PurposeOne of the important developments in brachytherapy in recent years has been the clinical implementation of complex modern technical procedures. Today, 3D-imaging has become the standard procedure and it is used for contouring and precise position determination and reconstruction of used brachytherapy applicators. Treatment planning is performed on the basis of these imaging methods, followed by data transfer to the afterloading device. Therefore, checking the entire treatment chain is of high importance. In this work, we describe an end-to-end test for computed tomography (CT)-based brachytherapy with an high-dose-rate (HDR) afterloading device, which fulfills the recommendation of the German radiation-protection-commission.Material and methodsThe treatment chain consists of a SOMATOM S64 CT scanner (Siemens Medical), the treatment planning system (TPS) BrachyVision v.13.7 (VMS), which utilizes the calculation formalism TG-43 and the Acuros algorithm v. 1.5.0 (VMS) as well as GammaMedplus HDR afterloader (VMS) using an Ir-192 source. Measurement setups for common brachytherapy applicators are defined in a water phantom, and the required PMMA applicator holders are developed. These setups are scanned with the CT and the data is imported into the TPS. Computed TPS reference dose values for significant points located on the side of the applicator are compared with dose measurements performed with a PinPoint 3D chamber 31016 (PTW Freiburg).ResultsThe deviations for the end-to-end test between computed and measured values are shown to be ≤ 5%, when using an implant needle or vaginal cylinder. Furthermore, it can be demonstrated that the test procedure provides reproducible results, while repositioning the applicators without carrying out a new CT-scan.ConclusionsThe end-to-end test presented allows a practice-oriented realization for checking the whole treatment chain for HDR afterloading technique and CT-imaging. The presented phantom seems feasible for performing periodic system checks as well as to verify newly introduced brachytherapy techniques with sufficient accuracy.

The ongoing development in therapies of head and neck malignomas has led to a further differentiation of treatment options. Complex surgical procedures, a wide variety of multi modal therapy options, changing radiation technologies (IMRT - Intensity-modulated radiation therapy) and numerous "targeted therapies" emphasize the need for a precise treatment plan. Beside this, imaging has seen significant improvements beyond the technical ones, e. g. with the implementation of PET/CT scanners. This increase in pre-therapeutic data volume, together with a diversification of treatment options calls for a further discussion of the basics of therapeutic decisions. Planning relevant data processing by computer assisted systems can aid in these decisions. This work describes the current status of relevant computer assisted systems undergoing first testing for head and neck cancer therapy planning. Here, the integration of 3-dimensional patient data plays a central role. This planning tool forms the integrated base for a further development in the areas of radiation planning, documentation and study management.

To evaluate the safety and cosmetic results (cosmetic outcomes and toxicity) of a novel (shortened) fractionation scheme using custom made surface molds for treatment of non-melanoma skin cancer (NMSC) with High Dose Rate (HDR) Brachytherapy. Materials and Methods: This is a retrospective review of our experience with 38 patients (42 non-melanoma skin cancers) treated between February 2003 and December 2014 with HDR Brachytherapy. There were 22 males and 16 females with ages ranging from 37 to 101 years. A shortened HDR fractionated schedule of 10 fractions with 4.85 Gy or 5 Gy each given twice weekly in 5 weeks was used. The tumor dose was equivalent to the conventional external beam radiation therapy (EBRT), usually given in 30 fractions of 2 Gy/day. Individually designed applicators were used in all patients; the size and shape of these varied according to the characteristics of the tumor and its location. Cosmesis was rated as excellent, good, fair or poor using a standardized cosmesis scale (RTOG) as reported by Cox et al. and acute and late toxicity were rated using Criteria for Adverse Events (CTCAEv4). Results: The follow-up period ranged from 4 to 152 months (median 85 months). Local control was 95% with two patients (5%) developing recurrent disease at the follow up time. Good to excellent cosmetic results were achieved in all patients. Conclusions: Brachytherapy is a safe and efficacious treatment option in the management of skin cancer patients. It may be especially useful to treat irregularly shaped lesions and at locations that are difficult to access. Based on this experience, the use of HDR brachytherapy delivered with custom made skin applicators may prove to be especially advantageous for patients with NMSC in anatomical locations where surgery could be mutilating. It is also a viable option for treating older patients and those with busy schedules, in whom the alternative would be several weeks of conventional EBRT.

One of the important proceedings of brachytherapy during the last years was the clinical implementation of complex modern technical procedures. 3D imaging is used regularly for the precise reconstruction of the applicator position. Afterwards irradiation planning is performed on basis of these imaging methods before the data transfer to the afterloading device itself proceeds. Therefore checking the whole treatment chain becomes increasingly important. In accordance with the recommendation of the Strahlenschutzkommission we describe in this work a STP for the CT-guided radiotherapy with an HDR afterloading device. A treatment chain consisting a SOMATOM S64 CT from Siemens and the treatment planning system (TPS) BrachyVision v13.7 from VMS utilizing the associated calculation formalism TG43 and the Acuros algorithm as well as a GammaMedplus HDR Afterloader with a 40.700U Ir-192 source is used for this study. First, several reproducible measurement setups for common applicators used in brachytherapy are developed with PMMA fixations for a water phantom (40x40x40cm3). Those setups are scanned with the CT and then the imaging data is imported into the TPS. Then, with the TPS calculated reference dose values for significant points on the side of the applicator (6.5cm) are verified with a PinPoint 3D chamber 31016 of the PTW Freiburg. It is shown that the deviations for the STP between calculation and measurement are ≤ 5% when using a metal implanting needle or a vaginal cylinder. Furthermore it can be shown that the STP provides reproducible results while repositioning the applicators without carrying out a new CT-scan. Thus the STP presented in this study allows a practice-oriented realization for checking the whole treatment chain for HDR afterloading technique. The presented system seems feasible to perform periodic system tests as well as to control the introduction of new techniques with sufficient accuracy. Radiotherapy with helium ions is considered as a possible alternative to proton and carbon ion therapy. Due to nuclear fragmentation of the projectiles during penetration through material, which leads to the loss of primary ions and to the build-up of fragments with different ranges, the Bragg curve gets altered and exhibits a tail. This implies that treatment planning codes must have realistic nuclear reaction models implemented. There is a lack of measurement data in the therapeutic energy range, therefore an experiment was performed to measure the charge-and mass-changing cross section at energies from 90 to 220 MeV/u on thin graphite targets at the Heidelberg ion beam therapy center (HIT). For measuring the charge-and mass-changing cross sections, a common attenuation method was applied at low intensities of about 500 ions/s: The helium ions remaining after traversing the targets (3 thicknesses from 5 to 10 mm plus a no-target measurement for each energy) were identified by a ∆E-E-telescope consisting of a thin plastic scintillator and a thick BaF 2 scintillator triggered by a start scintillator. For imp...