PubMed · 5435131
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D H Follett. 1970. A solid-state controlled gain receiver for ultrasonic section scanning.. https://pubmed.ncbi.nlm.nih.gov/5435131/
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OBJECTIVES: Diagnostic pancreatoscopy was performed in 56 patients using the newly developed peroral electronic pancreatoscope (PEPS). The diagnostic value of the PEPS for pancreatic diseases was evaluated. METHODS: The PEPS (external diameter = 2.1 mm, bidirectional tip deflection) was developed with a minute 50,000-pixel interline charge-coupled device. Pancreatoscopy was performed by means of an endoscopic retrograde approach without sphincterotomy. The cases examined were normal (three), chronic pancreatitis (32), pancreatic cancer (eight), and intraductal papillary mucinous tumors (13). RESULTS: Of the 56 cases, 42 (75%) were adequately seen. In normal cases, fine capillary vessels were clearly visualized on the smooth whitish-pink mucosa. Findings in chronic pancreatitis included protein plugs, calcified stones, rough whitish mucosa, scar formation, edema, erythema, and indistinct capillary appearance. All the stenoses of chronic pancreatitis could be differentiated from those of pancreatic cancer with the PEPS. In the pancreatic cancer cases, all patients had stenoses or duct cutoffs; most cases had friable mucosa with erythema and erosive changes, and a single patient had a compressed pancreatic duct wall covered with normal epithelium. In the cases of intraductal papillary mucinous tumors, papillary tumors were visualized with extreme clarity. In the case of adenocarcinoma, the PEPS revealed oval-shaped tumors with spotty redness or villous tumors with dilation of capillary vessels. Moderate acute pancreatitis was recognized after pancreatoscopy in one of the 56 cases (1.8%). CONCLUSIONS: Electronic pancreatoscopy with the PEPS is feasible in most patients and technically safe, and improves diagnostic yield over conventional pancreatoscopy.
BACKGROUND AND PURPOSE: For cervix cancer patients, treatment fields may extend up to vertebra L1. In clinical practice, set-up verification is based on measured displacements of the pelvic rim as visible in the caudal part of the treatment fields. The implications of this procedure for the positions of bony structures in the cranial part of the fields were investigated. MATERIALS AND METHODS: Twelve patients had four repeat simulator sessions. Both during treatment simulation (the reference) and the repeat sessions, anterior radiographs were acquired covering the whole treatment field. The films were used to investigate differences between the cranial and the caudal parts of the treatment field in day-to-day bony anatomy displacements. RESULTS: Both in the transversal and the longitudinal directions, these differences were significant (3.5 mm, 1 SD). Indications were found that large differences in the cranio-caudal direction may be correlated with (non-rigid) internal pelvic rim rotations around a lateral axis. In the longitudinal direction, the position of L1 correlated much better with the position of vertebra S1 than with the position of the pelvic rim, which is usually used for set-up verification. CONCLUSIONS: Due to the non-rigid bony anatomy of the studied patients, the usual set-up verification and correction procedure can result in set-up errors of 10 mm and more for structures in the cranial part of the treatment field, even in the case of a perfect set-up of the pelvic rim. Possibly, other patient set-up and immobilization procedures may result in a better day-to-day reproducibility of the 3D bony anatomy shape. (Remaining) Differences in anatomy position changes between the caudal and cranial field ends may be accounted for by using non-uniform clinical target volume-to-planning target volume margins, or by an adapted patient set-up verification and correction protocol.
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