Humphreys T R, Malhotra R, Scharf M J, Marcus S M, Starkus L, Calegari K
Department of Medicine, University of Massachusetts Medical Center, Worcester, USA.
Arch Dermatol. 1998 Oct;134(10):1247-52. doi: 10.1001/archderm.134.10.1247.
High-energy pulsed carbon dioxide (CO2) lasers have been used 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 underlying tissue. Our objective was to determine if a pulsed CO2 laser could effectively ablate superficial malignant cutaneous neoplasms (superficial multifocal basal cell carcinoma [BCC] and squamous cell carcinoma [SCC] in situ).
Thirty superficial neoplasms (17 BCCs and 13 SCCs) and their surrounding 3-mm margins were treated with either 2 or 3 passes of a pulsed CO2 laser (500 mJ, 2-4 W) using a 3-mm collimated handpiece. The treated areas were subsequently excised and evaluated histologically by serial sectioning at 5-micron intervals for residual 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 years; P = .001). The average tumor thickness of SCC in situ was significantly 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, and residual tumor in the deep margins was seen in 5 of 8 patients treated with 2 passes of the pulsed CO2 laser (P = .005). Incomplete vaporization of the SCC depth was seen in 3 of 7 patients treated with 3 passes and in 2 of 6 patients treated with 2 passes. Those SCCs incompletely 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.
Pulsed CO2 laser treatment can be effective in ablating superficial BCC. Treatment of the neoplasm and a minimum of 4-mm margins with 3 passes (500 mJ, 2-4 W) is recommended 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 direct comparison of efficacy can be made with other destructive modalities that have not been evaluated with comparably sensitive histological techniques. Further study is needed to establish any cosmetic advantage of pulsed CO2 lasers over other destructive modalities for treatment of superficial malignant neoplasms and long-term cure rates.
高能脉冲二氧化碳（CO₂）激光已被广泛用于改善皱纹和光损伤皮肤，且瘢痕形成风险较低。组织学研究结果表明，在治疗皮肤时，其消融深度精确，对深层组织的热损伤极小。我们的目的是确定脉冲CO₂激光能否有效消融浅表性恶性皮肤肿瘤（浅表多灶性基底细胞癌[BCC]和原位鳞状细胞癌[SCC]）。
使用3毫米准直手持器，对30个浅表肿瘤（17个BCC和13个SCC）及其周围3毫米边缘进行2次或3次脉冲CO₂激光（500 mJ，2 - 4 W）照射。随后切除治疗区域，并通过间隔5微米连续切片进行组织学评估，以检测深部和外侧边缘的残留肿瘤。SCC患者的平均年龄大于BCC患者（76.5岁对56.7岁；P = 0.001）。原位SCC的平均肿瘤厚度显著大于浅表BCC（0.57毫米对0.34毫米；P = 0.01）。所有（9例患者中的9个）BCC经3次照射后完全消融，在接受2次脉冲CO₂激光照射的8例患者中，有5例在深部边缘发现残留肿瘤（P = 0.005）。在接受3次照射的7例患者中有3例以及接受2次照射的6例患者中有2例出现SCC深度的不完全汽化。那些未完全治疗的SCC明显比完全消融的SCC厚（0.65毫米对0.41毫米；P = 0.01）。在1个BCC和3个SCC标本中发现外侧边缘阳性。
脉冲CO₂激光治疗可有效消融浅表BCC。对于使用该激光系统完全汽化，建议对肿瘤及其至少4毫米边缘进行3次照射（500 mJ，2 - 4 W）。由于3次照射未完全消融所有原位SCC，因此不建议单独使用这种方式治疗厚或角化性病变。无法与未用同样敏感的组织学技术评估的其他破坏性方式进行疗效的直接比较。需要进一步研究以确定脉冲CO₂激光在治疗浅表恶性肿瘤方面相对于其他破坏性方式的任何美容优势以及长期治愈率。
