Intenziteno modulirana radioterapija raka dojke – usporedba fIMRT i iIMRT tehnika

The intensity modulated radiotherapy (IMRT) of breast cancer is a newer irradiation technique used at the University Hospital for Tumors (University Hospital Center Sestre Milosrdnice, Zagreb, Croatia).Two IMRT radiotherapy techniques was used to treat patient with breast cancer. Forward intensity modulated radiotherapy (fIMRT) is a planning technique in which dose distribution, accomplished by main beams, is improved by additional conformed beams. Inverse intensity modulated radiotherapy (iIMRT) is a planning technique in which the terms of irradiation are set to the computer, and planning system is making the optimal intense modulated plan. We showed that it was possible to compare fIMRT and iIMRT results. Because of the treatment plan simplicity, shorter irradiation time and bett er dose control, fIMRT remains a method of choice at the University Hospital for Tumors.Intenzitetno modulirana radioterapija (IMRT) karcinoma dojke novija je tehnika zračenja koja se koristi u Klinici za tumore (Klinički bolnički centar Sestre milosrdnice, Zagreb, Hrvatska). U liječenju bolesnica s karcinomom dojke uspoređene su dvije tehnike: Forward intensity modulated radiotherapy (fIMRT) u kojoj se raspodjela doze postiže glavnim snopovima, a poboljšava dodatnim konformalno formiranim snopovima, te Inverse intensity modulated radiotherapy (iIMRT) u kojoj se željeni uvjeti radioterapije unose u kompjuter, a kompjuterski sustav planiranja stvara optimalni radioterapijski plan, koristeći veliki broj manjih snopova (segmenata). Pokazali smo da su rezultati primjene ovih tehnika usporedivi. Zbog jednostavnosti izrade plana, kraćeg vremena radioterapije i bolje kontrole doze, fIMRT ostaje metoda izbora u Klinici za tumore

Radioprotektivni učinci amifostina i melatonina na ljudske limfocite izložene gama-zračenju u uvjetima in vitro

Radioprotective effects of amifostine and melatonin as well as their ability to modulate the level of spontaneous and gamma-irradiation-induced genetic changes on human peripheral blood lymphocytes were investigated using the cytokinesis-block micronucleus (CBMN) assay and sister chromatid exchange (SCE). Parallel blood samples were pre-treated with amifostine, melatonin and their combination for 30 minutes. Negative controls were also included. After the treatment with radioprotectors, one blood sample of each experimental group was exposed to gamma-rays from a 60Co source. The radiation dose absorbed was 2 Gy. Our research confirmed the radioprotective effects of both chemicals in vitro, with no significant genotoxicity. Pre-treated irradiated blood samples showed a decrease in the total number of micronuclei (MN) and in the number of cells with more than one MN. They also showed significantly lower mean SCE values. This study shows that it is possible combine these radioprotectors by adjusting the doses of amifostine to achieve the best radioprotective effect with as few side effects as possible. However, further in vitro and clinical studies are needed to clarify their mechanisms of action and possible interactions.Primjena zračenja u liječenju zloćudnih bolesti (radioterapija) značajno pridonosi preživljenju bolesnika, ali izaziva i niz neželjenih učinaka na zdrave stanice i tkiva. Nuspojave ionizirajućeg zračenja mogu se značajno smanjiti s pomoću kemijskih spojeva s antioksidativnim učinkom koji djeluju kao ‘hvatači’ slobodnih radikala i štite vrlo osjetljivu molekulu DNA. Među spojeve s pretpostavljenim ili dokazanim radioprotektivnim učincima ubrajaju se amifostin i melatonin, koji su predmet istraživanja ovog rada. U literaturi nema dovoljno podataka o njihovoj genotoksičnosti ni međusobnim interakcijama. Stoga smo primjenom mikronukleusnog testa i analize izmjena sestrinskih kromatida (SCE) u uvjetima in vitro istražili djelovanje amifostina i melatonina na genom neozračenih i ozračenih ljudskih limfocita periferne krvi. Pojedinačno ili u kombinaciji, amifostin i melatonin dodavani su u uzorke pune krvi 30 minuta prije jednokratnog ozračivanja gama-zrakama izvora 60Co. Doza zračenja iznosila je 2 Gy, a koncentracije radioprotektora odgovaraju onima prije upotrebljavanim u kliničkoj primjeni ili u preliminarnim istraživanjima na ljudskoj populaciji. Ozračena krv kultivirana je 72 h u uvjetima in vitro prema standardnim protokolima za mikronukleusni test i test izmjena sestrinskih kromatida. Učinci amifostina i melatonina usporedo su istraživani i na kontrolnim, neozračenim uzorcima krvi. Dobiveni rezultati upućuju na značajno smanjenje ukupnog broja mikronukleusa i smanjenje udjela stanica s više od jednog mikronukleusa te sniženje ukupnog broja i raspona izmjena sestrinskih kromatida u pretretiranim uzorcima krvi. Potvrđen je vrlo dobar radioprotektivni učinak svakog spoja testiranog posebno, a ujedno je utvrđeno da oba spoja sinergistički djeluju na snižavanje razina oštećenja izazvanih u genomu limfocita pod utjecajem gama-zraka. S obzirom na to da primjenom citogenetičkih testova nije dokazana genotoksičnost navedenih radioprotektora za ljudske limfocite u uvjetima in vitro, dobiveni rezultati govore u prilog daljnjih istraživanja ovih spojeva i njima srodnih tvari u uvjetima in vivo te njihove moguće zajedničke primjene u kliničkoj praksi

Cytogenetic Follow-Up in Testicular Seminoma Patients Exposed to Adjuvant Radiotherapy

Early stage testicular seminoma is a radiosensitive tumor. Its incidence has significantly increased during the last decade especially in the young population. Although the therapy for testicular seminoma gives very satisfying results, the evaluation of genome damage caused by the therapy is of a great importance in order to recognize possible related health risks. The present study was performed on ten patients diagnosed with seminoma stage I; pT1/2N0M0S0, treated with adjuvant radiotherapy (a radiation dose of 25 Gy divided in 16 fractions) after orchidectomy. To assess the possible existence of an increased baseline DNA/chromosome damage in patients we also selected the appropriate control group of ten healthy men. The levels of primary DNA/chromosome damage in peripheral blood lymphocytes, as well as the dynamics of their repair were studied using the alkaline comet assay, chromosome aberration and cytokinesis-block micronucleus assay. Altogether four blood samples per patient were collected in the course of the therapy: before and after receiving the first dose of radiotherapy, in the middle of the radiotherapy cycle, and after the last dose of radiotherapy. Other two follow-up blood samples were collected six and twelve months after the cessation of therapy. As observed, the administration of the first radiation dose significantly increased the levels of DNA damage in almost all patients compared to their baseline values. Specific patterns of DNA damage were recorded in samples analyzed in the middle of radiotherapy and after receiving the last dose, indicating the possibility of an adaptive response in some patients. The levels of chromosomal aberrations and the incidence of micronuclei also increased in the course of therapy but gradually declined during the follow-up period. Our results confirmed the existence of post-irradiation damage in peripheral blood lymphocytes (and possibly in other non-target cells) of cancer patients which may represent a risk for the secondary cancer development. Considering that the majority of patients with testicular cancer are of a younger age, they represent a population deserving special attention. As cytogenetic screening may detect high-risk individuals, it might be useful in regular medical monitoring of seminoma patients after the successful therapy

Cytogenetic Follow-Up in Testicular Seminoma Patients Exposed to Adjuvant Radiotherapy

Early stage testicular seminoma is a radiosensitive tumor. Its incidence has significantly increased during the last decade especially in the young population. Although the therapy for testicular seminoma gives very satisfying results, the evaluation of genome damage caused by the therapy is of a great importance in order to recognize possible related health risks. The present study was performed on ten patients diagnosed with seminoma stage I; pT1/2N0M0S0, treated with adjuvant radiotherapy (a radiation dose of 25 Gy divided in 16 fractions) after orchidectomy. To assess the possible existence of an increased baseline DNA/chromosome damage in patients we also selected the appropriate control group of ten healthy men. The levels of primary DNA/chromosome damage in peripheral blood lymphocytes, as well as the dynamics of their repair were studied using the alkaline comet assay, chromosome aberration and cytokinesis-block micronucleus assay. Altogether four blood samples per patient were collected in the course of the therapy: before and after receiving the first dose of radiotherapy, in the middle of the radiotherapy cycle, and after the last dose of radiotherapy. Other two follow-up blood samples were collected six and twelve months after the cessation of therapy. As observed, the administration of the first radiation dose significantly increased the levels of DNA damage in almost all patients compared to their baseline values. Specific patterns of DNA damage were recorded in samples analyzed in the middle of radiotherapy and after receiving the last dose, indicating the possibility of an adaptive response in some patients. The levels of chromosomal aberrations and the incidence of micronuclei also increased in the course of therapy but gradually declined during the follow-up period. Our results confirmed the existence of post-irradiation damage in peripheral blood lymphocytes (and possibly in other non-target cells) of cancer patients which may represent a risk for the secondary cancer development. Considering that the majority of patients with testicular cancer are of a younger age, they represent a population deserving special attention. As cytogenetic screening may detect high-risk individuals, it might be useful in regular medical monitoring of seminoma patients after the successful therapy