Logo image
A study of the scintigraphic and microautoradiographic localization of thallium-201 in gliomas: correlation with histopathology and proliferation markers PCNA and Ki-67
Dissertation

A study of the scintigraphic and microautoradiographic localization of thallium-201 in gliomas: correlation with histopathology and proliferation markers PCNA and Ki-67

Lalitha Krishna
Doctor of Philosophy (Ph.D.), Hahnemann University
May 1995
DOI:
https://doi.org/10.17918/00007766
pdf
Krishna_Lalitha_19955.88 MB
PDF Access upon request, Email title, URL, or DOI to archives@drexel.edu

Abstract

Adenosine Triphosphatases Medical Oncology Neoplasms Potassium Sodium Thallium Radioisotopes--metabolism Radiotherapy
The role of thallium-201 as a proliferation marker in the management of gliomas was investigated both in an animal model and in a clinical setting. Microautoradiographic localization of thallium-201 was performed in a C6 glioma model in 6 Sprague Dawley rats. Simultaneously, immunohistochemical localization of two proliferation markers, proliferating cell nuclear antigen (PCNA) and Ki-67 was also performed. In all 6 animals, the localization index of thallium-201, PCNA and Ki-67 was significantly higher in the glioma versus normal brain (p < 0.05). This indicates that thallium-201 localization can be used to detect the proliferation potential of a glioma. A clinical study was then performed on 100 patients with gliomas. Forty two scans were performed on patients with gliomas on initial presentation. In this group, in predicting the presence of an actively proliferating/viable glioma, thallium-201 scintigraphy had a sensitivity of 0.97, specificity of 0.90, accuracy of 0.95, positive predictive value of 0.97 and negative predictive value of 0.90. One hundred and twelve scans were performed on patients with suspected recurrence of gliomas. In this group, in predicting the presence of an actively proliferating/viable glioma, thallium-201 scintigraphy had a sensitivity of 0.97, specificity of 0.84, accuracy of 0.94, positive predictive value of 0.95 and a negative predictive value of 0.88. There was no statistically significant difference in any of the above mentioned parameters in gliomas seen prior to and after therapy (p < 0.05). PCNA and Ki-67 localization was performed on 28 cases seen on initial presentation and 27 cases seen on suspected recurrence of a glioma. In both groups, while the mean labelling index (LI) was discrete for well differentiated vs malignant astrocytomas, the range of LI obtained was wide. Hence, in this study it was not possible to grade the gliomas based solely on the LI of PCNA and/or Ki-67. Based on the results obtained in both the animal and human studies, we conclude that thallium scintigraphy is a practical tool available to study the proliferative status of gliomas-both on initial presentation and on suspected recurrence. The advantages of this readily accessible technique are that it is non-invasive, evaluates the entire glioma which is a heterogeneous tumor and is relatively inexpensive.

Metrics

23 Record Views

Details

Logo image