Kinya Furukawa

Early detection of bronchial lesions using system of autofluorescence endoscopy (SAFE) 1000

Recently several endoscopic fluorescence detection systems have been developed. In some of them, laser light was used for the excitation of autofluorescence, and sophisticated techniques were also necessary to amplify the fluorescence signal as well. The result of fluorescence diagnosis using a simple system with a conventional Xenon lamp excitation and an image intensifier is reported. The respective results of sensitivity and positive predictive values of cancer plus dysplasia were 66%, and 62% by standard bronchoscopy and 92% and 88% by the newly developed autofluorescence system. In this paper, developed endoscope for detection of tissue/mucosal autofluorescence without the application of any photosensitizing agents or use of any lasers is evaluated.

Effectiveness of Photodynamic Therapy and Nd-YAG Laser Treatment for Obstructed Tracheobronchial Malignancies

Since 1980, advanced lung carcinomas were treated with palliative laser therapy for the purpose of opening the endobronchial stenosis and obstruction by either photodynamic therapy (PDT) or Nd-YAG laser treatment at Tokyo Medical University. A total of 258 lesions were treated, 81 by PDT and 177 by Nd-YAG laser treatment. PDT achieved effective results in 61 (75%) of 81 lesions. In the Nd-YAG laser group, 143 (81%) of 177 lesions showed effective results. When the tumor was located in the trachea or main bronchi, effective results were obtained in 73% (19 of 26) of cases treated by PDT and in 93% of cases (64 of 69) treated by Nd-YAG laser. However, in cases in which the tumor was located in lobar or segmental bronchi, the tumor response was effective in 76% (42 of 55) of PDT-treated patients and 73% (79 of 108) of Nd-YAG laser-treated patients. With a mortality rate of 0%, the greatest advantage of PDT over Nd-YAG treatment was safety. Considering complications, PDT seems to be useful for obstruction of lobar and segmental bronchus. Nevertheless, when deciding among alternative therapies, physicians treating patients with advanced lung carcinoma should give careful consideration to the benefit and complications of both laser therapies and decide the most suitable modality.

Lung Cancers Treated with Photodynamic Therapy and Surgery

Laser endoscopic surgery, especially the effectiveness of photodynamic therapy (PDT) using Photofrin as a photosensitizer, has now achieved a status as effective treatment modality for lung cancer. Twenty-six lung cancer patients received the preoperative PDT for the purpose of either reducing the extent of resection or increasing operability. Bronchoscopical PDT is performed with topical anesthesia approximately 48 h after the intravenous injection of 2.0 mg/kg body weight of Photofrin. Operation was performed 2–9 weeks after initial PDT. The initial purpose of PDT, i.e. either to reduce the extent of resection or convert inoperable disease to operable status, was achieved in 22 out of 26 patients treated. The survival rate of T3 (main bronchus invasion) cases treated by surgery alone increased significantly from 50.9% to 60.0% with the application of preoperative PDT. This remarkable result may imply that this new option of PDT as preoperative laser irradiation may contribute to the management of advanced lung malignancy.

Localization and treatment of transformed tissues using the photodynamic sensitizer 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a

Photofrin is the photosensitizer currently used in most clinical trials examining the efficacy of photodynamic therapy (PDT) for the treatment and/or palliation of neoplasia. Although this drug has been shown to be efficacious in many of these trials, it possesses less than ideal qualities for use in a systematically administered photosensitizer. A new photosensitizer, 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a (HPPH), was developed for PDT. HPPH possesses more rapid clearance from skin and greater cytotoxicity per drug dose than Photofrin. The aims of this study were to: (1) examine the uptake and retention of HPPH in tissues undergoing malignant transformation using laser‐induced fluorescence, and (2) evaluate the efficacy of HPPH and 665 nm light in treating carcinogen‐induced tumors of the hamster buccal cheek pouch.

Fluorescence detection of premalignant, malignant, and micrometastatic disease using hexylpyropheophorbide

We investigated the in vivo fluorescence detection of premalignant and malignant lesions in carcinogen-induced tumors of the hamster buccal cheek pouch and micrometastases in rat lymph nodes using hexylpyropheophorbide-a (HPPH) at 0.5 mg/kg and He-Ne laser-induced fluorescence photometry. Time course studies of HPPH in hamster tumor model showed maximal relative fluorescence readings at 48 hours after i.p. injection in each stage (dysplasia: 0.35, papilloma: 0.58, squamous cell carcinoma: 1.04). Squamous cell carcinoma showed significantly greater fluorescence than papillomas and dysplasias at all time points (p < 0.01). Metastatic lymph nodes were significantly greater than normal lymph nodes at all time points (p < 0.01). Maximal fluorescence levels of normal lymph nodes were observed at 6 hours after i.v. injection. Metastatic lymph nodes still showed high fluorescence levels at 72 hours. Micrometastases showed fluorescence levels between the levels of metastatic and normal lymph nodes (normal: 0.40 < micrometastasis: 0.62 < metastasis: 0.75 at 48 hours after i.v. injection). The results demonstrated good correlation between fluorescence levels and histopathological developments at all time points. Therefore, HPPH may be a promising fluorophore for the detection of developing malignancies and occult disease.

The Development of a New Setup for Video-assisted Thoracic Surgery

In order to accomplish video-assisted thoracic surgery (VATS) in a much easier and safer way, especially for assistant operators, we have developed a new display system for VATS. The original thoracoscope has been designed for this new system. The monitor is fixed at approximately 10 cm away from the surface of the chest wall just above the operative field. In using this procedure, the operator and assistants can see the patient and the monitor at the same time. According to this new idea, the previous problem in the area of hand–eye coordination and the three-dimensional understanding of this procedure can be improved compared to the image of the conventional thoracoscopy, because it is not necessary for the operator and assistants to look up at the monitors. When the thoracoscopy was placed in an adequate position to resect the target pathology, this new system led to good and easy handling of instruments, as it was with the standard thoracotomy.

Fluorescence photodiagnosis for malignant tumor

The effectiveness of a new excimer laser endoscopic imaging fluorescence analyzer system using the photosensitizer, mono-L-aspartyl chlorin e6 (NPe6) for the detection of tumors was evaluated. Autofluorescence (550 plus or minus 10 nm, green fluorescence) from normal sites, red fluorescence (664 nm) of NPe6 in areas of cancer and the red fluorescence/green fluorescence ratio (R/G ratio) as the color image can be detected respectively. The greatest NPe6 fluorescence from the lesion was obtained at 3 hours after injection and the fluorescence disappeared at 24 hours. The greatest difference in the fluorescence of NPe6 and the R/G ratio in areas of tumor and in normal areas were observed at 5 hours after administration. At this period, NPe6 fluorescence from normal sites was negligible. These data suggest that fluorescence photodiagnosis may be effective in the detection of cancers.

Point fluorescence measurements of transformed tissues using 2-[1-hexyloxyethel]-2-devinyl pyropheophorbide-a

Recently, a new photosensitizer, 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-1 (HPPH) was developed for PDT which possesses more rapid clearance from skin and greater cytotoxicity per drug dose than Photofrin. The spectral characteristics of HPPH shows an absorption band at 665 nm (50,000 M-1cm(superscript -1 and peak emission at 680 nm. The aid of this study was to examine HPPH as a fluorescent diagnostic compound for the detection of transformed tissues using the in vivo fluorescence photodetector. The model of tissue transformation was the carcinogen (DMBA [9, 10-dimethyl-1, 2- benzanthracene])-induced premalignant and malignant lesions of the hamster buccal cheek pouch. The results demonstrated significant correlations between fluorescence levels and histological developments at all time points after injection. Time course studies of HPPH showed highest fluorescence readings at 48 hours after injection of 0.5 mg/kg HPPH (mild-moderate dysplasia, 0.35 +/- 0.17 volts; papillary disease with severe dysplasia, 0.58 +/- 0.33 volts; and squamous cell carcinoma, 1.04

An importance of clinical proteomics for personalized medicine of lung cancer subtypes

OM 0.32 volts). Therefore, it appears that HPPH may be a promising fluorophore for the detection of transformed tissues.

Photodynamic therapy using a diode laser with mono-L-aspartyl chlorin e6 (NPe6)

Mass spectrometry-based clinical proteomic analysis, combined with collection of taegeted cancerous cells laser-microdissected (LMD) from formalin-fixed paraffinembedded (FFPE) tissues, has been promising to unveil both proteins expressed and their functional networks in lung cancer subtypes. Among lung cancer subtypes, both large cell neuroendocrine carcinoma (LCNEC) of the lung and small cell lung carcinoma (SCLC) are now classified to neuroendocrine tumor (NET) but pre-therapeutic histological distinction between LCNEC and SCLC has so far been problematic, leading to adverse clinical outcome. Protein biomarker candidates for LCNEC were found to be interestingly known as cancer stem cell (CSC) markers including aldehyde dehydrogenase 1 family member A1 (ALDH1A1), and those for SCLC included novel NET marker candidates, brain acid soluble protein 1 (BASP1) and secretagogin (SEGN), and a known NET marker, neural cell adhesion molecule (CD56). For three types of lung adenocarcinomas (ACs), which are adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic predominant invasive asenocarcinoma (LEP), their preliminary clinical proteomic analyses revealed protein expression profiles characterizing those lung cancer subtypes. The STRING protein-protein interaction (PPI) network analysis followed by gene set enrichment (GSE) for proteins expressed significantly to the three lung AC subtypes manifested characteristic associations of cancer-related pathways, which might play consertedly important roles in progression of disease mechanisms, and which would be quite useful to understand carcinogenic processes of lung adenocarcinom. Thus outcomes from clinical proteomic analysis reveal not only biomarker protein candidates expressed significantly to a disease but also serve to elucidate disease-oriented protein-protein interaction (PPI) networks including functional networks predicted from experimentally obtained proteome datasets. Abbreviations: LCNEC: Large-Cell Neuroendocrine Lung Carcinoma, OLC: Other Large-Cell Lung Cancer, SCLC: Small-Cell Lungcancer, GGO: Focal Ground-Glass Opacity, AIS: Adenocarcinoma In Situ, MIA: Minimally Invasive Adenocarcinoma, LEP: Lepidic Predominant Invasive Adenocarcinoma, FFPE: Formalin-Fixed and Paraffin-Embedded tissue sections, MS: Mass Spectrometry, PPI: Comparative Proteomics, Protein-Protein Interaction