Volume 50 (2016): Issue 2 (June 2016)

The number of patients with malignant brain tumours is on the rise, but due to the novel treatment methods the survival rates are higher. Despite increased survival the consequences of tumour properties and treatment can have a significant negative effect on the patients’ quality of life. Providing timely and appropriate rehabilitation interventions is an important aspect of patient treatment and should be started immediately after surgery. The most important goal of rehabilitation is to prevent complications that could have a negative effect on the patients’ ability to function.

By using individually tailored early rehabilitation it is often possible to achieve the patients’ independence in mobility as well as in performing daily tasks before leaving the hospital. A more precise evaluation of the patients’ functional state after completing additional oncologic therapy should be performed to stratify the patients who should be directed to complex rehabilitation treatment. The chances of a good functional outcome in patients with malignant brain tumours could be increased with good early medical rehabilitation treatment.

Malignant (high-grade) gliomas are rapidly progressive brain tumours with very high morbidity and mortality. Until recently, treatment options for patients with malignant gliomas were limited and mainly the same for all subtypes of malignant gliomas. The treatment included surgery and radiotherapy. Chemotherapy used as an adjuvant treatment or at recurrence had a marginal role.

Nowadays, the treatment of malignant gliomas requires a multidisciplinary approach. The treatment includes surgery, radiotherapy and chemotherapy. The chosen approach is more complex and individually adjusted. By that, the effect on the survival and quality of life is notable higher.

The aim of this study is to quantify the influence of the photon energy spectrum of brachytherapy sources on task group No. 43 (TG-43) dosimetric parameters.

Different photon spectra are used for a specific radionuclide in Monte Carlo simulations of brachytherapy sources.

MCNPX code was used to simulate 125I, 103Pd, 169Yb, and 192Ir brachytherapy sources. Air kerma strength per activity, dose rate constant, radial dose function, and two dimensional (2D) anisotropy functions were calculated and isodose curves were plotted for three different photon energy spectra. The references for photon energy spectra were: published papers, Lawrence Berkeley National Laboratory (LBNL), and National Nuclear Data Center (NNDC). The data calculated by these photon energy spectra were compared.

Dose rate constant values showed a maximum difference of 24.07% for 103Pd source with different photon energy spectra. Radial dose function values based on different spectra were relatively the same. 2D anisotropy function values showed minor differences in most of distances and angles. There was not any detectable difference between the isodose contours.

Dosimetric parameters obtained with different photon spectra were relatively the same, however it is suggested that more accurate and updated photon energy spectra be used in Monte Carlo simulations. This would allow for calculation of reliable dosimetric data for source modeling and calculation in brachytherapy treatment planning systems.

The purpose of the study was to analyse the dosimetric differences when using 10 MV instead of 6 MV for VMAT treatment plans for post-prostatectomy irradiation of the prostate bed.

Ten post-prostatectomy prostate bed irradiation cases previously treated using 6 MV with volumetric modulated arc therapy (VMAT) were re-planned using 10 MV with VMAT. Prescription dose was 66.6 Gy with 1.8 Gy per fraction for 37 daily fractions. The same structure set, number of arcs, field sizes, and minimum dose to the Planning Target Volume (PTV) were used for both 6 MV and 10 MV plans. Results were collected for dose to Organs at Risk (OAR) constraints, dose to the target structures, number of monitor units for each arc, Body V₅, Conformity Index, and Integral Dose. The mean values were used to compare the 6 MV and 10 MV results. To determine the statistical significance of the results, a paired Student t test and power analysis was performed.

Statistically significant lower mean values were observed for the OAR dose constraints for the rectum, bladder-Clinical Target Volume (bladder-CTV), left femoral head, and right femoral head. Also, statistically significant lower mean values were observed for the Body V₅, Conformity Index, and Integral Dose.

Several dosimetric benefits were observed when using 10 MV instead of 6 MV for VMAT based treatment plans. Benefits include sparing more dose from the OAR while still maintaining the same dose coverage to the PTV. Other benefits include lower Body V _5,Conformity Index, and Integral Dose.

Metastatic colorectal cancer (mCRC) is mainly a disease of elderly, however, geriatric population is underrepresented in clinical trials. Patient registries represent a tool to assess and follow treatment outcomes in this patient population. The aim of the study was with the help of the patients’ register to determine the safety and efficacy of bevacizumab plus chemotherapy in elderly patients who had previously untreated metastatic colorectal cancer.

The registry of patients with mCRC was designed to prospectively evaluate the safety and efficacy of bevacizumab-containing chemotherapy as well as selection of patients in routine clinical practice. Patient baseline clinical characteristics, pre-specified bevacizumab-related adverse events, and efficacy data were collected, evaluated and compared according to the age categories.

Between January 2008 and December 2010, 210 patients with mCRC (median age 63, male 61.4%) started bevacizumab-containing therapy in the 1^st line setting. Majority of the 210 patients received irinotecan-based chemotherapy (68%) as 1^st line treatment and 105 patients (50%) received bevacizumab maintenance therapy. Elderly (≥ 70 years) patients presented 22.9% of all patients and they had worse performance status (PS 1/2, 62.4%) than patients in < 70 years group (PS 1/2, 35.8%). Difference in disease control rate was mainly due to inability to assess response in elderly group (64.6% in elderly and 77.8% in < 70 years group, p = 0.066). The median progression free survival was 10.2 (95% CI, 6.7–16.2) and 11.3 (95% CI, 10.2–12.6) months in elderly and < 70 years group, respectively (p = 0.58). The median overall survival was 18.5 (95% CI, 12.4–28.9) and 27.4 (95% CI, 22.7–31.9) months for elderly and < 70 years group, respectively (p = 0.03). Three-year survival rate was 26% and 37.6% in elderly vs. < 70 years group (p = 0.03). Overall rates of bevacizumab-related adverse events were similar in both groups: proteinuria 21/22 %, hypertension 25/19 %, haemorrhage 2/4 % and thromboembolic events 10/6 %, for elderly and < 70 years group, respectively.

In routine clinical practice, the combination of bevacizumab and chemotherapy is effective and well-tolerated regimen in elderly patients with metastatic colorectal cancer.

The aim of the study was to evaluate short-term safety and efficacy of simultaneous modulated accelerated radiation therapy (SMART) delivered via helical tomotherapy in patients with nasopharyngeal carcinoma (NPC).

Between August 2011 and September 2013, 132 newly diagnosed NPC patients were enrolled for a prospective phase II study. The prescription doses delivered to the gross tumor volume (pGTV_nx) and positive lymph nodes (pGTV_nd), the high risk planning target volume (PTV1), and the low risk planning target volume (PTV2), were 67.5 Gy (2.25 Gy/F), 60 Gy (2.0 Gy/F), and 54 Gy (1.8 Gy/F), in 30 fractions, respectively. Acute toxicities were evaluated according to the established RTOG/EORTC criteria. This group of patients was compared with the 190 patients in the retrospective P70 study, who were treated between September 2004 and August 2009 with helical tomotherapy, with a dose of 70-74 Gy/33F/6.5W delivered to pGTV_nx and pGTV_nd.

The median follow-up was 23.7 (12–38) months. Acute radiation related side-effects were mainly problems graded as 1 or 2. Only a small number of patients suffered from grade 4 leucopenia (4.5%) or thrombocytopenia (2.3%). The local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), local-nodal relapse-free survival (LNRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 96.7%, 95.5%, 92.2%, 92.7% and 93.2%, at 2 years, respectively, with no significant difference compared with the P70 study.

Smart delivered via the helical tomotherapy technique appears to be associated with an acceptable acute toxicity profile and favorable short-term outcomes for patients with NPC. Long-term toxicities and patient outcomes are under investigation.

We explored the prognostic value of the up-regulated carbohydrate antigen (CA19-9) in node-negative patients with gastric cancer as a surrogate marker for micrometastases.

Micrometastases were determined using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for a subgroup of 30 node-negative patients. This group was used to determine the cut-off for preoperative CA19-9 serum levels as a surrogate marker for micrometastases. Then 187 node-negative T1 to T4 patients were selected to validate the predictive value of this CA19-9 threshold.

Patients with micrometastases had significantly higher preoperative CA19-9 serum levels compared to patients without micrometastases (p = 0.046). CA19-9 serum levels were significantly correlated with tumour site, tumour diameter, and perineural invasion. Although not reaching significance, subgroup analysis showed better five-year survival rates for patients with CA19-9 serum levels below the threshold, compared to patients with CA19-9 serum levels above the cut-off. The cumulative survival for T2 to T4 node-negative patients was significantly better with CA19-9 serum levels below the cut-off (p = 0.04).

Preoperative CA19-9 serum levels can be used to predict higher risk for haematogenous spread and micrometastases in node-negative patients. However, CA19-9 serum levels lack the necessary sensitivity and specificity to reliably predict micrometastases.

To assess the technical and clinical outcome of percutaneous insertion of tunneled peritoneal catheters in the palliative treatment of refractory malignant ascites and to determine the safety and feasibility of intraperitoneal administration of cytotoxic drugs through the tunneled catheter.

Consecutive patients palliatively treated with a tunneled peritoneal catheter to drain the malignant ascites were identified. Patients’ medical history, procedural and clinical follow-up data, including complications and estimated survival, were reviewed. Additionally, a sub analysis of the patients with widespread ovarian cancer and refractory ascites treated with or without intraperitoneal administration of cytotoxic drugs was made.

In all 94 patients it was technically feasible to insert the peritoneal drainage catheter and to drain a median of 3260 cc (range 100 cc – 8500 cc) of malignant ascitic fluid. Post procedural complications included catheter infection (n = 2; 2%), fluid leakage around the entry site (n = 4; 4%), catheter occlusion (n = 2; 2%), sleeve formation around the catheter tip (n = 1; 1%) and accidental loss of the catheter (n = 1; 1%). There was no increase in catheter infection rate in patients treated with or without intraperitoneal administration of cytotoxic drugs. Median overall survival after catheter insertion is 1.7 months.

Percutaneous insertion of a tunneled Tenckhoff catheter for the palliative drainage of malignant ascites and intraperitoneal infusion of cytotoxic drugs is feasible and associated with a very low complication rate, including catheter infection. These tunneled peritoneal lines are beneficial for symptomatic palliative treatment of refractory ascites and allow safe intraperitoneal chemotherapy.

The data on expression and clinical impact of cancer stem cell markers SOX2, NANOG and OCT4 in lung cancer is still lacking. The aim of our study was to compare SOX2, NANOG and OCT4 mRNA expression levels in whole blood between advanced small-cell lung cancer (SCLC) patients and healthy controls, and to correlate mRNA expression with progression-free survival (PFS) after first-line chemotherapy and overall survival (OS) in advanced SCLC patients.

50 advanced SCLC patients treated with standard chemotherapy and followed at University Clinic Golnik, Slovenia, between 2009 and 2013 were prospectively included. SOX2, NANOG and OCT4 mRNA expression levels were determined using TaqMan qPCR in whole blood collected prior to chemotherapy. Whole blood of 34 matched healthy individuals with no cancerous disease was also tested.

SOX2 mRNA expression was significantly higher in whole blood of SCLC patients compared to healthy controls (p = 0.006). Significant correlation between SOX2 mRNA expression levels and the number of distant metastatic sites was established (p = 0.027). In survival analysis, patients with high SOX2 expression had shorter OS (p = 0.017) and PFS (p = 0.046). In multivariate Cox analysis, an independent value of high SOX2 expression for shorter OS (p = 0.002), but not PFS was confirmed. No significant differences were observed for NANOG or OCT4 expression levels when comparing SCLC patients and healthy controls neither when analysing survival outcomes in SCLC patients.

SOX2 mRNA expression in whole blood might be a promising non-invasive marker for molecular screening of SCLC and important prognostic marker in advanced chemotherapy-treated SCLC patients, altogether indicating important role of cancer stem-like cell (CSC) regulators in cancer spread. Further evaluation of SOX2 as a possible screening/prognostic marker and a therapeutic target of SCLC is warranted.

Diffusion tensor imaging exploits preferential diffusional motion of water molecules residing within tissue compartments for assessment of tissue structural anisotropy. However, instrumentation and post-processing errors play an important role in determination of diffusion tensor elements. In the study, several experimental factors affecting accuracy of diffusion tensor determination were analyzed.

Effects of signal-to-noise ratio and configuration of the applied diffusion-sensitizing gradients on fractional anisotropy bias were analyzed by means of numerical simulations. In addition, diffusion tensor magnetic resonance microscopy experiments were performed on a tap water phantom and bovine articular cartilage-on-bone samples to verify the simulation results.

In both, the simulations and the experiments, the multivariate linear regression of the diffusion-tensor analysis yielded overestimated fractional anisotropy with low SNRs and with low numbers of applied diffusion-sensitizing gradients.

An increase of the apparent fractional anisotropy due to unfavorable experimental conditions can be overcome by applying a larger number of diffusion sensitizing gradients with small values of the condition number of the transformation matrix. This is in particular relevant in magnetic resonance microscopy, where imaging gradients are high and the signal-to-noise ratio is low.

Next generation sequencing and bio-informatic analyses were conducted to investigate the mechanism of reactivation of p53 and induction of tumor cell apoptosis (RITA)-enhancing X-ray susceptibility in FaDu cells.

The cDNA was isolated from FaDu cells treated with 0 X-ray, 8 Gy X-ray, or 8 Gy X-ray + RITA. Then, cDNA libraries were created and sequenced using next generation sequencing, and each assay was repeated twice. Subsequently, differentially expressed genes (DEGs) were identified using Cuffdiff in Cufflinks and their functions were predicted by pathway enrichment analyses. Genes that were constantly up- or down-regulated in 8 Gy X-ray-treated FaDu cells and 8 Gy X-ray + RITA-treated FaDu cells were obtained as RITA genes. Afterward, the protein-protein interaction (PPI) relationships were obtained from the STRING database and a PPI network was constructed using Cytoscape. Furthermore, ClueGO was used for pathway enrichment analysis of genes in the PPI network.

Total 2,040 and 297 DEGs were identified in FaDu cells treated with 8 Gy X-ray or 8 Gy X-ray + RITA, respectively. PARP3 and NEIL1 were enriched in base excision repair, and CDK1 was enriched in p53 signaling pathway. RFC2 and EZH2 were identified as RITA genes. In the PPI network, many interaction relationships were identified (e.g., RFC2-CDK1, EZH2-CDK1 and PARP3-EZH2). ClueGO analysis showed that RFC2 and EZH2 were related to cell cycle.

RFC2, EZH2, CDK1, PARP3 and NEIL1 may be associated, and together enhance the susceptibility of FaDu cells treated with RITA to the deleterious effects of X-ray.

An attractive approach in the study of human cancers is the use of transparent zebrafish (Danio rerio) embryos, which enable the visualization of cancer progression in a living animal.

We implanted mixtures of fluorescently labeled glioblastoma (GBM) cells and bonemarrow-derived mesenchymal stem cells (MSCs) into zebrafish embryos to study the cellular pathways of their invasion and the interactions between these cells in vivo.

By developing and applying a carbocyanine-dye-compatible clearing protocol for observation of cells in deep tissues, we showed that U87 and U373 GBM cells rapidly aggregated into tumor masses in the ventricles and midbrain hemispheres of the zebrafish embryo brain, and invaded the central nervous system, often using the ventricular system and the central canal of the spinal cord. However, the GBM cells did not leave the central nervous system. With co-injection of differentially labeled cultured GBM cells and MSCs, the implanted cells formed mixed tumor masses in the brain. We observed tight associations between GBM cells and MSCs, and possible cell-fusion events. GBM cells and MSCs used similar invasion routes in the central nervous system.

This simple model can be used to study the molecular pathways of cellular processes in GBM cell invasion, and their interactions with various types of stromal cells in double or triple cell co-cultures, to design anti-GBM cell therapies that use MSCs as vectors.

Despite complex treatment of surgery, radiotherapy and chemotherapy, high grade gliomas often recur. Differentiation between post-treatment changes and recurrence is difficult. ¹⁸F-methyl-choline (¹⁸F-FCH) is frequently used in staging and detection of recurrent prostate cancer disease as well as some brain tumours; however accumulation in inflammatory tissue limits its specificity. The ¹⁸F-ethyl-tyrosine (¹⁸F-FET) shows a specific uptake in malignant cells, resulting from increased expression of amino acid transporters or diffusing through the disrupted blood-brain barrier. ¹⁸F-FET exhibits lower uptake in machrophages and other inflammatory cells. Aim of this study was to evaluate ¹⁸F-FCH and ¹⁸F-FET uptake by human glioblastoma T98G cells.

Human glioblastoma T98G or human dermal fibroblasts cells, seeded at a density to obtain 2 × 10⁵ cells per flask when radioactive tracers were administered, grew adherent to the plastic surface at 37°C in 5% CO₂ in complete medium. Equimolar amounts of radiopharmaceuticals were added to cells for different incubation times (20 to 120 minutes) for ¹⁸F-FCH and ¹⁸F-FET respectively. The cellular radiotracer uptake was determined with a gamma counter. All experiments were carried out in duplicate and repeated three times. The uptake measurements are expressed as the percentage of the administered dose of tracer per 2 × 10⁵ cells. Data (expressed as mean values of % uptake of radiopharmaceuticals) were compared using parametric or non-parametric tests as appropriate. Differences were regarded as statistically significant when p<0.05.

A significant uptake of ¹⁸F-FCH was seen in T98G cells at 60, 90 and 120 minutes. The percentage uptake of ¹⁸F-FET in comparison to ¹⁸F-FCH was lower by a factor of more than 3, with different kinetic curves.¹⁸F-FET showed a more rapid initial uptake up to 40 minutes and ¹⁸F-FCH showed a progressive rise reaching a maximum after 90 minutes.

¹⁸F-FCH and ¹⁸F-FET are candidates for neuro-oncological PET imaging. ¹⁸F-FET could be the most useful oncological PET marker in the presence of reparative changes after therapy, where the higher affinity of ¹⁸F-FCH to inflammatory cells makes it more difficult to discriminate between tumour persistence and non-neoplastic changes. Additional studies on the influence of inflammatory tissue and radionecrotic cellular components on radiopharmaceutical uptake are necessary.

Commonly identified on screening mammography breast microcalcifications are the predominant manifestation of ductal carcinoma in situ (DCIS). The aim of this study was to investigate the association between clinico-radiological features and histological findings in patients with screen-detected DCIS.

Consecutive 127 patients with pure DCIS found on stereotactic vacuum-assisted biopsy of screen-detected suspicious microcalcifications without mass entered the study. Patient age, type and distribution of microcalcifications, DCIS nuclear grade (NG) and the presence of comedonecrosis were investigated. Association between parameters was statistically analysed with P < 0.05 as a significance level. Results. Powdery microcalcifications were most often clustered while regional were most common of casting-type (P < 0.001). High, intermediate and low NG of DCIS was significantly related to casting-type, crushed stone-like and powdery microcalcifications, respectively (P < 0.01). Low and intermediate NG DCIS were the most common in clustered and grouped microcalcifications while high NG DCIS was the most often when regional distribution was observed (P < 0.05). Comedonecrosis was significantly more common in high NG DCIS (P < 0.01). The association between comedonecrosis and type of microcalcifications was not significant, but with their distribution was close to the significance level (P = 0.07). Patient age was not significantly related to imaging or histological findings.

The association between pattern of mammographic microcalcifications and histological findings related to more aggressive disease can be helpful in optimal surgery planning in patients with screen-detected DCIS, regarding the extent of breast intervention and consideration of synchronous sentinel node biopsy.

Hepatic splenosis is rare condition, preceded by splenectomy or spleen trauma, the term refers to nodular implantation of normal splenic tissue in the liver. In patients with history of malignancy in particular, it can be mistaken for metastases and can lead to unnecessary diagnostic procedures or inappropriate treatment.

Twenty-two-year old male was treated for immature teratoma linked to undescended right testicle after birth. On regular follow-up examinations no signs of disease relapse or long-term consequences were observed. He was presented with incidental finding of mature cystic teratoma after elective surgery for what appeared to be left-sided inguinal hernia. The tumour was most likely a metastasis of childhood teratoma. Origin within remaining left testicle was not found. Upon further imaging diagnostics, several intrahepatic lesions were revealed. Based on radiologic appearance they were suspicious to be metastases. The patient underwent two ultrasound guided fine-needle aspiration biopsies. Cytologic diagnosis was inconclusive. Histology of laparoscopically obtained tissue disclosed presence of normal splenic tissue and led to diagnosis of hepatic splenosis.

Though hepatic splenosis is rare, it needs to be included in differential diagnosis of nodular hepatic lesions. Accurate interpretation of those lesions is crucial for appropriate management of the patient. If diagnosis eludes after cytologic diagnostics alone, laparoscopic excision of nodular lesion is warranted before considering more extensive liver resection.