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Biomedical subjects

G Notter

Publications and source records attributed to G Notter.

At least 19 recordsLinked to original sources
PubMed1988

Accelerated versus conventional fractionation. The degree of incomplete repair in human skin with a four-hour-fraction interval studied after postmastectomy irradiation.

A previously presented clinical assay with postoperative irradiation to bilateral parasternal fields in patients with breast cancer was used for a comparison of acute and late reactions in human skin after accelerated and conventional fractionation. Two and 3 fractions per day at 4-hour intervals were compared with one fraction per day. Dose fractions of about 2 Gy were used. Twenty-five fractions were given in 2.5, 1.5 and 5 weeks respectively. The acute reactions were similar regardless if 1, 2 or 3 fractions per day were given, i.e. equal total doses were isoeffective. The repair of intracellular damage was apparently completed within 4 hours. However, this might not be true due to a differential influence of proliferation and redistribution on the effect of different types of fractionation, which makes it difficult to interpret the result and estimate the degree of intracellular repair. The time to the acute peak reaction was shortened by 6 to 7 days with accelerated compared to conventional fractionation, explained by the differences in the dose delivery rates. Consequently, the onset of a compensatory proliferation is earlier after accelerated fractionation. Late reactions were more pronounced after accelerated than after conventional fractionation and 1 X 2.0 Gy/day was found to be equivalent to 2 X 1.80 Gy/day and 3 X 1.65 Gy/day at 4-hour intervals with an equal fraction number for all 3 schedules. Assuming that proliferation is negligible for late responding tissues, we interpret this finding as an expression of the degree of reduced intracellular repair. Finally, we would like to point out that the iso-effect dose relationships between acute and late reactions for accelerated versus conventional fractionation might vary, above all with the cell proliferation kinetics of acutely reacting tissue.

Breast Neoplasms↗
PubMed1986

The predictive value of skin telangiectasia for late radiation effects in different normal tissues.

Alterations in the microcirculation and parenchymal cell loss are common phenomena after irradiation of different organs. Whether parenchymal cell loss is a process well dissociated from vasculoconnective damage, or a consequence of this, is much debated. However, comprehensive radiopathological studies have shown that vasculoconnective tissue is an important common target for late effects in various organs. Scoring of skin telangiectasia was used by us as a clinical assay of late tissue effects after different dose schedules. All studies were done prospectively with standardized skin area, field size and radiation quality. The patients were scored regularly up to 10 years. The number of patients at risk for a prescribed score versus time was calculated with the life-table method. The late effects after 5 X 2.0 Gy/wk, in the dose range 40 to 70 Gy and after 2 X 4.0 Gy/wk, in the dose range 40 to 56 Gy have been established. The skin dose is 90% of the referred dose. Dose-response curves, relating the proportion of patients with a certain score at a fixed time and radiation dose and dose-latency curves, relating the latent period for a fixed proportion of patients with a certain score and radiation dose, were constructed. The analysis shows that: ED10/5 yr and ED50/5 yr for 5 X 2.0 Gy/wk is 50 Gy and 65 Gy, respectively, for distinct telangiectasia; The latent period, concerning both a certain frequency and degree of reaction, varies exponentially with dose level; The latent period for 50% of the patients, to obtain a certain score, LP50, is correlated to that for 10%, LP10, with LP50/LP10 = 2.2 +/- 0.2 (S.D.). This correlation is independent of score, total dose, and fractionation; Isoeffective doses for 5 X 2.0 Gy/wk and 2 X 4.0 Gy/wk, determined from the dose-response curves, resulted in the repair exp N between 0.31 and 0.32 and alpha/beta ratio between 2.9 and 3.1 Gy and determined from the dose-latency curves in exp N between 0.30 and 0.32 and alpha/beta ratio between 3.4 and 2.9 Gy. In conclusion, frequent and careful follow-up with registration of normal tissue reactions, until at least 10% of the patients have obtained the prescribed effect, is predictive for the further progression of the late effects. The fractionation characteristics for telangiectasia agree well with those for animal experimental morphological and functional endpoints for late effects in different organs and support the relevance of telangiectasia as a model for predicting late effects.

Breast Neoplasms↗
PubMed1986

Quality assurance control in the EORTC cooperative group of radiotherapy. 1. Assessment of radiotherapy staff and equipment. European Organization for Research and Treatment of Cancer.

A quality control study was carried out by the EORTC Cooperative Group of Radiotherapy. From January 1982 to December 1984, 17 institutions were visited by a group of "experts" in radiotherapy and radiation physics. The evaluation included three steps: a comparison of megavoltage units, technical and staff environment, and data present in clinical and radiotherapy charts for each center; radiation physics calibration of photon and electron beams; and radiation physics measurements on a stimulated clinical case using an Alderson Rando anatomical phantom. This paper presents the results of Part 1. The results of Parts 2 and 3 will be analyzed in separate papers. Large variations were observed in the number of patients treated per year, per radiotherapist, per radiation physicist and per technician. On average, 400 patients were treated per year per megavoltage unit, but 8/17 centers treated more than 500 patients per unit per year. The number of simulators was suboptimal in 12/17 centers. These observations were summarized by a workload and staff index, and this index shows that in 5/17 centers major problems are present which make it difficult to comply with all the requirements of EORTC protocols. The quality of work-up regarding tumor extension was considered to be satisfactory in all centers. Dental care in patients irradiated to the head and neck was not well organized in 5/17 centers. Interaction between CT scan and dosimetry treatment planning could be improved in most centers and this should be one of the primary objectives of future quality control.

Brain Neoplasms↗
PubMed1985

Local therapy of rhabdomyosarcoma, osteosarcoma and Ewing's sarcoma of children and adolescents.

Local control of the primary tumour is a fundamental requirement for clinical cure. Towards this aim, the primary tumour must be diagnosed early and identified histologically. The size, extension, and spread within the patient must be defined precisely. In planning effective local therapy, additional questions must be answered including resectability, mutilation, sensitivity to radio- and chemotherapy, anticipated morbidity from therapeutic measures, etc. For osteosarcoma there is no reasonable alternative to radical surgery. Because of the 20% local recurrence rate of Ewing's sarcoma following radiotherapy, radical surgical removal of the primary tumour should be attempted whenever possible. For rhabdomyosarcoma, particularly for its embryonal histology, non-radical removal of the primary sarcoma is still compatible with a cure, provided adequate radio- and chemotherapy is also administered. Primary irradiation is indicated in radiosensitive unresectable primary tumours and may convert these into an operable state. Chemotherapy is the domain of prevention and treatment of metastatic disease. It has, however, also a proved effect on primary tumours and, in several recent protocols, precedes local therapy.

Adolescent↗
PubMed1985

Normal tissue reactions to high dose-rate intracavitary irradiation of the vagina with different fractionation schedules and dose levels.

The radiation reactions in the normal tissues of the vagina, rectum and bladder were studied in 166 patients receiving prophylactic vaginal high dose-rate intracavitary irradiation. Most reactions were observed in the vaginal mucosa included in the intracavitary target and only a few in the rectum and bladder in close proximity to the same target. The influence of the total dose, the dose per fraction and the overall treatment time, summarized as the Cumulative Radiation Effect (CRE), correlated well to the rate of reactions after a correction of the formula for late effects.

Brachytherapy↗
PubMed1981

Combined modality therapy of operated astrocytomas grade III and IV. Confirmation of the value of postoperative irradiation and lack of potentiation of bleomycin on survival time: a prospective multicenter trial of the Scandinavian Glioblastoma Study Group.

In a controlled, prospective, randomized investigation, started in 1974, 118 patients with supratentorial astrocytoma Grade III--IV were divided into three groups. Groups 1 and 2 received 45 Gy postoperatively to the whole supratentorial brain. Bleomycin in 15-mg doses and a total dose of 180 mg or placebo was given intravenously three times a week, one hour prior to radiotherapy, during weeks 1, 2, 4 and 5. Group 3 received conventional care but no radiotherapy or chemotherapy. Median survival rates of patients were 10.8 months in Groups 1 and 2, and 5.2 months in Groups 3, a statistically significant difference. With regard to performance, the patients in Group 3 deteriorated faster than patients in Groups 1 and 2. Bleomycin had no positive or negative influence on survival.

Adult↗
PubMed1976

Control of dose administered once a week and three times a day according to schedules calculated by the CRE formula, using skin reaction as a biological parameter.

Patients with breast cancer were irradiated postoperatively to bilateral parasternal fields. The validity of the Cumulative Radiation Effect (CRE) formula for treatment once a week and three times a day was analyzed, and both schedules were compared with treatment once a day (five times a week). The biological radiation effect on normal tissue was studied by reflectance spectrophotometry of skin erythema and pigmentation. Early skin reactions were identical after irradiation daily and once a week, respectively, but were found to be significantly more pronounced after irradiation three times a day than after treatment once a day, corresponding to an overexposure of 7-10%.

Breast Neoplasms↗
PubMed1976

Prospective studies with the CRE formula of prolonged fractionation schedules.

Different dose schedules prospectively calculated with the Cumulative Radiation Effect (CRE) formula were used for irradiation of inoperable breast carcinomas. Fractionation with 2 X 260 rad and 2 X 450 rad twice a week, and total doses corresponding to CRE levels 1900 to 2300, were compared. The results showed that prolonged fractionation increased the tolerance of normal skin and the therapeutic ration with respect to early radiation reactions. Late reactions could not be assessed as yet because their development requires several years. With the prolonged course of treatment and 2 X 260 rad per week, no moist desquamation developed despite dose levels between 6800 and 9400 rad. Skin reactions were milder than those in the rapidly treated areas, indicating that the CRE formula cannot exactly predict acute skin reactions for very prolonged treatment schedules. The tumor regressed continuously during the irradiation schedule.

Breast Neoplasms↗
PubMed1976

Anti-oestrogen therapy of advanced mammary carcinoma.

Forty mg daily of tamoxifen (Nolvadex) was administered orally to 89 patients with advanced soft tissue mammary carcinoma. At two months 43 per cent of the patients responded. At 6, 12 and 18 months, 42, 35 and 32 per cent, respectively, were still responding to therapy. The side effects were limited, fatique being the most frequent complaint. Oestrogen dependent side effects were not encountered. The therapeutic effect of tamoxifen is similar to that of oestrogen, but the side effects are less.

Administration, Oral↗
PubMed1976

Skin reaction as a biologic parameter for control of different dose schedules and gap correction.

In patients with mammary carcinoma, irradiated postoperatively on the parasternal regions, prospective dose calculations for different fractionation schedules have been performed with the CRE formula. The biologic radiation effect on normal tissue was recorded by reflectance spectrophotometry of skin erythema and pigmentation. The right side received 4 050 R in 25 days, the left side 4 390 R in 47 days with a gap of 3 weeks. A compensation for the gap with 8 per cent of the total exposure was found to be adequate. The smallest exposure difference that could be clearly discriminated visually and with spectrophotometry was recorded in a special series and was found to be 6 to 7 per cent.

Breast Neoplasms↗
PubMed1975

Hormonal treatment of mammary carcinoma with Progynon-Depot and Depostat.

The results of combined treatment with 90 mg estradiol valerianate and 300 mg 17-alpha-hydroxy-19-norprogesterone-capronate (SH 834) (3 ml once a week i.m.) in 117 cases with disseminated or inoperable mammary carcinoma are reported. Objective remissions of 3 to 36 months were obtained in 48 patients. Soft tissue, lung and pleura metastases responded more favourably than bone metastases. Liver and brain metastases were unaffected.

Adult↗
PubMed1975

Skin reactions after different fractionation schedules giving the same cumulative radiation effect.

The CRE formula was used for calculation of biologically equivalent radiation doses with different fractionation schedules. The early radiation effects, skin erythema and pigmentation were measured with a reflectance spectrophotometer at wavelengths 578 and 660 nm. The course and maximum for both erythema and pigmentation agreed well with the two types of fractionation. The results seem to justify further use of this simple formula.

Breast Neoplasms↗
PubMed1975

Treatment of disseminated carcinoma of the breast by metenolone enanthate.

Forty-three patients with disseminated or inoperable carcinoma of the breast were treated with Metenolone Enanthate (Primobolan Depot) with doses of 400 to 1 200 mg/week for at least 3 months. Objective remissions lasting longer than 3 months occurred in 8 out of 41 evaluable patients. Soft tissue metastases responsed best. Liver and brain metastases were unaffected. The therapeutic efficiency of Primobolan Depot is comparable to that of testosterone propionate but the agent is less virilising.

Aged↗