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J Q Gildersleve

Publications and source records attributed to J Q Gildersleve.

4 recordsLinked to original sources
PubMed2003

Iridium-192 implantation for T1 and T2a carcinoma of the tongue and floor of mouth: retrospective study of the results of treatment at the Royal Berkshire Hospital.

Carcinomas of the tongue and floor of mouth are relatively rare tumours, which may be treated using several modalities. We reviewed the results of iridium wire implants performed at the Royal Berkshire Hospital between 1994 and 2000. 24 patients had iridium wire implants as primary treatment for tongue and floor of mouth cancers. Four patients were treated after excision biopsy with close or involved margins. One patient was treated for a recurrence after surgery. The median age at treatment was 61 years. There were 18 men and 11 women. 21 patients had tumours of the tongue and eight of the floor of mouth. 13 had T1 tumours and 11 had T2a tumours. The median follow up was 42 months. The primary tumour was controlled in 22 of the 29 patients by the implant alone. Of the seven patients with local recurrence four were successfully salvaged with surgery. The acturarial 2 year survival rates were: overall survival 81%, disease specific survival 91%, local recurrence free survival 85% and nodal relapse free survival 76%. The recorded complication rate was low, one patient developing radionecrosis of the mandible at 7 years post implant. We believe these results show that brachytherapy remains a treatment option for patients with early tongue carcinoma with a high rate of local control and low toxicity.

Adult↗
PubMed1993

Technical note: the implementation of patient position correction using a megavoltage imaging device on a linear accelerator.

The problem of using information from the analysis of megavoltage images to adjust patient set-up has been addressed. In the case of rotational corrections it has been assumed that the treatment head is to be adjusted, although for gantry angles of 0 degree and 180 degrees couch rotation may be used. In the case of translational shifts adjustment of the collimator jaws or of the couch have both been considered for arbitrary combinations of couch and gantry angle. For couch movement the case has been considered where it is desirable to minimize both the number of parameters to be adjusted and also the magnitude of the change in the patient's position. Values obtained for frequently used set-up parameters have been presented. Adjustment of the treatment couch positioning is the most desirable option, as this should bring the patient closer to the correct position for subsequent treatment fields. However, rotational errors are not correctable for all gantry angles and furthermore the collimator settings may be set more accurately than those of the treatment couch. Hence, in some cases, adjustment of the collimation system may be desirable or necessary. The formulae given in Equations (13) to (18) are currently being used in an intervention study to correct patient set-up during the course of a treatment fraction.

Humans↗
PubMed1992

Image comparison techniques for use with megavoltage imaging systems.

In this paper we describe software facilities for enabling patient positioning studies using the megavoltage imaging system developed at the Royal Marsden Hospital and Institute of Cancer Research. The study focuses on the use of the system for three purposes: patient position verification (by comparing images taken at treatment simulation with megavoltage images taken at treatment time); reproducibility studies (by analysing a set of megavoltage images); and set-up correction (by adjusting the set-up until the megavoltage image obtained at treatment registers with the simulation image). The need is discussed for suitably presented simulator images, a method of determining field boundaries and the possibility of delineating soft-tissue interfaces. Several algorithms of different types, developed specifically for the purpose of intercomparison of planar projection images, are presented. The techniques employed and their usefulness, in both the qualitative and the quantitative sense, are discussed. The results are presented of a phantom and clinical study, to evaluate the rigour and reproducibility of the algorithms. These results indicate that measurements can be made to an accuracy of about 1-2 mm, with a similar value for interobserver reproducibility for the best image comparison techniques available.

Algorithms↗