[Stereotactic radiosurgery of abdominal cancer metastases. Report on the first successful extracranial radiosurgical intervention in Hungary]. / Hasüregi daganatáttétek stereotaxiás sugárkezelése egy ülésben. Beszámoló az elso hazai, koponyán kívüli sugársebészeti beavatkozásról.

Due to the development and increasing effectiveness of novel cancer therapies, the role of local treatments in metastatic diseases have been increasing in the last decades. The aim of the authors was to present the first successful extracranial stereotactic radiosurgical intervention in Hungary. A 58-year-old male patient with gastric adenocarcinoma underwent surgery and adjuvant chemotherapy. Later, surgical removal of suprarenal gland metastases and first line chemotherapy were carried out. Four years after the first surgery a follow up computed tomographic scan revealed bifocal peritoneal metastases caudally from the edge of the liver and the left kidney with diameters of 2 cm in size. Definitive stereotactic body radiosurgery of 12 Gy single dose was performed using cone beam computed tomography image guidance and intensity modulated arc therapy with two pairs of arcs. The total duration of the procedure was only 25 min and early or late side effects were not observed. Follow up computed tomography scans performed 3 and 7 months after the intervention showed complete regression of the metastases. The authors conclude that stereotactic body radiosurgery can be a safe and effective alternative of metastasis surgery in case of slow growing oligo-metastases.

[Clinical experience in image-guided ultra-conformal hypofractionated radiotherapy in case of metastatic diseases at the University of Pécs]. / Áttétes betegségek képvezérelt, ultrakonformális, hipofrakcionált sugárkezelésével szerzett klinikai tapasztalatok ismertetése a Pécsi Tudományegyetem Onkoterápiás Intézetében.

With the development of radiation therapy technology, the utilization of more accurate patient fixation, inclusion of PET/CT image fusion into treatment planning, 3D image-guided radiotherapy, and intensity-modulated dynamic arc irradiation, the application of hypofractionated stereotactic radiotherapy can be extended to specified extracranial target volumes, and so even to the treatment of various metastases. Between October 2012 and August 2014 in our institute we performed extracranial, hypofractionated, image-többguided radiotherapy with RapidArc system for six cases, and 3D conformal multifield technique for one patient with Novalis TX system in case of different few-numbered and slow-growing metastases. For the precise definition of the target volumes we employed PET/CT during the treatment planning procedure. Octreotid scan was applied in one carcinoid tumour patient. Considering the localisation of the metastases and the predictable motion of the organs, we applied 5 to 20 mm safety margin during the contouring procedure. The average treatment volume was 312 cm3. With 2.5-3 Gy fraction doses we delivered 39-45 Gy total dose, and the treatment duration was 2.5 to 3 weeks. The image guidance was carried out via ExacTrac, and kV-Cone Beam CT equipment based on an online protocol, therefore localisation differences were corrected before every single treatment. The patients tolerated the treatments well without major (Gr>2) side effects. Total or near total regression of the metastases was observed at subsequent control examinations in all cases (the median follow-up time was 5 months). According to our first experience, extracranial, imageguided hypofractionated radiotherapy is well-tolerated by patients and can be effectively applied in the treatment of slow-growing and few-numbered metastases.

Metastasis blood test by flow cytometry: in vivo cancer spheroids and the role of hypoxia.

Cancer hypoxia correlates with therapeutic resistance and metastasis, suggesting that hypoxic adaptation is a critical survival advantage for cancer stem cells (CSCs). Hypoxic metabolism, however, may be a disadvantage in aerobic circulation as the extremely low incidence of metastasis-compared to the high circulating tumor-cell numbers (CTCs)-appears to suggest. As rare metastatic CSCs still survive, we searched for a mechanism that protects them from oxygen in circulation. CSCs form multicellular spheroids in vitro from virtually all cancers tested. We asked, therefore, whether cancers also form spheroids in vivo and whether circulating spheroids play a role in metastasis. We used metabolic, apoptotic and hypoxia assays, we measured aerobic barriers and calculated hypoxia vs. spheroid-size correlations. We detected metabolic/oxidative stress in spheroids, we found correlation between stem cell presence and hypoxia and we showed that the size of hypoxic spheroids is compatible with circulation. To detect spheroids in patients, we worked out a new light-scatter flow cytometry blood test and assayed 67 metastatic and control cases. We found in vivo spheroids with positive stem cell markers in cancer blood and they showed exclusive correlation with metastasis. In conclusion, our data suggest that metastatic success depends on CSC-association with in vivo spheroids. We propose that the mechanism involves a portable "micro-niche" in spheroids that may support CSC-survival/adaptation in circulation. The new assay may establish a potential early marker of metastatic progression.

[New methods in the treatment of localized prostate cancer: use of dynamic arc therapy and kV cone-beam CT positioning]. / Új módszerek a prosztatadaganatok sugárkezelésében: dinamikus ívbesugárzás és kilovoltos "cone-beam" komputertomográfiás ellenorzés.

INTRODUCTION: Prostate cancer is a common disease among elderly male patients in developed countries. In addition to prostatectomy, definitive irradiation plays an increasing role in the treatment of localized disease. AIM: The authors wanted to share their experience obtained with the use of the Novalis TX linear accelerator for the application of dose-escalation, dynamic, intensity modulated arc therapy with the routine usage of cone-beam computer tomography based or image guided radiotherapy in patients with prostate cancer. METHOD: Between 2011, December and 2013, February the authors performed 102 treatments. In 10 low risk and 10 high risk prostate cancer patients (median age: 72.5 years) three-dimensional conformal plans with the same target volume coverage were created and tolerance doses of organs at risk (OAR) were compared. RESULTS: Compared to three-dimensional conformal techniques, intensity modulated arc therapy treatments produced a significantly lower dose at organ at risk that led to a more favorable early toxicity rate. CONCLUSIONS: The intensity modulated arc therapy with image guided radiotherapy proved to be a safe standard treatment mode in the daily routine in the institute of the authors. Late toxicity and local control rates need to be further examined.