Current indications and future perspective of fluorescence bronchoscopy: A review study

Utility of auto fluorescence-guided biopsy in suspected lung cancer patients with bronchial mucosal lesions

BACKGROUND

Bronchoscopy is currently the most common technique for lung cancer diagnosis. Patients suspected of malignancy often undergo bronchoscopic examination, and biopsy is routinely used in patients with visible bronchial lesions. However, it is difficult to differentially diagnose lung cancer in patients with bronchial mucosal lesions. Thus, this study was conducted to investigate the utility of fluorescence-guided biopsy in suspected lung cancer patients with bronchial mucosal lesions.

METHODS

We conducted a retrospective study in a single screening center to assess the sensitivity and specificity of fluorescence-guided biopsy compared with white light bronchoscopy (WLB) in patients with bronchial mucosal lesions.

RESULTS

A total of 301 patients with bronchial mucosal lesions were enrolled in this study. The sensitivity for patients with fluorescence-guided biopsy was 60.3 % (95 % confidence interval [CI]: 53.1 %-67.1 %), which was higher than that of patients with WLB alone (45.2 %, 95 % CI: 38.2-52.4 %) (P = 0.0026). Additionally, compared with the WLB group, the fluorescence -guided biopsy group was found to have a significantly higher specificity (100 %, 95 % CI: 95.5-100 % versus 69.6 %, 95 % CI: 59.6-78.1 %), positive predictive value (100 %, 95 % CI: 96.1-100 % versus 74.3 %, 95 % CI: 65.5-81.7 %) and negative predictive value (56.3 %, 95 % CI: 48.8-63.6 % versus 39.4 %, 95 % CI: 32.3-47.0 %).

CONCLUSION

Fluorescence-guided biopsy can serve as an important adjunct to WLB for the differential diagnosis of lung cancer in patients with bronchial mucosal lesions.

Image-guided surgery and therapy for lung cancer: a critical review

Of the many imaging technologies, some have the potential to be used in image-guided surgery and therapy (IGS/IGT). This review of relevant papers on IGS/IGT for lung cancer indicates effective localization and IGS/IGT in early endobronchial lesions by fluorescence bronchoscopic technique. Visualization of early peripheral (nodular) tumors at operation can be achieved by a variety of imaging methods and devices which allow identification, localization and provision of intraoperative real-time images. Recent developments employing fluorescence contrasts and near infra-red light have shown encouraging feasibility and outcome in providing reliable methods for the IGS of cancer generally and lung cancer more specifically with provision of real time intraoperative imaging. The concept of the hybrid operating theater is touched upon.

Progress and prospects of early detection in lung cancer

Lung cancer is the leading cause of cancer-related death in the world. It is broadly divided into small cell (SCLC, approx. 15% cases) and non-small cell lung cancer (NSCLC, approx. 85% cases). The main histological subtypes of NSCLC are adenocarcinoma and squamous cell carcinoma, with the presence of specific DNA mutations allowing further molecular stratification. If identified at an early stage, surgical resection of NSCLC offers a favourable prognosis, with published case series reporting 5-year survival rates of up to 70% for small, localized tumours (stage I). However, most patients (approx. 75%) have advanced disease at the time of diagnosis (stage III/IV) and despite significant developments in the oncological management of late stage lung cancer over recent years, survival remains poor. In 2014, the UK Office for National Statistics reported that patients diagnosed with distant metastatic disease (stage IV) had a 1-year survival rate of just 15-19% compared with 81-85% for stage I.

Use of Spectroscopic Techniques for Evaluating the Coupling of Porphyrins on Biocompatible Nanoparticles. A Potential System for Photodynamics, Theranostics, and Nanodrug Delivery Applications

Modern medicine has been searching for new and more efficient strategies for diagnostics and therapeutics applications. Considering this, porphyrin molecules have received great interest for applications in photodiagnostics and phototherapies, even as magnetic nanoparticles for drug-delivery systems and magnetic-hyperthermia therapy. Aiming to obtain a multifunctional system, which combines diagnostics with therapeutic functions on the same platform, the present study employed UV/vis absorption and fluorescence spectroscopies to evaluate the interaction between meso-tetrakis(p-sulfonatofenyl)porphyrin (TPPS) and maghemite nanoparticles (γ-Fe₂O₃). These spectroscopic techniques allowed us to describe the dynamics of coupling porphyrins on nanoparticles and estimate the number of 21 porphyrins per nanoparticle. Also, the binding parameters, such as the association constants (K_a = 8.89 × 10⁵ M^-1) and bimolecular quenching rate constant (k_q = 2.54 × 10¹⁴ M^-1 s^-1) were obtained. These results suggest a static quenching process where the electrostatic attraction plays an essential role. The work shows that spectroscopic techniques are powerful tools to evaluate the coupling of organic molecules and nanoparticles. Besides, the system studied provides a relevant background for potential applications in bionanotechnology and nanomedicine, such as (1) nanodrug delivery system, (2) photodiagnostics/theranostics, and/or (3) a combined action of photodynamic and hyperthermia therapies, working in a synergetic way.

RGB and HSV quantitative analysis of autofluorescence bronchoscopy used for characterization and identification of bronchopulmonary cancer

Autofluorescence bronchoscopy (AFB) shows good sensitivity in detecting dysplasia and bronchopulmonary cancer. However, the poor specificity of AFB would lead to excessive biopsy. The aim of the study is to establish a more effective quantitative method (optimal identification index and reference value) for characterizing the AFB images within the region of interest and discuss AFB's significance in the diagnosis of central‐type lung cancer. A total of 218 suspected lung cancer patients were enrolled in this study. A quantitative analysis based on color space (red, green, blue[RGB] and HSV system) was conducted and the result was compared with the final diagnosis obtained by the pathology of biopsy. Cases were divided into different groups according to the pathological diagnosis of normal bronchial mucosa, inflammation, low‐grade preinvasive (LGD), high‐grade preinvasive (HGD), and invasive cancer. Quantitative analyses in multi‐color spaces for the lesions showed by AFB images were conducted by software MATLAB. Finally, there is statistical significance among the different groups in some parameter in RGB and HSV system. So, both RGB and HSV quantitative analysis of autofluorescence bronchoscopy are useful to define benign and malignant diseases, which can objectively guide the bronchoscopist in selecting sites for biopsy with good pathologic correlation.

Application of Quantitative Autofluorescence Bronchoscopy Image Analysis Method in Identifying Bronchopulmonary Cancer

Autofluorescence bronchoscopy shows good sensitivity and poor specificity in detecting dysplasia and cancer of the bronchus. Through quantitative analysis on the target area of autofluorescence bronchoscopy image, determine the optimal identification index and reference value for identifying different types of diseases and explore the value of autofluorescence bronchoscopy in diagnosis of lung cancer. Patients with 1 or more preinvasive bronchial lesions were enrolled and followed up by white-light bronchoscope and autofluorescence bronchoscopy. Color space quantitative image analysis was conducted on the lesion shown in the autofluorescence image using MATLAB image measurement software. A retrospective analysis was conducted on 218 cases with 1208 biopsies. One hundred seventy-three cases were diagnosed as positive, which included 151 true-positive cases and 22 false-positive cases. White-light bronchoscope associated with autofluorescence bronchoscopy was able to differentiate between benign and malignant lesion with a high sensitivity, specificity, positive predictive value, and negative predictive value (92.1%, 59.3%, 87.3%, and 71.1%, respectively). Taking 1.485 as the cutoff value of receiver operating characteristic of red-to-green value to differentiate benign and malignant diseases, the diagnostic sensitivity reached 82.3% and the specificity reached 80.5%. U values could differentiate invasive carcinoma and other groups well. Quantitative image analysis method of autofluorescence bronchoscopy provided effective scientific basis for the diagnosis of lung cancer and precancerous lesions.

A Surgical View of Photodynamic Therapy in Oncology: A Review

Clinical photodynamic therapy (PDT) has existed for over 30 years, and its scientific basis has been known and investigated for well over 100 years. The scientific foundation of PDT is solid and its application to cancer treatment for many common neoplastic lesions has been the subject of a huge number of clinical trials and observational studies. Yet its acceptance by many clinicians has suffered from its absence from the undergraduate and/or postgraduate education curricula of surgeons, physicians, and oncologists. Surgeons in a variety of specialties many with years of experience who are familiar with PDT bear witness in many thousands of publications to its safety and efficacy as well as to the unique role that it can play in the treatment of cancer with its targeting precision, its lack of collateral damage to healthy structures surrounding the treated lesions, and its usage within minimal access therapy. PDT is closely related to the fluorescence phenomenon used in photodiagnosis. This review aspires both to inform and to present the clinical aspect of PDT as seen by a surgeon.

Pulmonary Endogenous Fluorescence Allows the Distinction of Primary Lung Cancer from the Perilesional Lung Parenchyma

BACKGROUND

Pre-therapeutic pathological diagnosis is a crucial step of the management of pulmonary nodules suspected of being non small cell lung cancer (NSCLC), especially in the frame of currently implemented lung cancer screening programs in high-risk patients. Based on a human ex vivo model, we hypothesized that an embedded device measuring endogenous fluorescence would be able to distinguish pulmonary malignant lesions from the perilesional lung tissue.

METHODS

Consecutive patients who underwent surgical resection of pulmonary lesions were included in this prospective and observational study over an 8-month period. Measurements were performed back table on surgical specimens in the operative room, both on suspicious lesions and the perilesional healthy parenchyma. Endogenous fluorescence signal was characterized according to three criteria: maximal intensity (Imax), wavelength, and shape of the signal (missing, stable, instable, photobleaching).

RESULTS

Ninety-six patients with 111 suspicious lesions were included. Final pathological diagnoses were: primary lung cancers (n = 60), lung metastases of extra-thoracic malignancies (n = 27) and non-tumoral lesions (n = 24). Mean Imax was significantly higher in NSCLC targeted lesions when compared to the perilesional lung parenchyma (p<0,0001) or non-tumoral lesions (p<0,0001). Similarly, photobleaching was more frequently found in NSCLC than in perilesional lung (p<0,0001), or in non-tumoral lesions (p<0,001). Respective associated wavelengths were not statistically different between perilesional lung and either primary lung cancers or non-tumoral lesions. Considering lung metastases, both mean Imax and wavelength of the targeted lesions were not different from those of the perilesional lung tissue. In contrast, photobleaching was significantly more frequently observed in the targeted lesions than in the perilesional lung (p≤0,01).

CONCLUSION

Our results demonstrate that endogenous fluorescence applied to the diagnosis of lung nodules allows distinguishing NSCLC from the surrounding healthy parenchyma and from non-tumoral lesions. Inconclusive results were found for lung metastases due to the heterogeneity of this population.

[Quantization Methodology of Autofluorescence Bronchoscopy Image in the YUV System]

背景与目的

通过对不同病理类型的自荧光气管镜（autofluorescence bronchoscope, AFB）图像目标区域的YUV定量分析，确定区分不同疾病类型的最佳判别指标，探讨AFB在中央型支气管肺癌诊断中的价值。

方法

对研究对象进行白光气管镜+AFB检查，二者在镜下存在异常者行活检。并对荧光图像显示病变部位通过MATLAB图像测量软件进行YUV定量分析。根据正常支气管粘膜、炎症、低级别上皮样瘤变、高级别上皮样瘤变、浸润性癌的病理结果分组。研究各组与YUV值间的关系，所得数据采用SPSS 11.5软件进行统计学处理。

结果

Y值在浸润性癌和LGD组间存在统计学差异（P=0.040），在浸润性癌和炎症组也存在明显统计学差异（P < 0.001）。其他的各组间无统计学差异。U值在浸润性癌和HGD、LGD、炎症、正常支气管粘膜组之间存在统计学差异（P < 0.050），能较好鉴别正常粘膜及恶性病变。V值在浸润性癌和LGD组（P=0.003）、炎症组（P < 0.001）、正常支气管粘膜组（P < 0.001）存在统计学差异，能有效鉴别浸润性癌及良性疾病。V值在正常支气管粘膜组与HGD组（P=0.001）、炎症组（P=0.004）间比较也具有统计学差异。

结论

利用YUV色彩空间系统针对支气管和肺良恶性疾病鉴别有一定临床应用价值，为临床气管镜诊断肺癌及癌前病变提供有效科学依据。

Photodynamic therapy: oncologic horizons

Photodynamic therapy (PDT) is a light-based intervention with a long and successful clinical track record for both oncology and non-malignancies. In cancer patients, a photosensitizing agent is intravenously, orally or topically applied and allowed time to preferentially accumulate in the tumor region. Light of the appropriate wavelength and intensity to activate the particular photosensitizer employed is then introduced to the tumor bed. The light energy will activate the photosensitizer, which in the presence of oxygen should allow for creation of the toxic photodynamic reaction generating reactive oxygen species. The photodynamic reaction creates a cascading series of events including initiation of apoptotic and necrotic pathways both in tumor and neovasculature, leading to permanent lesion destruction often with upregulation of the immune system. Cutaneous phototoxicity from unintentional sunlight exposure remains the most common morbidity from PDT. This paper will highlight current research and outcomes from the basic science and clinical applications of oncologic PDT and interpret how these findings may lead to enhanced and refined future PDT.

The role of fluorescence diagnosis in clinical practice

Fluorescence diagnosis is a fast, easy, noninvasive, selective, and sensitive diagnostic tool for estimation of treatment results in oncology. In clinical practice the use of photodynamic diagnosis is focused on five targets: detection for prevention of malignant transformation precancerous changes, detection of neoplasmatic tissue in the early stages for fast removal, prevention of expansion and detection of recurrence of the cancer, monitoring therapy, and the possibility of excluding neoplasmatic disease. In this article, selected applications of fluorescence diagnosis at the Center for Laser Diagnostics and Therapy in Bytom, Poland, for each of these targets are presented.

Unique diagnostic and therapeutic roles of porphyrins and phthalocyanines in photodynamic therapy, imaging and theranostics

Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types. Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms. The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

Smoking, occupational risk factors, and bronchial tumor location: a possible impact for lung cancer computed tomography scan screening

INTRODUCTION

The aim of this study was to describe associations between lung tumor location and smoking as well as selected occupational exposures. In the context of lung cancer screening by computed tomography scan, tumor location may have an interest. Computed tomography scan is known to better detect more peripheral tumors.

METHODS

Lung cancer cases diagnosed in two French University hospitals between 1997 and 2009 were included. Tumors visible on white-light bronchoscopy were defined as central. Occupational exposures were assessed by the same expert. Data were analyzed by case-case comparisons using unconditional logistic regressions.

RESULTS

A total of 1701 cases were included, comprising mainly men (86.3%), current smokers (52.8%), or former smokers (42.8%). Main histological subtypes of cancer were adenocarcinomas (33.8%) and squamous cell carcinomas (32.6%). The tumor location was found to be central in 61% of cases, and never smokers and women had more often peripheral tumors. Exposure to asbestos was significantly associated with central location with dose-response relationship (odds ratio [OR] for peripheral tumors = 0.45, 95% confidence interval [CI] 0.29-0.70) for the highest level of exposure. Exposure to silica dust was significantly associated with peripheral tumor (OR for peripheral tumors = 3.28, 95%CI 1.50-7.17) for the highest level of exposure. Exposure to welding fumes was associated with central location (OR for peripheral tumors = 0.51, 95% CI 0.26-0.96) for the first level of exposure).

CONCLUSIONS

Smoking characteristics and occupational exposures have to be considered to define more accurately high-risk populations suitable for lung cancer screening or early detection programs.

Searching for metachronous tumours in patients with head and neck cancer: the ideal protocol!

PURPOSE OF REVIEW

As treatment changes in the management of head and neck cancer, patients are reportedly living longer; therefore, their death may be due to comorbidity, metastatic disease or the development of a metachronous second primary tumour (MSPT). This review describes recent developments in the identification of MSPTs of head and neck cancer, oesophagus and lung, and suggests/recommends an 'ideal surveillance protocol'.

RECENT FINDINGS

The rate of MSPT development ranges between 6 and 9% annually for life. Improved accuracy in the detection of mucosal asymptomatic premalignant and early cancer has been enhanced by incorporating fluorescence spectroscopy in addition to modern flexible endoscopic techniques in the outpatient setting. Newer imaging has replaced old techniques (chest radiograph, barium swallow, etc.) by using radiotracer PET-computed tomography to detect local tumour activity. Further advances are anticipated in optical diagnostics and the incorporation of radiopharmaceuticals with labelled antibodies to enhance PET imaging, thus making tumour identification more accurate. Genetic classification of head and neck cancer has already identified high-risk patient groups, thereby allowing expensive tumour screening techniques to be used selectively and specifically. Patients who continue to smoke and abuse alcohol must be helped and encouraged to quit.

SUMMARY

It is now possible to review traditional follow-up policy for treated head and neck cancer patients, to encourage the implementation of an evidence-based surveillance protocol, to identify only patients who are at high-risk of developing a MSPT, to incorporate modern targeted expensive tumour screening and to allow treatment of early cancer and effective treatment, thereby improving patients' quality of life and increasing survival.

Future of oncologic photodynamic therapy

Photodynamic therapy (PDT) is a tumor-ablative and function-sparing oncologic intervention. The relative simplicity of photosensitizer application followed by light activation resulting in the cytotoxic and vasculartoxic photodynamic reaction has allowed PDT to reach a worldwide audience. With several commercially available photosensitizing agents now on the market, numerous well designed clinical trials have demonstrated the efficacy of PDT on various cutaneous and deep tissue tumors. However, current photosensitizers and light sources still have a number of limitations. Future PDT will build on those findings to allow development and refinement of more optimal therapeutic agents and illumination devices. This article reviews the current state of the art and limitations of PDT, and highlight the progress being made towards the future of oncologic PDT.

Current status of medical pleuroscopy

Medical pleuroscopy (MP) offers a safe and minimally invasive tool for interventional pulmonologists. It allows diagnosis of unexplained effusion, while at the same time allowing drainage and pleurodesis. It can also help in the diagnosis of diffuse interstitial disease or associated peripheral lung abnormality in the presence of effusion. It can have a therapeutic role in pneumothorax and hyperhidrosis or chronic pancreatic pain. This article reviews the technical aspects and range of applications of MP.