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Biomedical subjects

R D Hunter

Publications and source records attributed to R D Hunter.

At least 73 records · Page 4Linked to original sources
PubMed1990

Radiological changes in the gastrointestinal and genitourinary tract following radiotherapy for carcinoma of the cervix.

The radiological examinations of 67 patients who had previous radiotherapy for carcinoma of the cervix uteri were reviewed. All had evidence of radiation damage proven surgically or histologically. Patients with known recurrent or metastatic disease were excluded. The commonest abnormalities (36 patients) were in the urinary tract, where hydronephrosis due to distal ureteric stricture was the most frequent finding. Changes observed in the bladder included mural thickening, mucosal irregularity, focal ulceration and reduction in size. Thirty-one patients had abnormalities of their large bowel. The majority of these had strictures of the recto-sigmoid which showed a smooth mucosa, fine surface ulceration, focal ulceration or a 'cobble-stone' appearance. Lesions observed in the small bowel included fixity of bowel loops, thickening of the wall, coarsening of the mucosal pattern and strictures. Two new features are described; the development of high ureteric strictures and the presence of a stricture within a large bowel stenosis. These findings are significant since they show the variation in appearance which can be produced by radiotherapy damage. The differentiation of these changes from recurrent malignancy can be difficult and the differential diagnosis is discussed.

Adult↗
PubMed1987

Cervical carcinoma: prognosis in younger patients.

Retrospective analysis of 2870 patients with invasive carcinoma of the cervix treated by radiotherapy from 1971 to 1978 showed that the prognosis for younger patients (defined as either under 35 or under 40) was better than that for older age groups, but young patients presented with earlier disease. When the effect of stage on prognosis was also considered the improved survival of patients under 35 was confirmed, although the result was of only borderline significance. The better survival of younger patients was particularly noticeable for stage IB disease, the corrected five year survival of those under 35 being 93% compared with 79% for those over 35. On the basis of this analysis and a review of previous reports it is concluded that age alone is a poor indicator of prognosis and should not be used as an indication for adjuvant treatment. There is no evidence in this series of an aggressive form of cervical carcinoma in younger patients during the 1970s.

Adult↗
PubMed1987

The relationship between the bladder and the cervix in patients undergoing intracavitary therapy.

Previous studies have shown a poor correlation between bladder damage and bladder dosage in patients treated with radiation therapy, including intracavitary therapy for uterine tumours. This study was undertaken to investigate prospectively the relationship between the cervical os and the bladder in patients undergoing intracavitary treatment. The computed tomography scans of 59 patients undergoing intracavitary treatment were analysed. The upper limit of the undistended bladder relative to the os extended from 5.5 cm cephalic to the cervix to 4.0 cm below it. The distance from the central tube to the posterior bladder wall at the level of the cervix ranged from 1.5 cm to 4.2 cm. This was positively associated with size of ovoid (p = 0.022), though with considerable individual variation. A separate analysis failed to show a consistent correlation with age or stage of disease. Thirty-nine of the 59 patients (65.5%) had asymmetrical bladders. Of these, half had "slight" asymmetry and the others had "marked" asymmetry. The thickness of the vesico-vaginal septum varied from 0.5 cm to 2.9 cm but was difficult to assess in some patients. In patients treated with medium-sized ovoids and those with Stage IB and IIB disease, the distance to the bladder base is greatest, though there is marked individual variation. These investigations reveal a marked variation in bladder position relative to the cervix in patients undergoing intracavitary therapy. The position of the bladder cannot be accurately predicted by any of these clinical criteria and requires to be defined by a radiological technique in the individual patient.

Brachytherapy↗
PubMed1987

Geometry adopted by Manchester radium applicators and Selectron afterloading applicators in intracavitary treatment for carcinoma cervix uteri.

Twenty-eight patients with early-stage carcinoma of the uterine cervix were treated using one standard Manchester radium application and one afterloading Selectron application. In each case, radiographs were analysed to determine differences in geometry of applicators relative to each other, or to the bony pelvis. During the Selectron treatment the applicators lay significantly more anterior in the pelvis, with a reduced angulation between the axes of the uterus and the vagina. The separation between the ovoids was increased. An identical analysis of 25 patients who had received two radium applications showed that the uterine tube lay significantly more anterior in the pelvis during the second application. Reasons for these differences and their possible clinical importance in terms of increased dose rate to critical tissue are discussed.

Brachytherapy↗
PubMed1986

A clinical trial of two conceptually different radical radiotherapy treatments in stage III carcinoma of the cervix.

Two hundred and ninety-six consecutive patients under the age of 70 years and having Stage III carcinoma of the cervix were randomised to receive one of two radical radiotherapy techniques. The first was a small-field, wedged, inhomogeneous 3-week X-ray treatment, followed by two radical radium insertions delivering 80% of a radical intracavity dose. The second was a 4-week homogeneous, large-field X-ray technique, supplemented by a single intracavitary insertion giving 50% of a radical intracavitary dose. Mature 5-year survival rates for the two techniques were 38.6% and 40.3% respectively (p = 0.76). Corrected 5-year results were 44.5% and 45% (p = 0.8). The time to pelvic recurrence and the sites of pelvic recurrence were not significantly different. The rate of major morbidity was eight out of 148 in the first group and five out of 148 in the second. This large, prospective, randomised trial failed to identify any significant advantage to two conceptually different techniques which explored different volumes, fractionation and balance between X-ray therapy and intracavitary therapy. The overall results remain very satisfactory when compared with recently published European results.

Aged↗
PubMed1986

Bladder base dosage in patients undergoing intracavitary therapy.

The maximum dose rate being delivered to the base of the bladder during intracavitary therapy was assessed in 20 patients by CAT scanning during treatment. This value was compared with the I.C.R.U. bladder reference point dose rate calculated from lateral radiographs taken after insertion. The ratio of the maximum bladder base dose rate to the I.C.R.U. reference dose rate varied from 1.01 to 3.59. In ten patients the maximum bladder dose rate was not in the midline. Re-examination of five patients revealed significant changes in bladder base dose rate in two due to changes in applicator positioning and packing. The bladder base dose rate on the vertical plane through the middle of the vaginal ovoids was within +/- 25% of the maximum bladder base dose rate in 22/25 examinations.

Adult↗
PubMed1986

Stage III carcinoma of cervix. The importance of increasing age and extent of parametrial infiltration.

The relative importance of a number of potential prognostic factors was analysed for a sequential group of 296 patients with stage III carcinoma of the cervix who had been treated in a mature prospective clinical trial. Using a log-rank analysis of survival curves generated by the life-table method increasing age (p = 0.05) and extent of parametrial infiltration (p = 0.001) were found to be significantly related to prognosis. These two factors were further demonstrated to be independent variables and, of the two, parametrial extension (p = 0.002) was more significant than increased age (p = 0.035). Involvement of the lower third of the vagina, the presence of bullous oedema and the histological differentiation of the disease were not prognostically significant in this study. It is suggested that tumour volume as defined by extent of parametrial infiltration is a sufficiently good prognostic factor to be incorporated into a revised staging system.

Adenocarcinoma↗
PubMed1983

Treatment of advanced head and neck cancer using synchronous therapy with methotrexate and irradiation.

A pilot study of synchronous methotrexate and radiation therapy was carried out in 50 patients with advanced carcinoma of the head and neck, of whom 48 were assessable for response. Complete resolution of disease, maintained for 2 years, was achieved in 21 patients (45%), and in 19 out of 36 patients (53%) with carcinoma of the oropharynx and hypopharynx. The treatment was well tolerated, with acceptable morbidity.

Adult↗
PubMed1983

Dose-incidence curves for tumour control and normal tissue injury, in relation to the response of clonogenic cells.

A probit analysis has been made of data from the literature on local control of tumours and injury to normal tissue as a function of dose of radiation. Fifteen series were analysed for local tumour control in man and ten series for complications. The analysis yielded values for the D50 dose (50% incidence of effect) and the probit width (K), a measure of the steepness of the dose-incidence curve. The same analyses were made of data for rodents. Broadly, K was proportional to D50 in the ratio 1:7, with no major differences between tumours and reported complications. D50 was plotted as a function of dose per fraction for four normal tissues and two tumours in rodents. D50 decreased more rapidly with increasing dose per fraction for the normal tissues than for tumours. The probit width, K, varied inversely with increasing dose per fraction for normal tissues and this contrasted with the tumour response. Thus with increasing dose per fraction, the threshold for effect decreased and the steepness of the ensuing dose-incidence curve increased, relatively more rapidly for normal tissue than for tumour. These curves of gross response have been analysed also by the double negative log method of Gilbert [23], in an attempt to estimate the number and survival characteristics of "tissue-rescuing cells". These were calculated to be less than 1 in 10(4) of the numbers of clonogenic cells measured by excision assays. The D0 values of the derived survival curves for these tissue-rescuing cells were higher than those measured by excision assays.

Animals↗
PubMed1983

The use of Selectron afterloading equipment to simulate and extend the Manchester System for intracavitary therapy of the cervix uteri.

When Selectron afterloading machines were introduced in the Christie Hospital the first aim was to reproduce, as closely as possible, the isodose distributions achieved with the traditional Manchester Radium System. This resulted in the establishment of standard pellet loading patterns, and standard treatment times, for programming the Selectron channels. However, the availability of whole-body CT scanning facilities provides a method of accurately locating the source positions with respect to the local anatomy and hence the possibility of dosage control based on doses to specific pelvic structures. Various computer programs have been written to extract source position data from the CT images, to allow the operator to propose pellet loading patterns and treatment times, and ultimately to display the resultant isodose distribution superposed on the cross-sectional scans. The effects on the dose distribution arising from changing the number of pellets, the pellet positions within the applicators, and the treatment times, are briefly discussed.

Brachytherapy↗
PubMed1983

Hypocalcaemia--an unusual complication of successful chemotherapy for metastatic breast cancer.

Three cases of metastatic carcinoma of the breast are described in patients who presented with hypercalcaemia. They achieved an excellent regression of their disease with combination chemotherapy but despite this they clinically deteriorated. Investigation showed them to be hypocalcaemic due to temporary hypoparathyroidism. Correction of their serum calcium resulted in good symptomatic relief. The possible mechanisms for these changes are discussed and we feel that this unusual complication of successful chemotherapy should be remembered when patients fail to improve symptomatically despite a good disease response.

Antineoplastic Agents↗
PubMed1982

11-week course of sequential methotrexate, thoracic irradiation, and moderate-dose cyclophosphamide for "limited"-stage small-cell bronchogenic carcinoma. A study from the Manchester Lung Tumour Group.

55 patients with inoperable but "limited"-stage small-cell carcinoma were treated sequentially with methotrexate, radiotherapy, and high doses of cyclophosphamide. The treatment was completed over 11 weeks and no maintenance chemotherapy was given. Follow-up lasted 9-29 months. Toxicity was acceptable, despite doses of cyclophosphamide of 1.5-3.5 g/m2. The complete response rate was 53%. Median survival for the total patient group was 12 months, range 2-29+. Patients who attained a complete response had a 17 month median survival; 17 patients remained in complete remission, 9 of whom first underwent treatment 14-29 months previously. Karnofsky performance scores improved after treatment and most patients were able to resume normal activity. The results are similar to those obtained with prolonged combination chemotherapy.

Carcinoma, Small Cell↗
PubMed1982

Megavoltage electron beam therapy in the treatment of basal and squamous cell carcinomata of the pinna.

Kilovoltage X-ray therapy has considerable limitations when trying to obtain good functional results in patients with skin carcinomas arising on the pinna. Megavoltage electron beams with their better quality of radiation and homogeneous dose distribution have been recognised to have theoretical advantages. Forty-three patients with basal and squamous cell carcinomata arising on the pinna were treated radically using a 10 MeV electron beam. The technique and dosage are described and discussed. Primary cancer control with retention of the pinna was achieved in 34 patients. Salvage pinnectomy was performed in four patients for recurrence and one patient for radiation necrosis. Two patients with large primary tumours failed to resolve and died of their disease. The advantages for the patient of the policy of primary radical electron mean therapy are discussed.

Aged↗
PubMed1982

Electron-beam treatment of scleromyxoedema.

A 42-year-old man is described with progressive scleromyxoedema. Clinical features included the development of transient central nervous system symptoms and a 5-year delay before the appearance of an IgG lambda-chain paraproteinaemia. Electron beam therapy resulted in significant improvement which lasted for 18 months.

Adult↗