Comparison of imaging modalities for the accurate delineation of arteriovenous malformations (AVM) and evaluation of setup accuracy with reference to non-invasive LINAC-based stereotactic radiosurgery (SRS).

AIMS: To compare the accuracy of nidus delineation using magnetic resonance angiography (MRA) to digital subtraction angiography (DSA) and to evaluate setup accuracy of non-invasive frame SRS treatments. SETTINGS AND DESIGN: A prospective observational study of 16 patients who underwent non-invasive frame LINAC-based SRS for brain AVMs. MATERIALS AND METHODS: The nidus was separately delineated using DSA and MRA after co-registration onto CT simulation images and compared with respect to their volume and maximum diameters. During treatment, the setup errors observed in x-, y-, and z-directions were recorded. STATISTICAL ANALYSIS: Paired t-test (to compare volume and maximum diameter). Wilcoxon signed-rank test (for setup accuracy). RESULTS: The mean volume of nidus contoured in MRA was 4.16 cc compared to 3.11 cc in DSA (P 0.297). The mean maximum diameters using MRA and DSA, respectively, in antro-posterior, cranio- caudal, and transverse diameters were 21.97 cc vs. 19.46 cc (P 0.2380), 6.59 cc vs. 9.63 cc (P 0.161), and 18.87 cc vs. 16.81 cc (P 0.178). But these modalities can potentially misinterpret the nidus volume, warranting caution for use of either modality alone. The mean translational shift observed in the x-, y-, and z-directions were 0.06 mm, 0.13 mm, and 0.13 mm, respectively, when couch was brought to neutral position after clockwise couch rotation and 0.07, 0, and 0, respectively, after counterclockwise couch rotation. CONCLUSION: This study could not demonstrate any statistically significant differences in nidus delineation between MRA and DSA. Setup accuracy achieved with non-invasive thermoplastic mask-based immobilization is within acceptable limits for SRS.

Loss of protective anti-HBs titers and seroconversion to hepatitis B vaccination in children during chemotherapy for acute lymphoblastic leukemia.

BACKGROUND: This study aimed to evaluate loss of protective anti-hepatitis B (HBs) titers and seroconversion to hepatitis B vaccine (HBV) during chemotherapy in children with acute lymphoblastic leukemia (ALL). METHODS: Anti-HBs titers were done at diagnosis. Patients were divided into two groups. Group I (protective titers >10 mIU/ml) received single double dose of HBV as booster. Titers were repeated at three time points: end of phase 1b, beginning of re-induction, and start of maintenance chemotherapy. Group II (nonprotective titers <10 mIU/L) received hepatitis B immunoglobulin (HBIG), prior to start of chemotherapy, followed by three double doses of HBV as booster. Titers were repeated at two time points: prior to first dose, and 4 weeks after third dose of vaccine. RESULTS: Total 125 patients were included: 88 in group I; 37 in group II. Among group I patients, 98.7%, 90%, and 84% retained protective titers at the three points, respectively. Subgroup analysis showed that those with initial titers greater than 100 mIU/L retained protective titers better than those with titers between 11 and 100 mIU/L (p = .0001). Among group II patients, 62% and 64% attained protective titers at the two points, respectively. CONCLUSIONS: HBV boosters helped maintain protective titers during intensive ALL chemotherapy in immunized children having titers more than 10 mIU/L, and more so if titer was more than 100 mIU/L. Therefore, we propose that cut off for protective anti-HBs titers be changed to greater than or equal to 100 mIU/L. Titers between 11 and 100 mIU/L may require combined active and passive immunization. Around one-third of group II patients who fail to attain protective titers may need frequent doses of HBIG.

Performance in 6-min walk test in prediction of post-operative pulmonary complication in major oncosurgeries: A prospective observational study.

BACKGROUND AND AIMS: Post-operative pulmonary complications (PPC) contribute to increased morbidity and mortality, necessitating pre-operative functional assessment. Six-minute walk test (6MWT) is a simple option for functional assessment. METHODS: This is a prospective observational study conducted in 75 patients who underwent elective abdominal or thoracic oncosurgery under general anaesthesia with either age above 60 years or with cardiopulmonary diseases or obstructive sleep apnoea or low serum albumin or smoking. Patients with history of acute coronary syndrome in past 6 months, dyspnoea at rest, severe pain, inability to walk or interpret instructions and haemodynamic instability were excluded. Preoperatively 6MWT was conducted according to the American Thoracic Society guidelines and patients were observed for PPC. Patients were divided into two groups: group 1-no PPC and group 2-developed PPC. Statistical analysis was done using SPSS software (version 11.0.1). Categorical variables were assessed using Chi-square/Fisher's exact test and continuous variables using student's t-test/Mann-Whitney U test. Association was tested using logistic regression. RESULTS: Out of the 75 patients, 40 patients had no PPC (group 1) and 35 patients had PPC (group 2) including a death. The 6MWD of group with PPCs was significantly less (344 ± 61.927 m) compared to the group without PPCs (442.28 ± 83.194 m, P value = 0.001). The cut-off 6MWD obtained was 390 m, which correlated with longer duration of hospital stay and ICU stay (P = 0.001). CONCLUSION: Six-minute walk test is a reliable predictor of post-operative pulmonary complications with a cut-off 6MWD of 390 m in the studied oncosurgery patients.

Reproductive factors and thyroid cancer risk: Meta-analysis.

BACKGROUND: Assessed pooled risk on reproductive factors and oral contraceptives (OC) on thyroid cancer (TC) using published studies (1996-2017). METHODS: Summary odds ratio (OR) for case-control studies (n = 10) and risk ratio (RR) for cohort studies (n = 9) was done. RESULTS: OR was 1.43 (95% CI: 1.16-1.77) for age at menarche >14 years, 1.49 (95% CI: 1.19-1.86) for parity >2, 1.38 (95% CI: 1.18-1.61) for miscarriage/abortion, and 2.05 (95% CI: 1.39-3.01) for artificial menopause. A protective effect (ORs: 0.85; 95% CI: 0.72-0.99) on TC was observed for prolonged use of OCs. RR was 1.17 (95% CI: 0.90-1.57) for age at menarche >14 years, 1.10 (95% CI: 0.94-1.27) for parity >2, 1.20 (95% CI: 1.03-1.40) for miscarriage/abortion, and 2.16 (95% CI: 1.41-3.31) for artificial menopause and protective effect (RR: 0.78; 95% CI: 0.65-0.92) for prolonged use of OCs. CONCLUSIONS: This meta-analysis supports an association due to changes in female hormones during menstrual cycle and pregnancy with the risk of TC and explains female preponderance.