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Kenneth Kazuto Sakata
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MTE 19 - Laser Therapy for Early Stage and Airway Obstruction (Sign Up Required) (ID 568)
- Event: WCLC 2017
- Type: Meet the Expert
- Track: Pulmonology/Endoscopy
- Presentations: 1
- Moderators:
- Coordinates: 10/17/2017, 07:00 - 08:00, Room 317
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MTE 19.01 - Laser Therapy for Airway Obstruction (ID 7801)
07:00 - 07:30 | Presenting Author(s): Kenneth Kazuto Sakata
- Abstract
- Presentation
Abstract:
Malignant central airway obstruction (mCAO) occurs in patients with lung cancer and in patients with pulmonary metastases from other malignancies, including thyroid, breast, renal cell, and colon(1). It is loosely defined as obstruction of >50% of the central airways(2). Malignant CAO results in dramatic alterations to quality of life (QOL), decreased functional status, bleeding, post-obstructive pneumonia, and a poor prognosis(3, 4). The principle goal in the management of mCAO is to restore airway patency, palliate, improve QOL and symptoms, spirometric values, and survival(1, 5-7). There are 3 classifications of mCAO: endobronchial, extrinsic, or mixed. Multiple ablative bronchoscopic tools are available to relieve endobronchial or mixed obstructions(8). Ablative techniques include lasers, electrocautery, argon plasma coagulation, photodynamic therapy, microdebriders, and cryotherapy(1). Stents are primarily used to treat patients with mixed and extrinsic airway obstruction(1). Lasers have no role in the management of extrinsic airway obstruction(9). Ost and colleagues(1) showed that among 26 physicians from 15 centers, performing over 1,100 procedures, there was significant practice pattern variability. They also report that there was no single best ablative technique with regard the primary goal of improvements in dyspnea or QOL. There are no large clinical trials comparing various ablative modalities head-to-head and thus, superiority of one technique over another remains undefined(3). However, all ablative techniques can be used alone or in combination(8). In order to obtain optimal treatment outcomes, physicians should be competent and versatile in the use of multiple complementary modalities. Herein, we provide a clinical review of lasers, a technique that delivers a non-contact heat energy by light via catheter(9, 10), in the management of mCAO. The effectiveness of lasers in achieving relief of obstruction and symptomatic improvement from mCAO in very large series established credibility of this modality(11). Although outcome data is limited, laser therapy appears to be effective in providing rapid relief of endobronchial obstruction with symptomatic improvement in 70-80%(9, 12-15). One-year survival following treatment was around 30%(9). Local disease recurrence with mCAO is typical unless tumor debulking is followed by adjunctive therapies(16). Several types of lasers exist and each use different media to generate light(10). The details and specific role of each laser is beyond the scope of this discussion. Special focus has been placed on the Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser because it has become the most frequently used nonsurgical technique in the management of malignant and benign endobronchial disorders(12, 13, 17-19). One significant advantage of the Nd:YAG laser is its balanced properties in its ability to photocoagulate or vaporize tumor and cut stenotic lesions. Its ability to photocoagulate and vaporize before mechanical debulking allows for improved control of hemorrhage in the airway during bronchoscopy(9, 10). Dumon et al. and Cavaliere et al were among the first to report their experience of the Nd:YAG laser in benign and mCAO(12, 13). Cavaliere and colleagues showed an improvement in airway lumen in 92% of patients with mCAO(12). In a follow up article, the largest series to date, radiographic improvement was noted in 93% of patients with bronchogenic carcinoma, and their overall complication rate was 2.3%(20). A disadvantage of the Nd:YAG laser is the associated considerable set-up, maintenance costs, and its bulky size. The power and distance of the fiber from the lesions as well as the ration of absorption and scattering coefficients of laser determine the tissue effect(10). Lower power or the farther the distance between the laser fiber and the lesion lead to a shallow effect and cause superficial tissue coagulation. Conversely, higher power settings or a shorter distance between the laser and lesion result in deeper penetration causing tissue carbonization and vaporization(10). Safety of Nd:YAG laser in airway procedures has been well established and with appropriate precautions, the safety record of laser therapy is excellent. Protective eyewear is mandatory when the laser beam is activated(17). A “timeout” should be performed to confirm that the fraction of inspired oxygen setting is <40%, which reduces the risk of airway fire. Literature suggests that complications can be minimized if particular attention is paid to keeping the power settings to less than 40W, pulse duration of 0.5-1 second, and always having the laser beam aimed parallel to the airway(9). Complete or nearly complete mCAO without adequate visualization of distal lumen is a relative contraindication due to a possible risk of perforation(4). Significant complications develop in fewer than 5% of cases. One study showed that in 7,000 laser treatments, the reported overall complication rate was 0.99%(16). Reported complications include marked fluctuations in oxygen saturations and end-tidal CO2, massive hemorrhage, airway perforation, pneumothorax, pneumomediastinum, airway fire, gas embolism, myocardial infarction, cardiac arrest, and death. Air embolism is a result of high flow of air coolant and contact probes. It is recommended that a non-contact mode be used while keeping the coaxial coolant air flow at a minimum level(21). Continuous suction is used during the procedure to remove smoke. Continuous inspection of the airways is performed to remove any debris and to optimize ventilation. Both rigid and flexible bronchoscopes are used successfully. With flexible bronchoscope, the lesion is either photocoagulated or carbonized prior to removal, or the whole lesion is vaporized(17). Flexible bronchoscope allows easier access to areas that may require acute angulation. Rigid bronchoscopy provides a wide operating channel allowing simultaneous use of multiple tools. Specifically, the patient can be ventilated, blood and secretions aspirated, and laser coagulation utilized. The aim is to devascularize the tumor and subsequently core out the tumor with the tip of the rigid bronchoscope(17). Additionally, mechanical sequential rigid bronchoscopic dilations can also be performed. When skilled in both techniques, the rigid technique is generally favored by many due to its multiple stated advantages(11, 13, 17, 22). However, in the absence of randomized controlled trials, expert opinion continues to guide therapeutic approaches. Most patients are managed in a multimodality fashion for the optimal outcome. Selection of a specific modality remains operator and institution specific. Irrespective of the type of ablative technique or choice of laser, the goal of treating mCAO remains the same, relieve the obstruction.
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P1.07 - Immunology and Immunotherapy (ID 693)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Immunology and Immunotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.07-016 - Comparison of PD-L1 Immunohistochemical Staining between EBUS-TBNA and Resected Non-Small Cell Lung Cancer Specimens (ID 8964)
09:30 - 09:30 | Presenting Author(s): Kenneth Kazuto Sakata
- Abstract
Background:
PD-L1 can be detected by immunohistochemical (IHC) analysis and has emerged as a biomarker that predicts which patients are more likely to respond to anti-PD-L1/PD-1 immunotherapies in non-small cell lung cancer (NSCLC)(1, 2). To date, there is no evidence to support or refute PD-L1 IHC staining on endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples. Our study aimed to establish the sensitivity, specificity, positive predictive value, and negative predictive value of PD-L1 IHC staining reliability on EBUS-TBNA samples, when compared to resected tumor specimens.
Method:
A retrospective review was performed on all patients who underwent an EBUS-TBNA of either a lymph node(s) or the tumor itself, who subsequently had surgical resection of their tumor between July 2006 through September 2016. Patients who had a concordant NSCLC EBUS-TBNA diagnosis with their resected tumor were included. Patients with small cell lung cancer were excluded. All EBUS-TBNA samples were obtained using Olympus EBUS bronchoscopes and a 22-gauge ViziShot needle (Olympus Medical Systems Corp., Tokyo, Japan). The Dako PD-L1 IHC 22C3 (Agilent Pathology Solutions) assay was used. A positive PD-L1 stain was defined as ≥1% of tumor cell positivity. EBUS-TBNA aspirates were compared with the surgically resected specimen to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
Result:
We performed 5448 EBUS-TBNA procedures for lung cancer. Seventy patients were included in our analysis. To date, 23 cases have been stained and reviewed (Table). The sensitivity and specificity was 71% and 100%, respectively. The PPV and NPV were 100% and 69%, respectively. We expect to complete our analysis of all patients prior to the IASLC World Conference.Comparison of PD-L1 IHC stain between EBUS-TBNA samples and resected tumor specimen.
Resected tumor PD-L1 positive Resected tumor PD-L1 negative EBUS-TBNA PD-L1 positive 10 0 EBUS-TBNA PD-L1 negative 4 9
Conclusion:
Positive PD-L1 IHC staining on EBUS-TBNA aspirates appears to have a strong correlation with resected tumor specimen. When EBUS-TBNA aspirates are negative for PD-L1 staining, additional tumor specimens are required to confirm the PD-L1 status.
