Conservative surgery followed by radical radiotherapy in the management of stage I carcinoma of the breast

History of the development of radiotherapy in Latin America

Radiotherapy was the first nonsurgical treatment for malignant tumours and represents one of the oldest disciplines of oncology. In Latin America, as in many parts of the world, the history of modern oncology begins with the implementation of radiation therapy facilities. The development of radiotherapy in Latin America was possible thanks to the seminal work of radiation oncologists in different countries. As a large territory, there is a need to implement modern facilities and equipment, but unfortunately there are disparities in the access and quality of radiotherapy services across Latin America and even within individual countries. In this review, we describe the history, challenges and success in the implementation of radiotherapy and the frustration caused by the lack of facilities in several Latin American countries.

Calculation of radiation induced complication probabilities for brain, liver and kidney, and the use of a reliability model to estimate critical volume fractions

Radiation induced normal tissue complication probability is calculated for three different organs: brain, liver and kidney. The model applied is a reliability model where the volume effect of the tissue is described by the structural parameter, k, which reflects the architecture of the functional subunits (p) and the irradiated volume fraction (n). For partial, homogeneous irradiation of the brain, a k-value close to unity was found, and the respective values for liver and kidney were 0.92 and 0.77. An extension of the reliability model to account for individual inactivation probability of the subunits allows calculation of complication probability for inhomogeneous dose distributions. For the brain, intercomparison of a three-field and a two-field technique demonstrated a small reduction in complication probability for the former at low total doses. At high total doses a minimum complication probability was achieved applying a three-field technique, being three times less than that associated with the two-field technique.

Conservative treatment of early breast cancer

At our Institution, the treatment policy for early carcinoma of the breast (T1-2, NO, AJC) is lumpectomy followed by radiotherapy to the breast and peripheral lymphatics. From October 1976 until December 1982, 171 patients have been admitted and treated. Radiotherapy was administered with 60 Co, 5.000 cGy in 5 weeks to the breast and lymphatics plus a boost to the scar giving q.s.p. 6.400 cGy at maximum tumor depth. With a minimum follow-up of 3 years and a median follow-up of 61.7 months the locoregional control was 94.2% and survival at 8 years with no evidence of disease (NED) was 77.2% with an overall survival rate of 90%. No difference in NED survival rate was found between Stage I and II. There was a tendency to better survival rate in those patients older than 50 years and also for post menopausal patients, however the difference did not reach statistical significance (66.7% NED survival at 8 years for premenopausal and 81.8% NED survival for post menopausal, also at 8 years, p = 0.056 Gehan). The time elapsed between surgery and radiation therapy (between 1 and 2 months) was found to be nonsignificant. Only 1 out of 171 patients had axillary dissection. The importance or lack of it, is discussed.

Conservative treatment of breast cancer: a report on 108 patients

Between 1975 and 1980, 108 breast cancers (T1 and small T2) were treated at the Centre Antoine-Lacassagne (Nice, France) by a combination of conservative surgery and irradiation. Ninety-two of these patients underwent axillary node dissection; 17% of them presented with nodal involvement. All irradiation was given by telecobalt: 45 Gy to the entire breast, 60 Gy to the site of the tumor. All cosmetic results were acceptable. Intramammary recurrences were rare (6%) and independent of the tumor site or size or of any nodal involvement. Solitary metastases (not associated with a local recurrence) were extremely rare (4%) and were observed in patients who had had no nodal involvement. The actuarial survival rate at 5 years is 90%.