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Abstract: Background. Thyroid cancer is one of the most common secondary cancers after treatment of malignancy in childhood or adolescence. Thyroid gland is very sensitive to the carcinogenic effect of ionizing radiation, especially in children. Imbalance between pro- and anti-oxidant factors may play a role in thyroid carcinogenesis. Our study aimed to assess the relationship between genetic variability of antioxidant defence-related genes and the risk of secondary thyroid cancer after treatment of malignancy in childhood or adolescence. Patients and methods. In a retrospective study, we compared patients with childhood or adolescence primary malignancy between 1960 and 2006 that developed a secondary thyroid cancer (cases) with patients (controls), with the same primary malignancy but did not develop any secondary cancer. They were matched for age, gender, primary diagnosis and treatment (especially radiotherapy) of primary malignancy. They were all genotyped for SOD2 p.Ala16Val, CAT c.-262C>T, GPX1 p.Pro200Leu, GSTP1 p.Ile105Val, GSTP1 p.Ala114Val and GSTM1 and GSTT1 deletions. The influence of polymorphisms on occurrence of secondary cancer was examined by McNemar test and Cox proportional hazards model. Results. Between 1960 and 2006 a total of 2641 patients were diagnosed with primary malignancy before the age of 21 years in Slovenia. Among them 155 developed a secondary cancer, 28 of which were secondary thyroid cancers. No significant differences in the genotype frequency distribution were observed between cases and controls. Additionally we observed no significant influence of investigated polymorphisms on time to the development of secondary thyroid cancer. Conclusions. We observed no association of polymorphisms in antioxidant genes with the risk for secondary thyroid cancer after treatment of malignancy in childhood or adolescence. However, thyroid cancer is one of the most common secondary cancers in patients treated for malignancy in childhood or adolescence and the lifelong follow up of these patients is of utmost importance.
Keywords: secondary thyroid cancer, antioxidant genes, genetic polymorphism
Published in DiRROS: 09.05.2024; Views: 72; Downloads: 47
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Abstract: Standard applicators for cervical cancer Brachytherapy (BT) do not always achieve acceptable balance between target volume and normal tissue irradiation. We aimed to develop an innovative method of Targetvolume Density Mapping (TDM) for modelling of novel applicator prototypes with optimal coverage characteristics. Patients and methods. Development of Contour-Analysis Tool 2 (CAT-2) software for TDM generation was the core priority of our task group. Main requests regarding software functionalities were formulated and guided the coding process. Software validation and accuracy check was performed using phantom objects. Concepts and terms for standardized workflow of TDM post-processing and applicator development were introduced. Results. CAT-2 enables applicator-based co-registration of Digital Imaging and Communications in Medicine (DICOM) structures from a sample of cases, generating a TDM with pooled contours in applicator-eye-view. Each TDM voxel is assigned a value, corresponding to the number of target contours encompassing that voxel. Values are converted to grey levels and transformed to DICOM image, which is transported to the treatment planning system. Iso-density contours (IDC) are generated as lines, connecting voxels with same grey levels. Residual Volume at Risk (RVR) is created for each IDC as potential volume that could contain organs at risk. Finally, standard and prototype applicators are applied on the TDM and virtual dose planning is performed. Dose volume histogram (DVH) parameters are recorded for individual IDC and RVR delineations and characteristic curves generated. Optimal applicator configuration is determined in an iterative manner based on comparison of characteristic curves, virtual implant complexities and isodose distributions. Conclusions. Using the TDM approach, virtual applicator prototypes capable of conformal coverage of any target volume, can be modelled. Further systematic assessment, including studies on clinical feasibility, safety and effectiveness are needed before routine use of novel prototypes can be considered.
Keywords: cervical cancer, brachytherapy, applicators, virtual modelling
Published in DiRROS: 09.05.2024; Views: 61; Downloads: 16
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Abstract: Primary treatment of patients with advanced epithelial ovarian cancer consists of chemotherapy either before (neoadjuvant chemotherapy, NACT) or after primary surgery (adjuvant chemotherapy). The goal of primary treatment is no residual disease after surgery (R0 resection) what is associated with an improvement in survival of patients. There is, however, no evidence of survival benefits in patients with R0 resections after prior NACT. Methods. We retrospectively reviewed the records of patients who were treated with diagnosis of epithelial ovarian cancer at Institute of Oncology Ljubljana in the years 2005%2007. The differences in the rates of R0 resections, progression free survival (PFS), overall survival (OS) and in five-year and eight-year survival rates between patients treated with NACT and patients who had primary surgery were compared. Results. Overall 160 patients had stage IIIC epithelial ovarian cancer. Eighty patients had NACT and eighty patients had primary surgery. Patients in NACT group had higher rates of R0 resection (42% vs. 20%; p = 0.011) than patients after primary surgery. PFS was 14.1 months in NACT group and 17.7 months after primary surgery (p = 0.213). OS was 24.8 months in NACT group and 31.6 months after primary surgery (p = 0.012). In patients with R0 resections five-year and eight-year survival rates were 20.6% and 17.6% in NACT group compared to 62.5% and 62.5% after primary surgery (p < 0.0001), respectively. Conclusions. Despite higher rates of R0 resections achieved by NACT, survival of patients treated with NACT was inferior to survival of patients who underwent primary surgery. NACT should only be offered to patients with advanced epithelial cancer who are not candidates for primary surgery.
Keywords: ovarian cancer, advanced ovarian cancer, neoadjuvant chemotherapy, primary surgery
Published in DiRROS: 30.04.2024; Views: 106; Downloads: 28
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Abstract: Aiming at improving treatment individualization in patients with prostate cancer treated with combination of external beam radiotherapy and high-dose-rate brachytherapy to boost the dose to prostate (HDRB-B), the objective was to evaluate factors that have potential impact on obstructive urination problems (OUP) after HDRB-B. Patients and methods. In the follow-up study 88 patients consecutively treated with HDRB-B at the Institute of Oncology Ljubljana in the period 2006-2011 were included. The observed outcome was deterioration of OUP (DOUP) during the follow-up period longer than 1 year. Univariate and multivariate relationship analysis between DOUP and potential risk factors (treatment factors, patients% characteristics) was carried out by using binary logistic regression. ROC curve was constructed on predicted values and the area under the curve (AUC) calculated to assess the performance of the multivariate model. Results. Analysis was carried out on 71 patients who completed 3 years of follow-up. DOUP was noted in 13/71 (18.3%) of them. The results of multivariate analysis showed statistically significant relationship between DOUP and anticoagulation treatment (OR 4.86, 95% C.I. limits: 1.21-19.61, p = 0.026). Also minimal dose received by 90% of the urethra volume was close to statistical significance (OR = 1.23; 95% C.I. limits: 0.98-1.07, p = 0.099). The value of AUC was 0.755. Conclusions. The study emphasized the relationship between DOUP and anticoagulation treatment, and suggested the multivariate model with fair predictive performance. This model potentially enables a reduction of DOUP after HDRB-B. It supports the belief that further research should be focused on urethral sphincter as a critical structure for OUP.
Keywords: prostate cancer, high-dose-rate brachytherapy boost, urinary stricture, obstructive urination problems
Published in DiRROS: 30.04.2024; Views: 75; Downloads: 49
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Abstract: Thrombotic events, arterial or venous in origin, still remain a source of substantial morbidity and mortality in cancer patients. The propensity for their development in oncology patients is partially a consequence of the disease itself and partially a result of our attempts to treat it. One of the rarest and deadliest thromboembolic complications is arterial mesenteric ischemia. The high mortality rate is caused by its rarity and by its non-specific clinical presentation, both of which make early diagnosis and treatment difficult. Hence, most diagnoses and treatments occur late in the course of the disease. The issue survivors of arterial mesenteric ischemia may face is short bowel syndrome, which has become a chronic condition after the introduction of parenteral nutrition at home. We present a 73-year-old rectal cancer patient who developed acute arterial mesenteric thrombosis at the beginning of the pre-operative radiochemotherapy. Almost the entire length of his small intestine, except for the proximal 50 cm of it, and the ascending colon had to be resected. After multiorgan failure his condition improved, and he was able to successfully complete radical treatment (preoperative radiotherapy and surgery) for the rectal carcinoma, despite developing short bowel syndrome (SBS) and being dependent upon home-based parenteral nutrition to fully cover his nutritional needs. Mesenteric ischemia and resultant short bowel syndrome are not absolute contraindications for radical oncological treatment since such patients can still achieve long-term remission.
Keywords: acute mesenteric ischemia, capecitabine, multiorgan failure, rectal cancer, short bowel syndrome
Published in DiRROS: 23.04.2024; Views: 75; Downloads: 26
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