The Canadian Practitioner

Vol. XLVIII

TORONTO, JANUARY 1, 1923.

No. 1

Original Communications

The Response of Various Types of Cancer to Radium By DOUGLAS QUICK, M.B., (Tor.), Attending Surgeon, Memorial Hospital, New York.

During the past two or three years radium has come to occupy a much stronger position in the treatment of malignant diseases. The mass of experience being accumulated, both clinically and experimentally, gives a definite basis upon which to continue the work. While this is far from complete, it nevertheless permits the drawing of certain conclusions at present. The results now obtained must not be compared with those of even three or four years ago. With an experience steadily being added to and with technique changing to meet this, we feel that results have been immeasurably improved. There is no doubt but that this improvement will continue.

The purpose of this paper is to give some idea of the present value of radium as a therapeutic agent. In the first place, it must be understood that radium is not a "cure-all." Neither does it fulfil the first principle of being a cancer cure —that of being a constitutional agent. It is, however, the greatest single agent at our disposal in combatting malignant disease. At times, it, alone, is sufficient to produce a complete regression of the disease; while at others, in combination with surgery, the greatest good can be accomplished. In dealing with most types of cancer, at present, our chief hope lies in the judicious combination of radium, X-rays and conservative surgery. Along these lines we feel that we have already accumulated considerable valuable evidence.

It is a fallacy to think that radium is an agent to be used where all others have failed. Much of our earlier information in this field was obtained on such cases, and, while valuable to us, I cannot say that it always resulted in benefit

to the patient. It is true that many cases may be given palliative relief for a considerable length of time where no hope could be entertained for a complete regression of their disease, but there is a limit beyond which it is not only useless but harmful to proceed. We must recognize the fact that, in dealing with malignant diseases, there comes a time when even the physical agents are of no avail for temporary relief.

While radium reactions are not always painful, there are certain types of cases in which complete regression of disease cannot be obtained without going through a distinctly painful period. This is an added reason for withholding it from the hopelessly advanced case.

There is, however, a vast difference between the inoperable and the hopelessly advanced case, in many instances.

Since our earlier results were obtained in dealing with inoperable cases, it was only reasonable to feel that more favorable cases would respond much better. Time has proven this to be a fact. There are many groups of cases which we now confine entirely to the use of radium, even though distinctly operable to the surgical sense.

The general impression is to regard cancer as one disease, or perhaps divide it into carcinoma and sarcoma, rather than as a large group of allied diseases. It is necessary to study the histology of all neoplasms very closely and correlate the radium results with this in order to arrive at any definite conclusions of therapeutic results.

In general, the rapidly growing cellular tumors respond more readily to radiation, but the end results are equally unstable, because of the danger of early and widespread metastases. Lympho-sarcoma belongs in this group, and hence we often hear the statement that sarcoma responds more favorably to radium than carcinoma. Nothing could be further from the truth. Lympho-sarcoma is by no means an index to the true sarcomas, such as the osteogenic sarcomas of bone -a type of malignant disease in which radium, like radical surgery, has done very little as yet.

Neoplasms which tend to remain localized and metastasize late in the course of the disease are most favorable. Those which metastasize locally only are more suitable than those which extend widely and early in the course of the disease. Tumors which extend through the lymphatics, as a rule, are more amenable to treatment than those spreading through the blood stream.

Certain types of tissue withstand radiation more than others. Nerve tissue and dense fibrous tissue are more resistant than epithelial tissue. Endothelial tissue is very promptly affected by radium. This at once explains why growths, such as neurogenic sarcomas, withstand large doses of radium with little effect. It also suggests the wisdom of aiming to cause a complete regression of an epithelial tumor at one dose rather than by divided doses. After the first dose to such a tumor fibrous tissue is formed as a result of the inflammatory reaction, and the effect on the endothelium of capillaries produces an obliterating endarteritis. It is obvious that if a subsequent radiation is necessary it will not be as effective as the first. Furthermore, these inflammatory reactions are distinctly painful, in many instances, and unnecessary repetition only results in lowering the patient's vitality with each subsequent exposure.

METHODS OF APPLYING RADIUM

Speaking in general, there are two ways of applying radium-filtered radium placed on the surface, or at a distance from it, and unfiltered emanation buried in the tumor tissue. Apart from the question of dosage, the most important factor at present is accuracy and, to a certain extent, intimacy of application. We have long since passed the time when a piece of radium could be placed in the neighborhood of a new growth in a haphazard manner, and a favorable result expected. This explains many of the results that we hear

quoted daily.

For many lesions the use of filtered radium over the surface is quite sufficient to produce a complete regression of the disease. It is, however, an extravagant method in one sense, because only a small fraction of the radiant energy is being directed toward the disease; the remainder is being wasted on surrounding healthy tissues-at times damaging them--or is going off into space. Placed over the surface, the greatest intensity of the dose is being delivered to the least vital part of the growth-its surface rather than the actively growing, infiltrating base. If the neoplasms be deep-seated, and the radium placed several centimeters from the surface, the healthy overlying tissues must absorb more radiation than the tumor itself.

this manner.

So far, we are forced to treat many growths in The fact remains that it results in a waste of energy, and, since radium is scarce, we must attempt to obviate this loss as far as possible.