RESUMEN
BACKGROUND/AIM: Adjuvant radiotherapy is an integral part of the interdisciplinary curative treatment of breast cancer. We aimed to examine the long-term clinical results of helical tomotherapy in female patients with local restricted, lymph node negative breast cancer after breast-conserving surgery. PATIENTS AND METHODS: In this single-centre analysis, 219 female patients with early-stage breast cancer (T1/2) and no lymph node metastasis (N0) following breast-conserving surgery and sentinel-node biopsy were treated with adjuvant fractionated whole breast radiation therapy using helical tomotherapy. When boost irradiation was indicated, it was administered sequentially or using the simultaneous-integrated boost technique. Local control (LC), metastasis and survival rates, acute toxicity, late toxicity, and secondary malignancy rates were analysed retrospectively. RESULTS: The mean follow-up time was 71 months. The 5- and 8-year overall survival (OS) rates were 97.7% and 92.1%, respectively. The 5- and 8-year LC rates were 99.5% and 98.2%, while the 5- and 8-year metastasis-free survival (MFS) rates of 97.4% and 94.3%, respectively. Patients with G3 grading or negative hormone receptor status did not show significantly different results. Acute erythema occurred in 79% (grade 0-2) and 21% (grade 3) of the patients. Lymphedema of the ipsilateral arm and pneumonitis occurred in 6.4% and 1.8% of the treated patients. None of the patients developed >grade 3 toxicities during follow-up, while 1.8% developed a secondary malignancy during follow-up. CONCLUSION: Helical tomotherapy showed excellent long-term results and low toxicity rates. The incidence rates of secondary malignancy were relatively low and correlated with pre-existing data on radiotherapy, suggesting wider implementation of helical tomotherapy in adjuvant radiotherapy for breast cancer patients.
Asunto(s)
Neoplasias de la Mama , Radioterapia de Intensidad Modulada , Femenino , Humanos , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Neoplasias de la Mama/patología , Radioterapia de Intensidad Modulada/efectos adversos , Radioterapia de Intensidad Modulada/métodos , Estudios Retrospectivos , Mastectomía Segmentaria , Biopsia del Ganglio Linfático Centinela , Radioterapia Adyuvante/efectos adversos , Radioterapia Adyuvante/métodosRESUMEN
Stochastic long-term damages at relatively low doses have the potential for cancer induction. For the first time we investigated the occurrence of breast cancer in female patients after radiotherapy of non-malignant disorders of the shoulder and made a comparison with the estimated spontaneous incidence of mammary carcinoma for this cohort. In a geographically defined district with a population of approximately 100.000 inhabitants, comprehensive data of radiological diagnostics and radiotherapy were registered nearly completely for 41 years; data included mammography and radiotherapy of breast cancer patients as well as of non-malignant disorders. Within this population a collective of 158 women with radiotherapy of the shoulder was investigated. Radiotherapy was performed with cobalt-60 photons (Gammatron) with an average cumulative-dose of 6 Gy. The average follow-up time was 21.3 years. Patients were 55 years old (median) when radiotherapy of the shoulder was performed. Seven patients (4.4%) developed breast cancer after a median of 21 years. According to the incidence statistics, 9.4 +/- 1.8 (95%CI) cases (5.9%) would be expected. In regard to the irradiated shoulder neither the ipsilateral nor the contralateral breasts showed increased rates of breast cancer. An induction of additional breast cancer caused by radiation of non-malignant disorders of the shoulder wasn't detected in the investigated cohort.
Asunto(s)
Neoplasias de la Mama/epidemiología , Mama/efectos de la radiación , Neoplasias Inducidas por Radiación/enzimología , Órganos en Riesgo/efectos de la radiación , Dolor de Hombro/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Mama/patología , Neoplasias de la Mama/etiología , Relación Dosis-Respuesta en la Radiación , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Órganos en Riesgo/patología , Fantasmas de Imagen , Dosificación Radioterapéutica , Estudios RetrospectivosRESUMEN
During radiation therapy of the female breast, the actual target volume compared to the planning target volume may change due to swelling or shrinking of the tissue. Under- or overdosage is to be expected, especially when performing IMRT or tomotherapy techniques. The objective of this study is to develop a model-based quantification of these dose effects, with a particular focus on the changes in the surface dose. A cylindrical phantom was used as an artificial surrogate of the human torso. By adding and removing Superflab layers of various thicknesses, both radial breast swelling and shrinking could be simulated. The effects on dose distribution were evaluated using film dosimetry. The results were compared to dose calculations. To estimate the true surface doses, we subtracted the influence of the film material on air measurements. During a swelling of 5, 10, and 15 mm, the planning target volume was consistently underdosed by 2%, 5%, and 7% of the prescribed dose, respectively. Swelling led to reduced dose values of up to 72%, 55%, and 50% at the outer edge of the actual target volume. The measured surface dose decreased successively from 31% to 23%. During shrinking, the dose in the planning target volume increased successively from 100% to 106%. The measured surface doses increased from 29% to 36%. The calculated dose values agreed with the measured values within error limits. During radiotherapy of the female breast, new planning appears to be essential for radial tissue swelling of 5 mm or more because of severe underdosing. Shrinking leads to moderate overdosing and an increased surface dose. In addition, caution is advised when removing bolus material with respect to the planned situation.