Influence Of Radiation Therapy Research Articles

298 Radiotherapy in the treatment of early breast cancer

Radiation Therapy (RT) plays an important role in early breast cancer, in conjunction with both conservative and radical surgery. This teaching lecture will address the following points: <ul><li>1.RT's quantitative contribution to local control when used as an adjuvant to conservative or radical surgery.</li><li>2.The influence of systemic therapies on local control when used in conjunction with surgery and RT.</li><li>3.The impact of RT on cosmesis after conservative surgery.</li><li>4.The long-term morbidity of RT and the importance of technique.</li><li>5.The possible influence of RT on survival.</li><li>6.Future clinical research questions involving RT.</li></ul>

Influence of radiation therapy on lung tissue in breast cancer patients. CT-assessed density changes 4 years after completion of radiotherapy.

CT-assessed density changes in lung tissues were measured in 22 disease-free breast cancer patients 4 years after completion of radiation therapy. All patients had previously undergone similar CT-examinations before treatment, 3 months, and 9 months after radiotherapy. In patients with visible areas of increased lung density at earlier CT-examinations a decrease of focal findings was observed at 4 years. In patients without focal findings, an increase in density relative to that before therapy was observed. The difference between the mean lung density values among those with visible radiological findings and those without was statistically significant both at 3 and 9 months after therapy. However, this difference did not persist at 4 years. These results may indicate a 2-phase development of radiation-induced lung damages--an acute phase and a late phase; the late phase emerging slowly, and in this study detectable 4 years after completion of radiation therapy.

The influence of radiation therapy on subperiosteal hydroxyapatite implants in rabbits

Granular hydroxyapatite (HA) was implanted into subperiosteal pockets along both the right and left proximal tibias of 12 adult New Zealand white rabbits. The left extremities of 10 rabbits served as controls, whereas the right sides were irradiated with 2,250 rad in three doses over 5 days. The animals were killed at 1-week intervals starting at 2 weeks postirradiation. One half of each site was evaluated using standard histologic techniques while the other half was examined as a nondecalcified section. The quantity and the quality of new bone formation was determined using a rating scale and histomorphometric digitization. The results of this 4-month study showed that the amount of new bone formation around the HA granules was significantly greater in the irradiated sites. The irradiation produced no deleterious effects on the implant or the surrounding tissue areas.

Influence of radiation therapy on the lung-tissue in breast cancer patients: CT-assessed density changes and associated symptoms

The relative electron density of lung tissue was measured from computer tomography (CT) slices in 33 breast cancer patients treated by various techniques of adjuvant radiotherapy. The measurements were made before radiotherapy, 3 months and 9 months after completion of radiation therapy. The changes in lung densities at 3 months and 9 months were compared to radiation induced radiological (CT) findings. In addition, subjective symptoms such as cough and dyspnoea were assessed before and after radiotherapy. It was observed that the mean of the relative electron density of lung tissue varied from 0.25 when the whole lung was considered to 0.17 when only the anterior lateral quarter of the lung was taken into account. In patients with positive radiological (CT) findings the mean lung density of the anterior lateral quarter increased 2.1 times 3 months after radiotherapy and was still increased 1.6 times 6 months later. For those patients without findings, in the CT pictures the corresponding values were 1.2 and 1.1, respectively. The standard deviation of the pixel values within the anterior lateral quarter of the lung increased 3.8 times and 3.2 times at 3 months and 9 months, respectively, in the former group, as opposed to 1.2 and 1.1 in the latter group. Thirteen patients had an increase in either cough or dyspnoea as observed 3 months after completion of radiotherapy. In eleven patients these symptoms persisted 6 months later. No significant correlation was found between radiological findings and subjective symptoms. However, when three different treatment techniques were compared among 29 patients the highest rate of radiological findings was observed in patients in which the largest lung volumes received the target dose. A tendency towards an increased rate of subjective symptoms was also found in this group.

Influence of brachytherapy ( 192Ir afterloading) on cell-mediated immune reactions in patients with stage I endometrial cancer

The influence of radiation therapy on cell-mediated immune reactions in cancer patients seems to depend on source, dose, and area of irradiation, as well as on the variables reflected by the patient population investigated. In the present study we demonstrated that brachytherapy ( 192Ir afterloading), applied to patients with inoperable stage I endometrial cancer, has no immediate or sustained effect on lymphocyte function. Both lymphocyte mitogen response and natural killer cell (NK) activity are not significantly changed in terms of baseline values compared with test results during and after therapy. Brachytherapy, as used in this study, has no influence on cell-mediated immunity in patients with endometrial cancer stage I.

Influence of radiation therapy on oral Candida albicans colonization: A quantitative assessment

An increase in quantity of oral Candida albicans was documented in patients receiving head and neck radiation therapy during and after therapy, as assessed by an oral-rinse culturing technique. The amount of the increase was greater in denture wearers and directly related to increasing radiation dose and increasing volume of parotid gland included in the radiation portal. A significant number of patients who did not carry C. albicans prior to radiation therapy developed positive cultures by 1 month after radiation therapy. The percentage of patients receiving head and neck radiation therapy who carried C. albicans prior to radiation therapy did not differ significantly from matched dental patient controls.

Influence of radiation therapy on oral candida albicans colonization. A quantitative assessment: [formula omitted], J.Taylor, F.M.Beck, S.Hodgson, G.Blozis, Ohio State U., Columbus

Influence of radiation therapy on oral candida albicans colonization. A quantitative assessment: [formula omitted], J.Taylor, F.M.Beck, S.Hodgson, G.Blozis, Ohio State U., Columbus

Cervico-facial adenoid cystic carcinoma: Study of 102 cases. Influence of radiation therapy

One hundred two patients with cervico-facial adenoid cystic carcinoma were treated with surgery alone, radiotherapy alone or both from 1951 to 1980. All the cases have a 5-year minimum follow-up. The local control rate is 55.5% at 5 years and 37.7% at 10 years. The 5-year local control rate is 44% with surgery alone, 65.8% with radiotherapy alone and 77.8% with post-operative radiotherapy. The difference between surgery alone and radiosurgical association is significant ( p < 0.01). The bone involvement diminished local control rate (32.2%/k 68.8%). The 5-year survival rate of the patients who recurred and have been retreated is 70.5%. The 5-year survival rate of the patients after the appearance of a metastasis is 38.1 % and 2 patients have survived more than 10 years. The NED 5-year survival rate is 48.8%. There is no significant difference in the NED 5-year survival rate according to sites or treatments. The crude 5-year survival rate is 70%, 51.4% at 10 years and 32.2% at 15 years. Our study shows that adenoid cystic carcinoma have a peculiar and slow evolution. Surgery with post-operative radiotherapy obtains the best local control. These results and the radiosensibility of these lesions allow us to propose an agressive treatment for the recurrence and the primary tumor of the directly metastatic patients.

Leukaemia after cervical cancer irradiation in Denmark.

A matched case-control study among cervical cancer patients in Denmark was conducted to evaluate the possible influence of radiation therapy on leukaemia risk. Among 25718 women treated between 1943-1977, 27 cases of leukaemia occurred one or more years after diagnosis. Four controls were matched to each case on age, calendar year of diagnosis and survival without developing a second cancer. Detailed medical records were abstracted, and individual radiation doses to active bone marrow were determined by medical physicists. All leukaemia diagnoses were classified by one haematopathologist. A 2.5-fold risk of radiogenic leukaemia was found, although the excess was not statistically significant (95% Cl = 0.5-12.1). The pattern of risk by dose was somewhat compatible with animal experiments, ie, the risk rose, peaked, and then decreased to near normal levels at the highest dose categories. The average dose to the total bone marrow was 783 rads, and thus a much greater risk of leukaemia was predicted on the basis of estimates from other exposed populations. Assuming that the pelvic bone marrow is essentially destroyed by high-dose radiotherapy and should, perhaps, be disregarded for the purpose of risk estimation, risk coefficients consistent with other studies can be computed. Nonetheless, the very low risk of radiogenic leukaemia found among cervical cancer patients suggests that the induction of leukaemia by radiation is a complex function of dose, and that very high doses may result in a decreased risk, possibly associated with cellular sterilization or other mechanisms.

The influence of radiation therapy on response, survival and patterns of relapse in limited oat cell carcinoma of the lung

The influence of radiation therapy on response, survival and patterns of relapse in limited oat cell carcinoma of the lung