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Between 1982 and 1993, 620 of 938 patients with pathologically staged I-II breast cancer were treated at the time of reexcision (perioperatively), with an iridium-192 (Ir-192) implant to the tumor bed to give 2000 cGy to the 30 to 40 cGy/ph isodose line. This was followed by 4500 cGy to the entire breast at 180 cGy/d for 25 fractions. The local control for the 620 patients at 5 and 10 years was 93 and 89%, respectively. The actuarial survival at 5 and 10 years was 92 and 81%. The cosmetic results were good to excellent for 87% of the patients. Chemotherapy had no impact on local control in this study. Ir-192 implant is especially useful for deep tumors, making possible more flexibility in the techniques used to boost the tumor volume. Perioperative implantation has increased the accuracy of placing the boost dose, shortened the overall treatment time, and, for some patients, eliminated the need for rehospitalization and anesthesia.

It is important that physicians be aware of the current theories on the etiology of breast cancer. This article reviews some of the more probable etiologic factors of breast cancer.

There is growing evidence in the world literature that radiation therapy plus lumpectomy produces survival rates equal to those of mastectomy for stage I and stage II breast cancer. The technique of using an interstitial implant at the time of lumpectomy could improve local control by increasing the accuracy of the interstitial implantation. It will certainly decrease hospital stay, anesthesia, and cost to the patient.

Malignant salivary gland tumors are rare. They represent less than one percent of all head and neck tumors. Approximately three fourths of all salivary gland tumors occur in the major salivary glands.Traditionally, the treatment of choice for these tumors is surgery. The majority of these tumors reoccur after curative surgical procedures. Local recurrence rate following surgery varies with the histology, grade, and extent of the disease.In spite of high local recurrence rate following curative surgical treatment of these tumors, radiotherapy has seldom been used as an adjuvant to surgery. The value of elective postoperative radiation therapy for subclinical microscopic disease was not recognized. Review of the literature supports the improved local control rate with the use of immediate postoperative radiotherapy. Radiation therapy proved to be effective as an adjuvant to surgery. A local control rate of better than 40 percent can be achieved by radiation therapy as a sole modality in inoperable and locally advanced cases. Radiation therapy provides an excellent palliation for locally advanced tumors or symptomatic metastases.

Until recently, non-Hodgkin lymphoma has been difficult to understand. This was due to a lack of appreciation for histologic types, their sub-classifications, modes of spread, and sites of recurrence.The treatment of choice for stage I-II disease is radiation therapy. The value of irradiating adjacent uninvolved node areas or the more extensive Hodgkin-type mantle or inverted "Y" fields is uncertain.Most patients already have reached stage III or IV when first seen. Stage III cases should be treated by a combination of radiation therapy and chemotherapy. There are protocol studies evaluating the role of chemotherapy alone in stage III disease. The primary treatment of stage IV disease probably should be chemotherapy followed by radiation therapy to involved areas or to residual bulky disease.

Surgery is the modality of choice in curative treatment for cancer of the colon and rectum. Since a majority of the patients present advanced disease where the surgical outlook is poor, adjuvant therapy may be warranted. Clinical and experimental data demonstrate the benefits from preoperative radiation therapy and some clinical reports indicate the beneficial effects of postoperative radiotherapy. Two national studies are underway to determine the effectiveness of preoperative radiation therapy in moderate doses. A similar study is suggested to establish the effectiveness of postoperative radiation therapy.For patients who are poor surgical risks, or for a tumor which is considered to be inoperable, and in a selected group, radiation therapy can be used as a curative procedure. Advantages include eliminating the need for a permanent colostomy. In case of failure, electrocoagulation and abdominal perineal resection are still available alternatives.A modest amount of radiation therapy can afford maximum palliation with minimum discomfort to the patient. About 80-90 percent of patients with pain and bleeding and 50 percent of patients with symptomatic liver metastasis respond favorably.

At the University of Kansas Medical Center, systemic use of strontium 89 ((89)Sr), a betaemitting radioisotope, was evaluated in the treatment of metastatic carcinoma to bone for relief of bone pain. Eighty-five patients were treated with systemic (89)Sr in the dosage of 30 to 40 μCi/kg. All patients had multiple bone metastases, the majority with primary breast or prostatic cancer. The response to treatment was evaluated by daily diary entries, changes in the amount of pain medication, periodic bone scans, and other laboratory values.In the patients who survived (47) and who were observed for three or more months, overall results showed 15 percent becoming pain free; 23 percent showed marked improvement with decreased consumption of pain medication; 53 percent showed mild but significant improvement in pain relief and decrease in pain medication requirement; and 9 percent showed no improvement. No patients noted a worsening of bone pain after the treatment. There was a combined favorable response in 91 percent (43/47) of patients with some meaningful palliation after (89)Sr therapy. This study, using (89)Sr systemic therapy, suggests that this isotope may be a valuable adjuvant therapy for palliation of pain from metastatic bone lesions.

Treatment of early breast cancer by lumpectomy and irradiation is well accepted. The five- and ten-year results of preservative treatment are comparable to more radical procedures. The technique of perioperative interstitial radiation has several advantages: (1) more accurate placement of the tubes in the tumor bed at the time of surgery; (2) implant volume is kept to a minimum, which improves cosmetic results; and (3) elimination of second general anesthesia for patients considered for implant boost therapy.Modified external radiation to regional lymphatics by combining electron and photon therapy at the 50 percent level can reduce side effects, such as skin reaction and esophagitis, and the dose to the heart, lungs, and opposite breast.

Bilateral pelvic lymphadenectomy was performed in 100 patients as a staging procedure. Sixty-one patients received iodine 125 radioisotope implant and 39 patients received external radiation therapy. The overall incidence of lymph node metastases was 27 percent. The incidence of lymph node involvement was 14 percent with clinical stage A2 disease, 3 percent with stage B1, 44 percent with stage B2, and 40 percent with stage C disease. The grade of the tumor influenced the incidence of lymph node metastases. Only 6 percent of grade I tumors had lymph node metastases, whereas 26 percent of grade II tumors and 71 percent of grade III tumors showed lymph node metastases.

A number of newly synthesized compounds whose chemical structure suggested possible or remotely possible ability to radiosensitize hypoxic mammalian cells were studied in an in-vitro system. Those compounds that were not excluded because of insolubility or extreme cytotoxicity were tested for radiosensitizing ability. The correlation between chemical structure and radiosensitizing ability will be used for the rational design of additional compounds with a high probability of being effective hypoxic cell radiosensitizers. It is hoped that this will contribute to attempts to improve the cure rate of patients with malignant tumors through the use of radiation therapy and hypoxic cell radiosensitizers.

From July 1975 to December 1980, 156 patients with localized carcinoma of the prostate received external radiation therapy at the University of Kansas Medical Center. Sixteen patients were lost to follow-up. The follow-up period for the remaining 140 patients ranged from 2 years to 7 years. Median follow-up period was 4.2 years. The overall survival according to stage was as follows: stage A2, 100 percent; stage B, 83 percent; and stage C, 53 percent. Corresponding disease-free survival was 91 percent, 70 percent, and 40 percent, respectively. Both stage and grade have great influence on survival. In stage B, about 44 percent of grade 3 tumors developed distant metastases compared with only 19 percent with grades 1 and 2 tumors. In stage C, 71 percent of grade 3 tumors showed progression of disease. A majority of patients with positive nodes showed progression of disease when compared with patients with negative nodes (75 percent vs 15 percent).