Modulated Arc Therapy for hippocampal-avoidance whole brain radiation therapy: planning comparison with intensity modulated Radiation Therapy.

This study aimed to evaluate the modulated arc therapy (mARC) technique as a planning and treatment option for hippocampal sparing whole brain radiotherapy (HS-WBRT) following the Radiation Therapy Oncology Group (RTOG) 0933 dosimetric criteria. Computed tomography (CT) and magnetic resonance imaging (MRI) were selected retrospectively for 15 patients. Two types of plans were created for each patient, namely an intensity-modulated radiation therapy (IMRT) and a mARC plan. IMRT and mARC plans were compared in terms of plan quality indices, absorbed dose to organs at risk (OARs), number of monitor units (MUs), and treatment time. All plans in both techniques were considered clinically acceptable for treatment. However, IMRT plans presented a higher conformity (p = 0.01) as well as a higher homogeneity as compared to mARC plans, but this difference was not statistically significant (p > 0.05). In terms of the preservation of the hippocampus, it was observed that the IMRT plans achieved significantly lower doses for both 100% of its volume and for its maximum dose (p < 0.001). The evaluation of the remaining OARs showed that the IMRT technique resulted in lower doses, and significant differences were observed for the following organs: left cochlea (p < 0.001), left eye (p < 0.001), right eye (p = 0.03), both lenses of the eye (p < 0.001), and right optic nerve (p = 0.02). Despite these differences, the absolute differences in all dosimetric parameters were low enough to bear any clinical relevance. A drastic (close to 65%) and significant (p < 0.001) decrease was observed in the number of MUs for the mARC plans. This resulted in a substantial decrease in treatment time (60.45%, p < 0.001). It is concluded that the mARC technique is a feasible planning and treatment solution for HS-WBRT that meets the RTOG 0933 criteria. The main advantage of using mARC over IMRT for HS-WBRT is the considerable reduction in MUs and treatment time.

Association between the cardiac contact distance and the maximum dose at the left anterior descending coronary artery in post mastectomized patients.

The clinical information on the relationship between the cardiac contact distance (CCD), the maximum dose (Dmax) delivered to the left anterior descending (LAD) coronary artery and the mean heart dose has mostly focused on patients with breast-conserving surgery (BCS), being scarce in postmastectomy patients. The aim of this study is to determine the association between the CCD and the Dmax delivered to the LAD. The secondary objective was to evaluate the dosimetric results of comparing three-dimensional conformal radiotherapy (3D-CRT) to intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques for post mastectomized breast cancer patients with irradiation to the left chest wall. 53 cases of women who received adjuvant standard fractionated postmastectomy radiotherapy (PMRT) were used. Three types of plans were created for each patient: 3D-CRT, seven equidistant IMRT fields, and four partial VMAT arcs. Correlations were evaluated using Pearson's correlation coefficient. Plans made with IMRT and VMAT showed improved homogeneity and conformity. Associations between CCD and Dmax to LAD were positive for all three plan types. Compared to 3D-CRT, the modulated intensity plans obtained better dose homogeneity and conformity to the target volume. The LAD and heart doses were significantly lower for IMRT and VMAT plans. The CCD can be used as a predictor of the maximum and mean doses of the LAD. Modulated intensity techniques allow for better dose distribution and dose reduction to the heart and LAD.

Dosimetric study of a hybrid plan technique for external beam radiotherapy in patients with cervical cancer.

The aim of this study was to investigate the effect of a hybrid technique which results from combining intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for the treatment of cervical cancer patients. Plans made with the hybrid technique and pure IMRT and VMAT were retrospectively compared in 20 patients with cervical cancer at different stages. All plans were made using the same contours based on the original computed tomography (CT) scans. Conformity (CI) and homogeneity (HI) indices of the planning target volumes (PTVs) were calculated for each technique in order to evaluate plan quality. All techniques were compared in terms of dose to organs at risk (OARs), number of monitor units (MUs) and treatment time. It turned out that plans made with the hybrid technique had improved dose conformity and homogeneity compared to plans made only with IMRT and VMAT (p < 0.001). Regarding the OARs, the maximum dose (Dmax) delivered to the bladder, rectum and femoral heads was lower for the hybrid plans compared to the IMRT and VMAT plans (p < 0.001). The volumes irradiated to doses of 50 Gy (V50Gy) for rectum, bladder and bowel were lower for the hybrid plans (p < 0.001, p = 0.002). Furthermore, the treatment time and MU values for the hybrid plans were found to be between of the values for the IMRT and VMAT plans. It is concluded that, as compared to IMRT and VMAT plans, the hybrid plan technique allowed a better conformity and homogeneity for the dose distribution in the PTV and a dose reduction to the OARs.

Performance of Indocyanine green for sentinel lymph node mapping and lymph node metastasis in colorectal cancer: a diagnostic test accuracy meta-analysis.

BACKGROUND: Indocyanine green has been widely employed as a secure and easy technique for sentinel lymph node mapping in different types of cancer. Nonetheless, the usage of Indocyanine green has not been fully implemented due to the heterogeneous results found in published studies. Thus, the objective of this meta-analysis is to evaluate the overall performance of Indocyanine green for sentinel lymph node mapping and node metastasis in patients undergoing colorectal cancer surgery. METHODS: An extensive systematic search was performed to identify relevant studies in English and Spanish with no time limit restrictions. For the meta-analysis, a hierarchical summary receiver operating characteristic curve (HSROCs) was constructed, and quantitative data synthesis was performed using random effects models. Specificity, sensitivity, positive, and negative likelihood ratios were obtained from the corresponding HSROC. Between-study heterogeneity was visually evaluated using Galbraith plot, and publication bias was quantified using Deeks' method. RESULTS: A total of 11 studies were included for analysis. The pooled detection rate for sentinel lymph node mapping was 91% (80-98%). Covariates significantly influencing the pooled detection rate were having colon cancer (estimate: 1.3001; 1.114 to 1.486; p < 0.001) and the usage of a laparoscopic approach (estimate: 1.3495; 1.1029 to 1.5961; p < 0.001). The performance of Indocyanine green for the detection of metastatic lymph nodes yielded an area under the roc curve of 66.5%, sensitivity of 64.3% (51-76%), and specificity of 65% (36-85%). CONCLUSIONS: Indocyanine green for the detection of sentinel lymph node mapping demonstrates better accuracy when used in colonic cancer and by a laparoscopic approach. Nevertheless, its overall performance for the detection of lymph node metastasis is poor.

Microsatellite marker diversity in common bean (Phaseolus vulgaris L.).

A diversity survey was used to estimate allelic diversity and heterozygosity of 129 microsatellite markers in a panel of 44 common bean (Phaseolus vulgaris L.) genotypes that have been used as parents of mapping populations. Two types of microsatellites were evaluated, based respectively on gene coding and genomic sequences. Genetic diversity was evaluated by estimating the polymorphism information content (PIC), as well as the distribution and range of alleles sizes. Gene-based microsatellites proved to be less polymorphic than genomic microsatellites in terms of both number of alleles (6.0 vs. 9.2) and PIC values (0.446 vs. 0.594) while greater size differences between the largest and the smallest allele were observed for the genomic microsatellites than for the gene-based microsatellites (31.4 vs. 19.1 bp). Markers that showed a high number of alleles were identified with a maximum of 28 alleles for the marker BMd1. The microsatellites were useful for distinguishing Andean and Mesoamerican genotypes, for uncovering the races within each genepool and for separating wild accessions from cultivars. Greater polymorphism and race structure was found within the Andean gene pool than within the Mesoamerican gene pool and polymorphism rate between genotypes was consistent with genepool and race identity. Comparisons between Andean genotypes had higher polymorphism (53.0%) on average than comparisons among Mesoamerican genotypes (33.4%). Within the Mesoamerican parental combinations, the intra-racial combinations between Mesoamerica and Durango or Jalisco race genotypes showed higher average rates of polymorphism (37.5%) than the within-race combinations between Mesoamerica race genotypes (31.7%). In multiple correspondance analysis we found two principal clusters of genotypes corresponding to the Mesoamerican and Andean gene pools and subgroups representing specific races especially for the Nueva Granada and Peru races of the Andean gene pool. Intra population diversity was higher within the Andean genepool than within the Mesoamerican genepool and this pattern was observed for both gene-based and genomic microsatellites. Furthermore, intra-population diversity within the Andean races (0.356 on average) was higher than within the Mesoamerican races (0.302). Within the Andean gene pool, race Peru had higher diversity compared to race Nueva Granada, while within the Mesoamerican gene pool, the races Durango, Guatemala and Jalisco had comparable levels of diversity which were below that of race Mesoamerica.

Neurofibromatosis tipo 1 (NF1) revisión y presentación de un caso clínico con manifestaciones bucofaciales / Neurofibromatosis type 1 (NF1) review and report of a case with buccofacial manifestation

La neurofibromatosis es una enfermedad hereditaria de transmisión autosómica dominante que compromete el desarrollo de las células de la cresta neural. Las manifestaciones bucofaciales de la neurofibromatosis tipo 1 (NF1) son muy escasas, presentando una prevalencia de 1:16.000.El caso que se presenta es de un paciente varón de 10 años de edad, de raza negra, que acudió al Servicio de Cirugía Oral y Maxilofacial del Hospital Universitario de Cartagena de Indias (Colombia) por presentar un nódulo en el suelo de la boca y una ligera asimetría facial provocada por una hipertrofia fibrosa que comprometía el maxilar superior y el cuerpo mandibular izquierdo. En el examen físico se encontraron, a nivel cutáneo, numerosas manchas café con leche dispersas por todo el cuerpo, mientras que la exploración oftalmológica reveló múltiples nódulos de Lisch (hamartomas del iris). Las imágenes radiográficas mostraron una compresión extra ósea y la tomografía computadorizada (TC) descartó la presencia de glioma de los nervios ópticos. Como antecedentes familiares, el padre, una hermana y una tía del paciente presentaban una NF1 confirmada clínicamente. De acuerdo con la determinación de los criterios diagnósticos de la NF1 establecidos en 1987 por el “National institut of health concensus development conference on neurofibromatosis”, esos tres hallazgos permitieron hacer un diagnóstico de NF1 y orientar la impresión clínica de las lesiones bucofaciales hacia neurofibromas, lo que fue confirmado histológicamente. El manejo de los pacientes con NF1 es difícil, como también lo es el tratamiento de las complicaciones que pueden producir las lesiones tales como deformidades (con el consiguiente problema psicológico), gliomas de los nervios ópticos (ceguera) o un alto riesgo de malignización. La ayuda del consejo genético, el aislamiento del gen implicado y los últimos avances en el campo de la genética, son muy esperanzadoras en cuanto al diagnóstico prenatal

Neurofibromatosis is a hereditary illness of dominant autosomic transmission which cope with cell development in the neural creek. Mouth-face manifestations caused by neurofibromatosis type 1 (NF1) are scarce, showing a dominance of 1 among 16,000.The case shown belongs to a patient – male, aged 10, black – who went into hospital in Cartagena de Indias (Colombia) in the section of Oral and Maxilofacial Surgery Service after detecting a nodule on the mouth soil and a light facial asymmetry caused by a swelling around the upper and lower left jaw. During the medical tests, several light-brown spots were found on the skin and the ophthalmology test revealed several Lisch nodules. Radiography showed bone compression and ,later on, computer thomography discarded the existence of optic nerves glioma. In the medic reports we could see that the patient’s father, sister and aunt suffered from NF1 as well. According to the diagnostic criteria regarding NF1 established in “National Institute of Health Concensus Development. A Conference on Neurofibromatosis” (1987), the evidence found in the patient after the tests (the3 sympthoms) led us to diagnose NF1 and made us focus and re-consider the case from a former mouth-faceinjury to a later neurofibroma, which was clinically and officially confirmed. The treatment of NF1 patients is hard as well as the complications derived from deformations (and its following psychological problem), gliomas of the optic nerves (blindness) or the high-risk of malignization. The genetic Council assistance, the isolation of the gen and the latest developments in the field of Genetics allowus to have great expectations in the pre-birth diagnostic

Isolation, geographical diversity and insecticidal activity of Bacillus thuringiensis from soils in Spain.

Bacillus thuringiensis is a spore-forming bacterium showing the unusual ability to produce endogenous crystals during sporulation that are toxic for some pest insects. This work was performed to study the composition, ecological distribution and insecticidal activity of isolates of this entomopathogenic bacterium from the Spanish territory. Using a standard isolation method, B. thuringiensis was isolated from 115 out of 493 soil samples collected in the Iberian Peninsula and the Canary and Balearic Archipelagos. The percentages of samples with B. thuringiensis were 31.7, 27.6 and 18.5 and the B. thuringiensis index 0.065, 0.067 and 0.11 for the Iberian Peninsula, Canary and Balearic Archipelagos, respectively. The prairies were shown to be the worst source of B. thuringiensis while forests, urban and agricultural habitats showed similar percentages. Strain classification based on H-antigen agglutination showed a great diversity among the Spanish isolates, which were distributed among 24 subspecies, including three new ones andaluciensis, asturiensis and palmanyolensis. We differentiated 65 different protein profiles of spore-crystal mixtures by sulfate-polyacrylamide gel electrophoresis and we selected 109 isolates representative of these profiles to evaluate their insecticidal activity against insects from the Orders Orthoptera, Dictyoptera, Coleoptera, Lepidoptera and Diptera. We found variable percentages of isolates active against Coleoptera and Lepidoptera, one isolate highly active against mosquito larvae and for the first time, three isolates active against cockroaches and locusts.

Molecular structure of substituted phenylamine alpha-OMe- and alpha-OH-p-benzoquinone derivatives. Synthesis and correlation of spectroscopic, electrochemical, and theoretical parameters.

Thirteen C(6) para-substituted anilinebenzoquinones derived from perezone (PZ) (2-(1,5-dimethyl-4-hexenyl)-3-hydroxy-5-methyl-1,4-benzoquinone) were prepared to analyze the effect of the substituents on quinone electronic properties. The effect of a hydrogen bond between the alpha-hydroxy and carbonyl C(4)-O(4) groups was determined in perezone derivatives by substituting electron-donor and electron-acceptor groups such as -OMe, -Me, -Br, and -CN and comparing the -OH (APZs) and -OMe (APZms) derivatives. Reduction potentials of these compounds were measured using cyclic voltammetry in anhydrous acetonitrile. The typical behavior of quinones, with or without alpha-phenolic protons, in an aprotic medium was not observed for APZs due to the presence of coupled, self-protonation reactions. The self-protonation process gives rise to an initial wave, corresponding to the irreversible reduction reaction of quinone (HQ) to hydroquinone (HQH(2)), and to a second electron transfer, attributed to the reversible reduction of perezonate (Q(-)) formed during the self-protonation process. This reaction is favored by the acidity of the alpha-OH located at the quinone ring. To control the coupled chemical reaction, we considered both methylation of the -OH group (APZms) and addition of a strong base, tetramethylammonium phenolate (Me(4)N(+)C(6)H(5)O(-)), to completely deprotonate the APZs. Methylation led to recovery of reversible, bi-electronic behavior (Q/Q(*)(-) and Q(*)(-)/Q(2)(-)), indicating the nonacidic properties of the NH group. The addition of a strong base resulted in reduction of perezonate (Q(-)) obtained from the acid-base reaction of APZs with Me(4)N(+)C(6)H(5)O(-) to produce the dianion radical (Q(*)(2)(-)). Although the nitrogen atom interferes with direct conjugation between both rings by binding the quinone with the para-substituted ring, the UV-vis spectra of these compounds showed the existence of intramolecular electronic transfer from the respective aniline to the quinone moiety. (13)C NMR chemical shifts of the quinone atoms provided additional evidence for this electron transfer. These findings were also supported by linear variation in cathodic peak potentials (E(pc)) vs Hammett sigma(p) constants associated with the different electrochemical transformations: Q/Q(*)(-), Q(*)(-)/Q(2)(-) for APZms or HQ/HQH(2) and Q(-)/Q(*)(2)(-) for APZs. The electronic properties of model anilinebenzoquinones were determined at a B3LYP/6-31G(d,p) level of theory within the framework of the density functional theory. Our theoretical calculations predicted that all the compounds are floppy molecules with a low rotational C-N barrier, in which the degree of conjugation of the lone nitrogen pair with the quinone system depends on the magnitude of the electronic effect of the substituents of the aniline ring. Natural charges show that C(1) is more positive than C(4) although the LUMO orbital is located at C(4). Hence, if the natural charge distribution in the molecule controls the first electron addition, this should occur at carbon atom C(1). If the process is controlled by the LUMO orbitals, however, electron addition would first occur at C(4). For the APZms series susceptibility of the first reduction wave to the substitution effect (rho(pi) = 147 mV) is lower than that of the second reduction wave (rho(pi) = 156 mV). Thus, the first, one-electron transfer in the quinone system is controlled by the natural charge distribution of the molecule and therefore takes place at C(1).

One-day admission for major lung resections in septuagenarians and octogenarians: a comparative study with a younger cohort.

OBJECTIVES: The proportion of elderly patients presenting with a potentially resectable lung malignancy is increasing. Due to their greater operative risk, these patients are frequently offered a lesser resection, non-surgical treatment, or no treatment at all. The goal of this study is to determine whether septuagenarians and octogenarians undergoing video-assisted major lung resections benefit from an accelerated recovery program as much as younger patients, enabling them to be discharged after an overnight hospital stay. A short length of hospital stay, per se, does not represent the actual goal of this clinical care pathway. Instead, it should be considered as a measurement of how quickly functional ability is restored. METHODS: Of 65 consecutive patients who underwent major lung resections, 30 were 70 years of age or older (25 septuagenarians and five octogenarians; mean age, 75.7 years). Forty-six lobectomies, eight bilobectomies, and 11 pneumonectomies were performed using a video-assisted muscle-sparing minithoracotomy. In the elderly group, 24 lobectomies, three bilobectomies, and three pneumonectomies were performed. Patient and family education, multimodal analgesia, and an accelerated recovery program were implemented for all patients and the results were compared between the elderly group and the younger cohort. Discharge criteria included: (a), pain controlled with oral analgesics; (b), clear lungs in chest radiograph and without evidence of pneumothorax with the chest tube off suction; (c), independent ambulation; (d), adequate oxygenation; and (e), patient's acceptance and with home support. Whenever these criteria were met, regardless of how early or late during the hospital stay, the patient was released from the hospital. RESULTS: There were no deaths within 30 days of the operation and only three complications (one in the elderly group), and none of them altered the patients' clinical courses. The mean length of hospital stay for the whole group was 1.2 days (54 patients had an overnight hospital stay and two were outpatient procedures). The mean length of hospital stay for the elderly group was 1 day (27 patients had an overnight hospital stay and one was an outpatient procedure). None of the patients required conversion to a standard posterolateral thoracotomy and no patient required readmission related to an early discharge. CONCLUSIONS: These data show that it is feasible to create strategies to prevent or attenuate physiological derangements during surgery while performing major lung resections. As a result, an early recovery with few complications has been attained, allowing patients to consistently meet stringent discharge criteria after only an overnight hospital stay, even in the case of septuagenarians and octogenarians.

Stapling of an aortic arch aneurysm.

Saccular aneurysms of the aortic arch are usually managed with patch graft aortoplasty or with tube graft replacement. In either case, hypothermic circulatory arrest is necessary. The use of stapling devices has revolutionized pulmonary and gastrointestinal surgery; however, these instruments have rarely been used in aortic surgery except during thromboexclusion procedures. We present a simple and seemingly innovative stapling method that eliminates the need for circulatory arrest.

Extrathoracic subclavian internal thoracic artery bypass grafting.

Interval development of a significant stenosis at the origin of the left internal thoracic artery (LITA) after this vessel has been used to revascularize the anterior descending coronary artery may be an indication for reoperation. We present an extrathoracic approach to bypass the proximal segment of the LITA that allows patients with this lesion a quick recovery, short hospital stay, and early resumption of normal activity.

Nonlinear effects in the electrophoresis of a spherical colloidal particle.

The reduced electrophoretic mobility-reduced zeta potential relationship for a charged macroparticle is shown to be nonuniversal and to be highly nonlinear. In agreement with experimental results, a mobility reversal due to the macroion's charge inversion and a nonlinear dependence of the mobility on salt concentration is obtained.

Muscle-sparing minithoracotomy with intercostal nerve cryoanalgesia: an improved method for major lung resections.

To decrease incisional pain, morbidity, and length of hospital stay (LOS) and, hopefully, to reduce costs, most surgical specialties have turned to minimally invasive procedures to access the body cavities during commonly performed operations. Video-assisted thoracic surgery (VATS) has emerged as the standard approach for a number of diagnostic and therapeutic procedures in thoracic surgery. Major lung resections (lobectomy, bilobectomy, and pneumonectomy), however, can be performed through an incision similar in size to the utility or access thoracotomy used in VATS to remove the specimen. The purpose of this study was to compare an oblique muscle-sparing minithoracotomy with intercostal nerve cryoanalgesia with the standard posterolateral thoracotomy incision and VATS to perform major lung resections. Forty consecutive patients with bronchogenic carcinoma, operated on by a single surgeon, were chronologically divided into two groups, each with equivalent age, sex distribution, physiologic parameters, tumor size, and clinical stage. In addition, data were collected from a MEDLINE search of all published studies in which major lung resections were performed via VATS. The first group (group A, n = 20) underwent posterolateral thoracotomy to access the chest cavity, whereas the patients in the second group (group B, n = 20) underwent oblique minithoracotomy with intercostal nerve cryoanalgesia. Group B compared favorably with group A in LOS (P = 0.002), narcotic requirements (P = 0.001), morbidity (P = 0.042), and cost (P = 0.058). Group B also compared favorably with VATS major lung resection published data regarding LOS and morbidity.

Minimally invasive approach for pneumonectomy culminating in an outpatient procedure.

STUDY OBJECTIVE: To establish the effects of the use of a clinical pathway that includes a minimally invasive access among patients undergoing pneumonectomy. DESIGN: Prospective study from February to December of 1997. SETTING: A community hospital. PATIENTS: Five consecutive patients with a mean age of 60 years (range 43 to 74 years) with lung malignancies who required pneumonectomy. INTERVENTIONS: Clinical pathway based on patient education, a meticulous minimally invasive operation (oblique muscle-sparing minithoracotomy), intercostal nerve cryoanalgesia, and a quick postoperative resumption of physical activity. RESULTS: All five patients were extubated in the operating room. They all had unrestricted shoulder mobility in the recovery room, and none required intravenous narcotics after leaving this unit. All patients were out of bed the day of the operation, and one patient was able to ambulate freely only a few hours after the procedure. Four patients were discharged the day after surgery, and one patient was discharged the same day of the operation. None required readmission related to the procedure. CONCLUSION: This initial experience seems to indicate that the application of this clinical pathway in patients undergoing pneumonectomy greatly accelerates their recovery and, for a select group of patients, converts it into an outpatient procedure.