[Radiobiological pitfalls of new techniques in radiotherapy]. / Radiobiologická úskalí nových technik v radioterapii.

Radiotherapy techniques in the last decade evolved to the stage where the potential dose distribution significantly differs from earlier practices. Rotational IMRT, robotic radiotherapy or proton radiotherapy enables extremely precise dose delivery to target volumes, on the other hand, these techniques can yield a number of problems. As for photon radiotherapy, this concerns primarily the effect of large volume irradiation with doses of 0.10.5 Gy. In this range, the hypersensitivity to low doses and the bystander effect may play an important role. Proton therapy is upredictable in its radiobiological effect at the end of the Bragg curve and there is also uncertainty about the peaks exact location. These effects should be taken into account when choosing among the irradiation techniques or when applying tolerance doses to critical organs in clinical practice, especially in younger patients with long survival expectation.

Influence of neoadjuvant treatment of rectal carcinoma on operability and incidence of distant metastases.

In the Czech Republic, rectal carcinoma does not only represent a medical problem, but also a socio-economic one. At our department, we treated totally 266 patients with rectal carcinoma in the years 1998 through 2006. Among our patients, neoadjuvant treatment led to a reduction in size of the tumour in 37.6 %, in 50.8 % the size did not change. In T3 tumours, the reduction in size was observed in 36.7 % of the patients and did not change in 56 %; in T4 tumours, the reduction in size was observed in 60% of the patients. In 88 % of the patients who underwent the operation, no residual tumour was found, in 9 % of patients, a residual tumour was detected. In 19 % of the patients, a local recurrence of the tumour was detected. A statistically significant relationship was proved between the appearance of the metastatic disease and the presence of angioinvasion and the size of the primary tumour according to the Duke's classification (Tab. 1, Fig. 4, Ref. 20).

Clinical, pathological and molecular characteristics of newly diagnosed breast cancers.

Selection of breast carcinoma therapy is based on standard prognostic markers, such as tumor size, infiltration of regional lymph nodes, tumor grade, and expression of hormonal receptors. Insufficient treatment results stimulate a search for new markers which may lead to a more precise characterization of these tumors and to a more effective treatment. In our study we determined essential clinical and histopathological characteristics of non-metastasizing breast cancer - primary tumor size, involvement of the regional lymph nodes, expression of hormonal receptors and a status of ERBB-2 protein (HER-2), DNA ploidy, and their possible inter-correlation. In this study 77 patients were analyzed. The mean age was 59.3 years. Tumor stage T1 was found in 53%, T2 in 39%, T3 in 5% of patients. 57% of patients did not show any metastases in the axillary lymph nodes. A higher tumor grade 3 was seen mainly in larger tumors, in 62% of T2 and 66% of T3 tumors; 77% of carcinomas expressed hormonal receptors. HER-2 expression was shown in 21 T1 tumors, 13 T2 tumors, and 1 T3 tumor. 47 tumors were diploid. 13 T1 tumors, 14 T2 tumors, and 2 T3 tumors were aneuploid. Any significant correlation among staging T, N and ERBB-2 expression, hormonal receptors expression, tumor grade and DNA ploidy was found.