Eliminating tattoos for short course palliative radiation therapy: Set-up error, satisfaction and cost

Purpose: Palliative patients are living longer thanks to advancements in systemic therapies and radiotherapy technologies. Prior to image guided radiotherapy, permanent ink tattoos were used to ensure set up accuracy. Permanent marks can cause psychological damage, physical pain and can reduce a patient's quality of life. In recent years, image guided radiation therapy (IGRT) has become standard practice and may eliminate the need for permanent tattoos in this patient population. Methods: Twenty-five patients were consecutively chosen from the Palliative Radiation Oncology Program (PROP). Each received 5 fractions of radiotherapy commencing within 72 hours of CT simulation. In place of permanent tattoos, patients were marked with permanent marker and an adherent transparent film dressing (Tegaderm TM ) was placed over the mark. Patients were educated on maintaining the marks and dressing. Daily cone beam CT (CBCT) isocentre mismatch values were compared with 25 patients who received tattoos for radiotherapy to similar body regions. Radiation therapist concerns, cost, variations in isocentre shift values and additional imaging requirements were obtained. Results: Isocentre shift values were similar (p<0.05) for Tegaderm TM vs. tattoo patients in the anterior-posterior (AP) and right-left (RL) directions. The mean shift value in the superior-inferior (SI) direction was larger for Tegaderm TM than for tattoos (p=0.01), however the magnitude was only 2 mm, which is clinically insignificant as these shifts were prior to IGRT guided correction. No patient required a repeat CBCT or a resimulation. The cost of the Tegaderm TM dressing was substantially less than the tattoo group. Radiation Therapists' satifaction with Tegaderm TM was overall high, however some expressed concerns with their durability and longevity. Conclusions: We found that the use of Tegaderm TM dressing did not result in increased set-up time, mismatch error or additional imaging procedures (CBCT or CTsimulation) and moreover cost substantially less than permanent ink tattoos.