Mark H. Mellow

Elastic scattering spectroscopy as a diagnostic tool for differentiating pathologies in the gastrointestinal tract: preliminary testing

We report preliminary clinical testing of elastic-scattering spectroscopy for the detection of pathologies of the gastrointestinal tract. Tissue pathologies are detected and diagnosed using spectral measurements of elastically scattered light in an optical geometry that results in sensitivity to both the absorption and scattering properties of the tissue, over a wide range of wavelengths (300 to 750 nm). The system employs a small fiber optic probe, which is amenable to use with most endoscopes or catheters, or to direct surface examination, as well as interstitial needles. In this paper we report the results of preliminary clinical measurements on various organ sites of the gastrointestinal tract. In several instances the data indicate promise for this diagnostic method to distinguish malignant and dysplastic conditions from normal or other diagnoses.

Endoscopic laser therapy as an alternative to palliative surgery for adenocarcinoma of the rectum—comparison of costs and complications

Endoscopic laser therapy has been used as an alternative to surgery for rectal cancer in certain patients with metastases or at high surgical risk. This report analyzes 35 patients undergoing surgery and 21 undergoing laser therapy for rectal cancer. The cost of treatment was compared as well as the length of hospital stay, intensive care stay, complications, and survival. In the surgical patients, complications, length of stay, and intensive care stay were all significantly greater than for patients treated by endoscopic laser. Mean total cost for surgery was

Detection of gastrointestinal cancer by elastic scattering and absorption spectroscopies with the Los Alamos Optical Biopsy System

23,156 compared with

Endoscopic Laser Therapy for Malignancies Affecting the Esophagus and Gastroesophageal Junction: Analysis of Technical and Functional Efficacy

5333 for inpatient laser treatment (p less than 0.001) and

Endoscopic therapy for esophageal carcinoma with Nd:YAG laser: prospective evaluation of efficacy, complications, and survival

2263 for outpatient laser treatment (p less than 0.001). Lifetime cost calculated in patients with metastases treated by surgery was

Guidelines for training non-specialists in screening flexible sigmoidoscopy

22,900 compared with

Endoscopic laser therapy in colorectal cancer

12,154 for laser therapy (p less than 0.05). Mean survival in patients with metastases was 28 weeks in the surgery group and 36 weeks for laser treatment. We conclude that the cost of endoscopic laser therapy is significantly less, and that hospital stay, intensive care time, and complications are significantly greater in patients undergoing palliative surgery for rectal cancer.

The Role of Laser in Gastroenterology, Lisbeth Mathus-Vliegen. Kluwert Academic Publishers, Dordrecht, Boston, London (1988), 224 pp.,

The Los Alamos National Laboratory has continued the development of the Optical Biopsy System (OBS) for noninvasive, real-time in situ diagnosis of tissue pathologies. In proceedings of earlier SPIE conferences we reported on clinical measurements in the bladder, and we report here on recent results of clinical tests in the gastrointestinal tract. With the OBS, tissue pathologies are detected/diagnosed using spectral measurement of the elastic optical transport properties (scattering and absorption) of the tissue over a wide range of wavelengths. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, exhibit significant architectural changes at the cellular and subcellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes in an optical signature that is derived from the wavelength-dependence of elastic scattering. Additionally, the optical geometry of the OBS beneficially enhances its sensitivity for measuring absorption bands. The OBS employs a small fiber optic probe that is amenable to use with any endoscope or catheter, or to direct surface examination, as well as interstitial needle insertion. Data acquisition/display time is < 1 second.