Prompt gamma imaging for the identification of regional proton range deviations due to anatomic change in a heterogeneous region

Objectives:Prompt gamma (PG) imaging has previously been demonstrated for use in proton range verification of a brain treatment with a homogeneous target region. In this study, the feasibility of PG imaging to detect anatomic change within a heterogeneous region is presented.Methods:A prompt gamma camera recorded several fractions of a patient treatment to the base of skull. An evaluation CT revealed a decrease in sinus cavity filling during the treatment course. Comparison of PG profiles between measurement and simulation was performed to investigate range variations between planned and measured pencil beam spot positions.Results:For one field, an average over range of 3 mm due to the anatomic change could be detected for a subset of spots traversing the sinus cavity region. The two other fields appeared less impacted by the change but predicted range variations could not be detected. These results were partially consistent with the simulations of the evaluation CT.Conclusion:We report the first clinical application of PG imaging that detected some of the expected small regional proton range deviations due to anatomic change in a heterogeneous region. However, several limitations exist with the technology that may limit its sensitivity to detect range deviations in heterogeneous regions.Advances in knowledge:We report on the first detection of range variations due to anatomic change in a heterogeneous region using PGI. The results confirm the feasibility of using PG-based range verification in highly heterogeneous target regions to identify deviations from the treatment plan.     

Local and systemic humoral immune response to protein I of Neisseria gonorrhoeae]

Knowledge of the immune response to natural infection with Neisseria gonorrhoeae is presupposition for the development of a gonococcal vaccine. Pili and protein I have gained importance for a subunite vaccine. A pilus vaccine proved to be ineffective in a field trial due to extensive pilus variability. According to an alternative strategy protein I may represent an important vaccine candidate for a gonococcal vaccine. To study the local and systemic, humoral immune response to N. gonorrhoeae cervical secretion, vaginal fluid and serum from prostitutes and family planning patients were compared by the use of a protein I ELISA. In local secretions and in serum patients in the study group showed significantly higher anti-protein-I-IgA-levels than patients in the control group. In cervical secretion immune response to an acute gonococcal infection consisted of a short lived, significant increase of anti-protein-I-IgA, while anti-protein-I-IgG showed a lower, but longer lasting significant increase. The course of the immune response in vaginal fluid reflected the immune response of cervical secretion at a lower level. In serum antigenic stimulus of a local gonococcal infection resulted in a significant but short lived protein I specific IgG immune response. In local infection with N. gonorrhoeae protein I represents a target antigen of the local and systemic immune response. Clear differences exist between local and systemic humoral immune response in the protein I reactive immunoglobulin class and in the course of reactivity. In the future it may be possible to define epitopes on protein I which induce protective immunity.     

Arzneimittelexantheme bei Therapie der HIV-Infektion mit Efavirenz und Nevirapin

Efavirenz and nevirapine are frequently used drugs in antiretroviral therapy. Rashes are common side effects of these drugs. In this study, we examined the characteristics of efavirenz- and nevirapine-associated rashes.This prospective nonrandomized multicenter study included 662 HIV-infected patients (efavirenz: 325, nevirapine: 337) to determine incidence, duration, cross-reactivity, and outcome upon reexposure.Of the treated patients, 4.5% (n=30) developed rashes (nevirapine: 2.4% and efavirenz: 6.4%). In four patients treatment was not interrupted. Three patients were re-exposed to the initial drug without any side effects.Therapy with nevirapine or efavirenz does not have to be interrupted if rashes exhibit no blistering, mucosal manifestations, or systemic signs.