Q-Switched Laser Settings for Tattoo Removal
For tattoo removal, use Q-switched lasers with pulse durations of 5-40 nanoseconds (not microseconds), fluence of 2-10 J/cm² depending on tattoo depth and color, and repetition rates of 1-10 Hz, with treatment sessions spaced at minimum 4-week intervals. 1, 2
Laser Selection by Tattoo Color
The wavelength must match the target pigment for optimal selective photothermolysis:
- Black and blue pigments: Q-switched Nd:YAG 1064 nm or Ruby 694 nm with pulse durations of 5-40 nanoseconds 3, 4
- Red pigments: Q-switched Nd:YAG 532 nm 3
- Green pigments: Q-switched Ruby 694 nm or Alexandrite 755 nm (25-40 nanosecond pulses) 1, 3
- Multicolored tattoos: Combination approach using multiple wavelengths across sessions 3
Critical Technical Parameters
Pulse Duration
- Nanosecond range is essential: 5-40 nanoseconds depending on laser type 1, 4
- Ruby lasers: 25-40 nanoseconds 1
- Nd:YAG lasers: 5-17 nanoseconds in modern systems 4
- Avoid microsecond pulses (1.7 microseconds) which are used for retinal therapy, not tattoo removal 5
Repetition Rate/Frequency
- Standard treatment: 1-10 Hz 1, 3
- Lower frequencies (1-5 Hz) preferred for darker skin types to minimize thermal damage 4
Fluence (Energy Density)
- Adjust based on skin phototype, tattoo depth, and pigment density 4
- Higher phototypes (IV-VI) require careful titration to avoid hypopigmentation 4
- Professional tattoos typically need higher fluences than amateur tattoos 3
Treatment Protocol Algorithm
Session Intervals:
- Minimum 4 weeks between treatments to allow phagocytosis and clearance of fragmented pigment 1, 2
- Longer intervals may reduce permanent pigmentary changes 2
- Free pigment becomes intracellular again within 4 weeks, necessitating this waiting period 2
Expected Treatment Course:
- Amateur tattoos: Fewer sessions required 3
- Professional multicolored tattoos: Multiple sessions, potentially 10-47 treatments for complex cases 1, 6
- Use Kirby-Desai score to estimate session numbers based on skin type, colors, and complexity 1, 2
Critical Safety Considerations
Immediate Post-Treatment Signs:
- White frosting of epidermis immediately after pulse indicates water vaporization (expected finding) 2
Common Pitfalls to Avoid:
- Improper training causes significant burns and scarring - ensure proper certification before use 1, 2
- Hypopigmentation occurs in up to 50% with some systems, particularly with inadequate session spacing or sun exposure 3, 4
- Paradoxical darkening can occur with certain pigments (especially cosmetic tattoos containing titanium dioxide or iron oxide) when treated with inappropriate wavelengths or fluences 7
- Textural changes reported in up to 12% of cases 3
Patient-Specific Factors:
- Darker skin types (IV-VI) require lower fluences and longer intervals to prevent hypopigmentation 4
- Avoid treating patients with keloid history due to scarring risk 2
- Counsel patients on toxicologic risks: cleavage products and tattoo particles migrate to regional lymph nodes 1, 2
Pain Management
Local lidocaine injection or topical anesthetic cream should be applied prior to treatment, as the procedure is painful 3
Cost Considerations
Patients should be counseled that treatment ranges from $49-300 per square inch per session, with multiple sessions required 1, 2