Small Radiation Detectors for Bronchoscopic Tumor Localization

Tumor detection at bronchoscopy involves a linear visual search throughout the accessible part of the bronchial tree with biopsy at suspicious locations. We have designed, built and tested a series of small radiation detector probes that can be passed through the biopsy channel of a bronchoscope and used to locate sites of increased uptake of tumor-seeking radiopharmaceuticals. Such probes can help to locate visually obscured or submucosal tumors and can identify sites for biopsy. NaI(Tl) and CsI(Tl) scintillation detectors with flexible fiber optic light guides and a CdTe semiconductor detector have been constructed. Tumor phantom studies have successfully predicted the performance of the NaI(Tl) probe in clinical studies using 57Co-bleomycin.