Radiation-induced cardiovascular disease: impact of dose and volume.

The radiation-induced cardiovascular pathology represents a major cause of morbidity and mortality in patients undergoing therapeutic chest irradiation. There is a broad range of clinical manifestations probably associated with dose, volume and technique of irradiation. From the assumption that prevention is the best way to manage radiation-induced cardiotoxicity, based on the pathophysiogenesis of heart structures, a number of reports of the literature are reviewed. They consider the incidence of cardiovascular disease in patients affected by Hodgkin's lymphoma and breast cancer. The dosimetric prevention is takled in terms of therapeutic procedures and doses (IMRT, 3DCRT) with particular reference to the impact on cardiotoxicity of parameters as maximum heart distance (MHD), mean lung dose (MLD), normal tissue complication probability (NTCP) and V30. The different evaluation criteria of cardiotoxicity are reported, based on the review of the major scoring scales of acute and late complications, which have been worked out in the course of time (LENT-SOMA, RTOG, CTC v.2.0 and CTC v.3.0). The monitoring system of late toxicity used by the authors is presented.

Biological factors and therapeutic modulation in brain tumor radiotherapy.

Diagnosticotherapeutic approaches aimed at the improvement of prognosis of the most aggressive brain tumors tend to include new tools of investigation. Functional imaging, biologic markers, radiosensitizers, the combination of different modalities of radiation therapy and chemotherapy are being experimented. These new approaches to the neoplastic metabolism require increased resources and a close follow-up during treatment to better define the biological target volume. More sophisticated and aggressive techniques as intensity modulated radiation therapy or brachycurietherapy can be suitably included in combined modality therapy.

Biological optimization of the dose in stereotactic radiotherapy of brain tumors.

The techniques of radiotherapy with a high dose gradient require several demanding choices but represent a major innovation in the radiation therapy of brain tumors. To optimize the expected outcomes in terms of effectiveness and efficacy some recent acquisitions of biological parameters of integration of the linear-quadratic model are illustrated, aimed at the progressive understanding of the role of histology, dose fractionation, timing, toxicity and combined modality therapy.