtain a film dosimeter. The influence of different headgroups on the colorimetric response to UV radiation has been studied. Among all the synthesized diacetylene analogues, the naphthylamine substituted diacetylene exhibited excellent color transition from white to blue color at 100 mJ cm-2 NB UVB radiation dose. The developed amide films can be easily pasted on multiple sites of the patient's skin to monitor doses during phototherapy simultaneously at different anatomical regions. The digital image processing of the scanned images of the irradiated films facilitates rapid dose measurement which enables facile implementation of the developed film dosimeters and promising application in routine clinical dosimetry.