Helical Tomotherapy for Scalp Recurrence of Primary Eccrine Mucinous Adenocarcinoma

Primary cutaneous mucinous carcinomas originating from sweat glands are rare tumors with patterns of spread that are difficult to predict. We present a case of a five times recurring eccrine mucinous adenocarcinoma of the scalp, previously treated with surgery and adjuvant radiation therapy. After magnetic resonance imaging (MRI) and 18F-fluoro-2-deoxyglucose positron-emission tomography/computed tomography (18FDG-PET/CT), which documented local recurrence, the patient was considered eligible for salvage irradiation of the scalp. We decided to use helical tomotherapy, which combines conformity of dose delivery with the possibility of daily control of the setup accuracy. Forty gray (2Gy/fraction) to the planning target volume and 50 Gy (2.5Gy/fraction) to the biological target volume defined on the basis of 18FDGPET/CT was prescribed with a simultaneous integrated boost technique. After 12 fractions the patient was submitted to intermediate evaluation by 18FDG-PET/CT, which showed a partial response to the treatment. After 2, 4, 8, and 12 months, 18FDG-PET/CT showed a complete metabolic local response. This experience suggests a possible role of 18FDG-PET/CT-guided helical tomotherapy as an alternative to repeated and frequently demolitive surgery approaches.

Enhancing effect of zinc on astroglial and cerebral endothelial histamine uptake

We have studied the effect of zinc ion on the uptake of histamine (HA) into cultured astroglial and cerebral endothelial cells and established that Zn(2+) enhances the uptake of the amine dose-dependently and in remarkable extents by increasing the V(max) to about 3-fold (from 3.25 +/- 0.42 to 8.50 +/- 0.97 pmol/mg protein/min in astroglial cells) without altering the K(M) (0.20 +/- 0.03 microM) significantly. The stimulatory effect of zinc ion showed strong sensitivity for VUF 8407, an inhibitory compound of astroglial and cerebral endothelial uptake of HA. In the presence of 20 microM VUF 8407 the zinc-enhanced uptake was reduced by about 50% in both cell types. Binding measurements revealed increased capacities of the zinc-exposed HA binding (B(max)= 0.41 +/- 0.05 increased to 1.21 +/- 0.16 pmol/mg protein in astroglial membranes and B(max) = 0.25 +/- 0.03 enhanced to 1.05 +/- 0.12 pmol/mg protein in cerebral endothelial membranes) but statistically unchanged affinity of the ligand for HA carrier (K(D) values calculated as 35.2 +/- 3.4 nM and 45.1 +/- 3.8 nM for astroglial bindings; whereas 25 +/- 2.1 nM and 30 +/- 2.6 nM for cerebral endothelial bindings of the amine). The compound VUF 8407 reduced the B(max) of zinc-exposed HA binding of astroglial membranes but did not modify the K(D) of the zinc-exposed membrane significantly. The ex vivo experiments confirmed our in vitro findings; an i.c.v. dose of 0.4 micromol/kg ZnSO(4,) 24 hr after the injection, enhanced the uptake of [(3)H]HA into dissociated hypothalamic and cerebellar cells to about 2- and 3-fold, respectively. Present data clearly showed that zinc exposures enhance the astroglial and the cerebral endothelial uptake of HA in vitro and it might be considered that zinc produces similar effects in vivo. Free zinc may participate in the regulation of the extraneuronal HA concentration and this metal ion (endogenous or exogenous) might be favored in the removal of the amine from the interstitial space especially in conditions with relatively high HA.