Results Of Radical Radiotherapy Research Articles

PO-0759: Results of radical radiotherapy with a tumour boost for bladder cancer in patients unfit for surgery

PO-0759: Results of radical radiotherapy with a tumour boost for bladder cancer in patients unfit for surgery

127 poster: Local Control Results of Radical Radiotherapy of Cervical Cancer. Our Experience

127 poster: Local Control Results of Radical Radiotherapy of Cervical Cancer. Our Experience

Radical Radiotherapy and Salvage Cystectomy as the Primary Management of Transitional Cell Carcinoma of the Bladder. Results Following the Introduction of a CT Planning Technique

ABSTRACT: The objective of this study was to review the results of our policy of primary radiotherapy (RT) and salvage cystectomy for transitional carcinoma (TCC) of the bladder in the light of changes in our radiotherapy planning procedure, in particular the introduction of CT planning. The case notes of 163 patients treated with radical radiotherapy using a CT planning technique were examined. The main endpoint for assessment was response at the time of the check cystoscopy 6 months after the completion of treatment. In addition survival was estimated by stage of disease and by response at the time of first cystoscopy. Patterns of relapse and time to relapse were analysed. All percentages quoted in the text use the initial 163 patients as the denominator. One hundred patients (61%) achieved a complete response. The complete response rate was significantly related to T stage at presentation being 90% for TI, 75% for T2, and 53% for T3 disease respectively. Of these patients 78 remain disease free in the bladder (47%). Twenty-two have relapsed in the bladder, of whom 5 have also relapsed at metastatic sites. Fifteen patients have relapsed outside the bladder whilst remaining disease free within the bladder. At the time of last follow up or death from other causes 63 of the 100 patients who had a complete response remained disease free with an intact bladder. There were 18 (11%) partial responders. Seven of these patients went on to have a cystectomy. Ten remain alive, 7 disease free, 4 with intact bladders. In 24 patients (15%) there was no response and these patients have all died, the median survival being 10 months. In 21 patients (13%) a postradiotherapy cystoscopy was not performed. In all but one patient, who was lost to follow up, this was because of progressive disease. The median survival of these 20 patients was 6 months. Of the 163 patients 35% are alive and well with an intact bladder. If patients dying from other causes are included then 42% were rendered disease free. Cause specific survival was significantly related to stage of disease at presentation with 5 year actuarial survival being 87%, 48% and 26%, for T1, T2 and T3 disease respectively. Survival was also related to response to treatment at 6 months with 5 year survival being 64%, and 52% for complete and partial responders respectively. Survival was extremely poor for non-responders with only 37.5% surviving 1 year and none 5 years. There was a highly significant relationship between response and the development of, and the time to developing metastatic disease. Of those who exhibited a response 21% developed metastatic disease compared to 78% of non-responders. Salvage cystectomy offers the possibility of cure in those who achieve a complete or partial response with 42% of such patients being rendered disease free. Results however are poor in those who did not respond with all patients dying of their disease. Response rates for all stages, and survival for stages T1 and T2 are much improved from those previously reported from this centre and compare favourably with other published series. These results confirm the place of radiotherapy and salvage cystectomy in the management of TCC of the bladder in selected patients. In about one-third of patients the desired outcome of curing the patient of their cancer with organ preservation is achieved. The prognostic significance of cystoscopic response at 6 months and stage at presentation is confirmed. The outcome for patients with early stage disease is excellent. The relationship between response and the development of metastatic disease would suggest that even if these patients had had a primary cystectomy they may have fared badly, a conclusion supported by the fact that these results are comparable with surgical series. This series supports the role of radiotherapy in the management of this disease and suggests that modern RT techniques including CT planning have had a beneficial effect on the results of radical radiotherapy.

Mathematical Models of Tumour and Normal Tissue Response

The historical application of mathematics in the natural sciences and in radiotherapy is compared. The various forms of mathematical models and their limitations are discussed. The Linear Quadratic (LQ) model can be modified to include (i) radiobiological parameter changes that occur during fractionated radiotherapy, (ii) situations such as focal forms of radiotherapy, (iii) normal tissue responses, and (iv) to allow for the process of optimization. The inclusion of a variable cell loss factor in the LQ model repopulation term produces a more flexible clonogenic doubling time, which can simulate the phenomenon of 'accelerated repopulation'. Differential calculus can be applied to the LQ model after elimination of the fraction number integers. The optimum dose per fraction (maximum cell kill relative to a given normal tissue fractionation sensitivity) is then estimated from the clonogen doubling times and the radiosensitivity parameters (or alpha/beta ratios). Economic treatment optimization is described. Tumour volume studies during or following teletherapy are used to optimize brachytherapy. The radiation responses of both individual tumours and tumour populations (by random sampling 'Monte-Carlo' techniques from statistical ranges of radiobiological and physical parameters) can be estimated. Computerized preclinical trials can be used to guide choice of dose fractionation scheduling in clinical trials. The potential impact of gene and other biological therapies on the results of radical radiotherapy are testable. New and experimentally testable hypotheses are generated from limited clinical data by exploratory modelling exercises.

Results of radical radiotherapy in carcinoma of the uterine cervix stage I-III

A retrospective analysis is described of 271 diagnosed cases of carcinoma of the uterine cervix who were treated with radical radiotherapy between January 1987 and July 1988 at the Institute Rotary Cancer Hospital. The mean age at presentation was 49 years and 89% of the tumours were FIGO Stage II and III. The median duration of follow-up was 60 months. The early cases were treated with two intracavitary insertions of 34 Gy each to point A with a Selectron LDR intracavitary system, followed by 36 Gy external radiotherapy to the parametrium. Late stage disease was treated with 50 Gy of external radiotherapy, followed by a single intracavitary insertion of 30 Gy to point A. To compensate for the higher dose rate of the Selectron (180 cGy/h) a dose reduction factor of 15% was applied over the intracavitary dose. There were 2.5% and 4.7% of late Grade III bladder and bowel complications, respectively, requiring surgical intervention. There was no relationship between haemoglobin level at diagnosis and the development of late complications. The actuarial 5-year survivals were 65%, 63% and 35% for Stages I, II and III disease, respectively. This study from the Indian subcontinent shows the effectiveness of radiotherapy in Stages I, II and III carcinoma of the uterine cervix, with acceptable morbidity rates.

Carcinoma of the prostate: Results of radical radiotherapy (1970–1985)

Purpose : To determine the outcome and prognostic factors in patients with localized carcinoma of the prostate treated with external beam radiation therapy. Methods and Materials : A retrospective review of 999 patients with histologically confirmed adenocarcinoma of the prostate treated radically with megavoltage irradiation at the Princess Margaret Hospital between 1970 and 1985. Prognostic factors were analyzed using recursive partitionning method. Results : Overall survival at 5 and 10 years were 69.8% and 40.1% for the whole group. The cause-specific survival rates were 78.9% and 53.5%, respectively. The cause-specific survival rates were significantly different at 10 years by T stage, T1 being 79.0%, T2 66.0%, T3 55% and T4 22%. The overall clinical local control rates was 77% in the first 5 years following treatment. There was no statistically significant difference in the local control rates of T1 and T2 stage disease at 5 years, the combined rate being 88%. Significant differences were observed between other stages, being 76% for T3 and 55% for T4. At 10 years the control rate for TI tumours was maintained for T1 stage disease (92%) but was significantly reduced for other stages, T2 75%, T3 67% and for T4 37%. In the whole group 33.5% of patients had distant metastases in the first 5 years. The distant relapse rates at 10 years were significantly different by T stage, being 20% for T1, 33% for T2, 55% for T3 and 87% for T4. Multivariate analysis demonstrated that only T stage and histological grade were independent prognostic covariates for cause specific survival. Age was the only other independent variate in terms of overall survival. The late radiation related morbidity was 2.3% overall; 1.3% affecting rectum and recto-sigmoid and 1.0% arising in the bladder. Conclusion : In terms of survival the results of radiotherapy of intracapsular disease were excellent, but they were less satisfactory in patients with direct extracapsular extension. The assessment of local control was difficult and may have reflected more the lack of local disease progression rather than true local tumor control. The treatment was well tolerated and there were few serious late complications.

Continuous, hyperfractionated, accelerated radiotherapy (CHART) in non-small cell lung cancer

The results of radical radiotherapy in patients with non-small cell lung cancer (NSCLC) confined to the mediastinum remain poor. Cellular repopulation during a course of radiotherapy may be an important cause of local failure. A scheme of radiotherapy was devised whereby the overall duration of treatment was reduced from 42 to 12 days. Radiotherapy was given 3 times per day, inclusive of the week-end, to a total dose of 54 Gy in 36 fractions over 12 consecutive days. Treatment is thus continuous, hyperfractionated, accelerated radiation therapy (CHART). The results of CHART are compared in terms of local tumour control and survival with those previously achieved. Randomized controlled trials have been commenced in which CHART is compared with conventional fractionated radiotherapy in patients with NSCLC confined to the thorax.

Recent results of oral cancer research in Kerala, India.

Findings from a research program in oral cancer at Regional Cancer Centre, Trivandrum, Kerala, India are reviewed. There is evidence of immune impairment in oral cancer patients. Plant lectins are being investigated for specific binding characteristics in various oral precancers and different histological subtypes of oral cancer. Tobacco and alcohol have been identified as the major risk factors for oral cancer. The chemopreventive potential of carotenoids and retinoids have been evaluated in oral leucoplakias. Beta-carotene and vitamin A in heavier doses induced remission of oral leukoplakias in 25%-50% of trial participants who continued with their tobacco and alcohol habits during the trial. The remission could be maintained with lower doses. Less than 20% of our patients with oral cancer were initially seen in localized stages. Various community-oriented programs for prevention of primary and secondary oral cancers are being evaluated. These include antitobacco health education, oral self-examination, and oral examination by trained volunteers. The results of radical radiotherapy and surgical salvage of radiation failure are also discussed. The 5-year disease-free survival rate of 34% is a reflection of the advanced stages of the disease when initially seen. Salvage rates with surgery for radiation failures were encouraging.

Management of early supraglottic laryngeal carcinoma by irradiation with surgery in reserve.

The results of radical radiotherapy with surgery in reserve for 136 patients with stage T1 and T2 NO supraglottic laryngeal carcinoma seen during a 20-year period are analyzed herein. Approximately one half of all patients were alive and well five years after treatment, while one fifth of patients died of supraglottic cancer. The cancer in two thirds of these patients was locally controlled by irradiation; of particular note was an 11% to 18% recurrence rate in patients whose necks were initially noted to be free of cancer. Analysis of the results of irradiation treatment disclosed a major reduction in nodal recurrence from the use of irradiation fields larger than 7 X 7 cm (3%, as compared with 19% with a smaller irradiation field). During the 20-year period of the study, there was a major reduction observed in tumor-related deaths; this is attributed to the use of larger irradiation fields and more aggressive use of surgery for irradiation failures. The results obtained are compared herein with the results of primary surgery, and conclusions are drawn as to the optimal management of early-stage supraglottic cancer.

Inoperable lung cancer: Evaluation of prognostic factors and results of radical radiotherapy

Inoperable lung cancer: Evaluation of prognostic factors and results of radical radiotherapy

Carcinoma of the tongue and floor of the mouth, results of radical radiotherapy

Carcinoma of the tongue and floor of the mouth, results of radical radiotherapy

Carcinoma of the tongue and floor of the mouth. Results of radical radiotherapy.

A review was made of 104 cases of carcinoma of the tongue and floor of the mouth treated at the Hunter Radiation Center of the Yale New Haven Hospital from October 1958 through December 1966. This study was undertaken to determine the cure rates and complications of irradiation therapy in the management of this disease. The cure rates varied according to the location and stage of the tumor. The overall, corrected, cumulative 3-year survival was 45%. Serious complications developed in 5% of the patients. Twenty-six patients considered to be radiation failures underwent resectional surgery. The results of this study justify continuation of the approach thus far employed. To improve the cure rates, emphasis ought to be put on earlier detection of cases.