Photodynamic diagnoses of malignant pleural diseases using the autofluorescence imaging system

Our plain-English summary of Photodynamic diagnoses of malignant pleural diseases using the autofluorescence imaging system, by M. Kitada, Y. Ohsaki, Y. Matsuda, et al (Annals of Thoracic and Cardiovascular Surgery, 2014).

The study

• Authors: M. Kitada, Y. Ohsaki, Y. Matsuda, S. Hayashi, K. Ishibashi
• Journal: Annals of Thoracic and Cardiovascular Surgery
• Published: 2014;20(5):378-82
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: We conducted a study on photodynamic diagnosis (PDD) using autofluorescence in video-assisted thoracic surgery for minute intrathoracic small dissemination or early malignant pleural mesothelioma.

Methods: Autofluorescence is the spontaneous emission of light that occurs when mitochondria, lysosomes, and other intracellular organelles absorb light. In normal tissues, green autofluorescence of approximately 520 nm is observed in response to 400-450 nm blue excitation rays. However, in cancer lesions, green autofluorescence is reduced due to thickening of the mucosal epithelium, a decrease in autofluorescent substances, etc., and the color spectrum thus shifts to red-violet. This phenomenon is the basis of PDD.

Results: The color spectrum shift was observed in all tumors located on the pleural surface but not in cases with pleural fibrous disease. Among patients with primary lung cancer, those with pleural infiltration (pl) scores of 1 or greater showed color spectrum shifts due to reduced autofluorescence.

Conclusion: Localization of pleural lesions by autofluorescence imaging was found to be useful. In primary lung cancer cases, differentiation between pl0 and pl1 lesions appears to be useful for determining therapeutic strategies including surgical procedures.

In plain English

This Japanese study tested whether a thoracoscope, a camera put into the chest during surgery, fitted with an autofluorescence imaging system could help show cancer on the pleura, the lining of the chest. Under blue light, normal tissue glowed green, while tumor sites appeared violet to red-violet. Between February 2012 and February 2013, 31 consenting patients having chest surgery were examined: 22 with primary lung cancer, five with metastatic lung tumors, two with malignant pleural mesothelioma (the article's table lists one), and two with benign tumors. The color shift was seen in all patients with metastatic lung tumors on the pleural surface. It was also seen in patients with dissemination or malignant pleural mesothelioma on the parietal pleura, but not in pleural fibrous disease. All 4 lung cancer patients with pleural infiltration of pl1 or greater showed the shift, as did 2 of 18 (11.1%) with pl0 lesions. The authors concluded that lesions on the pleural surfaces could be localized. They noted darker, less clear images, low light intensity and unclear lesion borders. The study did not examine asbestos exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: single-center clinical study (case series) of patients examined with an autofluorescence imaging thoracoscope during surgery
• Who was studied: 31 consenting patients undergoing thoracoscopic respiratory surgery between February 2012 and February 2013 at Asahikawa Medical University, Japan: 22 with primary lung cancer (one with pleural dissemination), five with metastatic lung tumors, two with malignant pleural mesothelioma (Table 1 lists one), two with benign tumors
• Exposure: No asbestos or fiber exposure was studied. The 'exposure' was examination with a thoracoscope fitted with an autofluorescence imaging system, modified from the PDS-2000 endoscopy system, using a 300 W xenon light source.
• Main results:
  • The color spectrum shift was seen in all patients with metastatic lung tumors located on the pleural surface.
  • The shift was seen in patients with dissemination or malignant pleural mesothelioma on the parietal pleural surface. It was not seen in patients with pleural fibrous disease.
  • Among lung cancer patients, all 4 with pleural infiltration of pl1 or greater showed a color spectrum shift.
  • Among lung cancer patients with pl0 lesions, the shift was seen in 2 of 18 (11.1%). Both had been diagnosed as having pl1 lesions before and during surgery.
  • No differences in histological type or malignancy grade were noted.
• The authors' conclusion: The authors concluded that autofluorescence imaging allowed them to localize lesions exposed on the visceral and parietal pleural surfaces. They also suggested that telling pl0 from pl1 lesions in primary lung cancer could be useful for planning treatment, including surgery.
• Limitations the authors state:
  • The images were slightly darker and less clear than white-light images, which lowered accuracy.
  • The light intensity from the device was rather low for optimal observation.
  • The depth of pleural infiltration in lung cancer could make actual tumors hard to delineate, and lesion borders were unclear on some images.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Thoracic Surgery, Intrathoracic, Pleural Mesothelioma, Epithelium, Lung Cancer.

Related studies

• Value of autofluorescence in video-assisted thoracoscopic surgery in pleural diseases — S.T. Liman, A. Elicora, et al. (2013)
• Rigid Mini-Thoracoscopy: The New Kid on the Block — E.O. Bedawi, N.M. Rahman (2020)
• Intraoperative fluorescence imaging in thoracic surgery — A.D. Newton, J.D. Predina, et al. (2018)
• Imaging features, complications and differential diagnoses of abdominal cystic lymphangiomas — M. Raufaste Tistet, O. Ernst, et al. (2020)
• Radical pleurectomy and intraoperative photodynamic therapy for malignant pleural mesothelioma — J.S. Friedberg, M.J. Culligan, et al. (2012)
• Practical approaches to diagnose and treat for T0 malignant pleural mesothelioma: a proposal for diagnostic total parietal pleurectomy — S. Hasegawa, N. Kondo, et al. (2012)

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