Fibre-based fluorescence-lifetime imaging microscopy: a real-time biopsy guidance tool for suspected lung cancer

Lung cancer is the most common cause of cancer-related deaths worldwide. Early detection improves outcomes, however, existing sampling techniques are associated with suboptimal diagnostic yield and procedure-related complications. Autofluorescence-based fluorescence-lifetime imaging microscopy (FLIM), a technique which measures endogenous fluorophore decay rates, may aid identification of optimal biopsy sites in suspected lung cancer. Our fibre-based fluorescence-lifetime imaging system, utilising 488 nm excitation, which is deliverable via existing diagnostic platforms, enables real-time visualisation and lifetime analysis of distal alveolar lung structure. We evaluated the diagnostic accuracy of the fibre-based fluorescence-lifetime imaging system to detect changes in fluorescence lifetime in freshly resected ex vivo lung cancer and adjacent healthy tissue as a first step towards future translation. The study compares paired non-small cell lung cancer (NSCLC) and non-cancerous tissues with gold standard diagnostic pathology to assess the performance of the technique. Paired NSCLC and non-cancerous lung tissues were obtained from thoracic resection patients (N=21). A clinically compatible 488 nm fluorescence-lifetime endomicroscopy platform was used to acquire simultaneous fluorescence intensity and lifetime images. Fluorescence lifetimes were calculated using a computationally-lightweight, rapid lifetime determination method. Fluorescence lifetime was significantly reduced in ex vivo lung cancer, compared with non-cancerous lung tissue [mean ± standard deviation (SD), 1.79±0.40 vs. 2.15±0.26 ns, P<0.0001], and fluorescence intensity images demonstrated distortion of alveolar elastin autofluorescence structure. Fibre-based fluorescence-lifetime imaging demonstrated good performance characteristics for distinguishing lung cancer, from adjacent non-cancerous tissue, with 81.0% sensitivity and 71.4% specificity. Our novel fibre-based fluorescence-lifetime imaging system, which enables label-free imaging and quantitative lifetime analysis, discriminates ex vivo lung cancer from adjacent healthy tissue. This minimally invasive technique has potential to be translated as a real-time biopsy guidance tool, capable of optimising diagnostic accuracy in lung cancer.

Intranodal Palisaded Myofibroblastoma Masquerading as N2 Non-Small Cell Lung Carcinoma

Intranodal palisaded myofibroblastoma is a rare and benign tumor that usually presents in the inguinal region. We report the case of a 68-year-old woman with a right paratracheal mass and right upper lobe non-small cell lung carcinoma initially staged as T1b N2 M0. After mediastinal staging, the right paratracheal mass was found to be an intranodal palisaded myofibroblastoma, which had caused erroneous upstaging of the lung carcinoma to N2 disease. This had the potential of leading to suboptimal treatment of the primary lung carcinoma if formal mediastinal staging had not been performed. To the best of our knowledge, this is the first report in the English literature of an intranodal palisaded myofibroblastoma occurring concurrently with lung cancer. This case highlights the importance of mediastinal staging in lung cancer. Mediastinoscopy remains the gold standard.

Wide-field digital retinal imaging versus binocular indirect ophthalmoscopy for retinopathy of prematurity screening: a two-observer prospective, randomised comparison

AIM

To compare the diagnostic accuracy of wide-field digital retinal imaging (WFDRI) with the current "gold standard" of binocular indirect ophthalmoscopy (BIO) for retinopathy of prematurity (ROP) screening examinations.

METHODS

A consecutive series of premature infants undergoing ROP screening at Edinburgh Royal Infirmary were eligible for recruitment into this prospective, randomised, comparative study. Infants were screened using both WFDRI (Retcam II with neonatal lens) and BIO by two paediatric ophthalmologists who were randomised to the examination technique. Both examiners documented their clinical findings and management plans in a masked fashion. WFDRI eye findings were compared with those of BIO.

RESULTS

A total of 81 infants were recruited, and information from 245 eye examinations was analysed. The sensitivity of WFDRI in detecting any stage of ROP, stage 3 ROP and "plus" disease was 60%, 57% and 80%, respectively, and specificity 91%, 98% and 98%, respectively. The proportional agreement between WFDRI and BIO was 0.96 for detecting stage 3 disease and 0.97 for detecting "plus" disease. There was very good agreement on management decisions (kappa 0.85).

CONCLUSION

When used in a routine ROP screening setting, a randomised comparison of WFDRI and BIO, WFDRI showed relatively poor sensitivity in detecting mild forms of ROP in the retinal periphery. This resulted in difficulty in making decisions to discharge infants from the screening programme. Sensitivity was better for more severe forms of ROP, but at present WFDRI should be regarded as an adjunct to, rather than a replacement for, BIO in routine ROP screening.

Incidence of retinopathy of prematurity in Lothian, Scotland, from 1990 to 2004

BACKGROUND

To report the trends in incidence of retinopathy of prematurity (ROP) within Lothian, a geographically defined region in southeast Scotland over a 15-year period from 1990 to 2004.

METHODS

This was a prospective observational study of all infants born with gestational age <32 weeks and/or birth weight <1500 g who were born to mothers resident in Lothian between 1 January 1990 and 31 December 2004. Eligible infants underwent eye screening by two experienced paediatric ophthalmologists (BF and EW). Lothian population data were obtained from the Scottish Health Service. The trends in survival rates, incidence and treatment of ROP were analysed from 1990 to 1994, 1995 to 1999 and 2000 to 2004.

RESULTS

Lothian population data showed a steady decline in the number of live births from 1990 to 2004. The proportion of babies born with birth weight <1500 g and/or gestational age <32 weeks remained constant (p = 0.271 using chi(2) test), although the proportion of these babies surviving to 42 weeks corrected gestation increased from 1990 to 2004 (p<0.001 using chi(2) test for trend). There was a statistically significant linear trend towards a reduction in the number of babies undergoing treatment for ROP throughout the study period (p<0.01 using chi(2) test for trend). A reduction in the incidence of any degree of ROP and severe (stage 3 or greater) ROP was also observed although this did not reach statistical significance.

CONCLUSIONS

There was a significant increase in survival of infants with birth weight <1500 g and/or gestational age <32 weeks together with a significant reduction in the number of infants treated for ROP in the Lothian region of southeast Scotland from 1990 to 2004.