Stereotactic Body Radiotherapy in Latin America: Real-World Evidence of Health Outcomes

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is an ultrafractionated radiotherapy modality approach to treat oligometastatic disease. Randomized trials have shown significant benefit on overall survival and disease-free survival. In the last decade multiple studies have support efficacy and safety of this new technique. However, data from Latin America and Mexico are limited. In Mexico only 5% of facilities develop SBRT in daily practice. Therefore, the aim of this study was to investigate the real-world outcomes of applying SBRT for oligometastatic in a Mexico institution.

MATERIALS/METHODS

This study investigated a consecutive cohort of patients treated with SBRT. at Centro medico ABC in Mexico City (Mexico). Oligometastatic disease have been treated using different schedules from 30-60Gy/5-8 fractions (fx.). All p. were treated on LINAC (Novalis Tx), IGRT with ConeBeam CT and Exactrack. The study primary outcome was local control rates per lesion. Secondary outcomes included progression-free survival (PFS), overall survival (OS), and toxicity profile (CTCAE 3.0).

RESULTS

Between February 2015 and October 2022, 51 patients (p.) have been treated with SBRT in 71 lesions. The median follow-up was 17 months (2-60). Mean age was 59 years old (8-99), 1:1 sex ratio. primary tumor 21p. GI tumors, 10p. GU tumors, 6 p. sarcomas, 6 p. lung cancer, 6p., 5p. breast ca. and others 7p. locations treated were 21p. lung lesions, 16p. bone, 10p. liver, 6p. nodes and others (9p.). The average number of fractions and total dose prescribed was 5 (1-8)/38 Gy (18-60 Gy). Local response rates were complete response 24p. (33%), partial response 16p. (22%), stable 8p. (11%), progression 13p. (18%). Overall survival rate was 55 months. Acute toxicity grade 3 was observed in 2p. gastric ulcer surgically treated, 1p. liver disfunction (prior Child B). Late toxicity was observed in 2 p. painful lung fibrosis surgically resected.

CONCLUSION

Our results indicate that SBRT is effective (high local control and acceptable toxicity) for treating oligometastatic in a real-world scenario in Mexico.

Visceral leishmaniasis: diagnosis by ultrasound-guided fine needle aspiration of an axillary node

A 77-year-old woman presented with fever up to 39 degrees C and acute pain in the left upper quadrant and renal fossa. Full blood count and biochemical screen revealed a haemoglobin (Hb) of 9.8 g dl(-1), an increased erythrocyte sedimentation rate and an elevated lactate dehydrogenase, all other parameters were normal. Thoracic and abdominal CT demonstrated two enlarged lymph nodes in the left axilla, and splenic infarcts. Ultrasound-guided fine needle aspiration of one of the axillary lymph nodes revealed macrophages filled with leishmanias.

[Corynebacterium urealyticum in renal trasplantation. CT and sonography imaging characteristics of encrusted cistitis and pielitis]

PURPOSE

Its described three cases of Corynebacterium urealyticum (CU) infection in patients with renal transplantation and one of its most serious consequences: encrusted pyelitis and cystitis. It is explained the principal keys for its diagnosis, based in the appearance of alkaline pH in in urine analysis (alkaline urine), positives urinary cultures for CU, and the CT and US studies revealed the characteristic images of calcifications in the wall of renal pelvis and bladder.

PATIENTS

Three male patients with renal transplantation and CU infection that caused encrusted pyelitis in two of the cases and encrusted cystitis in one case.

RESULTS

Calcifications of the urinary tract were noticed in CT in all the patients. In two cases bladder stones were linear, and in the third case they were fundamentally coarse and placed in pelvis. The diagnosis suspicion showed by the images was confirmed by the use of prolonged urine cultures, necessary for detecting CU. All the patients were treated with vancomycin, with success in two of the cases and, finally needing surgery, and after loss of the graft, in the other case.

CONCLUSION

Encrusted pyelitis and cystitis are cronic and severe infections of the urinary tract. Calcic struvite incrustations in the urothelium are characteristics of this infection. CT is a choice technique for the diagnosis and followup of the calcifications after treatment.

Sterol composition of gonad, muscle and digestive gland of Pecten maximus from Málaga (South Spain)

Sterol composition and content and their seasonal variations over 18 months were investigated in adductor muscle, digestive gland and gonads of Pecten maximus. Sterols were isolated by Silicagel 60 thin layer chromatography and identified by gas chromatography/mass spectrometry. Eleven sterols were identified, with cholesterol, brassicasterol, 24-methylenecholesterol and 22-trans-dehydrocholesterol being the principal components. The same sterols were found in all three tissues independent of season. The relative amounts of each sterol present in each tissue differed. Total sterol levels in gonad and muscle were higher than in digestive gland. Statistically significant differences (P<0.05) were found between the concentrations of each of the sterols isolated from the gonad or muscle and digestive gland. The seasonal variations in the sterol content of the gonad seem be related to the reproductive cycle, while the sterol content of the digestive gland appears to be linked to diet, mainly diatoms or dinoflagellates. The muscle sterol content showed minor changes throughout the year.

[Knowledge about breast feeding and attitude to breast feeding in public of a group of high school students in the Caguas Educational Region]

The objective of this study was to identify the knowledge and attitudes towards breastfeeding and towards breastfeeding in public of a group of high school students in the Caguas Educational Region. The study design was a descriptive survey. The sample consisted of 101 students registered in the Health Course. A self administered questionnaire was used to gather the information. Descriptive and inferential statistics (chi square and t test) were used for data analysis. We found that the majority of the participants have the intention of breastfeeding or supporting breastfeeding for their children. We found, nevertheless, that there were misconceptions regarding breastfeeding which could develop into barriers for effective breastfeeding. It was also observed that support for breastfeeding varied depending on the location where it took place. Support was greater if it was done in non-public places. In conclusion, it became evident that there is a need for educational programs with correct information on breastfeeding and the importance of breastfeeding in public.

[The use of ELISA and ultramicro ELISA in identifying a Coxsackie A9 strain isolated during the epidemic of neuropathy in Cuba]

During 1993 an outbreak of epidemic neuropathy characterized by 2 major clinical forms: the optic neuropathy and peripheral neuropathy, occurred in our country. Although the cause of the disease was considered to be multifactorial (mainly due to neurotoxic agents and to nutritional deficiency) an Enterovirus was isolated from the cerebrospinal fluid of a patient (strain 47/93, IPK) which was subsequently classified as a Coxsackie A9 virus (Cox A9) by the neutralization test, and using pools of Lim Benyesh Melnick (LBM) serum. Results obtained during the application of ELISA and ultramicro ELISA techniques for the identification of this agent from the supernatant of a culture of infected cells are reported, as well as the detection of antibodies to the strain found within populations with high and low incidence rates of the disease.

[ELISA identification of agents causing light cytopathic effect isolated during the neuropathy outbreak in Cuba, 1991]

Using as a reference the strain 44/93 isolated during the neuropathy epidemic in 1991 and characterized as a producer of a light cytopathic effect (L-CPE), it was possible the standardization of an ELISA for the fast identification of other strains with similar effect. The assay consisted in a sandwich-type ELISA where the conditions selected for each reactive (10 micrograms/mL for the coating antibody, 1 mg/mL for the antigen, and dilution 1/2,000 for the conjugate) allowed to have an adequate discrimination between the antigen and the antigen control for the reference strain used. The evaluation of a panel of reference viral strains and of other L-CPE producing strains showed a 100% of coincidence between this method and the isolation in cellular culture. The results obtained permit us to recommend the use of this assay as a more precise alternative to identify these agents.

[Estimation of IgG Adenovirus antibody titers using a standard curve and an indirect ultramicroELISA essay]

It was possible to standardize a procedure which combined an indirect microELISA assay with a standard curve and that allowed to estimate the titre of IgG antibodies to Adenovirus in samples of human serum, using only one dilution of these. Based on the end-point titre previously determined for a panel of 117 serum samples, we selected 90 of these samples (r2 = 0.98) to build 4 standard curves that related the natural logarithm of the fluorescence responses to the natural logarithm of the end-point titre for a wide range of serum dilutions (1:40 = 1:320). It was selected the curve corresponding to serum dilution 1:40 (r2 = 0.81), which made possible an optimum utilization of those accessories designed to handle the volumes in the ultramicro range and, therefore, the automation of the whole procedure. The results obtained as regards the complement fixation test (100% of sensitivity and 97.3% of specificity) support the use of this method in our laboratory as a complementary tool to carry out seroepidemiological studies on a large scale and with diagnostic ends.

Inbred mouse strains differ in the regulation of startle and prepulse inhibition of the startle response

The startle response and adaptability of the startle response (prepulse inhibition and habituation) have been observed in animals. The studies reported here screened 8 inbred mouse strains to determine whether genetic factors influence these behaviors. Strain differences were found in both the sensitivity to acoustic startle and the magnitude of both the auditory and tactile startle as well as the magnitude of prepulse inhibition (PPI) of both tactile and acoustic startle. Neither the 2 startle responses nor the 2 forms of PPI were significantly correlated with one another, suggesting that different genes regulate these 2 forms of startle and PPI. Acoustic-acoustic PPI was significantly correlated, however, with hippocampal auditory gating (TC ratio) suggesting an overlap in the genes that regulate these 2 forms of sensory gating.

[Description of a population with four associated cardiovascular risk factors and the relationship of these with basal insulinemia]

OBJECTIVES

To describe patients who have four cardiovascular risk factors linked: hypertension, carbohydrate metabolic disturbances, overweight and dyslipaemia. To determine basal insulin levels.

DESIGN

A descriptive crossover study.

SETTING

Tórtola Health Centre, East Valladolid.

PARTICIPANTS

Of the 6,950 patients with medical records and over 45, 76 cases met the 4 factors. An appointment was made by phone to determine basal insulinaemia.

RESULTS

Average age was 64.38; 75% were women. 92.1% were non-smokers and 26.3% moderate consumers of alcohol. 43.4% were intolerant; the rest, diabetics. 52.6% received no drugs treatment. The commonest monotherapy was sulfonylureas and insulin. Mean BMI was 30.20, and obesity, 63.2%. The commonest hypertension drugs were ACEIs and diuretics, as monotherapy: both together was the commonest association. All the patients were hypercholesterolaemic. 25% were on antilipaemiant treatment, the commonest fibrates. All the patients were on a prescribed diet. 34.2% had hyperuricaemia. Mean insulinaemia was 12.63. There were 5 cases with high values.

CONCLUSIONS

There is 1.09% prevalence of the four cardiovascular risk factors linked. High levels of basal insulin were only found in 5 patients. Biguanidines were not used in treatment of DM II. There were more obese patients vs those with overweight. Failure of diet to control dyslipaemias. Insulin should not be systematically determined in primary care because it is of little use.

[Changes in hemoglobin in patients with hemolytic anemia]

Hb alterations studied throughout 2 years in 129 patients are reported, these patients had hemolytic anemia or the possibility of a hemoglobinopathy : 5 were heterozygotes to thalassemia b; 3 were compound-heterozygote of thalassemia a1 and thalassemia a2; 2 for thalassemia b and 2 for thalassemia b and Hb S; 2 homozygotes and 2 heterozygotes for Hb S; 2 was bearing unstable Hb and the other had Hereditary Persistence of Hb F. These results allow the conclusion that thalassemia is the Hb alteration which most frequently causes hemolytic anemia in our population and underscores the importance of the study of these pathologies in selected populations.

Risk of diarrhea during the first year of life associated with initial and subsequent colonization by specific enteropathogens

The incidence of colonization by enteropathogenic, enterotoxigenic, enteroinvasive, and enterohemorrhagic Escherichia coli (detected by DNA hybridization with specific radiolabeled probes), Salmonella sp., Shigella sp., Campylobacter jejuni, and rotavirus was related to the presence of diarrhea in a cohort of 75 rural infants followed longitudinally during the first year of life. The study was carried out between August 1985 and February 1987 in the village of Lugar Sobre la Tierra Blanca, in the state of Morelos, 180 km southwest of Mexico City. Intestinal colonization by specific enteropathogens was followed with fecal cultures taken every fortnight and every time a child had diarrhea. Pathogens isolated from cultures taken in the 48 hours prior to the initiation of the diarrheal episode were considered to be associated with the disease. Diarrhea was detected in 82% of the children with initial isolation of enterohemorrhagic E. coli and in 64% of the children with enteropathogenic E. coli or Shigella sp. The risk of diarrhea associated with the initial isolation of other pathogens was lower, at 41% for rotavirus and approximately 25% for enterotoxigenic E. coli, Salmonella sp., and C. jejuni. Initial colonization by the enteropathogens studied, whether or not they were associated with diarrhea, prevented disease, but not colonization by the same organism, when the children were reinfected during the first year of life. Enteropathogenic E. coli adherence factor, human or porcine heat-stable enterotoxins, fimbrial colonization factor antigens, and Shiga-like toxins I and II were important pathogenic characteristics related to the presence of diarrhea and to protection against subsequent infection by the same organisms.

Effect of hydralazine on intrapulmonary shunt

We compared the acute effects of bilateral arteriovenous may be related to levels of PvO2. The hydralazine-associated (p less than .05) decrease in resistance. Mixed venous oxygen fistulas to those of hydralazine infusion on hemodynamics and pulmonary gas exchange in dogs with pulmonary edema induced by administration of oleic acid. Oleic acid significantly (p less than .01) increased intrapulmonary shunt (Qsp/Qt) and pulmonary and systemic vascular resistance, and reduced cardiac output. Once the lesion stabilized, both opening the fistula and infusing hydralazine produced a similar and significant (p less than .01) increase in cardiac output, and a significant (p less than .05) decrease in resistance. Mixed venous oxygen tension (PvO2) closely followed the changes in cardiac output; however, PaO2 did not change. Qsp/Qt significantly (p less than .01) increased with the fistulas open and with hydralazine infusion. Closure of the fistulas or bleeding the animal at the end of the experiment reversed the changes in cardiac output and Qsp/Qt. The comparable increases in cardiac output and Qsp/Qt produced by opening the fistulas or infusing hydralazine may be related to levels of PvO2. The hydralazine-associated PvO2 increase indicates that this drug increased oxygen transport to the tissues even as Qsp/Qt became larger.

[Effect of chronic altitude hypoxia on the behavior of the respiratory center. Study on normal subjects living at the altitude of Mexico City (2,240 meters)]

Respiratory center (RC) output has been shown to be increased in hypoxemic Chronic Obstructive patients at sea level. In order to asses the separate role of chronic hypoxia on the RC output we studied 30 normal subjects all of them native and residents of Mexico City (altitude: 2,240 m, PaO2: 65-70 torr.). The parameters studied were: occlussion pressure (P0.1), mean inspiratory flow (Vi), and the ratio inspiratory time to total duration of the respiratory cycle (Ti/Ttot). The inspiratory impedance of the respiratory system as well as the minute ventilation (VE) and lastly to ensure isocapnic conditions, the end-tidal CO2 (PECO2), were also measured. These parameters were determined: 1) While breathing room air (RA), 2) after 30 min of breathing an inspired oxygen fraction (FiO2) of 30% and again 3) after 30 min of breathing and FiO2 of 100%. Fifteen of the subjects were studied on supine and the other 15 in the seated position. In most of the subjects the baseline (RA) values of P0.1 were found to be higher than those reported for normals at sea level. In every case, independent of body position, the P0.1 decreased (less than 0.01) to normal sea level values after 30 min of breathing O2 30%. Likewise, Vi and mechanical impedance also decreased (p less than 0.01) and no changes in Ti/Ttot were noted at this FiO2. No further changes occurred after breathing 100%. The above results show that: 1) The RC output in normal people at altitude (i.e. without mechanical abnormalities but with chronic hypoxia) is increased as compared to sea level.(ABSTRACT TRUNCATED AT 250 WORDS)

Variability between and within laboratories in the analysis of structural chromosomal abnormalities

The frequency of structural chromosomal aberrations in two samples (AM and PM of the same day) from each of nine normal subjects, cultured in two different laboratories, was studied by six observers. The results were analyzed in order to determine the relative importance of inter- and intralaboratory factors in the variability of chromosomal abnormalities. In addition to the difference in the frequency of the abnormalities between the subjects studied, there were differences due to observers from different laboratories (P less than 0.01), as well as between laboratories (P less than 0.01). These results could be explained in part by insufficient agreement between observers from different laboratories and by differences in the quality of the method used.

[Finding of anaerobic bacteria in blood cultures]

Out of the blood cultures sent to the Bacteriology Laboratory of Hospital del Niño DIF, during the period of one year, in 1.4% of samples, isolation of anaerobic bacteria was obtained. Isolation was more frequent in infants under one year of age, but specially in newborns. The species most frequently found were Propionibacterium acnes, Bacteroides melaninogenicus and Clostridium subterminale. The presence of this finding in blood cultures of infants is noted, but there is no purpose to establish a clinical relationship with the finding of this group of bacteria.