TREATMENT OF SUPERFICIAL BASAL-CELL CARCINOMA AND SQUAMOUS-CELL CARCINOMA IN-SITU WITH A HIGH-ENERGY PULSED CARBON-DIOXIDE LASER

Background: High-energy pulsed carbon dioxide (CO2) lasers have been u sed extensively to resurface wrinkled and photodamaged skin with a low risk of scarring. Results of histological studies demonstrate precise ablation depths in treated skin with minimal thermal damage to underl ying tissue. Our objective was to determine if a pulsed CO2 laser coul d effectively ablate superficial malignant cutaneous neoplasms (superf icial multifocal basal cell carcinoma [BCC] and squamous cell carcinom a [SCC] in situ). Observations: Thirty superficial neoplasms (17 BCCs and 13 SCCs) and their surrounding 3-mm. margins were treated with eit her 2 or 3 passes of a pulsed CO2 laser (500 mJ, 2-4 W) using a 3-mm c ollimated handpiece; The treated areas were subsequently excised and e valuated histologically by serial sectioning at 5-mu m intervals for r esidual tumor at the deep and lateral margins. Average patient age was greater for those with SCCs than for those with BCCs (76.5 vs 56.7 ye ars; P = .001). The average tumor thickness of SCC in situ was signifi cantly greater than that of superficial BCC (0.57 vs 0.34 mm; P = .01) . All (9 of 9 patients) BCCs were completely ablated with 3 passes, an d residual tumor in the deep margins was seen in 5 of 8 patients treat ed with 2 passes of the pulsed CO2 laser (P = .005) incomplete vaporiz ation of the SCC depth was seen in 3 of 7 patients treated with 3 pass es and in 2 of 6 patients treated with 2 passes. Those SCCs incomplete ly treated were significantly thicker than those completely ablated (0 .65 vs 0.41 mm; P = .01). Positive lateral margins were seen in 1 BCC and 3 SCC specimens. Conclusions: Pulsed CO2 laser treatment can be ef fective in ablating superficial BCC. Treatment of the neoplasm and a m inimum of dr-mm margins with 3 passes (500. mJ, 2-4 tit) is recommende d for complete vaporization using this laser system. Because 3 passes did not completely ablate all SCC in situ, use of this modality alone is not recommended for treatment of thick or keratotic lesions. No dir ect comparison of efficacy can be made with other destructive modaliti es that have not been evaluated with comparably sensitive histological techniques. Further study is needed to establish any cosmetic advanta ge of pulsed CO2 lasers over other destructive modalities for treatmen t of superficial malignant neoplasms and long-term cure rates.