A mathematical model to predict the different isodose volumes using TRAK value in HDR intracavitary brachytherapy for revised Manchester and ICRU-89 based Point A plans using computer tomography images.

Purpose: To find out the simple relationship between Total Reference Air Kerma (TRAK) and various isodose volumes. Calculated isodose volumes were compared with experimental data for revised Manchester and International Commission on Radiation Units and measurements (ICRU)-89 Point A-based treatment plans. The accuracy of the formula was compared with the results of other relationships available in the literature. Materials and Methods: Dosimetric data from 62 intracavitary brachytherapy (ICBT) treatment plans of 31 patients with cervical cancer were studied. Each patient had treatment plans normalized to revised Manchester and ICRU-89 Points A (Aflange and Aicru89). For each treatment plan, TRAK values, V350, V700, V1050, and V1400 were obtained. The modeling curve was plotted between Isodose volume (Vd) and the ratio of d/TRAK obtained from Aflange plans to get a mathematical relation. The results of this formula were compared with the experimental data and outcomes of other formulas available in the literature. A paired-sample t-test was performed to assess the statistical significance. Results: In the case of revised Manchester-based Aflange normalization plans, the mean isodose volume of V350, V700, V1050, and V1400 were 285.98 ± 32.3 cm3, 101.96 ± 10.63 cm3, 52.71 ± 4.72 cm3, and 31.44 ± 2.33 cm3 respectively. Likewise, for ICRU-89 based Aicru89 normalization plans, the mean isodose volumes of V350, V700, V1050, and V1400 were 304.11 ± 26.17 cm3, 108.88 ± 8.29 cm3, 56.62 ± 3.69 cm3 and 34 ± 2.23 cm3 respectively. The mean difference was significant. The Mathematical relationship developed was [INLINE:1]. No correlation was found between TRAK and D0.1cm3,D2cm3 for organs at risk. Conclusions: The developed formula calculated isodose volumes within the accuracy of ± 3% in ICBT plans.

Feasibility of using polytetrafluoroethylene flexible implant tube for interstitial brachytherapy patients.

PURPOSE: To design the different Polytetrafluoroethylene (PTFE) based flexible implant tubes using an in-house developed device and to evaluate them for High dose rate (HDR) interstitial brachytherapy using computer tomography images. METHODS AND MATERIALS: PTFE hollow tube having a 2 mm (6 French) outer diameter (OD) and 1.4 mm inner diameter (ID) was used to design in-house single and/or double leader flexible catheters for interstitial brachytherapy implant. An in-house Plastic Wire Drawing Plate (PWDP) machine was developed. Customization of PTFE hollow flexible implant tube (FIT) was done through PWDP. Different percentages of BaSO4 (5%, 10%, & 15%) were added to Nylon 6 to make radiopaque button. Various quality assurance tests were performed with the PTFE tubes implanted in the brinjal (phantom) before using them on the patients. That is, coupling of brachytherapy machine transfer tube with flexible PTFE Tubes, CT scan artifacts, tube kinks, breast template, and free-hand compatibility. RESULTS: With the help of the PWDP machine, plastic wires of different lengths were made for single leader and double leader tubes. The different plastic leader ends of 1 cm to 50 cm lengths having 1 mm diameter were created. The radiopaque button of Nylon 6 in circular shape having 1 cm diameter and 0.5 cm thick was created. Developed radiopaque buttons were visible on CT scan images as well as on radiograph images. CONCLUSIONS: PTFE tubes of the desired length can be made depending upon the size of the brachytherapy implant and are inexpensive than commercially available flexible implant tubes.

A comparison between revised Manchester Point A and ICRU-89-recommended Point A definition absorbed-dose reporting using CT images in intracavitary brachytherapy for patients with cervical carcinoma.

PURPOSE: This study is a comparison between revised Manchester Point A and International Commission on Radiation Units and measurements (ICRU) 89 report-recommended Point A absorbed-dose reporting in intracavitary brachytherapy for patients with cervical carcinoma. METHODS AND MATERIALS: The retrospective dosimetric study is based on the data of 32 patients with cervical carcinoma treated with high-dose-rate brachytherapy. Patients received 21 Gy in three fractions (7.0 Gy X three fractions) to Point A (Aflange, revised Manchester definition). All the patients were replanned with a new Point A (Aicru89) defined on CT images as per the American Brachytherapy Society/ICRU-89. The data collected were compared with the data obtained from Point A (Aflange). RESULTS: When using the Aflange plan normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 820.79 ± 207.47 cGy, 654.66 ± 152.69 cGy, and 588.91 ± 136.35 cGy, respectively. Likewise, when using the ICRU-89 Point Aicru89 normalization method, the mean dose of 0.1 cc, 1 cc, and 2 cc bladder volumes was 869.30 ± 224.67 cGy, 693.24 ± 166.20 cGy, and 616.61 ± 150.32 cGy, respectively. For the rectum, Point Aflange normalization plans, the mean dose of 0.1 cc, 1 cc, and 2 cc volumes was 589.37 ± 163.26 cGy, 487.51 ± 126.03 cGy, and 442.70 ± 111.43 cGy, respectively. Likewise, using the Aicru89 plan, the mean 0.1 cc, 1 cc, and 2 cc rectum volume was 625.07 ± 171.31 cGy, 517.50 ± 131.05 cGy, 464.94 ± 121.81 cGy, respectively. The statistical mean difference of Total Reference Air Kerma rate, V100 (cc), bladder, rectum and sigmoid, was found significant. CONCLUSIONS: It has been found that the position of revised Manchester (Aflange) and ICRU-89 Point A does not match on CT images/radiograph, which resulted in variation in doses to the tumor, V100 (cc), organ at risk, and Total Reference Air Kerma.

Downregulated Expression of WWOX in Cervical Carcinoma: A Case-Control Study.

Integration of human papilloma virus (HPV) in human genome is a random event, and fragile sites are one of the most susceptible sites for viral integrations. WWOX (WW-domain containing oxidoreductase) gene harbours the second most common fragile site, FRA16D, and can be an important candidate for HPV integration and cervical carcinogenesis. Our aim was to evaluate the potential role of WWOX in cervical carcinogenesis. Presence of HPV and its genotype was detected by PCR in normal cervix tissues and human cervical carcinoma. The expression of WWOX transcript and its protein was examined by RT-PCR, RNA in situ hybridization, and immunoblotting. Southern blotting and sequencing were used to determine the alternative transcripts of WWOX. Statistical analysis were performed by Mann Whitney U-test, Pearson correlation coefficient test at significance level of P value < 0.05. Prevalence of HPV was observed in cervicitis (40%), cervical intraepithelial neoplasia patients (50%), and invasive cervical carcinoma patients (89.6%). Clinicopathological findings suggested a correlation of reduced level of WWOX protein and progression of cervical carcinoma deciphering its role in tumorigenesis. Furthermore, we observed aberrant WWOX transcript having deleted exon 6-8 region in invasive cervical cancer tissues as well as normal cervix samples. More than 60% of cervical carcinoma samples showed reduced protein level with an increase in wild type transcript level suggesting the involvement of a negative regulator, pAck1 (activated Cdc42- associated kinase) which might ubiquitinate WWOX protein leading to its degradation. Also, nuclear retention of WWOX transcript in invasive cervical carcinoma tissues suggests its regulation at post-transcriptional level. Our findings suggest that WWOX acts as a tumor suppressor in cervical carcinoma and could act as a potential therapeutic target for the disease.

Search of an ideal location of isocenter in intensity-modulated radiotherapy treatment plans: A dosimetrical approach.

AIM: The aim of this study is to identify an ideal location of isocenter in intensity-modulated radiotherapy (IMRT) treatment plans. MATERIALS AND METHODS: A total of 28 clinical target volumes and 4 English capital letters (C, L, T, and H) target volumes were considered in this study. Two IMRT treatment plans were generated for each target volume in the ECLIPSETM treatment planning system (TPS), first one with isocenter automatically placed (ISOAUTO) by TPS and the second one with geometric center-based isocenter (ISOGEOM). The geometric center of a cuboid volume, which was formed encompassing around the target volume in sagittal, transverse, and frontal planes, is considered as the geometric center of the target volume as well as the isocenter (ISOGEOM) of the IMRT plans. While performing the IMRT treatment plans using the beam angle optimization and dose volume optimization, the normal tissue objectives and target volume objectives were kept similar in both the plans. The dosimetrical parameters between the two groups of plans were compared. RESULTS: The distance between ISOGEOM and ISOAUTO ranged from 0.16 cm to 3.04 cm with a mean and median of 0.85 cm and 0.69 cm, respectively. The ISOGEOM-based IMRT plans exhibited statistically significant advantages in total monitor units reduction (100% of cases, P ≤ 0.001), total number of field reduction (66% of cases, P ≤ 0.001), and reduction of patient mean dose (69% of cases, P ≤ 0.001) over ISOAUTO-based IMRT plans. The conformity index, homogeneity index and target mean dose were comparable between both group of plans. CONCLUSION: Significant dosimetrical advantages may be observed, when the geometric centroid of target volume is considered as isocenter of IMRT treatment plan.

Epidemiological Study on Breast Cancer Associated Risk Factors and Screening Practices among Women in the Holy City of Varanasi, Uttar Pradesh, India.

BACKGROUND: Breast cancer is the second most cause of death (1.38 million, 10.9% of all cancer) worldwide after lung cancer. In present study, we assess the knowledge, level of awareness of risk factors and screening practices especially breast self examination (BSE) among women, considering the non-feasibility of diagnostic tools such as mammography for breast screening techniques of breast cancer in the holy city Varanasi, Uttar Pradesh, India. MATERIALS AND METHODS: A cross-sectional population based survey was conducted. The investigation tool adopted was self administrated questionnaire format. Data were analysed using SPSS 20 version and Chi square test to determine significant association between various education groups with awareness and knowledge, analysis of variance was applied in order to establish significance. RESULTS: The attitude of participants in this study, among 560 women 500 (89%) responded (age group 18-65 years), 53.8% were married. The knowledge about BSE was very low (16%) and out of them 15.6% were practised BSE only once in life time. study shown that prominent age at which women achieve their parity was 20 yrs, among 500 participants 224 women have achieved their parity from age 18 to 30 yrs. Very well known awareness about risk factors of breast cancer were alcohol (64.6%), smoking (64%) and least known awareness risk factors were early menarche (17.2%) and use of red meat (23%). The recovery factors of breast cancer cases were doctors support (95%) and family support (94.5%) as most familiar responses of the holy city Varanasi. CONCLUSIONS: The study revealed that the awareness about risk factors and practised of BSE among women in Varanasi is extremely low in comparison with other cities and countries as well (Delhi, Mumbai, Himachal Pradesh, Turkey and Nigeria). However, doctors and health workers may promote the early diagnosis of breast cancer.