Biomedical subjects

C S Harper

Publications and source records attributed to C S Harper.

3 recordsLinked to original sources

PubMed1999

Implementation of a stereotactic radiotherapy system.

The tests carried out on a recently-installed stereotactic radiotherapy system capable of fully frameless stereotaxy are outlined. The two principle investigations carried out on the planning system were a dosimetry test, and a test to verify the accuracy of localisation from CT examination through to patient treatment. The method employed in frameless relocation for fractionated stereotactic radiotherapy--position detection using stereoscopic infra-red cameras and a set of fiducials attached to a bite-block--was tested for reproducibility. The results of these tests suggest a mean accuracy in treatment localisation of 1.23 mm (maximum 2.72 mm) for single fraction techniques, and 1.77 mm (maximum 4.53 mm) for treatments involving repeated (frameless) localisation. The implications of these accuracies for treatment with single, multiple-fraction and multi-isocentre techniques are discussed.

Brain Diseases↗

PubMed1997

Endoluminal brachytherapy for recurrent laryngeal carcinoma.

Early-stage squamous cell carcinoma of the larynx is usually treated with local field radiotherapy. Surgery is used for salvage following recurrence. Further recurrences present a more difficult therapeutic problem which requires individualized management. The aims of local control, survival, maintenance of function and minimizing side effects all need to be balanced according to the site and extent of disease. The present case study looks at the management of a 54-year-old man with multiple recurrences from a squamous cell carcinoma of the larynx. It describes a technique of endoluminal brachytherapy using an iridium-192 wire spiralled around the outer part of a tracheostomy tube that achieves good local control while enabling self-insertion and self-cleaning during the procedure. The dose given was 2500 cGy at 5 mm over 25.2 h and was achieved with minimal early or delayed side effects. The patient had no further symptoms relating to the stomal recurrence until his death from metastatic disease 6 months later.

Brachytherapy↗

PubMedDate not supplied

Cancer in neck nodes with unknown primary site: role of mucosal radiotherapy.

Sixty-nine patients with metastatic squamous cell carcinoma in neck nodes with an unknown primary lesion were treated with curative intent between October 1964 and December 1986. Sixty-five patients received radiotherapy to the neck and at least part of the mucosa of the head and neck, whereas 4 patients received treatment to the neck only. Mucosal doses were approximately 5,000 cGy-6,000 cGy at 170 cGy-180 cGy per fraction. Eight patients (12%) subsequently developed mucosal site failures, a figure that did not differ significantly from the incidence of a second metachronous head and neck cancer following definitive irradiation in a series of 393 patients with lesions of the supraglottic larynx, pharyngeal wall, pyriform sinus, or tonsillar area. This suggests that radiotherapy was highly effective in preventing the appearance of cancer at the unknown primary site from which the neck metastasis arose. Absolute and cause-specific 5-year survival rates were 48% and 66%, respectively.

Adult↗