Prospective Evaluation of Patient-Reported Outcomes of Invisible Ink Tattoos for the Delivery of External Beam Radiation Therapy: The PREFER Trial

Abstract

Invisible ink tattoos allow for setup accuracy while avoiding the cosmetic permanence of visible ink tattoos. The goal of this trial was to evaluate patient-reported preference for the use of invisible ink tattoos in a radiation oncology clinic. In an IRB-approved, prospective, feasibility trial, patients at a single institution receiving pencil beam scanning proton therapy to the thorax, abdomen, or pelvis underwent invisible ink tattoo-based treatment setup. Patient preference surveys comparing visible and invisible ink tattoos were completed prior to simulation (17 questions), immediately following simulation (5 questions), and at the end of treatment (18 questions), with preference scored on a 5-point Likert scale from strongly disagree to strongly agree, and cosmesis scored on a 4-point Likert scale of excellent-good-fair-poor. Differences in distributions were examined using Wilcoxon rank-sum tests, Fisher's exact tests, or chi-square tests, where statistical significance was considered at p<0.05. Of 107 patients screened, 102 were enrolled and 94 completed all surveys. Mean age was 55.0 years, and 58.5% were female. Most patients were white (79.1%) and non-Hispanic (92.6%). Patients most commonly had breast (34.0%), prostate (16.0%), and lung (9.6%) cancer. An average of 5 (range 3-8) invisible ink tattoos were placed per patient. Overall, 75.5% of patients reported that they would prefer to receive invisible tattoos vs. visible tattoos, and 88.3% rated the overall cosmetic outcome of invisible ink tattoo marks as excellent or good. Compared to males, females were more willing to travel farther from their home in order to avoid receiving visible tattoos (45.4% vs. 23.1%, p = 0.035) and would pay additional money to avoid receiving visible tattoos (34.5% vs. 5.1%, p = 0.002). Patients who had previously received any tattoo (cosmetic or visible RT tattoos) were more satisfied with the appearance of their invisible ink tattoos compared to those who had never previously received tattoos (82.9% vs. 61.5%, p = 0.022). Patients receiving definitive intent RT were more satisfied with the appearance of the tattoos compared to those receiving palliative intent RT (67.1% vs. 38.9%, p = 0.011). Patients with at least a college education were less satisfied with the appearance of tattoos compared to those without a college education (67.0% vs. 95.0% p = 0.018). These findings demonstrate stronger avoidance of visible tattoos and patient preference for invisible tattoos. The standard incorporation of invisible ink tattoos for patient setup should be strongly considered.