Evaluation and comparison of second-check monitor unit calculation software with Pinnacle3 treatment planning system.

The purpose of this study was to evaluate and compare the accuracy of dose calculations in second check softwares (Diamond, IMSure, MuCheck, and RadCalc) against the Phillips Pinnacle3 treatment planning system. Eighteen previously treated patients' treatment planning files consisting of a total of 204 beams were exported from the Pinnacle3 TPS to each of the four second check software. Of these beams, 145 of the beams used were IMRT plans while 59 were VMAT arcs. The values were represented as a percent difference between primary and secondary calculations and used for statistical analysis. Box plots, Pearson Correlation, and Bland-Altman analysis were performed in MedCalc. The mean percent difference in calculated dose for Diamond, IMSure, MuCheck, and RadCalc from Pinnacle3 were -0.67%, 0.31%, 1.51% and -0.36%, respectively. The corresponding variances were calculated to be 0.07%, 0.13%, 0.08%, and 0.03%; and the largest percent differences were -7.9%, 9.70%, 9.39%, and 5.45%. The dose differences of each of the second check software in this study can vary considerably and VMAT plans have larger differences than IMRT. Among the four second check softwares, RadCalc values has shown a high agreement on average with low variation, and had the smallest percent range from Pinnacle3 values. The closest in average percent difference from the Pinnacle3data was the IMSure software, but suffered from significantly larger variance and percent range. The values reported by Diamond and MuCheck had significantly high percent differences with TPS values.

Radiobiological evaluation of intensity modulated radiation therapy treatments of patients with head and neck cancer: A dual-institutional study.

In clinical practice, evaluation of clinical efficacy of treatment planning stems from the radiation oncologist's experience in accurately targeting tumors, while keeping minimal toxicity to various organs at risk (OAR) involved. A more objective, quantitative method may be raised by using radiobiological models. The purpose of this work is to evaluate the potential correlation of OAR-related toxicities to its radiobiologically estimated parameters in simultaneously integrated boost (SIB) intensity modulated radiation therapy (IMRT) plans of patients with head and neck tumors at two institutions. Lyman model for normal tissue complication probability (NTCP) and the Poisson model for tumor control probability (TCP) models were used in the Histogram Analysis in Radiation Therapy (HART) analysis. In this study, 33 patients with oropharyngeal primaries in the head and neck region were used to establish the correlation between NTCP values of (a) bilateral parotids with clinically observed rates of xerostomia, (b) esophagus with dysphagia, and (c) larynx with dysphagia. The results of the study indicated a strong correlation between the severity of xerostomia and dysphagia with Lyman NTCP of bilateral parotids and esophagus, respectively, but not with the larynx. In patients without complications, NTCP values of these organs were negligible. Using appropriate radiobiological models, the presence of a moderate to strong correlation between the severities of complications with NTCP of selected OARs suggested that the clinical outcome could be estimated prior to treatment.

SU-E-T-570: Improvement to the Histogram Analysis in Radiation Therapy (HART): An Open Source Software System for the Multi-Dimensional Dose- Volume Histogram Analysis in Digital Image Communication in Medicine - Radiation Therapy (DICOM-RT) Treatment Plans.

PURPOSE: Histogram Analysis in Radiation Therapy (HART) is an efficient and accurate dose-volume histogram (DVH) computational tool in radiotherapy research. Several applications of the program have been presented previously (J Appl Clin Med Phys 11(1): 3013, 2010; Med Phys 38(6), p.3678, 2011) for the Radiation Therapy Oncology Group (RTOG) users. The program has been further developed to incorporate various types of DVH analysis features to support the research using DICOM-RT plans. The main objective of this work was to present the improvement and compatibility of the program for the DICOM-RT plans. METHODS AND MATERIALS: MATLAB based codes were primarily designed to read and write a simpler HART format from the standard DICOM-RT data objects exported from the Xio treatment planning system (CMS Inc., St. Louis, MO). This format employed an optimal polynomial fitting technique to interpolate the co-ordinates of the contours in the regions-of-interest. The format was efficient for the (a) precise extraction of the cumulative DVH (cDVH) and spatial DVH (sDVH; x-,y-, and z-DVHs respectively) data- statistics, (b) universal-plan indices evaluation, (c) biological modeling based outcome analyses (BMOA), (d) radiobiological dose-response modeling, and (e) physical parameterization modules. The fundamental DVH statistics were validated using the DVH statistics extracted from the Computational Environment for Radiotherapy Research program. RESULTS: HART offers various types of DVH computational functionalities, several plan evaluation and radiobiological outcome analysis modules in a user- friendly software package for the RTOG and DICOM-RT planners. The cDVH and BMOA modules were found to be the most applicable features for the global researchers. CONCLUSIONS: HART is a novel and universal multi-dimensional DVH analysis tool for the radiation therapy research. We further expect to develop HART for the space-time DVH analysis and proton therapy applications. The software is available online (http://www2.uic.edu/∼apyaku1) for the radiotherapy research. This work was partially supported by NIH-NIDCD grant.

Rock phosphate enriched compost: an approach to improve low-grade Indian rock phosphate.

In this study, rock phosphate enriched composts (RP-compost) were prepared by mixing four low-grade Indian rock phosphates with rice straw with and without Aspergillus awamori. RP-compost had higher total P, citrate soluble P (CSP), organic P (Org.P), acid and alkaline phosphatase activities, and lower water soluble P (WSP) and microbial biomass C (MBC) than normal compost. Inoculation with A. awamori increased total P, WSP, CSP, Org.P, MBC and acid phosphatase activity. RP-compost recorded lower Olsen P at the initial period of incubation study than diammonium phosphate (DAP), but improved significantly with the progress of time. RP-compost prepared at 4% charged rate resulted in higher Olsen P throughout the incubation period compared to 2% charged rate. Similar trend were obtained with those RP-composts prepared with A. awamori. Data on pot experiment revealed higher yield and P uptake by mungbean (Vigna radiata) due to addition of RP-composts over control. The effectiveness of RP-compost ranged from 61.4% (MussoorieRP-compost) to 94.1% (PuruliaRP-compost) as that of DAP on dry matter yield and 48.8% (JhabuaRP-compost) to 83.7% (PuruliaRP-compost) on total P uptake. Enriched compost prepared at 4% charged rate recorded 15.8% and 10.6% extra yield and P uptake, respectively by mungbean over 2% charged compost. Also RP-compost inoculated with A. awamori resulted in 13.0 and 21.5% extra yield and P uptake than without A. awamori treated group. Thus, RP enriched compost could be an alternative and viable technology to utilize both low-grade RPs and rice straw efficiently.

Dengue fever outbreaks in two villages of Dharmapuri district in Tamil Nadu.

BACKGROUND & OBJECTIVES: Dengue fever is an important public health problem in India. In recent years this disease has extended to rural areas also due to rapid urbanization. In Tamil Nadu, fever outbreaks were reported in two villages of Dharmapuri district during May and September 2001 with clinical symptoms suggestive of dengue fever. Epidemiological, virological and entomological investigations were carried out in these two villages to ascertain the etiology of the outbreaks. METHODS: Paired serum samples were collected from febrile patients clinically suspected to have dengue and were tested for the presence of IgM antibodies to dengue virus by MAC ELISA. Samples were also tested by Dengue Duo IgM/IgG rapid strip. Surveys of larval and adult Aedes mosquitoes were carried out before and after anti-larval and anti-adult measures were implemented. Female Ae. aegypti mosquitoes collected in Mampatti village were tested individually for the presence of dengue-2 viral antigen by indirect immunofluorescence assay (IIFA). In addition, two pools of female Ae. aegypti mosquitoes were tested for the presence of dengue viral antigen by ELISA and then subjected to Toxo-IFA system for demonstration of dengue virus. RESULTS: A total of 124 and 267 fever cases with clinical symptoms and signs suggestive of dengue were reported in Kadumuchandiram and Mampatti villages of Dharmapuri district, respectively. Serodiagnosis revealed that 13 of 31 and 14 of 52 patients tested were positive for dengue-2 virus by MAC ELISA in Kadumuchandiram and Mampatti villages respectively. Dengue Duo rapid strip test also detected 14 (of 31 tested) patients positive for dengue virus specific IgM antibodies in Kadumuchandiram village and 8 (of 12 tested) in Mampatti village. Application of temephos and fogging with pyrethrum 2 per cent extract were found to be effective against immatures and adults respectively. Both the pools of Ae. aegypti tested for the presence of dengue viral antigen were positive by ELISA and one mosquito (tested individually) was positive by IIFA. Supernatants of two pools were found to be positive for dengue-2 virus by Toxo-IFA. INTERPRETATION & CONCLUSION: Virological and serological investigations confirmed that the outbreaks of fever were due to dengue virus infection. High breeding of Ae. aegypti in the study villages, detection of dengue-2 viral antigen and isolation of dengue-2 virus in Ae. aegypti mosquitoes confirmed the etiology.

Susceptibility status of vectors of Japanese encephalitis to insecticides in south Arcot and Tirunelveli districts of Tamil Nadu.

Villages in South Arcot and Tirunelveli districts with high incidence of Japanese Encephalitis were selected for the study of insecticidal resistance to vectors. Culex vishnui and Anopheles hyrcanus group were found to be resistant to DDT (4 per cent for 60 min. exposure) and dieldrin (0.4 per cent for 60 min. exposure) but susceptible to Malathion (5 per cent for 60 min. exposure). So far, this is perhaps the first report of Anopheles hyrcanus group resistant to DDT and dieldrin to be reported from this area. The resistance may be due to extensive use of DDT and HCH for agricultural purposes.

Ultra low volume (ULV) malathion application as a supplementary malaria control measure in two villages of South Arcot district, Tamil Nadu.

Ultra low volume (ULV) ground application of technical malathion as a supplementary malaria control measure was carried out in two riverine villages of South Arcot district, Tamil Nadu which had high persistent transmission since 1975. Malaria incidence was reduced to one fifth in villages under ULV malathion as against a 50% drop in the control village. The cost of ULV spray alone came to Rs. 1.07 per capita per year. ULV can be an effective supplementary measure in rural areas with specific problems.