Pathways of metastatic spread of malignant tumors.

In order to produce viable metastases, the neoplastic cells must first be able to survive in the fluid system that they attain and that transport them. An important circumstance that has escaped the attention of most observers is the fact that the establishment of metastatic colonies is favored by the sluggish transportation of the detached neoplastic cells. Such leisurely transport is provided by lymphatic channels and peritoneal fluid; in the peritoneal cavity, the favorable circumstance aids the spread of relatively benign tumors such as pseudomyxoma peritonei and ovarian adenomas. In the blood, the slow transport is assured only by the venous access to the vertebral vein system; this avenue to blood-borne spread is particularly favorable to well differentiated tumors with a slow rate of growth and explains the widespread bone metastases from tumors with a low degree of malignancy, such as well differentiated adenocarcinomas of the thyroid and prostate. In contrast, neoplastic cells that enter the swift arterial circulation from the left heart are not often successfully implanted, in spite of their high degree of malignancy, and more often perish. Otherwide, we should observe a greater number of metastases in the small bones of the wrists and hands and of the ankles and feet, where the arterial circulation would bring them.

Training in therapeutic radiology in the United States, 1984.

The 1984 survey of training programs in Therapeutic Radiology in the United States revealed little change in the number of training programs and the number of residency positions offered. However, there has been a striking increase in the number of residents in training since the survey of 1982. The numbers of residents training in the PG-II and PG-III years are more than 50% greater than any previous survey. The proportion of foreign medical graduates is smaller than reported in 1982, but the proportion of women in residency is unchanged.

Twenty years follow-up of patients with inoperable cancer of the prostate (stage C) treated by radiotherapy: report of a national cooperative study.

PURPOSE: To evaluate the longevity and curability of patients with inoperable, Stage C, carcinomas of the prostate by means of external pelvic irradiation. METHODS AND MATERIALS: 372 patients, averaging 61 years of age, with histologically proven adenocarcinoma of the prostate, Stage C, received radiotherapy as part of a National Research Study, from 1967 to 1973. Treatments were administered in accordance with a strict protocol. Portals of entry were optional but it was required that the total dose received at the center of the prostate should be no less than 7000 cGy in no less than 47 days or 7500 cGy in 54 days. RESULTS: 245 of the 372 patients survived 5 years without evidence of recurrence of metastases; 142 were living after 10 years, 64 after 15 years, and 24 after 20 years. A total of 167 patients (44%) survived for years and died from intercurrent diseases without evidence of prostatic cancer. A total of 177 patients (47%) died of prostatic cancer in decreasing proportions in the years after treatment. Mild episodes of hematuria and of rectal bleeding were recorded in a number of patients; urethral and rectal strictured occurred following cystitis and proctitis but no life-threatening complications occurred. CONCLUSIONS: Adequately fractionated external pelvic irradiation can eradicate inoperable intrapelvic prostatic cancer. A simple statement of survival would disregard the fact that these elderly patients may be cured of cancer and yet may die of intercurrent diseases proper of their age. Also, it may be expected that a number of patients with Stage C may have unsuspected subclinical bone metastases when first seen and that death from metastases is not necessarily a reflection on the effectiveness of the regional treatment.

Radiation oncology: postgraduate medical education in the United States, 1988.

The fourteenth survey of postgraduate medical education in radiation oncology in the United States was conducted in the first three months of 1988. It revealed stability in the number of approved programs, positions offered, and physicians in training compared with 1986. The proportion of trainees who were U.S. citizens by birth rose to an all-time high of 88%, and the proportion of foreign medical graduates decreased to 9%. The proportion of women in residency has remained unchanged (24%) over the past 6 years. At present, approximately 150 physicians complete residency and enter practice each year, one-third of whom commence in an academic setting. A high proportion of recent graduates of approved programs successfully completes the examinations and becomes certified by the American Board of Radiology.

Postgraduate training in radiation oncology in the United States, 1986.

The thirteenth survey of training in Radiation Oncology in the United States, conducted in the first half of 1986, revealed a reduction in the number of approved programs, but little change in the number of positions offered. For the first time, every program had trainees, and every available training position was filled. The proportion of foreign exchange students in training fell from 52% 20 years ago, to 12% a decade later, to less than 1% at present. The proportion of foreign medical graduates fell from 29% in 1984 to 18% at present. The proportion of women in residency remained unchanged from 1982 and 1984. Approximately 150 physicians can be expected to complete training and enter the practice of radiation oncology each year for at least the next 4 years.

The tracks of the Compton effect.

The observation of scattered radiations of larger wavelength than the primary had been repeatedly rejected or explained away by many researchers, including Compton. After years of vacillations, he recognized the effect named after him and was the first to develop a quantal equation predicting the wavelength of scattered radiation. It became one of the most significant contributions to modern radiation physics, opening the doors of quantum mechanics.

[Results of twenty year follow-up of patients with inoperable prostate cancer (stage C) treated by radiotherapy. Report of a national multicenter study]. / Résultats du suivi à 20 ans de patients porteurs de cancer prostatique non curables chirurgicalement (stade C) traités par radiothérapie. Rapport d'une étude nationale multicentrique.

This is a report on a National Cooperative study of Radiotherapy for inoperable patients with cancer of the prostate: 372 patients with adenocarcinoma of the prostate, stage C, received radiotherapy from 1967 to 1973, according to a very strict protocol. With minor variations, all patients received the same total dose: 7000 cGy in 47 days or 7500 cGy in 54 days. Mild episodes of hematuria and rectal bleeding were observed in a number of patients: urethral and rectal strictures also resulted in a few cases, but were no life-threatening complications. A total of 177 patients (47%) died from prostatic cancer, mostly bony metastases that may have been present when the patients were first seen; death from prostatic cancer decreased as the years went by. Only 4 patients (1%) were lost to follow-up, only one before ten years, and none had evidence of cancer when last seen. However, 167 (44%) of the 372 patients lived for various periods of times and died without ostensible evidence of prostatic cancer. In addition 24 were still living after 20 years. Thus, more than half of these elderly inoperable patients treated by radiotherapy lived to die of something else.