Sierra Heidy, Damanpour Shadi, Hibler Brian, Nehal Kishwer, Rossi Anthony, Rajadhyaksha Milind
Dermatology Service, Memorial Sloan Kettering Cancer Center, 16 E. 60th Street, 4th Floor, New York, 10022, New York.
University of Miami Miller School of Medicine, Miami, 33136, Florida.
Lasers Surg Med. 2016 Feb;48(2):133-9. doi: 10.1002/lsm.22415. Epub 2015 Sep 22.
Laser ablation can be an effective treatment for the minimally invasive removal of superficial and early nodular basal cell carcinomas (BCCs). However, the lack of histological confirmation after ablation results in high variability of recurrence rates and has been a limitation. Reflectance confocal microscopy (RCM) imaging, combined with a contrast agent, may detect the presence (or absence) of residual BCC tumors directly on the patient and thus provide noninvasive histology-like feedback to guide ablation. The goal of this ex vivo bench-top study was to determine affective ablation parameters (fluence, number of passes) for a CO2 laser that will allow both removal of BCCs and control of the underlying thermal coagulation zone in post-ablated tissue to enable uptake of contrast agent and RCM imaging.
We used 72 discarded fresh normal skin specimens and frozen BCC tumor specimens to characterize the depth of ablation and to evaluate uptake of contrast agent and image quality. Acetic acid was used to enhance nuclear brightness ("acetowhitening") during imaging pre- and post-ablation. Histology sections of the post-ablated imaged surface were visually examined for the appearance of nuclear and dermal morphology and compared to the RCM images.
Results for 1-3 passes of 5.5 J/cm(2), 6.5 and 7.5 J/cm(2), and 1-2 passes of 8.5 J/cm(2) showed the uptake of acetic acid for contrast and RCM imaging of the presence and absence of residual BCC tumors in post-ablated tissue. Morphologic details in the images were validated by the histology.
The use of effective ablation parameters may enable RCM imaging to guide ablation.
激光消融术可有效微创切除浅表及早期结节性基底细胞癌（BCC）。然而，消融术后缺乏组织学确认导致复发率差异很大，这一直是个限制因素。反射式共聚焦显微镜（RCM）成像结合造影剂，可直接在患者身上检测残余BCC肿瘤的存在与否，从而提供类似非侵入性组织学的反馈以指导消融。本体外台式研究的目的是确定二氧化碳激光的有效消融参数（能量密度、照射次数），既能切除BCC，又能控制消融后组织中潜在的热凝固区，以便造影剂摄取和RCM成像。
我们使用72份废弃的新鲜正常皮肤标本和冷冻的BCC肿瘤标本，以确定消融深度，并评估造影剂摄取情况和图像质量。在消融前后成像过程中，使用乙酸增强细胞核亮度（“醋酸白现象”）。对消融后成像表面的组织学切片进行视觉检查，观察细胞核和真皮形态，并与RCM图像进行比较。
5.5 J/cm²、6.5和7.5 J/cm²能量密度下照射1 - 3次，以及8.5 J/cm²能量密度下照射1 - 2次的结果显示，消融后组织中残余BCC肿瘤存在与否的造影及RCM成像中乙酸摄取情况良好。图像中的形态学细节经组织学验证。
使用有效的消融参数可使RCM成像指导消融。
