Thermographic spectrum of breast radiotherapy and occurrence of acute radiation dermatitis: results of a prospective trial on 64 patients

we examine the feasibility of the use of thermography in the study of radiation dermatitis. The characteristics of our population, the ratio of high-grade dermatitis and its occurrence in various subgroups stand well within the boundaries reported in literature. The study of thermography provides insight about the possible usefulness of this diagnosis tool: First, as expected from the intense inflammatory phenomena involved in the pathophysiology of radiation-induced dermatitis, a noticeable increase of temperature during the course of radiotherapy was seen in all patients, except in one patient suffering for carcinomatous mastitis and excluded from the study. Second, we noticed that most patients had already a slight but positive difference in temperature before radiotherapy occurred. In patients treated after mastectomy, the explanation may be simple. The fat tissues contained in the breast act as a poorly vascularized thermal shield retaining heat produced below that layer. The removal of the breast exposes a wide surface of skin that directly tops muscles and ribs and strongly radiates heat. In the case of lumpectomy, the treated breast is probably under the influence of inflammatory phenomena during the course of post-surgical healing. As a consequence of this difference, the initial temp gap is higher and remains so as radiotherapy sessions follow. Furthermore, it is clear that high-grade dermatitis is strongly associated to an increase in local temperature, which is probably linked to the intense inflammatory reaction that leads to moist desquamation, but also to higher levels of pain and discomfort. The very preliminary results provided by the study yielded promising values. Indeed, with a 1.4 deg. C threshold set beforehand, it is possible to anticipate the occurrence or not of radiation dermatitis, with an interesting positive predictive value of 70% and negative predictive value of 77% in our population. This results need to be confirmed with a dedicated study. Besides, whether it is clinically possible to prevent or at least decrease the severity of RD is still in discussion, but some local treatments, including specific dressings showed some efficacy in the healing of RD and may be used in prophylaxis. In the future, we would like to inquire about the predictive ability of thermography, including for head and neck cancers, as well as the possible association between increase in temperature and hot spots during dosimetric calculations. A thorough study of sensitivity and specificity is required