Document(s) 16 of 31

Introduction

The field of surgical pathology and cytology involves a cascade of operator-dependent technical, scientific and medical processes. The preparation and interpretation of surgical pathology and cytology material requires trained technical personnel, excellent technical support, skill, experience and some basic infrastructure. Developing nations such as India are typically flawed by vast socioeconomic differences. In India, there is a truly heterogeneous and uneven development of health care facilities, which results in major disparities: some medically privileged areas have expertise on par with the industrialized world, while other remotely located, rural, under-served populations are almost totally deprived of any medical facilities. Telemedicine provides a method of bridging this gap.^1–5

Telepathology for the developing world

Telepathology is the practice of pathology at a distance using telecommunications. It involves viewing images on a video monitor rather than directly through a microscope. The minimum requirements for telepathology are:

• a light microscope (motorized for dynamic telepathology);
  
  
• a high-resolution camera (either a digital camera or a video camera with a frame grabber card);
  
  
• a workstation for the telepathologist;
  
  
• access to a telecommunications network.

Telepathology can be performed using a static, or ‘store-and-forward’, approach; it can also be conducted using a dynamic, or real-time, approach; or it may employ a hybrid of the two.^1,2 There are obvious disadvantages associated with static telepathology, the major one being sampling error, which reflects the passive nature of this exercise. In contrast, dynamic telepathology overcomes the basic drawback of static telepathology, although techniques such as ultra-rapid virtual slide processing⁶ are prohibitively expensive in a developing country setting. Sampling error in static telepathology consultation could be reduced by the referring pathologist sending a set of images covering both ambiguous and unambiguous areas. There is general agreement that a reasonably accurate histopathological diagnosis is possible on the basis of the examination of judiciously selected digital images. It has been our observation that mutual trust, rapport and close interaction between referring pathologist and telepathologist, and adequate training of the referring pathologist, are very important to achieve successful teleconsultations.²

The quality of the images is largely dependent on the quality of the basic starting material, which is the stained slide. The mode of transmission and the image compression will not compromise the quality of images if chosen carefully. It has been suggested that successful telepathology diagnoses can be achieved using adaptive colour reduction algorithms to reduce image file size, thus facilitating transmission without sacrificing quality.⁷

The single most important factor that influences selection of the system in the developing world is the cost. The potential customer, in addition, also faces the problem of commercial pressure by the vendors. Dealing with single-vendor proprietary systems, i.e. buying the camera, software and microscope in a package, implies an inability to negotiate costs. However, it is heartening to note that the costs of most of the components of telepathology system are declining.

Constraints

There are a number of constraints that limit the introduction of telepathology in the developing world. These include the following.

Inadequate infrastructure

The essential components of any telepathology system, i.e. the microscope, a camera with software and a computer, may not available in rural areas of developing countries. Procurement of these items may be difficult. Telecommunication facilities may not be developed at all, or they may be so poorly developed that it may be difficult or impossible to transmit cases. Moreover, the development and availability of telecommunication facilities may be non-uniform.^3,4,8,9

Non-uniform processing of pathology material

The limiting step in telepathology is availability of a well-processed histology or cytology glass slide. In the developing world, the lack of infrastructure, equipment and uniform standards makes for poor pathology material or suboptimal technical material.

Lack of accreditation

Telepathology is a combination of surgical pathology, information technology and imaging. All three processes lack defined standards. A few centres conduct accreditation for histopathology, but there are no standards laid down for telepathology in particular.

Low level of training

A well-processed stained slide is the most important factor for success in telepathology. Lack of trained manpower for histopathology processing has a very negative effect on the subsequent quality of a telepathology consultation. As training is required for surgical pathology and cytology specimen processing, it is also required for information technology and handling of camera and computer. The natural tendency of the staff to initially resist any new technology may also need to be managed carefully.

Lack of dedicated personnel

It is often difficult to find dedicated personnel to carry out telepathology or to staff a telemedicine department. The staff are expected to perform multitasking, especially in a low-volume centre.

Applications of telepathology

Intraoperative consultation between pathologist and surgeon requires rapid and accurate diagnosis, which is rendered on a frozen section and provides the necessary guidance to the operating surgeon. For interpretation of intraoperative frozen sections, transmission of live images is required using dynamic telepathology. The same also holds true for primary diagnosis of routine surgical pathology. Although this technique is well developed in certain parts of Europe and the USA,^5,10 in developing countries, the constraints of cost mean that intraoperative consultation is rare.

However, telepathology has proven its merit in developing countries where dynamic teleconsultation is not required, for example to obtain second opinions,^3,4,8,9 expert-to-expert consultations, quality assurance, distance education, consensus diagnosis for pathology review in clinical trials and proficiency testing. In the USA, ultra-rapid turnaround time in surgical pathology has recently been demonstrated in breast cancer clinics. These combine digital mammography imaging and interpretations, the latest advances in rapid specimen processing (microwave and automated immunostaining), and biopsy diagnosis by telepathology, producing a ‘one-stop shop’ for patients being investigated.⁶ Although this is attractive, promising and useful for the industrialized world, it is not practical in the developing world because of the high costs.

Another potential use of telepathology is for consultations generated in the industrialized world to be outsourced to experts in developing countries. This is currently practised in the field of radiology at some centres. However, credentialing requirements, issues related to licensure and malpractice coverage need to be resolved for this approach.¹¹ If these factors are dealt with appropriately then this model of tele-pathology may have potential.

Telepathology is not yet validated in the field of exfoliative cytology, which involves microscopic examination of cells that are shed from the lesion. Most cytologists would agree that telecytology is not a preferred mode for reporting exfoliative cytology. However, it is worth noting that there have been a few studies of telecytology involving fine-needle aspiration cytology (FNAC).⁹

Tele-surgical pathology and telecytology

The distinction between tele-surgical pathology and telecytology is based on the inherent differences between the cytology and surgical pathology material. Surgical pathology material consists of cells and tissue architecture. Hence, the telepathologist and referring pathologist can make use of the tissue architecture as a reference point to discuss the case and/or obtain additional images from any suspicious areas. Cytology smears mainly consist of cells with a few stromal fragments and are spread over a large area. The whole smear needs to be scanned. Hence, telecytology requires more comprehensive and optimized initial sampling of the smears, which increases the number of images produced. Telecytology largely depends on the images chosen by the referring pathologist. Hence, it is desirable to have the problematic areas adequately represented in the initial images in telecytology.⁹

Experience of telepathology in Mumbai

The Tata Memorial Hospital in Mumbai, India is a tertiary cancer referral centre, delivering comprehensive care to cancer patients in the Indian subcontinent. The hospital has a static telepathology link with two rural cancer centres located 500 km from Mumbai (Figure 14.1). The process to establish a static telepathology link with one of the rural cancer centres, the Nargis Dutt Memorial Cancer Hospital, began in October 2000 and came to fruition in January 2002. The delays were mainly due to hurdles related to the communication link. However, once it became fully operational, tele-pathology was able to sustain itself.3,5,8,9 The communication medium employed is the ordinary telephone system, with the 56 kbit/s dial-up modem providing access to the Internet. A set of compressed images in conjunction with clinical data are sent as email attachments.

Figure 14.1 Static telepathology workstation at the referring pathologist’s end in Barshi, Solapur, India

The performance of static telepathology was assessed by comparing the diagnoses rendered on telepathology and glass slides, respectively. The comparison was categorized as follows:

Analysis of tele-surgical pathology consultations

In a study of 299 static telepathology consultations accrued over a period of 3 years to December 2004, there were 251 surgical pathology, 2 international consultations and 46 cytology cases.^3,4,8,12 Concordance (absolute concordance, qualified diagnosis or minor, clinically unimportant discrepancies) for tele-surgical pathology was 96% (199 of 207 cases). The diagnosis was deferred in 30 cases.

Our experience of deferred diagnoses on telepathology indicates that the ‘probable’ diagnosis rendered in complex cases such as lymphoid neoplasia, sarcoma and round cell tumours matched the final glass slide diagnosis in 47% of cases. The ‘probable’ telepathology diagnosis rendered on potentially difficult cases does give the referring pathologist a direction or impart a different thought process during decision making.¹²

We believe that static telepathology consultation helps the referring pathologist to unravel the diagnosis while dealing with potentially complex cases, even in the event of deferral. Static telepathology has the potential to provide specialist support in the clinical management of such cases.

Analysis of telecytology consultations

A total of 46 cases accrued over period of 3 years were analyzed.⁹ The cases included 44 FNAC and 2 exfoliative cytology smears. The concordance (absolute concordance, qualified diagnosis or minor, clinically unimportant discrepancies) for telecytology was 91% (39 of 43 cases). The diagnosis was deferred in 5 cases.

The reasons for major discrepancies for both telesurgical pathology and telecytology were interpretative errors, inadequate sampling, poor-quality sections and images, and inadequate clinical data. We believe that effective use of static telepathology can be achieved by thorough sampling by the referring pathologist, expertise in surgical pathology at the telepathologist’s end and effective interaction between the two ends.^3,4,8,9,12

Conclusion

Telepathology is a powerful technique. To make best use of it, the raw material, i.e. the stained glass slide, must be of optimum quality. We have found that telepathology is valuable in bridging the gap between under-served areas and specialty centres, and can build confidence and capacity in the professionals working in under-served areas. This also reduces professional isolation, as expressed by referring pathologists. Patients from under-served areas receive better professional advice, while saving their travel costs to tertiary centres. Another major advantage of teleconsultation is effective management of turnaround time. In our study, 48% of cases were reported within 8 hours (a single working day) and 91% of cases within 3 days.

It is obvious that telepathology is potentially useful in the developing world. A decision to implement a diagnostic telepathology system in developing countries will be based on numerous factors, but the pivotal factor will be the need for telepathology. A strong impetus to establish communication between distantly located centres can help to establish successful, inexpensive and effective teleconsultation and to transfer knowledge and expertise to medically underprivileged areas and bridge the gap of knowledge and expertise at low cost. I believe that once the advantages of tele-pathology are visible to pathologists generally, the technique will rapidly gain in popularity.

Acknowledgements

I am grateful to Dr KA Dinshaw, Dr Ashok Mohan, Dr BM Nene, Mr MK Chauhan, Mr TK Ghosh, Mr Manoj Chavan, Mr Amit Satvekar and Mr Bipin Gadhave. I thank Dr Roshni Chinoy, Dr Shubhada Kane, Dr Tanuja Shet and Dr Mukta Ramadwar for reporting telepathology cases and Dr Rajasa Patil and Dr Sanica Bhele for providing logistical support.

Further reading

Arizona Telemedicine Program. Available at: www.telemedicine.arizona.edu/index.cfm.

Armed Forces Institute of Pathology. Department of Telemedicine. Available at: www.afip.org/consultation/telemedicine.

International Union against Cancer (UICC) Telepathology Consultation Center. Available at: pathoweb.charite.de/UICC-TPCC/default.asp.

Kayser K, Szymas J, Weinstein RS. Telepathology. Berlin: Springer-Verlag, 1999.

Li X, Gong E, McNutt MA et al. Assessment of diagnostic accuracy and feasibility of dynamic telepathology in China. Hum Pathol 2008; 39: 236–42.

Wells CA, Sowter C. Telepathology: a diagnostic tool for the millennium. J Pathol 2000; 191: 1–7.

References

¹ Wootton R. Recent advances: telemedicine. BMJ 2001; 323: 557–60.

² Weinstein RS, Descour MR, Liang C et al. Telepathology overview: from concept to implementation. Hum Pathol 2001; 32: 1283–99.

³ Desai S, Ghosh TK, Chinoy R et al. Telepathology at Tata Memorial Hospital, Mumbai and Barshi, a rural centre in Maharashtra. Natl Med J India 2002; 15: 363–4.

⁴ Desai S, Patil R, Chinoy R et al. Experience with telepathology at a tertiary cancer centre and a rural cancer hospital. Natl Med J India 2004; 17: 17–19.

⁵ Cross SS, Dennis T, Start RD. Telepathology: current status and future prospects in diagnostic histopathology. Histopathology 2002; 41: 91–109.

⁶ Weinstein R, Descour MR, Liang C et al. An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study. Hum Pathol 2004; 35: 1303–14.

⁷ Doolittle MH, Doolittle KW, Winkelman Z, Weinberg DS. Color images in telepathology: How many colors do we need? Hum Pathol 1997; 28: 36–41.

⁸ Desai S, Patil R, Kothari A et al. Static telepathology consultation service between Tata Memorial Centre, Mumbai and Nargis Dutt Memorial Charitable Hospital, Barshi, Solapur, Maharashtra: an analysis of the first 100 cases. Indian J Pathol Microbiol 2004; 47: 480–5.

⁹ Jialdasani R, Desai S, Gupta M et al. An analysis of 46 static telecytology cases over a period of two years. J Telemed Telecare 2006; 12: 311–14.

¹⁰ Frierson HF Jr, Galgano MT. Frozen-section diagnosis by wireless telepathology and ultra portable computer: use in pathology resident/faculty consultation. Hum Pathol 2007; 38: 1330–4.

¹¹ Kalyanpur A, Neklesa VP, Pham DT et al. Implementation of an international teleradiology staffing model. Radiology 2004; 232: 415–19.

¹² Bhele S, Jialdasani R, Kothari A et al. Analysis of deferrals on static telepathology consultation service. Ind J Pathol Microbiol 2007; 50: 749–53.

Document(s) 16 of 31