# Picosecond Q-Switched 1064/532 nm Laser in Tattoo Removal: Our Single Center Experience
## 2 Materials and Methods  
Outpatients seeking tattoo removal from 1 August 2019 to 30 December 2020 at Magna Graecia University's Dermatology Unit (Catanzaro, Italy) were included in our study. Patients suffering from light hypersensitivity, or taking drugs capable of increasing it, were excluded from the study. Further, patients taking gold-based medications, immunosuppressiveants, and/or anticoagulants, those who were pregnant, those previously affected by skin malignancies, those who had experienced strong sun exposure within the previous three weeks, those previously treated with other tattoo removal or exfoliation procedures, and those suffering from diseases associated with the Koebner phenomenon were excluded from the study. All patients signed an informed consent regarding the possible side effects related to the medical procedure.  
Participants have been treated with a picosecond Q-switched 1064/532 nm laser system ([PERSON], Deka M.E.L.A., Calenzano, Italy), capable of obtaining selective photothermolysis of the tattoo ink, with minimal injury to the adjacent skin. The treatment parameters were as follows: 450 picoseconds (ps) at 1064 nm and 370 ps at 532 nm; up to 5 J/cm\({}^{2}\) at 1064 nm for black and blue pigments; and up to 3 J/cm\({}^{2}\) at 532 nm for all other colors. Treated tattoos were stratified based on their characteristics and anatomical location, using a previously proposed scale [16] (Table 1).  
Tattoos simultaneously displaying multiple colors were treated with both wavelengths, using the appropriate wavelength for each area. Up to seven sessions have been performed to provide the best possible cosmetic result.  
An 8-week interval between each laser treatment up to the fourth session was performed; the interval was then increased to 12 weeks for subsequent sessions. Patients' satisfaction was the primary endpoint. A 6-month follow-up visit was scheduled after the last laser treatment.  
Before the first treatment, a photographic evaluation was performed and repeated at the 6-month follow-up. Pictures were taken with the same device (Nikon 5600d, Nikon Corporation, Minato City, Tokyo, Japan), parameters, settings, and ambient light.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Group** & **Description** \\ \hline Dark Tattoos & Qualified professionals tattooed the patient \\  & using mostly black-colored ink \\ \hline Red Tattoos & Qualified professionals tattooed the patient \\  & using mostly red-colored ink \\ \hline Mixed-Color Tattoos & Qualified professionals tattoed the patient \\  & using a variety of colors \\ \hline Amateur & Unqualified professionals tattoed the patient \\ \hline Medical & Usually blue superficial tattoos before \\  & radiotherapy \\ \hline Traumatic & Caused by traumatic events \\ \hline Cosmetic & Performed by professionals; Usually ferric \\  & oxide is present \\ \hline \hline \end{tabular}
\end{table}
Table 1: Tattoo classes identified and included in the study.  
Data analyses (mean, standard deviations, etc.) were performed using Statistica 14.0 (TIBCO Software, Palo Alto, CA, USA).