A high dose-rate (60Co) afterloading technique was evaluated in a series of 73 patients with prostatic carcinoma stages I-IV. The intraurethral irradiation was combined with external pelvic radiotherapy. A minimum total dose of 78 Gy was delivered to the target volume. In a subgroup of patients estramustine (Estracyt) was given as adjuvant chemohormonal therapy during irradiation. The median follow-up for the whole group was 63 months. The crude 5-year survival rate was 60% and the corrected survival rate 90%. Survival was related to the tumor grade. Local pelvic recurrences were recorded in 17.8%. 'Viable cells' in posttherapy aspiration biopsy were not associated with tumor recurrences or survival. Four patients (5%) had grade 3 late radiation reactions with urethral stricture or bladder fibrosis. Urinary tract infections and prior transurethral resections were not associated with a higher frequency of reactions. Concurrent estramustine therapy seemed to increase the frequency of both acute and chronic radiation reactions. Local control, recurrence, and survival were not affected by chemohormonal therapy. The use of tomography, magnetic resonance, and ultrasound as aids to computerized dosimetry may improve local dose distribution and reduce the irradiated volume.

In a retrospective analysis of 203 cases of laryngeal carcinoma treated with radiation therapy, conventional absorbed dose levels and CRE calculations were compared as regards the prediction of treatment failure, tumor recurrences and major complications. The recurrence rate for T1 and T2 tumors was 14 per cent and for T3-4 tumors 26 per cent. Poorly differentiated (grade 3) tumors had a significantly higher recurrence rate than well and moderately well differentiated (grades 1 and 2) ones. Corrected 10-year survival rates were 89, 82 and 52 per cent, respectively for T1, T2 and T3-4 tumors. There was a significant relationship between the recurrence rate and the CRE level while the total absorbed dose in Gy or the size of the treatment field could not be correlated to treatment failure. Major complications occurred in 8 (3.9%) patients and they had all received treatment giving CRE values of 1920 reu or more.

In a series of 90 consecutively treated cases of ovarian carcinoma, stages I–IIA (FIGO), adjunctive postoperative irradiation was administered to the lower abdomen and pelvis using a combined external and intracavitary afterloading technique. Early and late radiation reactions were evaluated by Cumulative Radiation Effect (CRE) calculations according to J. Kirk, W. M. Gray, and E. R. Watson (Clin. Radiol.22, 145–155 (1971)). The mean observation time was 49.2 months and the 5-year survival rate was 83.5%. Early reactions were reported by 44% and late radiation reactions and/or injuries by 23%. Most of these reactions were mild and reversible. Ten women had recurrences during the observation period and another five died from other diseases. Severe early reactions and both mild and severe late reactions were positively correlated with the CRE values. Area and volume corrected CRE seemed to correlate even better with radiation complications when the means were tested by Student's t test. It was not possible, however, to predict the occurrence of mild early reactions either from CRE calculations or total dose in gray or from any other parameter studied in this series. Upper limits for uncorrected and area or volume corrected CRE values are proposed for adjunctive external irradiation to the lower abdomen and pelvis in connection with the treatment of ovarian carcinomas.

The interpretation of results obtained when using a clearance technique with radioactive tracers, in measuring the blood flow through an organ, remains a matter of dispute. A comparative study therefore was made in 6 men in whom the testicular blood flow was measured intraoperatively both by means of venous occlusion plethysmography and a Xenon wash-out technique with intratesticular injection. Plethysmography gives the total blood flow in the testis, epididymis, and the tunics while the Xenon technique measures the blood flow in the testis alone. Previous studies in rams have shown the same blood flow in the testis as in the epididymis expressed in ml/100 g tissue/min. Assuming that the ratio is the same in the human male, the plethysmographic flow of the testis could be calculated. The plethysmographic flow calculated in this way was 9 ml/100 g/min. Compared with various techniques of evaluating the Xenon activity curves, this is in agreement with the flow calculated according to Zierler or from the slow component of the Xenon disappearance curve. The possible influence of a counter current exchange on the results obtained by the Xenon clearance technique, is discussed.

The possibility of a quantitative evaluation of the separate function of each kidney by means of radiorenography is tested. The influence of the blood background activity on the renogram curves is investigated and the results are correlated to the values obtained by the conventional clearance determination technique. It is shown that, in accordance with a clinical routine which includes total clearance determination and fractional evaluation from the renogram, it is possible to give individual clearance values with an accuracy similar to that found with a conventional separate clearance technique.