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1.
Science ; 185(4151): 609-10, 1974 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-17791234

RESUMEN

A micrometeorological technique has been used to measure the flux of ammonia and related gaseous nitrogen compounds into the atmosphere from a pasture grazed by sheep. During 3 weeks in late summer, the average daily flux density of nitrogen in these forms was 0.26 kilogram per hectare. This is a substantial part of the nitrogen turnover in grazed pastures.

2.
J Phys Chem B ; 110(47): 23801-5, 2006 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-17125343

RESUMEN

Model composites of DNA-wrapped single-wall carbon nanotubes in poly(acrylic acid) are used to evaluate metrics of nanotube dispersion. By varying the pH of the precursor solutions, we introduce a controlled deviation from ideal behavior. On the basis of small-angle neutron scattering, changes in near-infrared fluorescence intensity are strongly correlated with dispersion, while optical absorption spectroscopy and resonant Raman scattering are less definitive. Our results represent the first systematic comparison of currently accepted measures of nanotube dispersion.


Asunto(s)
Nanotecnología , Nanotubos de Carbono/química , Acrilamidas/química , ADN/química , Concentración de Iones de Hidrógeno , Espectrofotometría Infrarroja , Espectrometría Raman
3.
Nanoscale Horiz ; 1(4): 317-324, 2016 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-32260652

RESUMEN

Chemical control of the endohedral volume of single-wall carbon nanotubes (SWCNTs) via liquid-phase filling is established to be a facile strategy to controllably modify properties of SWCNTs in manners significant for processing and proposed applications. Encapsulation of over 20 different compounds with distinct chemical structures, functionalities, and effects is demonstrated in SWCNTs of multiple diameter ranges, with the ability to fill the endohedral volume based on the availability of the core volume and compatibility of the molecule's size with the cross-section of the nanotube's cavity. Through exclusion of ingested water and selection of the endohedral chemical environment, significant improvements to the optical properties of dispersed SWCNTs such as narrowed optical transition linewidths and enhanced fluorescence intensities are observed. Examples of tailoring modified properties towards applications or improved processing by endohedral passivation are discussed.

4.
Diabetes Care ; 18(7): 940-2, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7555553

RESUMEN

OBJECTIVE: To determine the feasibility of a randomized double-blind controlled trial of an infant formula without intact cow's-milk protein for preventing type I diabetes in high-risk children. RESEARCH DESIGN AND METHODS: We surveyed 83 people who either were parents of a child with type I diabetes or were pregnant women with type I diabetes in the ambulatory diabetes and obstetrics clinics in a university hospital. After a written and verbal description of the cow's milk-diabetes hypothesis, participants were asked to sign a sham consent form. A questionnaire designed to explore factors affecting their decision to either sign or not sign the consent form, as well as infant-feeding patterns, was subsequently administered. RESULTS: Overall, 69.9% (95% confidence interval, 60.0-79.8%) consented to participation in the proposed randomized trial. The decision to consent was not affected by the degree of belief in the cow's milk-diabetes hypothesis, the child's risk of diabetes, the respondent's demographic data, or infant feeding habits. CONCLUSIONS: A randomized feeding intervention study is an acceptable and feasible way to determine whether avoidance of cow's-milk protein during the first 6 months of life prevents type I diabetes in North American children.


Asunto(s)
Lactancia Materna , Diabetes Mellitus Tipo 1/prevención & control , Alimentos Infantiles , Cooperación del Paciente , Embarazo en Diabéticas , Negativa del Paciente al Tratamiento , Animales , Bovinos , Intervalos de Confianza , Estudios de Factibilidad , Femenino , Humanos , Lactante , Recién Nacido , Consentimiento Informado , Selección de Paciente , Embarazo , Factores de Riesgo , Encuestas y Cuestionarios
5.
Int J Radiat Oncol Biol Phys ; 8(11): 1869-76, 1982 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6818190

RESUMEN

Fifty patients with biopsy-proven cerebellar medulloblastoma were retrospectively analyzed for prognostic factors, survival and patterns of failure. Five- and ten-year actuarial survivals for the entire group were 51% and 42%. Survival and local control were significantly better for the 21 patients who received doses greater than 5000 rad to the posterior fossa (85% and 80% respectively) than for the remaining patients (38% and 38%, respectively). Significant prognostic factors included achievement of local control in the posterior fossa (p = .0001) and dose to the posterior fossa (p = .0005). Sex, age, duration of symptoms, extent of surgery and initial T-stage of disease were not significant. Posterior fossa was the predominant site of failure (71% of failures), but 10% of patients failed in the cerebrum and 12% outside the CNS. This experience confirms that survival rates of 70-80% are achievable with current treatment policies but accurate and consistent dose delivery to the posterior fossa is essential.


Asunto(s)
Neoplasias Cerebelosas/radioterapia , Meduloblastoma/radioterapia , Adolescente , Niño , Preescolar , Fosa Craneal Posterior , Femenino , Humanos , Masculino , Recurrencia Local de Neoplasia , Dosificación Radioterapéutica , Radioterapia de Alta Energía , Estudios Retrospectivos
6.
Int J Radiat Oncol Biol Phys ; 15(5): 1103-10, 1988 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3182342

RESUMEN

Prognostic factors and results of therapy were analyzed in a retrospective review of 70 patients with pituitary adenomas treated with radiotherapy alone from January 1954 through December 1982 at the Radiation Oncology Center, Mallinckrodt Institute of Radiology. The 10-year overall and disease-free survival was 77.8 and 76.0%. The expected survival for an age-, sex-, and race-matched population was not significantly greater at 87.2%. The 10-year disease-free survival for the distinct tumor types was 100% for Cushing's disease, 82.3% for patients with amenorrhea/galactorrhea, 79.6% for non-functioning adenomas, 69.0% for acromegaly, and 66.7% for Nelson's syndrome. Prognostic variables analyzed were age, race, sex, tumor type, tumor extent, visual field defects at diagnosis, and volume irradiated. Only the presence of visual field defects at diagnosis conferred a poor prognosis (p less than 0.001). There was a tendency toward superior tumor control with radiation doses greater than 4500 cGy (p = 0.15). The median time to progression of disease was 4.2 years, with the last failure occurring at 12 years following the completion of radiotherapy. Severe complications were apparent in 5 patients (7.1%), including one death from central nervous system radionecrosis.


Asunto(s)
Adenoma/radioterapia , Neoplasias Hipofisarias/radioterapia , Acromegalia/radioterapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Amenorrea/radioterapia , Niño , Síndrome de Cushing/radioterapia , Femenino , Galactorrea/radioterapia , Humanos , Masculino , Persona de Mediana Edad , Síndrome de Nelson/radioterapia , Pronóstico , Estudios Retrospectivos
7.
Int J Radiat Oncol Biol Phys ; 13(4): 531-9, 1987 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3558044

RESUMEN

The records of 125 patients treated for superior vena cava syndrome secondary to malignant disease were reviewed retrospectively. The mean age of patients was 55 years. Bronchogenic carcinoma was the cause of the syndrome in 79% of cases, malignant lymphoma 18%, and other tumors 6%. Approximately 80% of the patients obtained good to excellent symptomatic relief. High initial dose radiation therapy (300-400 cGy daily for three fractions) yielded good symptomatic relief in less than 2 weeks in 70% of patients; conventional dose radiation therapy (200 cGy daily, five weekly fractions) yielded the same response in 56% of patients (p = 0.09). Lymphoma patients displayed a 1 year survival of 41%, small cell carcinoma 24%, and other types of bronchogenic carcinoma 17%. Combination of radiation and chemotherapy did not improve response rate, degree of symptomatic relief or long-term survival. Patients exhibiting symptomatic relief within 30 days had a significantly better survival rate than those who did not (p = 0.002). Thirteen percent of patients showed a recurrence of superior vena cava syndrome. There was no correlation between tumor regression and symptomatic relief. Side effects of therapy were minimal; dysphagia was the most common complaint (26% of patients).


Asunto(s)
Neoplasias/complicaciones , Síndrome de la Vena Cava Superior/radioterapia , Adulto , Anciano , Antineoplásicos/uso terapéutico , Carcinoma Broncogénico/complicaciones , Terapia Combinada , Trastornos de Deglución/etiología , Humanos , Neoplasias Pulmonares/complicaciones , Linfoma/complicaciones , Persona de Mediana Edad , Radioterapia/efectos adversos , Estudios Retrospectivos
8.
Int J Radiat Oncol Biol Phys ; 12(3): 359-63, 1986 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3957734

RESUMEN

Over the past 2 years, an afterloading technique has been developed and refined to implant radioactive Ir-192 sources into brain tumors. The implantation procedure integrates a stereotaxic system with computerized tomography (CT), which provides tumor position, volume, and guides the placement of catheters. A radiolucent ring-frame immobilizes the head as holes are made at 1 cm intervals with the aid of a template. Catheters containing dummy sources 1 cm apart are then inserted to the desired depth, and their position verified in three dimensions to insure complete coverage of visible tumor volume as defined by contrast enhancement. Once catheters are secured, the anesthetized patient is moved to the intensive care unit where the dummy sources are replaced by ribbons of Ir-192 seeds (specific activity 0.6-1.0 mg Ra eq). CT scans with the dummy sources in place are used to designate spatial coordinates of the active sources. A computer program converts position data and source strength into isodose contours in any plane. The implant duration (70-100 hours) for the desired dose to the tumor periphery (60-120 Gy) is then calculated. Dose rate contours are superimposed on preimplant CT scans. Maximum and minimum doses are determined in each of the various planes. Verification dosimetry has been carried out with thermoluminescent dosimeters placed in a catheter located in a plane along the tumor periphery. In vivo isodose values compared to idealized plans agree within +/-5%-10%.


Asunto(s)
Braquiterapia/métodos , Neoplasias Encefálicas/radioterapia , Iridio/uso terapéutico , Tomografía Computarizada por Rayos X , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Planificación de Atención al Paciente/métodos , Radioisótopos/uso terapéutico , Dosificación Radioterapéutica
9.
Int J Radiat Oncol Biol Phys ; 17(1): 29-34, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2745204

RESUMEN

A retrospective analysis was performed of 51 patients with locoregional recurrence of endometrial carcinoma, treated by radiotherapy between 1959 and 1986. There were 17 patients (33%) with isolated vaginal recurrence, 12 patients (24%) with vaginal recurrence with pelvic extension, 7 patients (14%) with pelvic recurrence only, and 15 patients (29%) with simultaneous locoregional and distant failure. Eighty percent of the recurrences occurred within 3.5 years from primary treatment; time to relapse was shorter in patients with advanced-stage, high-grade malignancy at original diagnosis. Locoregional control was achieved in 18 patients (35%). Complete tumor regression in the vagina, irrespective of extravaginal pelvic disease status or distant metastasis, occurred in 28 of 34 patients with vaginal involvement (82%). The 5- and 10-year overall actuarial survivals for all patients were 18 and 12.5%, respectively. The 5- and 10-year progression-free survivals of patients with isolated vaginal recurrences were 40% and 29%, respectively; the 5-year progression-free survival of patients with vaginal recurrence with pelvic extension was 20%. There were no survivors beyond 1.5 years among patients with pelvic recurrence (p = 0.02). All patients with simultaneous locoregional and distant failure were dead by 3.5 years. Stage at original diagnosis, time to relapse from primary treatment, histologic pattern, and grade of malignancy were prognosticators of survival. Five patients (10%) developed a total of ten radiation-related sequelae.


Asunto(s)
Recurrencia Local de Neoplasia/radioterapia , Neoplasias Uterinas/radioterapia , Anciano , Relación Dosis-Respuesta en la Radiación , Femenino , Estudios de Seguimiento , Humanos , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Traumatismos por Radiación/epidemiología , Inducción de Remisión , Estudios Retrospectivos , Neoplasias Uterinas/mortalidad , Neoplasias Uterinas/patología , Neoplasias Vaginales/radioterapia
10.
Int J Radiat Oncol Biol Phys ; 8(2): 303-8, 1982 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7085386

RESUMEN

From August 1978 through December 1979, 51 patients with advanced non-oat cell carcinoma of the lung were enrolled in a Phase I/II trial sponsored by the Radiation Therapy Oncology Group (RTOG) employing misonidazole (a 2-nitroimidazole) as a hypoxic cell sensitizer and radiation. The purpose of this study was to test drug and radiation tolerance and to assess the short term efficacy of this unconventional treatment. Tumor doses of 600 rad wer given twice weekly for three weeks for a total of 3600 rad, preceded four to six hours by misonidazole in a dose of 2 gm/m2 or 1.75 gm/m2, administered orally. Forty-nine patients were evaluable. Serious toxicity from this treatment was rare. Grade 2 or 3 peripheral neuro-toxicity occurred in eight of 24 patients (33%) with drug doses of 2 gm/m2 and in four of 26 patients (15%) who received 1.75 gm/m2. Grade 3 or 4 central nervous system toxicity occurred in two patients. Two patients developed serious late radiation complications: one patient had a transverse myelitis that appeared one year following delivery of 3600 rad to the spinal cord; a second patient developed a tracheoesophageal fistula and pericarditis eight months following treatment. Objective responses were reported in 67% of patients (complete in 18%); 70% of the patients died with a median survival time of nine months. Of 32 patients eligible for 12 month follow-up, 34% survived more than one year. Patterns of relapse after initial treatment and comparison with results from other RTOG trials using conventional fractionation are discussed.


Asunto(s)
Adenocarcinoma/radioterapia , Carcinoma de Células Escamosas/radioterapia , Neoplasias Pulmonares/radioterapia , Misonidazol/administración & dosificación , Nitroimidazoles/administración & dosificación , Adulto , Anciano , Evaluación de Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Misonidazol/toxicidad , Radioterapia/efectos adversos , Dosificación Radioterapéutica
11.
Int J Radiat Oncol Biol Phys ; 11(4): 751-8, 1985 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2579938

RESUMEN

Between June 1973 and February 1979, 409 patients with inoperable advanced non-oat cell carcinoma of the lung were randomized on RTOG protocol 73-02. Three treatment arms were evaluated: 40 Gy split course, 30 Gy continuous course, and 40 Gy continuous course. Patients were also randomized to receive cytoxan or no further therapy following irradiation. Three hundred sixteen patients were evaluable. Palliation of symptoms was achieved in 60% with 1/4 of the patients becoming symptom-free. Complete regression of local and regional tumor was produced in 15% and partial regression in 26%. There is no significant difference between the treatment arms in these objective response rates. Median survival times were approximately 6 months. No significant benefit was demonstrated by the adjuvant use of Cytoxan. Although the number of complete responses produced was relatively small, patients achieving a complete response had a significantly longer median survival than the remaining patients, i.e., 14.5 months versus 6 months. Significant toxicity occurred in fewer than 6% of patients. Radiation pneumonitis counted for the majority of these adverse reactions. Toxicity occurred somewhat more often in the group treated with 40 Gy split course therapy. Implications for further studies are discussed.


Asunto(s)
Carcinoma/radioterapia , Neoplasias Pulmonares/radioterapia , Adenocarcinoma/patología , Adenocarcinoma/radioterapia , Adolescente , Adulto , Anciano , Antineoplásicos/administración & dosificación , Carcinoma/patología , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Femenino , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Cuidados Paliativos , Traumatismos por Radiación/etiología
12.
Int J Radiat Oncol Biol Phys ; 16(6): 1411-7, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2722585

RESUMEN

Prognostic factors and results of therapy were analyzed in a retrospective examination of 121 patients with pituitary adenomas treated with surgery and postoperative irradiation (RT) from January 1954 through December 1982 at the Radiation Oncology Center, Mallinckrodt Institute of Radiology. The 10-year overall and disease-free survival for all patients was 85.1 and 89.4%. The expected survival for an age-, gender-, and race-matched population was not significantly distinct at 85.3% (p = 0.72). Follow-up of 94 surviving patients ranged from 3.4 to 29.5 years (mean, 11.7). Statistical analysis was performed for multiple prognostic factors including age, race, gender, disease bulk, visual field symptoms, disease type, surgical approach, and irradiation dose and volume. The only prognostic variable identified by univariate analysis to significantly alter disease-free survival was irradiation dose. Patients receiving 5000-5400 cGy had a tumor control rate of 94.1% (64/68) compared to 85.0% (17/20) for 4000-4999 cGy, 75.0% (18/24) for 3000-3999 cGy, and 28.6% (2/7) for less than 3000 cGy (p = 0.000059). Factors evaluated but established to be insignificant were age, race, gender, disease bulk, visual field symptoms, disease type, surgical approach, and irradiated volume. The 10-year disease-free survival by classification was 93.3% for patients with amenorrhea/galactorrhea, 89.9% for non-functioning adenomas, and 76.4% for acromegaly (p = 0.21). Overall improvement in visual field defects subsequent to treatment occurred in 48.4% (44/91) of those with visual field defects before RT and was significantly correlated with RT dose. The median time to progression of disease was 10.2 years with the last failure occurring at 25 years following the fulfillment of RT. Severe complications related to RT were apparent in 1.7% (2/121). None were known to have endured brain radionecrosis. Serious surgical complications occurred in 9.9% (12/121).


Asunto(s)
Adenoma/cirugía , Neoplasias Hipofisarias/cirugía , Adenoma/radioterapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Hipofisarias/radioterapia , Pronóstico , Dosificación Radioterapéutica , Estudios Retrospectivos
13.
Int J Radiat Oncol Biol Phys ; 21(1): 243-52, 1991 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-2032892

RESUMEN

Over 300 treatment plans for a total of eight disease sites based on 3-D treatment planning considerations utilizing serial CT delineated target volumes were generated by four institutions as part of an NCI supported contract to both assess the current state-of-the-art capabilities and point directions for future efforts. Two patients with stage C prostate cancer were evaluated with protocol plans which required treatment of the prostate to 70 Gy and the pelvic lymph nodes to 46 Gy. When full 3-D target definition and multiple beam arrangements were employed, all institutions were able to submit plans which scored higher on tumor coverage and had lower normal tissue complication scores compared to traditional plans. The 3-D plans using standard beam arrangements, however, were often rated as highly as the 3-D unconstrained plans due to the multiple beam arrangements already selected to optimize standard plans at most institutions. For this site, heterogeneity corrections, beam energy changes and changes in CT number did not substantially change plan scores.


Asunto(s)
Neoplasias de la Próstata/radioterapia , Planificación de la Radioterapia Asistida por Computador , Anciano , Humanos , Masculino , Persona de Mediana Edad , Dosificación Radioterapéutica , Tomografía Computarizada por Rayos X
14.
Int J Radiat Oncol Biol Phys ; 21(2): 379-85, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2061114

RESUMEN

A retrospective analysis is reported in 858 patients with clinical Stage I carcinoma of the endometrium treated definitively from January 1960 through December 1986 with combined irradiation and total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO). Most patients received a preoperative intracavitary insertion (2500-4000 mgh to the uterus with Heyman capsules and tandem and 6500 cGy surface dose to the upper vagina) followed by a TAH-BSO within 6 weeks. Some patients received postoperative external beam irradiation (2000 cGy whole pelvis and an additional 3000 cGy to the parametria, with a midline stepwedge) when deep myometrial invasion was present. Occasionally patients were treated with preoperative external beam irradiation (2000 cGy whole pelvis) and intracavitary insertion. The 5-year overall survival for all patients was 84.0% compared to an expected survival of 88.8%. The 5-year progression-free survivals were 92% for FIGO clinical Stage IA and 86% for stage IB (p = 0.12). The dose to the uterine fundus from the preoperative intracavitary insertion was found to have a significant correlation with progression-free survival in patients with grade 3 tumors. Those receiving less than 2500 mgh to the uterine cavity had a 48.9% 5-year progression-free survival compared to 62.7% for 2500-3500 mgh and 87.4% for those receiving greater than 3500 mgh. Analysis of sites of failure showed that less than 1% (7/858) failed in the pelvis alone, 3% (30/858) in the pelvis combined with distant sites, and 7% (60/858) developed distant metastasis only. The lateral pelvic sidewall was the most common site of failure within the pelvis (20/37) and intraperitoneal failures (28/90) and lung (21/90) were the most common sites of distant metastasis. The overall severe (grades 2, 3, and 4) complication rate was 2.7% (23/858).


Asunto(s)
Neoplasias Uterinas/radioterapia , Adenocarcinoma/epidemiología , Adenocarcinoma/radioterapia , Adenocarcinoma/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Braquiterapia , Carcinoma Papilar/epidemiología , Carcinoma Papilar/radioterapia , Carcinoma Papilar/cirugía , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirugía , Trompas Uterinas/cirugía , Femenino , Humanos , Histerectomía , Persona de Mediana Edad , Recurrencia Local de Neoplasia/epidemiología , Ovariectomía , Estudios Retrospectivos , Análisis de Supervivencia , Neoplasias Uterinas/epidemiología , Neoplasias Uterinas/cirugía
15.
Int J Radiat Oncol Biol Phys ; 26(4): 593-9, 1993 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-8330987

RESUMEN

PURPOSE: To determine the incidence, pattern of regional nodal failure, and treatment sequelae as determined by the extent of lymphatic irradiation. METHODS AND MATERIALS: The records of 511 patients with 519 Stage I and II breast cancers treated with breast conserving surgery with or without axillary dissection and irradiation were reviewed. The extent of nodal irradiation was at the discretion of the attending radiation oncologist and varied considerably over the years. Management of the axilla consisted of axillary dissection alone in 351, axillary dissection and supplemental irradiation in 74, irradiation alone in 75, and simply observation in 21 patients. RESULTS: Overall, axillary recurrence was uncommon (1.2%), but was slightly more frequent after irradiation alone (2.7%) than after surgery alone (0.3%), p = 0.14. There was no benefit for supplemental axillary irradiation after an axillary dissection yielding negative or 1 to 3 positive nodes. In the 21 patients in whom the axilla was observed, axillary recurrence was not observed. Supraclavicular failures were rare in women with negative or 1 to 3 positive axillary lymph nodes (0.5%), and not significantly affected by elective irradiation. Internal mammary node recurrence was seen in only one patient, and was not significantly influenced by elective internal mammary irradiation. Both arm and breast edema were significantly more common in women having breast and nodal irradiation than after breast irradiation alone. These sequelae were not influenced significantly by the number of lymph nodes obtained in the axillary dissection specimen. Radiation pneumonitis was seen with increased frequency with more extensive nodal radiotherapy. Pneumonitis was not found to be affected by the administration or sequencing of chemotherapy. CONCLUSION: There is little justification for axillary or supraclavicular irradiation following an axillary dissection which yields negative or minimally involved (1 to 3 positive) lymph nodes. There were too few patients with extensive axillary node metastases (> or = 4 positive) in our series to draw conclusions about the optimal extent of nodal irradiation in this subset. Elective internal mammary lymph node irradiation increases technical complexity, does not appear to be advantageous, and when combined with supraclavicular irradiation places the patient at highest risk for pneumonitis.


Asunto(s)
Neoplasias de la Mama/cirugía , Escisión del Ganglio Linfático , Ganglios Linfáticos/efectos de la radiación , Mastectomía Segmentaria , Adulto , Anciano , Anciano de 80 o más Años , Brazo , Axila , Mama , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/radioterapia , Terapia Combinada , Edema/epidemiología , Edema/etiología , Femenino , Humanos , Persona de Mediana Edad , Neumonía/epidemiología , Neumonía/etiología , Radioterapia/efectos adversos , Estudios Retrospectivos
16.
Int J Radiat Oncol Biol Phys ; 27(5): 1045-50, 1993 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-8262825

RESUMEN

PURPOSE: To evaluate the association between age and breast/regional nodal relapse following breast conserving surgery and irradiation. METHODS AND MATERIALS: The results of treatment in 511 patients with 519 Stage I and II breast cancers treated at Mallinkrodt Institute of Radiology and affiliated hospitals between 1958 and 1988 were reviewed. RESULTS: Seventy women, of whom 96% had axillary dissections, were 39 years of age or younger. These young patients were more likely to have chemotherapy (p < 0.0001), and tumor bed reexcision (p < 0.01), and less likely to have an undissected axilla (p < 0.01), or estrogen receptor positive tumor (p = 0.02) than the older women (> 40 years). Although breast recurrence tended to appear earlier in the younger patients (12% at 5 years for those < 40 years vs. 6% at 5 years for those older), by 7 years the breast failure rate for the two groups was the same (12%), p = 0.13. In the 37 women 35 years of age or younger, the actuarial rate of breast recurrence was 9% at 7 years. Compared to other series in the literature, in which cancers were grossly excised without regard to the microscopic margins of resection, and reexcision was not routinely performed, young women treated with breast conserving surgery and irradiation at our institution frequently underwent reexcision of the tumor bed (57%), and had negative pathologic margins of resection (75%). Regional nodal relapse was in general uncommon, and not seen with increased frequency in the youngest cohort. CONCLUSION: Our experience suggests that young age is not a contraindication to breast conserving surgery and irradiation. Although breast cancers in this cohort may have certain features rendering them prone to local failure, we believe this risk can be mitigated by appropriate patient selection and optimal surgical resection.


Asunto(s)
Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Metástasis Linfática , Recurrencia Local de Neoplasia , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Femenino , Humanos , Escisión del Ganglio Linfático , Persona de Mediana Edad , Análisis Multivariante , Invasividad Neoplásica , Estadificación de Neoplasias , Pronóstico , Receptores de Estrógenos/análisis , Receptores de Progesterona/análisis , Reoperación , Estudios Retrospectivos , Factores de Tiempo
17.
Int J Radiat Oncol Biol Phys ; 27(4): 933-44, 1993 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-8244826

RESUMEN

PURPOSE: We describe our 3-dimensional (3-D) radiation treatment planning system for external photon and electron beam 3-D treatment planning which provides high performance computational speed and a real-time display which we have named "room-view" in which the simulated target volumes, critical structures, skin surfaces, radiation beams and/or dose surfaces can be viewed on the display monitor from any arbitrary viewing position. METHODS AND MATERIALS: We have implemented the 3-D planning system on a graphics superworkstation with parallel processing. Patient's anatomical features are extracted from contiguous computed tomography scan images and are displayed as wireloops or solid surfaces. Radiation beams are displayed as a set of diverging rays plus the polygons formed by the intersection of these rays with planes perpendicular to the beam axis. Controls are provided for each treatment machine motion function. Photon dose calculations are performed using an effective pathlength algorithm modified to accommodate 3-D off-center ratios. Electron dose calculations are performed using a 3-D pencil beam model. RESULTS: Dose distribution information can be displayed as 3-D dose surfaces, dose-volume histograms, or as isodoses superimposed on 2-D gray scale images of the patient's anatomy. Tumor-control-probabilities, normal-tissue-complication probabilities and a figure-of-merit score function are generated to aid in plan evaluation. A split-screen display provides a beam's-eye-view for beam positioning and design of patient shielding block apertures and a concurrent "room-view" display of the patient and beam icon for viewing multiple beam set-ups, beam positioning, and plan evaluation. Both views are simultaneously interactive. CONCLUSION: The development of an interactive 3-D radiation treatment planning system with a real-time room-view display has been accomplished. The concurrent real-time beam's-eye-view and room-view display significantly improves the efficacy of the 3-D planning process.


Asunto(s)
Sistemas de Computación , Presentación de Datos , Procesamiento de Imagen Asistido por Computador , Planificación de la Radioterapia Asistida por Computador , Humanos
18.
Int J Radiat Oncol Biol Phys ; 26(2): 239-44, 1993 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-8387988

RESUMEN

PURPOSE: The influence of tumor site, size, and extent of surgery on the survival of patients with glioblastoma multiforme treated on three consecutive prospectively randomized Radiation Therapy Oncology Group trials employing surgery and irradiation plus or minus chemotherapy was studied. METHODS AND MATERIALS: Six hundred forty-five patients with a diagnosis of glioblastoma multiforme on central pathological review were analyzed for survival with respect to known prognostic factors, that is, age and Karnofsky Performance Status, as well as extent of surgery, site, and size. Surgical treatment consisted of biopsy only in 17%, partial resection in 64%, and total resection in 19%. Tumors were located in frontal lobe in 43%, temporal lobe in 28%, and parietal lobe in 25%. Maximum tumor diameter as determined on computed tomography or magnetic resonance imaging scans was less than 5 cm for 38%, between 5-10 cm for 56% and greater than 10 cm for 6% of patients. The extent of surgical therapy was the same for tumors greater than 5 or greater than 10 cm, whereas total resection was more often performed for tumors less than 5 cm. The extent of surgery did not appear to vary with age or site. RESULTS: Patients undergoing total resection had a median survival of 11.3 months compared to 6.6 months for patients with a biopsy only. A significant difference in median survival was also found for partial resection versus biopsy only treatment (10.4 vs. 6.6 months). There was no difference in survival for the different tumor sizes. Patients with frontal lobe tumors survived longer than those with temporal or parietal lobe lesions (11.4 months, 9.1 months, and 9.6 months, respectively) (p = 0.01). A Cox multivariate model confirmed a significant correlation of age, Karnofsky Performance Status, extent of surgery, and primary site with survival. The best survival rates occurred in patients who had at least three of the following features: < 40 years of age, high Karnofsky Performance Status, frontal tumors, and total resection (17 months median). CONCLUSION: We conclude that biopsy only yields inferior survival to more extensive surgery for patients with glioblastoma multiforme treated with surgery and radiation therapy.


Asunto(s)
Neoplasias Encefálicas/cirugía , Lóbulo Frontal , Glioblastoma/cirugía , Lóbulo Parietal , Lóbulo Temporal , Adulto , Factores de Edad , Neoplasias Encefálicas/epidemiología , Neoplasias Encefálicas/radioterapia , Terapia Combinada , Glioblastoma/epidemiología , Glioblastoma/radioterapia , Humanos , Persona de Mediana Edad , Análisis Multivariante , Estudios Prospectivos , Análisis de Supervivencia
19.
Int J Radiat Oncol Biol Phys ; 22(5): 905-11, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1555983

RESUMEN

A retrospective analysis is reported in 858 patients with clinical Stage I carcinoma of the endometrium treated definitively with combined irradiation and total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO) from January 1960 through December 1986. Most patients received a preoperative intracavitary insertion (3500-4000 mgh to the uterus and a 6500 cGy surface dose to the upper vagina) followed by a TAH-BSO within 1-2 weeks. Some patients received postoperative external beam irradiation (2000 cGy whole pelvis and an additional 3000 cGy to the parametria, with a midline stepwedge) when factors such as deep myometrial invasion were present. Occasionally patients were treated with a preoperative intracavitary insertion and preoperative external beam irradiation (2000 cGy whole pelvis). The 5-year progression-free survivals by FIGO (1988) surgical stage were 93% for IA, 90% for IB, and 91% for Stage IC. An analysis of multiple variables was performed to ascertain their prognostic significance. Factors that significantly affected the 5-year progression-free survivals by univariate analysis were grade (grade 1 = 95%, grade 2 = 88%, grade 3 = 73%; p less than 0.0001), histology (adenoacanthoma = 96%, clear cell = 89%, adenocarcinoma = 89%, papillary = 81%, adenosquamous = 80%; p = 0.04), lower uterine segment involvement (uninvolved = 89%, involved = 73%; p = 0.006), depth of myometrial invasion (no residual tumor = 91%, limited to the endometrium = 96%, less than 1/3 myometrial penetration = 92%, 1/3 - 2/3 = 100%, greater than 2/3 = 50%; p = 0.02), peritoneal cytology (negative = 92%, positive = 56%, p less than 0.0001), uterine serosal involvement (uninvolved = 89%, involved = 55%; p less than 0.0001), vascular space invasion (absent = 89%, present = 75%; p = 0.001), and the presence of extrauterine disease (absent = 90%, present = 64%; p less than 0.0001). A multivariate analysis of these prognostic variables showed that histological grade (p = 0.001), peritoneal cytology (p = 0.004), and uterine serosal involvement were prognostic for local failure and that peritoneal cytology (p less than 0.001), grade (p = 0.001), age (p = 0.002), and extrauterine disease (p = 0.02) were prognostic for the development of distant metastasis.


Asunto(s)
Neoplasias Uterinas/terapia , Braquiterapia , Terapia Combinada , Femenino , Humanos , Histerectomía , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias/métodos , Ovariectomía , Estudios Retrospectivos , Análisis de Supervivencia , Tasa de Supervivencia , Neoplasias Uterinas/epidemiología , Neoplasias Uterinas/patología
20.
Int J Radiat Oncol Biol Phys ; 16(6): 1483-91, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2542197

RESUMEN

From September 1979 to February 1983, 268 patients with unresectable, locally advanced (RTOG Stage III), non-small cell lung cancer were randomized to receive radiation therapy alone (RT) (50 Gy large field and 10 Gy boost), or combined with misonidazole (400 mg/m2 2-4 hr prior to RT daily for 5-6 weeks to a maximum dose of 12 g/m2 or until tumor progression). One hundred twenty-three patients who received irradiation alone and 116 given RT + misonidazole were evaluable for toxicity, time to tumor progression, and survival as of April 1987. The distribution of patient characteristics was similar in both treatment groups; 59% of the patients had a Karnofsky score of 90 or better, 53% had adenocarcinoma or large cell tumors, and 47% had Stage T3 tumors. Complete tumor regression was reported for 33 (27%) patients treated with radiation therapy alone and 24 (21%) who received misonidazole + RT. Median survival was 8 months with RT alone and 7.4 months with misonidazole + RT. Ninety-five percent of the patients have died. Seventy percent of the patients treated with radiation alone and 77% of those treated with misonidazole + RT died of progressive disease. Three patients treated with radiation alone and two with RT + misonidazole died subsequent to radiotherapy-related pneumonitis or pulmonary fibrosis. There was no significant improvement in response rates, local control, or survival for patients who received daily misonidazole along with irradiation compared with patients treated by irradiation alone.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/radioterapia , Misonidazol/uso terapéutico , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/radioterapia , Adulto , Anciano , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Pronóstico , Estudios Prospectivos , Distribución Aleatoria
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