18F-FDG PET/CT- and MRI-Based Locally Advanced Cervical Cancer Early-Response Assessment after Concurrent Chemo- and Radiotherapy-Impact on Patient Outcomes and Survival Prediction.

With one third of patients with locally advanced cervical cancer (LACC) expected to develop cancer recurrence in the first two years after therapy, accurate assessment of the response and timely detection of cancer recurrence after concurrent chemo- and radiotherapy (CCRT) treatment is of great importance. Although there is neither definite consensus about the preferred imaging modality, nor the time interval until the first diagnostic examination after CCRT, the National Comprehensive Cancer Network (NCCN) recommends the use of MRI and 18F-FDG PET/CT as a post-treatment LACC response-assessment imaging tools. In this study, we tried to appraise the early therapy response in LACC patients by both 18F-FDG PET/CT and MRI in regard to the follow-up imaging results and their mutual interrelationship, and to ascertain if the post-treatment 18F-FDG PET/CT and MRI results were related to the progression-free and overall survival rate in women with LACC after CCRT. We also aimed to estimate the early and follow-up diagnostic imaging impact on further therapy management. Based on our results, we concluded that 18F-FDG PET/CT did surpass MRI in the early assessment of therapeutic response in LACC patients after CCRT. Both modalities provided information that may serve as predictive biomarkers of outcome and LACC patients' survival.

The VEGF gene polymorphism in glioblastoma may be a new prognostic marker of overall survival.

PURPOSE: Glioblastoma (GBM) is the most aggressive primary brain tumor. Vascular endothelial growth factor (VEGF) gene polymorphisms and overexpression are involved in high-grade malignant gliomas. The aim of this study was to assess the distribution of +405C>G VEGF gene polymorphism in patients diagnosed by glioblastoma and to test its association with the overall survival (OS). METHODS: Patients diagnosed for glioblastoma were randomly selected, and follow-up was conducted for a minimum of 36 months. Tissue paraffin embedded GBM samples were subjected for the VEGF polymorphism detection. The associations of the observed genotypes and clinical data were evaluated. RESULTS: The most frequent single nucleotide polymorphism (SNP) variant was G (72.58%). The GG genotype was proved to have statistically significant longer OS and patient status (alive/dead) compared to CC and CG genotypes (p=0.022 and 0.005, respectively). CONCLUSION: Our results indicate that +405C>G VEGF gene polymorphism may be used as prognostic genetic marker of OS in GBM patients.

Radiobiological effects of multiple vs. single low-dose pre-irradiation on the HT29 cell line.

AIM OF THE STUDY: Aim of the study was to compare radiobiological effects of multiple vs. single low-dose pre-irradiation on the HT29 cell line. This regime is designed to be as similar as possible to fractionated tumour radiotherapy treatment, and to provide data on radiobiological effects on human tumour cells. MATERIAL AND METHODS: The cell line used in the study was HT29 (human colorectal adenocarcinoma, American Type Culture Collection HTB-38™). Also, for comparison, the MRC5 cell line (human foetal lung fibroblasts, American Type Culture Collection CCL 171) was used. Four-day treatment in a 4 × 2 Gy regime was performed. Cell viability was evaluated by tetrazolium colorimetric MTT assay. RESULTS: Multiple low-dose pre-irradiation induced a stronger radioadaptive response compared to single low-dose application in the HT29 cell line. Multiple pre-irradiation with 0.03 Gy and 0.05 Gy caused radioadaptive effects, while in both single and multiple low-dose pre-irradiation regimes 0.07 Gy led to radiosensitivity. Radiobiological effects induced in the HT29 cell line by low-dose pre-irradiation were evidently weak during the treatment time, because a single low-dose applied only on the first day gave no radioadaptive effects. In the MRC5 cell line different effects were registered, since radioadaptive response has not been observed after multiple or single pre-irradiation. CONCLUSIONS: The obtained data are interesting, especially for the possible application of low-dose pre-irradiation in radiotherapy.

Dynamic magnetic resonance imaging of endoscopic third ventriculostomy patency with differently acquired fast imaging with steady-state precession sequences.

The aim of the study was to determine the possibilities of two differently acquired two-dimensional fast imaging with steady-state precession (FISP 2D) magnetic resonance sequences in estimation of the third ventricle floor fenestration patency after endoscopic third ventriculostomy (ETV) in the subjects with aqueductal stenosis/obstruction.Fifty eight subjects (37 males, 21 females, mean age 27 years) with previously successfully performed ETV underwent brain MRI on 1.5T MR imager 3-6 months after the procedure. Two different FISP 2D sequences (one included in the standard vendor provided software package, and the other, experimentally developed by our team) were performed respectively at two fixed slice positions: midsagittal and perpendicular to the ETV fenestration, and displayed in a closed-loop cinematographic format in order to estimate the patency. The ventricular volume reduction has been observed as well.Cerebrospinal fluid (CSF) flow through the ETV fenestration was observed in midsagittal plane with both FISP 2D sequences in 93.11% subjects, while in 6.89% subjects the dynamic CSF flow MRI was inconclusive. In the perpendicular plane CSF flow through the ETV fenestration was visible only by use of experimentally developed FISP 2D (TR30/FA70) sequence. Postoperative volume reduction of lateral and third ventricle was detected in 67.24% subjects.Though both FISP 2D sequences acquired in midsagittal plane may be used to estimate the effects of performed ETV, due to achieved higher CSF pulsatile flow sensitivity, only the use of FISP 2D (TR30/FA70) sequence enables the estimation of the treatment effect in perpendicular plane in the absence of phase-contrast sequences. 

Radiotherapy treatment planning: benefits of CT-MR image registration and fusion in tumor volume delineation.

BACKGROUND/AIM: Development of imaging techniques, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), made great impact on radiotherapy treatment planning by improving the localization of target volumes. Improved localization allows better local control of tumor volumes, but also minimizes geographical misses. Mutual information is obtained by registration and fusion of images achieved manually or automatically. The aim of this study was to validate the CT-MRI image fusion method and compare delineation obtained by CT versus CT-MRI image fusion. METHODS: The image fusion software (XIO CMS 4.50.0) was applied to delineate 16 patients. The patients were scanned on CT and MRI in the treatment position within an immobilization device before the initial treatment. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated on CT alone and on CT+MRI images consecutively and image fusion was obtained. RESULTS: Image fusion showed that CTV delineated on a CT image study set is mainly inadequate for treatment planning, in comparison with CTV delineated on CT-MRI fused image study set. Fusion of different modalities enables the most accurate target volume delineation. CONCLUSION: This study shows that registration and image fusion allows precise target localization in terms of GTV and CTV and local disease control.

Lung 99mTc-MIBI scintigraphy: impact on diagnosis of solitary pulmonary nodule.

Most of today available non-invasive procedures cannot clearly determinate between benign and malignant solitary pulmonary nodules (SPN). The purpose of the study was to assess the possibility of using 99mTc labeled hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) to differentiate benign from malignant SPN. Sixty patients were included in the study if the CT scan showed indeterminate SPN. Prior to definitive diagnosis 99mTc-MIBI single photon emission computerized tomography (SPECT) was performed: early scan 10 minutes and delayed 60-120 minutes after the intravenous injection of 740 MBq 99mTc-MIBI using dual-headed Gamma camera. The results were considered positive if there was an increased accumulation of the radiopharmaceutical in the area of the lung corresponding to the location of the lesion. The mean nodule size ± SD measured on CT scan was 2.96 cm. Lung cancer was diagnosed in 30/60 patients (14 squamocellular, 10 adenocarcinoma, 3 large-cell and 3 microcellular lung carcinomas). Of the 30 patients with malignant lesions, 27 patients (90%) had positive 99mTc-MIBI scan results by qualitative assessment. Among benign lesions, 23/30 (76.7%) were negative on 99mTc-MIBI scan. The size and PH report of SPN is statistically significantly influencing on 99mTc-MIBI accumulation in the SPN (p<0.01). The sensitivity, specificity, accuracy, positive and negative predictive value were 90%, 76.6%, 79.4%, 88.5% and 83.3% respectively. 99mTc-MIBI SPECT is an inexpensive non-invasive diagnostic procedure which might be useful diagnostic modality in the evaluation of SPN. Easy availability and low cost makes 99mTc-MIBI SPECT an attractive method in evaluating SPN.

[Magnetic resonance imaging and bone scintigraphy in bone metastasis detection: a comparative study].

BACKGROUND/AIM: Bone scintigraphy is well-known method for the detection of neoplastic lesions with a high sensitivity and, at the same time, a lower specificity. On the other hand magnetic resonance imaging (MRI) is previously established noninvasive imaging method regar ding its diagnostic specificity. The aim of this study was to determine the possibilities and to correlate two different diagnostic methods--bone scintigraphy and MRI in the detection of bone metastasis in the spine and pelvic bones. METHODS: A total of 123 patients who underwent both bone scintigraphy and spine and pelvic MRI on 1.5 T MR imager were enrolled in this study. Scans were subsequently analyzed in total and divided in regions of interest (cervical, upper, middle and lower thoracic, upper and lower lumbar and pelvic region, which includes sacral spinal segment); afterwards the total number of 585 mat ching regions were compared and statistically analyzed. RESULTS: The statistical analysis demonstrated significant correlation between the findings of both methods in total. Divided by regions of interest, significant degrees of correlation were demonstrated in all of them, except in the cervical spine region where the r-value was in the range of low correlation. CONCLUSION: Having a high mutual correlation, bone scintigraphy and MRI are to be considered as the complementary diagnostic methods in the detection of bone metastases. Still, increased diagnostic potential of MRI may highlights negative bone scintigraphy findings in the patients with solitary metastatic lesions or diffuse vertebral infiltration. Advances in the bone scintigraphy (single photon emission tomography--SPECT, SPECT-computed tomography--SPECT-CT) and MRI (whole body MRI, diffusion MRI), make it possible the diagnostic potential of both methods will result in a further improvement in bone metastasis detection.

[Current diagnostic trends in radiology].

Since the discovery of X-rays by Wilhelm Conrad Röentgen at the end of the 19th century, diagnostic imaging techniques have been continously improved by technological advances, bringing radiological diagnosis into the very center of modern medicine. Nowadays, it is hard to imagine therapy planning without previous radiological examination. Great advances in the field of computer technology have been accompanied by development of radiological techniques, and today they include not only morphological and anatomical, but also dynamic, functional and molecular imaging. This paper is an overview of new and improved radiological techniques and their implementation.