Search

•Male survivors of HL treated with chest radiotherapy have an increased risk of developing BC compared with the general population.•Although the occurrence of male BC is an uncommon event, clinicians should be alert to BC symptoms in male survivors of HL.

Different planning and treatment systems for intracranial stereotactic radiosurgery available in the Netherlands are compared. The systems for intracranial radiosurgery include: Gamma Knife, Cyberknife, Novalis, and Tomotherapy. Electronic data of 5 patients was transferred to all participating centres and treatment plans were generated according to 2 different prescription protocols. For this study, plans were also generated for a conventional linac. Even systems with a high resolution (Gammaknife and Novalis) have conformity indices in violation with RTOG guidelines (CI > 2.5) when target volumes of <0.5 cc are treated. For medium sized targets (0.5–1 cc) all systems performed reasonably well, but for the different systems a large range of conformity indices was seen (1.1 to 3.7). The differences are partly system dependent but depend also on specific planning choices made. For larger target volumes (>1 cc), all systems perform well. The workload of the different techniques was comparable although the treatment times were usually longer for Gamma Knife radiosurgery. We conclude that small targets should be treated by dedicated systems, larger volumes (>0.5–1 cc) can also be treated using conventional treatment systems equipped with a MLC.

Demyelination is one of the pathological conditions identified as a late response of the central nervous system (CNS) to irradiation. We have proposed that radiation-induced depletion of glial stem cells, which are the source of myelinating cells in the CNS, would lead to a lack of replacement of senescent or otherwise damaged oligodendrocytes. This impaired process of cell renewal would result in a decline of oligodendrocytes, i.e. demyelination. In the present study the repair capacity of glial stem cells was investigated and compared with the repair capacity of the CNS in vivo using functional endpoints. For this purpose, glial stem cells, derived from the adult rat optic nerve, were subjected to fractionated irradiation in vivo and in vitro and their survival was quantified with an in vitro clonogenic assay. The data were analysed by three different methods, all based on the LQ-model (single dose survival curve; 'βRR', 'Fe-plot'). The resulting value of the β-parameter of adult glial stem cells is consistent with values obtained for functional endpoints after irradiation of the CNS in vivo. The α/β-ratio (4·9-7·3 Gy) of adult glial stem cells, however, is higher than the α/β-ratio (∼ 2 Gy) obtained for CNS in vivo and is closer to that of an acute responding tissue.

Abstract: Purpose: In a study to determin the effectiveness of ionizing radiation on the deterioration of visual acuity (VA) due to choroidal neovascularisation (CNV) the affected eyes of 10 patients were treated with a total dose of 24 Gy (6 Gy fractions). A special lens-sparing technique was used to avoid cataract development. During 30 months of follow-up the visual acuity (VA) and scar size (SS) of the treated eyes and fellow eyes of all 10 patients were evaluated.Results: After 30 months of follow-up 5 eyes showed a stable VA and fluorescein angiogram (FA) appearance. Concerning 4 out of 5 eyes with progressive disease, the 4 eyes treated with radiation therapy had better VA and smaller SS as compared with the untreated fellow eyes with exudative AMD.Conclusions: The results suggest that 24 Gy either stabilizes or delays the deleterious effects of CNV on the visual acuity. Until now no late side effects have been observed.

In this pilot study the effect of radiation therapy on subfoveal CNV membranes associated with age-related macular degeneration was evaluated. Four groups of 10 patients were treated with external beam radiotherapy (16 MV photons) on an area of 1 cm2 (macular region) using a lens-sparing technique and total dose of 8 to 24 Gy. The first group received 8 Gy in a single fraction. In this group only 30% had a stable visual acuity and a stable FA after 18 months follow-up. In 50% of patients in group 2 (12 Gy) and 40% of patients in group 3 (18 Gy) the visual acuity and FA appearance remained stable after 18 months of follow-up. In the last group (24 Gy) 80% of patients had a stable visual acuity and FA appearance after 12 months follow-up. Comparison of these findings with the natural history data of subfoveal age-related CNV, suggests a beneficial effect of radiation therapy with a total dose of 12 Gy or more on the progression of CNV membranes.

Normal glial progenitor cells can be isolated from the rat central nervous system (CNS) and cultured in vitro on a monolayer of type-1 astrocytes. These monolayers are able to support and stimulate explanted glial progenitor cells to proliferate. Employing these in vitro interactions of specific glial cell types, an in vivo-in vitro clonogenic assay has been developed. This method offers the possibility to study the intrinsic radiosensitivity, repair and regeneration of glial progenitor cells after in vitro or in vivo irradiation.