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Biomedical subjects

H M Mayles

Publications and source records attributed to H M Mayles.

5 recordsLinked to original sources
PubMed1996

Inadequacy of iridium implant as sole radiation treatment for operable breast cancer.

In order to avoid a prolonged course of external irradiation as part of breast conservation therapy, 27 patients received an iridium implant to the primary tumour bed as sole radiation treatment. Surgery was standardised comprising tumourectomy and axillary clearance. Using a rigid implant afterloading with iridium192 wires, 55 Gy was delivered on a continuous basis over 5 days. After 6 years median follow-up, relapse of cancer within the treated breast has occurred in 10 of the 27 patients (37%). Compared with historical controls treated by similar surgery and iridium192 implant (20 Gy) with external radiotherapy (46 Gy), there was a significantly increased breast relapse rate in those treated by iridium implant alone. However, the incidence of distant metastases and overall survival was similar. Thus, a continuous iridium192 implant delivering 55 Gy in 5 days is not an effective means of achieving local control in patients with operable breast cancer.

Brachytherapy↗
PubMed1991

Iridium implant treatment without external radiotherapy for operable breast cancer: a pilot study.

A pilot study has been conducted to examine a new approach to the treatment of operable breast carcinoma. 27 patients with tumours measuring up to 4 cm in diameter have been treated by tumourectomy, axillary clearance and high dose iridium-192 implant (55 Gy) without any external beam radiotherapy. This enabled the entire local primary treatment of the breast carcinoma to be given in five days. The technique was compatible with adjuvant chemotherapy for those with involved axillary nodes. Local complications have been few and locoregional control has to date been satisfactory. With a relatively short median follow-up of 27 months, cosmesis was objectively rated as good or excellent in over 80% of cases and subjectively rated good/excellent in 96%. High dose brachytherapy now requires testing in a prospective clinical trial to determine whether it is as effective as standard breast conservation techniques for management of early breast cancer.

Adult↗
PubMed1988

Assessment of skin dose and its relation to cosmesis in the conservative treatment of early breast cancer.

A conservation technique has been developed for the treatment of early breast cancer which involved removal of the tumor, axillary clearance, tumor site implantation with Iridium-192 wires for a boost dose and subsequent treatment of the breast with radical megavoltage external beam therapy. Although the cosmetic results were satisfactory in the majority of the patients, for some it was rated as fair or poor. One variable factor which could have carried some morbidity was the dose of radiation received by the skin. In 51 patients, doses were measured at several points over the treated breast using Thermoluminescent Dosimetry (TLD) at the time of the iridium implant and during the subsequent external beam therapy. Development of skin pigmentation, oedema, and fibrosis were unrelated to the dose received by the skin but the findings suggested that doses greater than 50 Gy to the skin increased the possibility of late (greater than 24 months) telangiectasia over the boosted area. Treatment of tumors in the lower half of the breast, or in large breasts, was associated with a higher incidence of poor cosmesis. This may have been the result of varying posture on the interstitial dose distribution from the Iridium-192 wires and comparison of dose distribution in both supine and erect positions was carried out.

Adult↗
PubMed1985

Physical aspects of interstitial therapy using flexible iridium-192 wire.

A semi-automated procedure for the calculation of point doses and isodose distributions for a curved multi-wire implant is described. A dose optimisation method has been developed for producing acceptable dose distributions from non-ideal implants and the dosimetry of such implants is discussed. Source preparation, handling and stock control methods are described which facilitate the re-use of the encapsulated wire with consequent benefits in the reduction of staff radiation exposure and the costs of treatment.

Brachytherapy↗