Influence of the correlation modeling period on the prediction accuracy of infrared marker-based dynamic tumor tracking using a gimbaled X-ray head

PurposeTo assess the utility of 10 s and 20 s modeling periods, rather than the 40 s currently used, in the clinical construction of practical correlation models (CMs) in dynamic tumor tracking irradiation using the Vero4DRT.MethodsThe CMs with five independent parameters (CM parameters) were analyzed retrospectively for 10 consecutive lung cancer patients. CM remodeling was performed two or three times per treatment session. Three different CMs trained over modeling periods of 10, 20, and 40 s were built from a single, original CM log file. The predicted target positions were calculated from the CM parameters and the vertical displacement of infrared markers on the abdomen (P_IR) during the modeling. We assessed how the CM parameters obtained over modeling periods of T s (T = 10, 20, and 40 s) were robust to changes in respiratory patterns after several minutes. The mimic-predicted target positions after several minutes were computed based on the previous CM parameters and P_IR during the next modeling. The 95th percentiles of the differences between mimic-predicted and detected target positions over 40 s (E95_robust,T: T = 10, 20, and 40 s) were then calculated.ResultsStrong correlations greater than 0.92 were observed between the E95_robust,20 and E95_robust,40 values. Meanwhile, irregular respiratory patterns with inconsistent amplitudes of motion created differences between the E95_robust,10 and E95_robust,40 values of ≥10 mm.ConclusionsThe accuracies of CMs derived using 20 s were almost identical to those obtained over 40 s, and superior to those obtained over 10 s.     

A comparative study of prostate PTV margins for patients using hydrogel spacer or rectal balloon in proton therapy

PurposeTo compare the planning target volume (PTV) margins needed for prostate patients who have used hydrogel spacer or rectal balloon during proton treatments.MethodTotal of 190 prostate patients treated with proton therapy during 2017 were selected for this study. Of these patients, 96 had hydrogel spacer injection and 94 patients had only rectal balloons insertion. All patients had implanted gold markers inside the prostate for daily target alignment. Post-treatment radigraphs were obtained to evaluate prostate intrafraction motion. The systematic and random components of patient setup residual error and prostate intrafraction motion error were obtained. PTV margins were calculated using the van Herk formula for both patient groups.ResultsFor setup residual error, the mean values in the superior-inferior (SI) direction and the variances in the left–right (LR) direction were statistically different between the two groups. For intrafraction motion, there were significant differences of the mean values in the SI direction and of the variances in both LR and anterior-posterior (AP) directions. The population PTV margins for hydrogel spacer group were 2.6 mm, 3.3 mm, and 1.6 mm in LR, SI, AP directions, respectively. For the rectal balloon group, the PTV margins were 2.1 mm, 3.1 mm, and 2.0 mm in LR, SI, AP directions, respectively.ConclusionStatistically significant differences were observed in the patient setup and prostate intrafraction motion errors of the two patient groups. However, under the current protocol of bladder preparation and daily marker-based x-ray image-guidance, population PTV margins were comparable between the two patient groups.     

Local control rates in stereotactic body radiotherapy (SBRT) of lung metastases associated with the biologically effective dose

AimTo evaluate dose differences in lung metastases treated with stereotactic body radiotherapy (SBRT), and the correlation with local control, regarding the dose algorithm, target volume and tissue density.BackgroundSeveral studies showed excellent local control rates in SBRT for lung metastases, with different fractionation schemes depending on the tumour location or size. These results depend on the dose distributions received by the lesions in terms of the tissue heterogeneity corrections performed by the dose algorithms.Materials and methodsForty-seven lung metastases treated with SBRT, using intrafraction control and respiratory gating with internal fiducial markers as surrogates (ExacTrac, BrainLAB AG), were calculated using Pencil Beam (PB) and Monte Carlo (MC) (iPlan, BrainLAB AG).Dose differences between both algorithms were obtained for the dose received by 99% (D_99%) and 50% (D_50%) of the planning treatment volume (PTV). The biologically effective dose delivered to 99% (BED_99%) and 50% (BED_50%) of the PTV were estimated from the MC results. Local control was evaluated after 24 months of median follow-up (range: 3–52 months).ResultsThe greatest variations (40.0% in ΔD_99% and 38.4% in ΔD_50%) were found for the lower volume and density cases. The BED_99% and BED_50% were strongly correlated with observed local control rates: 100% and 61.5% for BED_99% > 85 Gy and <85 Gy (p < 0.0001), respectively, and 100% and 58.3% for BED_50% > 100 Gy and <100 Gy (p < 0.0001), respectively.ConclusionsLung metastases treated with SBRT, with delivered BED_99% > 85 Gy and BED_50% > 100 Gy, present better local control rates than those treated with lower BED values (p = 0.001).     

Retrospective assessment of a single fiducial marker tracking regimen with robotic stereotactic body radiation therapy for liver tumours

AimTo investigate tumour motion tracking uncertainties in the CyberKnife Synchrony system with single fiducial marker in liver tumours.BackgroundIn the fiducial-based CyberKnife real-time tumour motion tracking system, multiple fiducial markers are generally used to enable translation and rotation corrections during tracking. However, sometimes a single fiducial marker is employed when rotation corrections are not estimated during treatment.Materials and methodsData were analysed for 32 patients with liver tumours where one fiducial marker was implanted. Four-dimensional computed tomography (CT) scans were performed to determine the internal target volume (ITV). Before the first treatment fraction, the CT scans were repeated and the marker migration was determined. Log files generated by the Synchrony system were obtained after each treatment and the correlation model errors were calculated. Intra-fractional spine rotations were examined on the spine alignment images before and after each treatment.ResultsThe mean (standard deviation) ITV margin was 4.1 (2.3) mm, which correlated weakly with the distance between the fiducial marker and the tumour. The mean migration distance of the marker was 1.5 (0.7) mm. The overall mean correlation model error was 1.03 (0.37) mm in the radial direction. The overall mean spine rotations were 0.27° (0.31), 0.25° (0.22), and 0.23° (0.26) for roll, pitch, and yaw, respectively. The treatment time was moderately associated with the correlation model errors and weakly related to spine rotation in the roll and yaw planes.ConclusionsMore caution and an additional safety margins are required when tracking a single fiducial marker.     

Transvenous lead extraction on uninterrupted anticoagulation: A safe approach?

IntroductionCurrent guidelines advocate reviewing peri-procedural anticoagulation on individual case basis for transvenous lead extraction (TLE). We investigated the safety of TLE on uninterrupted warfarin with therapeutic INR.MethodsRetrospective registry of consecutive patients undergoing TLE on uninterrupted warfarin (Warfarin Group) across two centres. Age and sex matched controls not on anticoagulation (No-Warfarin Group) and undergoing TLE over the same time-period were included. Both groups were compared over one-year.Results121 TLEs over 18-months. 22 patients on uninterrupted anticoagulation were compared to 22 controls. Groups were well matched for baseline demographics other than INR. Warfarin group had mean INR of 2.2 ± 0.6 (range 2–3.5). Primary end point was procedural safety and efficacy. Amongst cases, 43/45 (96%) leads were removed in their entirety compared to 37/40 (93%) in controls (p = 0.66). In the cases, these included 44% defibrillator, 47% pace-sense and 9% CS leads of average duration 7yrs. There was no reported tamponade, haemothorax or procedural mortality in either group. One patient amongst cases required inotropic support while two patients amongst controls had device-site haematomas. No significant difference reported in Hb drop post-procedure or overall complication rate between the groups (p = 0.11,0.32). Cox regression showed a significant association between procedural success and device infection, number of leads extracted, serum creatinine (p = 0.03, 0.04, 0.02). Over a 1-year follow-up, there was lead displacement in one case and one control had infection of the re-implanted device.ConclusionTLE can be carried out safely in anticoagulated patients with therapeutic INRs. Larger multicentre studies are required to confirm these findings.     

Time and frequency to observe fiducial markers in MLC-modulated fields during prostate IMRT/VMAT beam delivery

ObjectiveThis work investigates the time and frequency to observe fiducial markers in MLC-modulated fields during intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) beam delivery for real-time prostate localization.MethodsThirty seven prostate patients treated with IMRT or VMAT were included in this retrospective study. DRR images were generated for all MLC segments/control points using the TPS. The MLC leaf pattern of each control point was overlaid on the DRR, and the number of fiducials within the MLC opening was analyzed. EPID images of fiducials in a pelvic phantom were obtained to demonstrate the fiducial visibility during modulated beam delivery.ResultsGold fiducials were visible on EPID images. The probability of seeing a number of fiducials within the MLC opening was analyzed. At least one fiducial was visible during 42 ± 2% and 52 ± 2% beam-on time for IMRT of the prostate with and without lymph nodes, and during 81 ± 4% and 80 ± 5% beam-on time for VMAT of the prostate with and without lymph nodes, respectively. The mean time interval to observe at least one fiducial was 8.4 ± 0.7 and 5.9 ± 0.5 s for IMRT of the prostate with and without the lymph nodes, respectively, and 1.6 ± 0.1 s for VMAT prostate patients. The estimated potential dosimetric uncertainty was 7% and 2% for IMRT and VMAT, respectively.ConclusionsOur results demonstrated that the time and frequency to observe fiducial markers in MLC-modulated fields during IMRT/VMAT beam delivery were adequate for real-time prostate localization. The beam’s eye view fiducial positions could be used for intrafractional target monitoring and motion correction in prostate radiotherapy.     

Interplay between Caveolin-1 and body and tumor size affects clinical outcomes in breast cancer

BackgroundCaveolin-1 (CAV1) is associated with cholesterol-rich membrane raft domains and is a master regulator of cell signaling and membrane transport. Here, we investigated CAV1’s role in cellular compartments of breast cancer in relation to signaling pathways, clinicopathological features, and clinical outcomes.MethodsCAV1 levels were evaluated with immunohistochemistry in cytoplasm of invasive tumor cells and stromal cells in tumor tissue microarrays from a cohort of 1018 breast cancer patients (inclusion 2002–2012, Sweden). Cytoplasmic and stromal CAV1 were categorized as positive/negative and strong/not strong, respectively. CAV1 expression in relation to clinical outcomes was assessed with Cox regression. Investigations into CAV1 functional pathways was conducted in the STRING, GOBO, and TCGA databases.ResultsCAV1 expression was associated with non-luminal subtypes, cell cycle control, inflammation, epithelial-mesenchymal transition, and the IGF/Insulin system. Generally, CAV1 was not associated with recurrence risk. Stromal CAV1’s impact on recurrence risk was modified by BMI ≥25 kg/m² (P_interaction = 0.002), waist ≥80 cm (P_interaction = 0.005), and invasive tumor size (pT2/3/4) (P_interaction = 0.028). In low-risk patients only, strong stromal CAV1 significantly increased recurrence risk (HRs_adj ≥1.61). In all patients, positive cytoplasmic CAV1 conferred >2-fold risk for contralateral disease HR_adj 2.63 (95% CI 1.36–5.10). Strong stromal CAV1 conferred nearly 2-fold risk for locoregional recurrence HR_adj 1.88 (95% CI 1.09–3.24).ConclusionsCAV1’s prognostic impact depended on its localization, anthropometric, and tumor factors. Stromal CAV1 predicted high recurrence risk in a group of supposedly ‘low-risk’ patients. Cytoplasmic CAV1 predicted metachronous contralateral disease. If confirmed, CAV1 could be used as treatment target and for risk-stratification.     

Asociación de la fuerza muscular con marcadores tempranos de riesgo cardiovascular en adultos sedentarios

ObjectiveTo assess the association between muscle strength and early cardiovascular risk (CVR) markers in sedentary adults.Materials and methodsA total of 176 sedentary subjects aged 18-30 years were enrolled. Body mass index and fat percentage were calculated, and waist circumference, grip strength by dynamometry, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and maximal oxygen uptake by VO_2max were measured as CVR markers. A multivariate logistic regression analysis was used to assess associations between muscle strength and CVR markers.ResultsInverse correlations were found between muscle strength and adiposity (r = -.317; P = .001), waist circumference (r = -.309; P = .001), systolic blood pressure (r = -.401; P = .001), and mean arterial pressure (r = -.256; P = .001). Subjects with lower levels of muscle strength had a 5.79-fold (95% CI 1.57 to 9.34; P = .008) risk of having higher adiposity levels (≥ 25%) and a 9.67-fold (95% CI = 3.86 to 19.22; P < .001) risk of having lower physical capacity values for VO_2max (≤ 31.5 mL/kg/min^-1).ConclusionsIn sedentary adults, muscle strength is associated to early manifestations of CVR. It is suggested that muscle strength testing is added to routine measurement of VO_2max and traditional risk factors for prevention and treatment of cardiovascular risk.     

Purification and characterization of trypsin-like enzymes from North Pacific krill (<Emphasis Type="Italic">Euphausia pacifica</Emphasis>)

Two trypsin-like enzymes (TLEs) were purified from North Pacific krill (Euphausia pacifica) by ammonium sulfate precipitation, ion-exchange and gel-filtration chromatography. The purified enzymes were identified as trypsins by LC-ESI-MS/MS analysis. The relative molecular mass of TLE I and TLE II were 33 and 32.3 kDa, respectively, with isoelectric points of 4.5 and 4.3, respectively. The TLEs showed excellent thermal stable in the crude extract and the purified TLEs were active over a wide pH (6.0–11.0) and temperature (10–70°C) range. Compared with trypsins from other organisms, the purified TLEs had physiological efficiencies of 1.6–6.7-fold. The difference in Arg, Ile and Asp content might explain why E. pacifica TLEs have good thermal stability and physiological efficiency.     

Genetic diversity and population structure of the Asian green mussel Perna viridis in South China Sea based on microsatellite markers

The green mussel, Perna viridis is ecologically and economically important in the coastal region of the South China Sea. Determining its population genetic structure at this fine geographic scale will help sustainable management of natural stocks. In this study, we examined the genetic diversity and population genetic structure of P. viridis from four locations in the South China Sea (n = 45–48) using nine microsatellite loci. The results showed moderate levels of genetic diversity in all four samples (mean A = 13.222–14.000, mean A_e = 7.092–7.571, mean A_r = 12.894–13.746, mean H_o = 0.596–0.656, mean H_e = 0.690–0.733) and a large effective population size estimate for the pooled sample (total N_e estimates = infinity, 95% CI = 1869.0-infinity). We did not detect any sign of recent bottleneck events in P. viridis populations in the South China Sea. The conventional and a model-based analysis reveal low, non-significant genetic divergence among the four samples (F_ST = − 0.001–0.005, P > 0.05/6). The results obtained from this study can provide valuable genetic information for the conservation and fishery management of P. viridis by retaining the high N_e estimates.     

Comparison of CT artifacts and image recognition of various fiducial markers including two types of thinner fiducial markers for CyberKnife treatment

AimThe aim of the study was to evaluate computed tomography (CT) artifacts and image recognition of the CyberKnife system. Regarding fiducial markers, VISICOIL of 0.5 mm × 5.0 mm and 0.75 mm × 5.0 mm, ball-shaped Gold Anchor (GA) of 0.28 mm × 10 mm and 0.28 mm × 20 mm, were compared with the standard cylinder marker of 0.9 mm × 3.0 mm (ACCULOC).BackgroundRecently, various kinds of commercial fiducial markers have been available in CyberKnife treatment.Materials and methodsThe CT images of a water equivalent gel with each fiducial marker were acquired for the evaluation of CT artifacts. The evaluation was performed using the standard deviation of Hounsfield Unit (HU) value for a rectangle region near the fiducial marker. Then, to evaluate the image recognition, each fiducial marker was located to overlap in the target locating system (TLS) for the two sites; the vertebral bone and the pubic bone.ResultsFor CT artifacts, the standard deviations of the VISICOIL of 0.5 mm × 5.0 mm was the smallest. The image recognition of four fiducial markers had a value close to the standard cylinder marker and was feasible for common use, but was slightly poorer when using GA of 0.28 mm × 10 mm in the dynamic conditions.ConclusionOur results indicated that VISICOIL 0.5 × 5.0 mm and the GAs can be used nearly always for CyberKnife treatment in spite of their much thinner needles than those of cylinder types.     

Diabetes Status and Race are Associated With Cardiovascular Risk Markers in Obese Adolescents

ObjectiveThe objective of this study was to evaluate differences in cardiovascular disease (CVD) risk markers in obese adolescents based on diabetes status and race in order to improve risk-reduction intervention strategies.MethodsThis was a retrospective, cross-sectional study of obese adolescents, age 10 to 21 years, who were evaluated at Children’s of Alabama between 2000 and 2012. Subjects were classified by glycated hemoglobin (HbA_1c) as having normoglycemia, prediabetes, or type 2 diabetes mellitus (T2DM).ResultsThere were a total of 491 African American (AA) or Caucasian American (CA) subjects. Body mass index was not different between HbA_1c and racial groups. Compared to subjects with normoglycemia or prediabetes, subjects with T2DM had higher levels of total cholesterol (TC) (178.6 ± 43.8 mg/dL vs. 161.5 ± 32.5 mg/dL vs. 162.4 ± 30.6 mg/dL; P < .0001) and low-density-lipoprotein cholesterol (107.4 ± 39.2 mg/dL vs. 97.0 ± 31.0 mg/dL vs. 97.5 ± 26.9 mg/dL; P = .0073). Compared with AA subjects, CA subjects had lower high-density-lipoprotein cholesterol (HDL-C) levels (40.4 ± 10.4 mg/dL vs. 44.3 ± 11.9 mg/dL; P = .0005) and higher non-HDL-C levels (129.6 ± 36.2 mg/dL vs. 122.5 ± 37.5 mg/dL; P = .0490). Of the characteristics studied, HbA_1c had the most significant positive association with dyslipidemia and was strongly correlated with both TC (β, 4.21; P < .0001) and non-HDL-C (β, 4.3; P < .0001).ConclusionObese adolescents with T2DM have more abnormal lipoprotein profiles than those with normoglycemia or prediabetes. Obese CA adolescents have more abnormal lipids than obese AA adolescents. HbA_1c was the characteristic most highly associated with abnormal lipoprotein profiles in our subjects. Our results show that CVD risk markers in obese adolescents vary by race and HbA_1c concentration. (Endocr Pract. 2015;21:165-173)     

Endoscopic Gold Fiducial Marker Placement into the Bladder Wall to Optimize Radiotherapy Targeting for Bladder-Preserving Management of Muscle-Invasive Bladder Cancer: Feasibility and Initial Outcomes

ResultsBetween 1/2007 and 7/2012, a total of 89 markers (3–5 per tumor site) were placed into 18 patients of mean age 73.6 years. Two patients elected cystectomy before starting treatment; 16/18 completed chemo-radiotherapy. All (100%) markers were visible with all on-table (portal, cone-beam CT), fluoroscopy, plain-film, and CT-scan imaging. In two patients, 1 of 4 markers placed at the tumor site fell-out (voided) during the second half of radiotherapy. All other markers (80/82, 98%) were present through the end of radio-therapy. No intraoperative (e.g. uncontrolled bleeding, collateral injury) or post-operative complications (e.g. stone formation, urinary tract infection, post-TUR hematuria >48 hours) occurred. Use of micro-tined fiducial tumor-site markers afforded a 2 to 6-fold reduction in bladder-area targeted with high-dose radiation.DiscussionPlacement of the micro-tined fiducial markers into the bladder was feasible and associated with excellent retention-rate and no complications. All markers were well-visualized during radiotherapy with all imaging modalities. Bladder fiducial markers improve targeting accuracy, and may increase treatment efficacy and reduce morbidity from collateral radiation.     

Nonobese Young Females with Polycystic Ovary Syndrome Have Nutritive Microvascular Dysfunction: A Pilot Study

ObjectiveTo investigate nutritive microvascular function in young nonobese females with polycystic ovary syndrome (PCOS) and to correlate microvascular reactivity with sex steroids, inflammatory markers, and metabolic variables.MethodsFourteen nonobese females with PCOS (24.6 ± 2.7 years, body mass index [BMI] 23.7 ± 3.1 kg/ m²) and 13 age- and BMI-matched controls (22.8 ± 2.3 years, 22.5 ± 3.4kg/m2) underwent anthropometric, hormonal, and microvascular evaluations. The main outcome measures were capillary density, red blood cell velocity (RBCV) at resting and peak during postocclusive reactive hyperemia (RBCV_max), and time taken to reach RBCV_max (TRBCV_max).ResultsSubjects with PCOS had lower RBCV and higher TRBCV_max compared to controls, respectively (0.237 [0.220-0.324] vs. 0.362 [0.297-0.382] mm/s, F < .01) and (5 [5-6] vs. 4 [3-5] s, P < .05]. The free androgen index (FAI) and sex hormone-binding globulin (SHBG) level were different between groups. FAI correlated to RBCV_max (ρ = -0.49, P < .05) and to TRBCV_max (ρ = 0.41, P < .05). SHBG correlated with RBCV_max (ρ = 0.52, P < .01) while estradiol (E₂) levels correlated with RBCV (ρ = 0.80, P < .001) and RBCV_max (ρ = 0.46, P < .05).ConclusionMicrovascular dysfunction characterized by reduced RBCV_maxand prolonged TRBCV_maxwas present in young, nonobese PCOS subjects. FAI was associated with observed impairments, suggesting a possible common mechanism linking sex hormones and microvascular dysfunction. (Endocr Pract. 2014;20:1281-1289)     

Polymorphic microsatellites identified by cross-species amplifications in the European Coot Fulica atra

We tested the cross-amplification of 26 microsatellites developed for passerines and an additional three developed for Gallinula species in eight European Coots from two populations. Sixteen microsatellite markers successfully amplified, of which nine were polymorphic with 2–6 alleles (mean 3.7 alleles) and an expected heterozygosity (H _e) ranging from 0.375 to 0.805 (mean H _e = 0.589). On average, we found 2.22 alleles/locus and a mean H _e of 0.440 in one nest, and 2.56 alleles/locus and a mean H _e of 0.494 in the other one. These nine polymorphic markers could be of potential use in studies of genetic variability, population structure and reproductive strategy of European Coots.     

Highly differentiated populations of the narrow endemic and endangered species Primula cicutariifolia in China,revealed by ISSR and SSR

The perennial herb Primula cicutariifolia Pax is an endangered and endemic species with narrow distribution in eastern Anhui and Zhejiang provinces of China. In this study, the levels of genetic variation and the pattern of genetic structure in five natural populations of P. cicutariifolia were assessed by inter-simple sequence repeats (ISSR) and simple sequence repeat (SSR) markers. Both markers revealed that there was remarkably low genetic variation within populations (e.g., H_e = 0.19 and 0.18, for ISSR and SSR respectively) and high differentiation among populations (G_ST = 0.714 and 0.611; Φ_ST = 0.698 and 0.599, for ISSR and SSR respectively). The level of population genetic diversity was correlated to population size only detected by ISSR markers. The genetic structure of P. cicutariifolia may be explained by limited gene flow that was caused by habitat fragmentation and limited seeds and pollen dispersal ability, self breeding system and biennial life form. To protect and avoid disappearance of P. cicutariifolia, much more attentions should be paid to protect all the remnant populations and their habitats, and three management units, i.e. Tianmushan, Damodao, and Panan units, were proposed.     

Genome‐wide association study discovered candidate genes of Verticillium wilt resistance in upland cotton (Gossypium hirsutum L.)

Verticillium wilt (VW), caused by infection by Verticillium dahliae, is considered one of the most yield‐limiting diseases in cotton. To examine the genetic architecture of cotton VW resistance, we performed a genome‐wide association study (GWAS) using a panel of 299 accessions and 85 630 single nucleotide polymorphisms (SNPs) detected using the specific‐locus amplified fragment sequencing (SLAF‐seq) approach. Trait–SNP association analysis detected a total of 17 significant SNPs at P < 1.17 × 10^–5 (P = 1/85 630, –log₁₀P = 4.93); the peaks of SNPs associated with VW resistance on A10 were continuous and common in three environments (RDIG2015, RDIF2015 and RDIF2016). Haplotype block structure analysis predicted 22 candidate genes for VW resistance based on A10_99672586 with a minimum P‐value (–log₁₀P = 6.21). One of these genes (CG02) was near the significant SNP A10_99672586 (0.26 Mb), located in a 372‐kb haplotype block, and its Arabidopsis AT3G25510 homologues contain TIR‐NBS‐LRR domains that may be involved in disease resistance response. Real‐time quantitative PCR and virus‐induced gene silencing (VIGS) analysis showed that CG02 was specific to up‐regulation in the resistant (R) genotype Zhongzhimian2 (ZZM2) and that silenced plants were more susceptible to V. dahliae. These results indicate that CG02 is likely the candidate gene for resistance against V. dahliae in cotton. The identified locus or gene may serve as a promising target for genetic engineering and selection for improving resistance to VW in cotton.     

Possibility of limiting the un-justified irradiation in 131I therapy of Graves' disease: A thyroid mass-reduction based method for the optimum activity calculation

ObjectiveIn Graves' disease therapy, the amount of ¹³¹I is usually decided following two different modalities: the administration of a fixed activity or of an activity individually calculated based on a fixed value of target absorbed dose. Although the effectiveness of each of these approaches is good (about 80% of patients cured), the ALARA principle must be applied avoiding the un-justified radioactivity to the patient himself, the people living/working near him and the environment. In this paper a new approach to the ¹³¹I therapy in Graves' disease, based on the optimum value of the final thyroid mass, is presented.Design97 Graves' disease patients (29 males) were randomly assigned into three groups (GR1, GR2, GR3). In two of them (GR1, GR3) the radioiodine administering activity was calculated based on two fixed thyroid absorbed dose values (100 Gy for GR1; 400 Gy for GR3), in GR2 it was calculated based on the desired final optimum thyroid mass value m_f = 0.24 m₀/U₀ResultsThe rate of cured patients are 48% (GR1), 97% (GR2) (z-test, p < 0.001) and 97% (GR3). The average activity administered to GR2 (393 ± 157 MBq) is lower than that administrered to GR3 patients (524 ± 201 MBq) (p = 0.007, two-tails unpaired t-test); the thyroid absorbed dose in GR2 (262 ± 78 Gy) is lower than in GR3 patients (407 ± 23 Gy) (p < 0.001, two-tails unpaired t-test).ConclusionOur results demonstrate that the thyroid-mass based approach optimizes the treatment avoiding an un-justified excess or a not-effective too low activity without time and resources consuming.     

Gamma and X-ray irradiation as a phytosanitary treatment against various stages of Planococcus lilacinus (Hemiptera: Pseudococcidae)

The cacao mealybug, Planococcus lilacinus Cock, is an important quarantine pest. Infested commodity should be subject to appropriate phytosanitary treatment, while irradiation is recommended for the cacao mealybug. Radio-tolerance comparison tests were conducted on the crawler, nymphs, and adult females of P. lilacinus at the X-ray radiation doses of 40, 80, and 120 Gy, respectively. The results showed that irradiation had a strong effect on preventing of development and reproduction; the adult female stage was identified as the most tolerant. During the following dose–response tests, among young and late females X-ray-irradiation (20–100 Gy), the late females were most tolerant when preventing F₁ generation 2nd instars emergence was used as the evaluation criterion. Minimum absorbed dose and its 95 % fiducial limits to provide probit 9 efficacy at 95 % confidence level (100 % mortality/inhibition in an estimated population of 93,616 individuals) were 131.5 Gy (122.5, 142.6 Gy) and 144.4 Gy (132.7, 159.4 Gy), estimating from the probit analysis on dose-mortality data of 1–30 and 1–10-day-old neonates laid by late females, respectively. In the large-scale confirmatory tests, a total of estimating 97,384 late females of P. lilacinus rearing on the pumpkins fruits were irradiated with gamma-ray at the target dose of 135 or 145 Gy (measured doses 126.1–163.0 Gy), which resulted in no F₁ generation 2nd nymphs developing during a 6-week post-treatment period. The treatment efficacy calculated is 99.9969 % at the 95 % confidence level. Therefore, a minimum absorbed dose of 163.0 Gy is recommended for phytosanitary treatment of P. lilacinus in infested commodity.