RESUMEN
BACKGROUND: Recent data from ACOSOG Z0011 and NSABP B32 trials suggested no need for axillary lymph node dissection (ALND) in patients with micrometastatic involvement of the sentinel lymph node (SLN). The low rate of axillary recurrence was attributed to the axilla coverage by the tangential fields (TgFs) irradiation and systemic therapy. This study aimed to evaluate dose distribution and coverage of the axilla levels I-II and the SLN area. PATIENTS AND METHODS: One hundred and nine patients were analyzed according to three groups: group 1 (50 Gy; n = 18), group 2 (60 Gy; n = 34) and group 3 (66 Gy; n = 57). Patients were treated using the standard (STgF; n = 22) or high (HTgF; n = 87) TgF. RESULTS: The median doses delivered to level I using HTgF versus STgF were 33 and 20 Gy (P = 0.0001). The mean dose delivered to the SLN area was only 28 Gy. Additionally, the SLN area was totally included in the HTgF in 1 out of 12 patients who had intraoperative clip placement in the SNL area. CONCLUSIONS: TgFs provide a limited coverage of the axilla and the SNLB area. This information should be considered when only TgFs are planned to target the axilla in patients with a positive SLN without ALND. Standardization of locoregional radiotherapy in this situation is urgently needed.
Asunto(s)
Neoplasias de la Mama/radioterapia , Metástasis Linfática/radioterapia , Recurrencia Local de Neoplasia/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Axila , Neoplasias de la Mama/mortalidad , Femenino , Humanos , Ganglios Linfáticos/efectos de la radiación , Persona de Mediana Edad , Estudios Prospectivos , Dosificación Radioterapéutica , Sobrevida , Tasa de SupervivenciaRESUMEN
PURPOSE: To investigate if the regular use of kV-CBCT notably increases the dose delivered to tumor and surrounding healthy tissues. MATERIAL AND METHODS: Images were obtained using a Varian equipment (OBI version 1.3, 645 to 650 projections in 370 degrees to acquire image), and patients were irradiated at source-tumor distance: 100cm. In vivo measurements were performed using radio-thermoluminescent dosimeters Harshaw-TLD700H (TLD) at skin (anterior-posterior and lateral axis crossing the rotation axis), with a fourth TLD group under the table thanks to a retrolaser. TLD's were calibrated at the kV-CBCT effective energy (64 keV), and the method validated using an anthropomorphic phantom, in which Gafchromic EBT films were also inserted. RESULTS: The phantom study showed that the dose distribution depends on the phantom position relative to the axis and that the doses measured at the phantom surface using TLD and films (good agreement) were maximum at the entrance of the anterior-posterior axis. Their arithmetic mean was equal, or a slightly greater than doses measured at mid-thickness of the phantom and at the level of the rectum (OAR). In vivo measurements performed on the five first patients (125 kV-CBCT) yield a mean skin dose per kV-CBCT varying from 5.8+/-0.1 to 7.3+/-0.2 cGy on the anterior-posterior axis. Lateral skin doses vary from 3.4+/-0.2 to 4.5+/-0.2 cGy. CONCLUSION: Doses delivered by repeated kV-CBCT are not negligible. They should be taken into account, but questions about the RBE to be applied to kilovoltage X-rays are raised.
Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Neoplasias de la Próstata/radioterapia , Recto , Piel , Tomografía Computarizada de Haz Cónico/instrumentación , Humanos , Masculino , Fantasmas de Imagen , Neoplasias de la Próstata/diagnóstico por imagen , Dosificación Radioterapéutica , Dosimetría Termoluminiscente/instrumentación , Dosimetría Termoluminiscente/métodos , Película para Rayos XRESUMEN
OBJECTIVES: To understand the evolution of lung uptake of 111-In-Pentetreotide in a rat model of pulmonary radiation pneumonitis. METHODS: A 15 Gy 60-Co thoracic irradiation (1.4 Gy/min) was delivered to Wistar rats. Irradiated and control animals were studied during 8 weeks after irradiation. 24 hours after an injection of 111-In-pentetreotide (12-18 MBq), the uptake in the lung tissue (ULT), in the alveolar cells (UpC) and in different organs, was determined. Histological examinations were performed. RESULTS: ULT and UpC after irradiation increased significantly peaking at 4 weeks (ULT: 32.8 +/- 13.0 in 10(-5) of the injected dose versus 10.8 +/- 2.0 for control; and, UpC was 19.3 +/- 7.2 versus 7.3 +/- 4.1) and decreased afterwards. Pre-injection of cold octreotide decreased the lung uptake. This evolution parallels the histological changes: alveolitis with granulomas in the interstitium at 4 weeks followed by development of sites of interstitial fibrosis. These observations suggest that the uptake is due to activated cells, mainly macrophages within the granulomas and in the alveoli, expressing somatostatin receptors. CONCLUSION: 1) The uptake of 111-In-pentetreotide in injured lungs after irradiation, already described in man, was confirmed in a rat model; 2) our results suggest that it is possible to follow the evolution of radiation lung injury by using In-111-pentetreotide.
Asunto(s)
Radioisótopos de Indio/farmacocinética , Neumonitis por Radiación/diagnóstico por imagen , Neumonitis por Radiación/patología , Somatostatina/análogos & derivados , Animales , Radioisótopos de Cobalto , Humanos , Pulmón/metabolismo , Pulmón/patología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patología , Masculino , Alveolos Pulmonares/metabolismo , Alveolos Pulmonares/patología , Neumonitis por Radiación/metabolismo , Cintigrafía , Ratas , Ratas Wistar , Somatostatina/farmacocinética , Distribución TisularRESUMEN
Cell cycle progression and apoptosis are controlled by regulatory proteins, including p53, of which functional alterations are linked to carcinogenesis. Recently, malignant mesothelioma (MM), a primary tumour related to asbestos exposure, alternatively to post therapeutic radiations, has proven to be an important problem in oncogenesis. The p53 protein does not seem mutated or deleted in MM but a possible inactivation by binding to other proteins [mdm2; SV40 large T antigen (Tag)] has been suggested. The present work investigated cell cycle regulation in normal rat pleural mesothelial cells (RPMC) and in RPMC expressing Tag (RPMC-TSV40), under exposure to asbestos and radiations. In RPMC, these agents induced activation of cell cycle checkpoints located at G1/S and G2/M and/or mitosis but a lack of control at G1/S was found in RPMC-TSV40. A loss of G2/M control may account for the formation of micronuclei observed after exposure of RPMC-TSV40 to radiations. In RPMC-TSV40 the enhancement of abnormal mitoses and apoptosis after asbestos exposure, in comparison with RPMC, suggests a loss of mitotic control and a p53-independent mechanism of apoptosis. Thus Tag expression in mesothelial cells might have both adverse and beneficial effects by impairing the control of DNA integrity and enhancing apoptosis respectively.
Asunto(s)
Antígenos Transformadores de Poliomavirus/fisiología , Apoptosis/fisiología , Amianto/toxicidad , Carcinógenos/toxicidad , Ciclo Celular/fisiología , Daño del ADN , Rayos gamma/efectos adversos , Pleura/citología , Pleura/metabolismo , Animales , Antígenos Transformadores de Poliomavirus/biosíntesis , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Ciclo Celular/efectos de los fármacos , Ciclo Celular/efectos de la radiación , Células Cultivadas , Aberraciones Cromosómicas , ADN/efectos de los fármacos , ADN/metabolismo , ADN/efectos de la radiación , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Pleura/efectos de los fármacos , Proteínas Proto-Oncogénicas p21(ras)/biosíntesis , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Ratas , Proteína p53 Supresora de Tumor/biosíntesis , Proteína p53 Supresora de Tumor/fisiologíaRESUMEN
The Créteil method is a logical and simple system for intracavitary therapy of cervical and uterine cancer. The system is based on the use of a plastic cervico-vaginal moulage loaded with 0.5 mm diameter iridium 192 wire sources. The dimensions of both the moulage and the sources correspond to the size of the cervix being treated according to precisely defined relationships. The dose is specified on a reference isodose of a "fixed" value enclosing the pear-shaped target volume whose dimensions depend on the geometry of the sources. Source geometry in turn, depends on the size of the cervix. Thus, the dimensions of the target volume can be accurately predicted at the time of the application. Furthermore, treatment can be performed in a single application, with all sources having the same linear reference air kerma rate (or activity). Radioprotective measures are simple but effective and the patient is not subjected to the restrictions imposed by attachment to an after-loading apparatus. Our clinical results for early Stage T1 and T2a cervical tumors show excellent local control without major treatment complications or long term sequelae.