Evidence - Uniportal VATS Segment-3 resection right with ICG

The question of parenchyma-sparing resection in bronchial carcinoma has been intensely discussed for some time. In the revised S3 guideline for lung carcinoma, anatomical segment resection is now recommended for the first time as an alternative and equivalent therapeutic option to lobectomy for tumors < 2cm in stages I and II. In cases of limited operability, anatomical segment resection is also the best oncological therapeutic option for larger tumors in stages I and II. (1)

Extended Tumor Criteria for Limited Resection

In international literature and with the conclusion of some major studies in 2022, additional important radiological criteria besides tumor size have been evaluated. Particularly, the reduction in transparency around the tumor site (ground-glass opacity; GGO) and the derived ratio to the tumor nodule (Consolidation to Tumor Ratio; C/T-Ratio) appear to be promising indicators.

In Japan, a large multicenter study including over 1100 patients demonstrated that segment resection showed improved overall survival compared to lobectomy for patients in stage IA UICC with a C/T-ratio > 0.5. (2)

In another multicenter study, considering GGO typing, a wedge resection even proved to be an oncologically equivalent first-line therapy. (3) This seems plausible since a radiomorphological GGO dominance strongly correlates with the presence of a low-grade adenocarcinoma. (4)

Another prognostic factor is the presence of Spread Through Air Spaces (STAS). This involves tumor spread through the air spaces. While further research and studies on the biological mechanism, genetics, and significance in oncological therapy are required, detection in the pathological specimen is likely an exclusion criterion for limited resection. (5)

Outlook

Following the conclusion of several major studies in recent years, the indication for anatomical segment resection is also being expanded in the updated German S3 guideline. Besides tumor size, no additional criteria for patient selection have been defined so far. It is hoped that after the completion of some ongoing and future studies, criteria can be defined that will further reduce the extent of parenchyma resection (wedge resection, anatomical segment resection, or lobectomy) while achieving the best possible oncological outcome.

ICG in Thoracic Surgery

A key point in the successful execution of a segment resection is the intraoperative visualization of segment boundaries. Here, the method using the fluorescent dye ICG (Indo-Cyanine Green), which has been used in other specialties for some time, is experiencing a small renaissance in thoracic surgery. A study showed that visualization of segment boundaries with ICG is more effective than selective ventilation and independent of external influences such as chronic obstructive pulmonary disease. (6) In 2022, a Chinese expert group recommended the routine use of ICG. (7)

• A non-randomized confirmatory trial of segmentectomy for clinical T1N0 lung cancer with dominant ground glass opacity based on thin-section computed tomography (JCOG1211)
• Comparison of Different Types of Surgery in Treating Patients With Stage IA Non Small Cell Lung Cancer (CALGB 140503 study, ClinicalTrials.gov Identifier:NCT00499330)

(1) Expertise in Thoracic Surgery. Müller M, Wanka S, Inderbitzi R, Kiefer T, Stubenberger E, Eds. 1st Edition. Stuttgart: Thieme; 2015.

(2) Saji, Hisashi, et al. “Segmentectomy versus Lobectomy in Small-Sized Peripheral Non-Small-Cell Lung Cancer (JCOG0802/WJOG4607L): A Multicentre, Open-Label, Phase 3, Randomised, Controlled, Non-Inferiority Trial.” The Lancet, vol. 399, no. 10335, Apr. 2022, pp. 1607–17.

(3) A nonrandomized confirmatory phase III study of sublobar surgical resection for peripheral ground glass opacity dominant lung cancer defined with thoracic thin-section computed tomography (JCOG0804/WJOG4507L). Kenji Suzuki, Shunichi Watanabe, Masashi Wakabayashi, Yasumitsu Moriya, Ichiro Yoshino, Masahiro Tsuboi, Tetsuya Mitsudomi, and Hisao Asamura, Journal of Clinical Oncology 2017 35:15_suppl, 8561-8561 

(4) Nakamura, Shota & Fukui, Takayuki & Kawaguchi, Koji & Fukumoto, Koichi & Hirakawa, Akihiro & Yokoi, Kohei. (2015). Does Ground Glass Opacity-Dominant Feature Have a Prognostic Significance Even in Clinical T2aN0M0 Lung Adenocarcinoma?. Lung Cancer. 89. 10.1016/j.lungcan.2015.04.011. 

(5) Jia M, Yu S, Gao H, Sun PL. Spread Through Air Spaces (STAS) in Lung Cancer: A Multiple-Perspective and Update Review. Cancer Manag Res. 2020 Apr 23;12:2743-2752. doi: 10.2147/CMAR.S249790. PMID: 32425593; PMCID: PMC7186879.

(6) Yotsukura M, Okubo Y, Yoshida Y, Nakagawa K, Watanabe SI. Indocyanine green imaging for pulmonary segmentectomy. JTCVS Tech. 2021 Jan 6;6:151-158. doi: 10.1016/j.xjtc.2020.12.005. PMID: 34318180; PMCID: PMC8300924.

(7) Cui F, Liu J, Du M, Fan J, Fu J, Geng Q, He M, Hu J, Li B, Li S, Li X, Liao YD, Lin L, Liu F, Liu J, Lv J, Pu Q, Tan L, Tian H, Wang M, Wang T, Wei L, Xu C, Xu S, Xu S, Yang H, Yu BT, Yu G, Yu Z, Lee CY, Pompeo E, Azari F, Igai H, Kim HK, Andolfi M, Hamaji M, Bassi M, Karenovics W, Yutaka Y, Shimada Y, Sakao Y, Sihoe ADL, Zhang Y, Zhang Z, Zhao J, Zhong W, Zhu Y, He J. Expert consensus on indocyanine green fluorescence imaging for thoracoscopic lung resection (The Version 2022). Transl Lung Cancer Res. 2022 Nov;11(11):2318-2331. doi: 10.21037/tlcr-22-810. PMID: 36519017; PMCID: PMC9742622.