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Biomedical subjects

C McGinn

Publications and source records attributed to C McGinn.

5 recordsLinked to original sources
PubMed2001

Determination of ventilatory liver movement via radiographic evaluation of diaphragm position.

PURPOSE: To determine the accuracy of estimation of liver movement inferred by observing diaphragm excursion on radiographic images. METHODS AND MATERIALS: Eight patients with focal liver cancer had platinum embolization microcoils implanted in their livers during catheterization of the hepatic artery for delivery of regional chemotherapy. These patients underwent fluoroscopy, during which normal breathing movement was recorded on videotape. Movies of breathing movement were digitized, and the relative projected positions of the diaphragm and coils were recorded. For 6 patients, daily radiographs were also acquired during treatment. Retrospective measurements of coil position were taken after the diaphragm was aligned with the superior portion of the liver on digitally reconstructed radiographs. RESULTS: Coil movement of 4.9 to 30.4 mm was observed during normal breathing. Diaphragm position tracked inferior-superior coil displacement accurately (population sigma 1.04 mm) throughout the breathing cycle. The range of coil movement was predicted by the range of diaphragm movement with an accuracy of 2.09 mm (sigma). The maximum error observed measuring coil movement using diaphragm position was 3.8 mm for a coil 9.8 cm inferior to the diaphragm. However, the distance of the coil from the top of the diaphragm did not correlate significantly with the error in predicting liver excursion. Analysis of daily radiographs showed that the error in predicting coil position using the diaphragm as an alignment landmark was 1.8 mm (sigma) in the inferior-superior direction and 2.2 mm in the left-right direction, similar in magnitude to the inherent uncertainty in alignment. CONCLUSIONS: This study demonstrated that the range of ventilatory movement of different locations within the liver is predicted by diaphragm position to an accuracy that matches or exceeds existing systems for ventilatory tracking. This suggests that the diaphragm is an acceptable anatomic landmark for radiographic estimation of liver movement in anterior-posterior projections for most patients.

Diaphragm↗
PubMed2000

NCCN Practice Guidelines for Colorectal Cancer.

The NCCN Colorectal Cancer Guidelines panel believes that a multidisciplinary approach is necessary for the management of the patient with colorectal cancer. The panel endorses the concept that treatment of patients in a clinical trial has priority over standard or accepted therapy. The recommended surgical procedure for resectable colon cancer is an en bloc resection; laparoscopic surgery should be done only in the context of a clinical trial. For patients with stage III disease, 5-FU-based adjuvant therapy is recommended. A patient who has metastatic disease in the liver or lung should be considered for surgical resection if he or she is a candidate for surgery and if surgery can extend survival. Surgery should be followed by adjuvant chemotherapy. The panel advocates a conservative post-treatment surveillance program for colon and rectal carcinoma patients. Serial CEA determinations are appropriate if the patient is a candidate for aggressive surgical resection, should recurrence be detected. Abdominal and pelvic CT scans should be utilized only when there are clinical indications of possible recurrence. Patients whose disease progresses during 5-FU-based therapy should be treated with irinotecan or encouraged to participate in a phase I or phase II clinical trial.

Colorectal Neoplasms↗
PubMed1990

Definitive radiation therapy in the management of symptomatic patients with optic glioma. Survival and long-term effects.

We reviewed 24 children who had symptomatic gliomas that involved the optic chiasm and were treated with definitive radiation therapy from 1971 to 1986. In eight patients (33%), histologic confirmation of low-grade astrocytoma was obtained. Patients had radiation therapy only if there was evidence of visual deterioration or other clinical or radiographic evidence of disease progression. Radiation doses ranged from 4500 to 5660 cGy (median, 5400 cGy) with up to a 17-year follow-up period (median, 6 years). The 6-year actuarial freedom from disease progression and overall 6-year survival are 88% and 100%, respectively. Visual improvement or stabilization was seen in 21 (91%) patients after radiation. A high incidence of endocrine abnormalities is reported, with 15 of the 18 patients evaluated after treatment showing growth hormone deficiency. We conclude that definitive radiation therapy is associated with tumor control in most of the patients with progressive optic chiasm gliomas. However, neuropsychiatric and endocrine abnormalities are significant problems that need additional evaluation in these children.

Adolescent↗