Long-Term Results of Intraoperative Radiation Therapy for Early Breast Cancer Using a Nondedicated Linear Accelerator.

Purpose: To present the long-term results of intraoperative radiation therapy (IORT) for early breast cancer using a nondedicated linear accelerator. Methods and Materials: The eligibility criteria were biopsy-proven invasive carcinoma, age ≥40 years, tumor size ≤3 cm, and N0M0. We excluded multifocal lesions and sentinel lymph node involvement. All patients had previously undergone breast magnetic resonance imaging. Breast-conserving surgery with margins and sentinel lymph node evaluation using frozen sections were performed in all cases. If there were no margins or involved sentinel lymph nodes, the patient was transferred from the operative suite to the linear accelerator room, where IORT was delivered (21 Gy). Results: A total of 209 patients who were followed up for ≥1.5 years from 2004 to 2019 were included. The median age was 60.3 years (range, 40-88.6), and the mean pT was 1.3 cm (range, 0.2-4). There were 90.5% pN0 cases (7.2% of micrometastases and 1.9% of macrometastases). Ninety-seven percent of the cases were margin free. The rate of lymphovascular invasion was 10.6%. Twelve patients were negative for hormonal receptors, and 28 patients were HER2 positive. The median Ki-67 index was 29% (range, 0.1-85). Intrinsic subtype stratification was as follows: luminal A, 62.7% (n = 131); luminal B, 19.1% (n = 40); HER2 enriched 13.4% (n = 28); and triple negative, 4.8% (n = 10). Within the median follow-up of 145 months (range, 12.8-187.1), the 5-year, 10-year, and 15-year overall survival rates were 98%, 94.7%, and 88%, respectively. The 5-year, 10-year, and 15-year disease-free rates were 96.3%, 90%, and 75.6%, respectively. The 15-year local recurrence-free rate was 76%. Fifteen local recurrences (7.2%) occurred throughout the follow-up period. The mean time to local recurrence was 145 months (range, 12.8-187.1). As a first event, 3 cases of lymph node recurrence, 3 cases of distant metastasis, and 2 cancer-related deaths were recorded. Tumor size >1 cm, grade III, and lymphovascular invasion were identified as risk factors. Conclusions: Despite approximately 7% of recurrences, we may infer that IORT may still be a reasonable option for selected cases. However, these patients require a longer follow-up as recurrences may occur after 10 years.

Incidental irradiation of internal mammary lymph nodes in breast cancer: conventional two-dimensional radiotherapy versus conformal three-dimensional radiotherapy.

OBJECTIVE: To evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. MATERIALS AND METHODS: This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). RESULTS: Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. CONCLUSION: Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique.

OBJETIVO: Avaliar a irradiação incidental dos linfonodos da cadeia mamária interna (LCMIs) com campos tangenciais opostos por meio de radioterapia bidimensional (2D) convencional ou tridimensional (3D) e comparar as duas técnicas quanto aos resultados obtidos. MATERIAIS E MÉTODOS: Trata-se de um estudo retrospectivo com 80 pacientes com câncer de mama sem indicação de radioterapia dos LCMIs: 40 foram submetidos a radioterapia 2D com tomografia computadorizada para controle dosimétrico e 40 foram submetidos a radioterapia 3D. A dose total prescrita foi 50,0 Gy ou 50,4 Gy (2,0 ou 1,8 Gy/dia, respectivamente). Os planos de tratamento foram analisados e os LCMIs foram definidos conforme as recomendações do Radiation Therapy Oncology Group. No tocante aos LCMIs, foram analisadas a proporção do volume que recebeu 45 Gy, a proporção do volume que recebeu 25 Gy, a dose para 95% do volume, a dose para 50% do volume, a dose média, a dose mínima (Dmín) e a dose máxima (Dmáx). RESULTADOS: Tratamentos do lado esquerdo predominaram na coorte 3D. Não houve diferenças entre as coortes 2D e 3D quanto ao estágio do tumor, ao tipo de cirurgia (mastectomia, cirurgia conservadora ou mastectomia com reconstrução imediata) ou à média do volume delineado dos LCMIs (6,8 vs. 5,9 mL; p = 0,411). À exceção da Dmín, todos os parâmetros dosimétricos apresentaram médias maiores na coorte 3D (p < 0,05). A mediana da Dmáx na coorte 3D foi 50,34 Gy. No entanto, a dose média nos LCMIs foi 7,93 Gy na coorte 2D e 20,64 Gy na coorte 3D. CONCLUSÃO: Nenhuma das duas técnicas emitiu doses suficientes aos LCMIs para que se alcançasse o controle subclínico da doença. No entanto, todos os parâmetros dosimétricos foram significativamente maiores com a técnica 3D.

Incidental irradiation of internal mammary lymph nodes in breast cancer: conventional two-dimensional radiotherapy versus conformal three-dimensional radiotherapy / Irradiação incidental da cadeia mamária interna no câncer de mama: comparação entre a técnica convencional (bidimensional) e a técnica tridimensional

Abstract Objective: To evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. Materials and Methods: This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). Results: Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. Conclusion: Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique.

Resumo Objetivo: Avaliar a irradiação incidental dos linfonodos da cadeia mamária interna (LCMIs) com campos tangenciais opostos por meio de radioterapia bidimensional (2D) convencional ou tridimensional (3D) e comparar as duas técnicas quanto aos resultados obtidos. Materiais e Métodos: Trata-se de um estudo retrospectivo com 80 pacientes com câncer de mama sem indicação de radioterapia dos LCMIs: 40 foram submetidos a radioterapia 2D com tomografia computadorizada para controle dosimétrico e 40 foram submetidos a radioterapia 3D. A dose total prescrita foi 50,0 Gy ou 50,4 Gy (2,0 ou 1,8 Gy/dia, respectivamente). Os planos de tratamento foram analisados e os LCMIs foram definidos conforme as recomendações do Radiation Therapy Oncology Group. No tocante aos LCMIs, foram analisadas a proporção do volume que recebeu 45 Gy, a proporção do volume que recebeu 25 Gy, a dose para 95% do volume, a dose para 50% do volume, a dose média, a dose mínima (Dmín) e a dose máxima (Dmáx). Resultados: Tratamentos do lado esquerdo predominaram na coorte 3D. Não houve diferenças entre as coortes 2D e 3D quanto ao estágio do tumor, ao tipo de cirurgia (mastectomia, cirurgia conservadora ou mastectomia com reconstrução imediata) ou à média do volume delineado dos LCMIs (6,8 vs. 5,9 mL; p = 0,411). À exceção da Dmín, todos os parâmetros dosimétricos apresentaram médias maiores na coorte 3D (p < 0,05). A mediana da Dmáx na coorte 3D foi 50,34 Gy. No entanto, a dose média nos LCMIs foi 7,93 Gy na coorte 2D e 20,64 Gy na coorte 3D. Conclusão: Nenhuma das duas técnicas emitiu doses suficientes aos LCMIs para que se alcançasse o controle subclínico da doença. No entanto, todos os parâmetros dosimétricos foram significativamente maiores com a técnica 3D.

Intraoperative radiation therapy in early breast cancer using a linear accelerator outside of the operative suite: an "image-guided" approach.

PURPOSE: To present local control, complications, and cosmetic outcomes of intraoperative radiation therapy (IORT) for early breast cancer, as well as technical aspects related to the use of a nondedicated linear accelerator. METHODS AND MATERIALS: This prospective trial began in May of 2004. Eligibility criteria were biopsy-proven breast-infiltrating ductal carcinoma, age >40 years, tumor <3 cm, and cN0. Exclusion criteria were in situ or lobular types, multicentricity, skin invasion, any contraindication for surgery and/or radiation therapy, sentinel lymph node involvement, metastasis, or another malignancy. Patients underwent classic quadrantectomy with intraoperative sentinel lymph node and margins evaluation. If both free, the patient was transferred from operative suite to linear accelerator room, and IORT was delivered (21 Gy). Primary endpoint: local recurrence (LR); secondary endpoints: toxicities and aesthetics. Quality assurance involved using a customized shield for chest wall protection, applying procedures to minimize infection caused by patient transportation, and using portal films to check collimator-shield alignment. RESULTS: A total of 152 patients were included, with at least 1 year follow-up. Median age (range) was 58.3 (40-85.4) years, and median follow-up time was 50.7 (12-110.5) months. The likelihood of 5-year local recurrence was 3.7%. There were 3 deaths, 2 of which were cancer related. The Kaplan-Meier 5-year actuarial estimates of overall, disease-free, and local recurrence-free survivals were 97.8%, 92.5%, and 96.3%, respectively. The overall incidences of acute and late toxicities were 12.5% and 29.6%, respectively. Excellent, good, fair, and bad cosmetic results were observed in 76.9%, 15.8%, 4.3%, and 2.8% of patients, respectively. Most treatments were performed with a 5-cm collimator, and in 39.8% of the patients the electron-beam energy used was ≥12 MeV. All patients underwent portal film evaluation, and the shielding was repositioned in 39.9% of cases. No infection or anesthesia complications were observed. CONCLUSIONS: Local control with IORT was adequate, with low complication rates and good cosmetic outcomes. More than one-third of patients benefited from the "image-guidance" approach, and almost 40% benefited from the option of higher electron beam energies.

Tratamento conservador do câncer de mama T2 (≥ 4 cm) e T3 por quimioterapia neoadjuvante, quadrantectomia, braquiterapia com alta taxa de dose como reforço de dose, teleterapia complementar e quimioterapia adjuvante: análise de controle local e sobrevida global / Breast conserving treatment of breast carcinoma T2 (≥ 4 cm) and T3 by neoadjuvant chemotherapy, quadrantectomy, high dose rate brachytherapy as a boost, external beam radiotherapy and adjuvant chemotherapy: local control and overall survival analysis

OBJETIVO: Avaliar o tratamento de carcinomas de mama T2 (≥ 4 cm) e T3, por quimioterapia neoadjuvante, quadrantectomia e braquiterapia com alta taxa de dose como reforço de dose (boost), radioterapia complementar e quimioterapia adjuvante, quanto ao controle local e sobrevida global.MATERIAL E MÉTODO: Trata-se de estudo clínico prospectivo descritivo que avaliou 88 pacientes com idade entre 30 e 70 anos, portadoras de carcinoma ductal infiltrante, nos estádio clínico IIb e IIIa, responsivas à quimioterapia neoadjuvante, tratadas entre junho de 1995 e dezembro de 2006. A resposta do tumor foi avaliada por método clínico antes e após três ou quatro ciclos de quimioterapia contendo antracíclicos. O seguimento mediano foi de 58 meses. Sobrevida global e controle local foram analisados segundo o método de Kaplan-Meier. RESULTADOS: O controle local e a sobrevida global em cinco anos foram de 90% e 73,5%, respectivamente. CONCLUSÃO: O controle local e a sobrevida global são comparáveis aos observados em outras formas terapêuticas.

OBJECTIVE: To assess the treatment of breast cancer T2 (≥ 4 cm) and T3 through neoadjuvant chemotherapy, quadrantectomy and high dose rate brachyterapy as a boost, complementary radiotherapy and adjuvant chemotherapy, considering local control and overall survival. MATERIAL AND METHOD: This clinical prospectivedescriptive study was based on the evaluation of 88 patients rangingfrom 30 to 70 years old, with infiltrating ductal carcinoma, clinical stage IIb and IIIa, responsive to the neoadjuvant chemotherapy, treated from June/1995 to December/2006. Median follow-up was 58 months. Using clinical methods the tumor was evaluated before and after three or four cycles of chemotherapy based on antraciclins. Overall survival and local control were assessed according to Kaplan-Meier methodology. RESULTS: Local control and overall survival in five years were 90% and 73.5%, respectively. CONCLUSION: Local control and overall survival were comparable to other forms of treatment.