Correspondence

Radiation Oncology

N Engl J Med 1995; 333:392-393August 10, 1995

Article

To the Editor:

There are two distinct areas of radiation oncology — external-beam radiotherapy and brachytherapy. The paper by Lichter and Lawrence (Feb. 9 issue)1 mainly summarizes the advances in external-beam radiotherapy, without noting the advances in brachytherapy. The current advances in external-beam radiation have greatly enhanced the precision with which radiation treatment is planned and delivered. They have also reduced radiation-related toxic effects and improved the rates of locoregional control in various cancers.

The advances in brachytherapy, and the resulting advantages, are equally noteworthy.2-5 Brachytherapy deals with the delivery of radiation from sources positioned either close to the tumor, as in the case of intracavitary brachytherapy, or inside the tumor, as in the case of interstitial brachytherapy. Advances in brachytherapy have included the development of new radiation sources and new techniques, such as afterloading, computerized remote afterloading, and three-dimensional conformal treatment, in which the distribution of the dose conforms to the size and shape of the target. In addition, brachytherapy radiation can be delivered at desired doses (in grays per minute) and in low, medium, pulsed, and high doses. In brachytherapy, the radioactive sources are in close contact with the target area, maximizing the dose distribution to the tumor. At the same time, the adjacent normal tissues receive a substantially lower dose of radiation, thus improving the therapeutic ratio. This treatment has been found to be highly effective in patients with gynecologic, urologic, head and neck, and thoracic tumors. Advances in remote afterloading techniques of brachytherapy have improved precision, safety, and cost effectiveness. The majority of radiation oncologists believe that, when used in combination, conformal three-dimensional external-beam radiation and brachytherapy radiation complement each other in delivering maximal doses to the tumor. These advances have enabled oncologists to escalate the dose of radiation to the tumor with resultant improvements in locoregional control and no substantial increase in damage to normal tissue.

Dattatreyudu Nori, M.D.
New York Hospital–Cornell Medical Center, New York, NY 10021

Nandanuri M.S. Reddy, Ph.D.
Adrian D. Osian, M.S.
New York Hospital Medical Center of Queens, Flushing, NY 11355

5 References

1. 1

   Lichter AS, Lawrence TS. Recent advances in radiation oncology. N Engl J Med 1995;332:371-379
   Full Text | Web of Science | Medline

2. 2

   Nori D, Hilaris BS. Role of brachytherapy in the treatment of soft tissue sarcomas of the extremities — techniques and results. In: Bamberg M, Hoffmann W, Hossfeld DK, eds. Soft tissue sarcomas in adults. Recent results in cancer research no. 138. Berlin, Germany: Springer-Verlag, 1995:57-71.
   

3. 3

   Hilaris BS, Nori D, Anderson LL, eds. An atlas of brachytherapy. New York: Macmillan, 1988.
   

4. 4

   Nori D, Allison R, Kaplan BL, Samala E, Osian A, Karbowitz S. High dose-rate intraluminal irradiation in bronchogenic carcinoma: technique and results. Chest 1993;104:1006-1011
   CrossRef | Web of Science | Medline

5. 5

   Nori D, Sundaresan N, Bains M, Hilaris BS. Bronchogenic carcinoma with invasion of the spine: treatment with combined surgery and perioperative brachytherapy. JAMA 1982;248:2491-2493
   CrossRef | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: We thank Dr. Nori and colleagues for their thoughtful comments on the role of inserting or implanting sources of radiation (brachytherapy) in the modern practice of radiation oncology. Brachytherapy has been with us from the first use of radioactivity to treat cancer. In fact, many people believe that Alexander Graham Bell's suggestion that radiation be encapsulated and implanted in the cervical os to treat carcinoma of the cervix1 actually heralded the advent of this treatment method shortly after the turn of the century. Since that time, brachytherapy has been one of the standard treatments for a variety of diseases, but especially for gynecologic cancers.

Dr. Nori and colleagues are absolutely correct that we are seeing advances in the use of brachytherapy. With the three-dimensional reconstructions that we mentioned in our article, brachytherapy can now be planned with great precision. Dose distributions can be calculated three-dimensionally, and precise dosimetric displays can be created. Implanting sources of radiation in brain tumors is an outstanding example of this form of technology.2 With the use of ultrasound or computed tomographic guidance, the implantation of radioactive sources in the prostate has reached levels of precision unmatched in the history of brachytherapy for this cancer.3 The rapid dose fall-off from radioactive sources can create a major gradient from the full doses administered to target tissues to the low doses delivered to nearby normal structures in a fashion that cannot easily be accomplished with any technique of external-beam radiation.

By its very nature, brachytherapy is a technically demanding art practiced by skilled physicians who have had years of experience with this technique. Although virtually every radiation oncologist becomes familiar during training with the routine gynecologic implantation of radioactive sources, far fewer become skilled at their implantation in the prostate, brain, lung, head and neck, soft tissues, and the like. Patients who may benefit from brachytherapy should ideally be referred to departments of radiation oncology that take a special interest in this type of therapy. Dr. Nori and colleagues certainly qualify as leaders among such practitioners, and they are correct in bringing this matter to our attention and to the attention of the readers of the Journal.

Allen S. Lichter, M.D.
Theodore S. Lawrence, M.D., Ph.D.
University of Michigan Medical Center, Ann Arbor, MI 48109-0010

3 References

1. 1

   Sowers ZT. The uses of radium. Am Med 1903;6:261-261
   

2. 2

   Gutin PH, Prados MD, Phillips TL, et al. External irradiation followed by an interstitial high activity iodine-125 implant “boost“ in the initial treatment of malignant gliomas: NCOG study 6G-82-2. Int J Radiat Oncol Biol Phys 1991;21:601-606
   CrossRef | Web of Science | Medline

3. 3

   Wallner K, Roy J, Zelefsky M, Fuks Z, Harrison L. Short-term freedom from disease progression after I-125 prostate implantation. Int J Radiat Oncol Biol Phys 1994;30:405-409
   Web of Science | Medline