Advances in Skin Brachytherapy: Cosmesis and Function Preservation.

Skin brachytherapy represents an excellent alternative treatment for patients with non-melanoma skin cancers. It offers superior conformity of dose distribution with rapid dose fall off, reducing the risk of radiotherapy-related treatment toxicity. A smaller treatment volume in brachytherapy, when compared with external beam radiotherapy, is conducive for hypofractionation, which is an attractive option for decreasing outpatient visits to the cancer centre, especially for elderly and frail patients. Skin brachytherapy is an excellent option to preserve function and cosmesis, especially in skin cancers located in the head and neck region. Electronic brachytherapy, image-guided superficial brachytherapy and 3D printed moulds are all emerging advances in skin brachytherapy.

[Radiochemotherapy for invasive bladder cancer : An update]. / Radiochemotherapie beim Harnblasenkarzinom : Ein Update.

BACKGROUND: The standard treatment for muscle-invasive bladder cancer is radical cystectomy with pelvic lymphadenectomy. Primary organ-preservation by means of multimodal therapy, however, can be a viable alternative to radical surgery. OBJECTIVES: The concept and results of multimodal therapy, consisting of initial transurethral resection of the bladder tumor (TUR-B), followed by simultaneous radiochemotherapy (RCT), are presented. MATERIALS AND METHODS: Evaluation of retrospective cohorts and prospective therapy optimization studies on organ-preservation treatment regimens. Comparative meta-analyses comparing cystectomy with multimodal treatment are presented. RESULTS: Complete TUR-B, including bladder mapping and tumor biopsy, should precede simultaneous RCT. Radiosensitization should be cisplatin-based or consist of a combination of 5­fluorouracil and mitomycin C. Complete response rates after TUR-B plus RCT are generated in 60-90% of patients along with 5­year survival rates of 40-75% and preservation of the bladder in approximately 80% of surviving patients. CONCLUSIONS: Multimodal therapy by means of TUR-B followed by simultaneous RCT is a viable alternative to radical cystectomy for patients with muscle-invasive urinary bladder carcinoma. Patients with early tumors (cT2/3N0) are particularly suitable in whom initial TUR-B leads to complete tumor resection (R0).

High Dose Rate Brachytherapy as Monotherapy for Localised Prostate Cancer: Review of the Current Status.

The aim of this article is to review and present the published data on high dose rate (HDR) brachytherapy as monotherapy in the treatment of localised prostate cancer. A search and review of the literature was carried out on PubMed and MedLine using the medical subject headings 'high-dose-rate, brachytherapy, prostate cancer, monotherapy' as search terms. The search yielded more than 100 articles and abstracts published between 2000 and 2016. Only original clinical data on HDR monotherapy reporting oncological outcomes were included. When more than one series from the same institution were identified, the most recent one encompassing the largest patient number was considered for analysis. For citation crosscheck, the ISI web of science database was used employing the same search terms. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control and toxicity scores. Fifteen articles comprising 3546 patients reported clinical outcome and toxicity, with follow-up ranging from median 1.4 to 8.0 years. A variety of dose and fractionation schedules were described, including 19.0 Gy as a single fraction to 54.0 Gy in nine fractions. Biochemical control rates ranged from 66 to 100% in low-risk, 63 to 98% in intermediate-risk and 81-93% in high-risk patients. Late grade 3 genitourinary and gastrointestinal toxicity was 0-16% and 0-2%, respectively. The reported potency preservation rates ranged from 60 to 90%. In conclusion, high biochemical control and low complication rates are reported with HDR monotherapy. It is a safe and effective local treatment modality for organ-confined prostate cancer with reproducible high-quality dosimetry.

Evaluation of time, attendance of medical staff, and resources during interstitial brachytherapy for prostate cancer : DEGRO-QUIRO trial.

INTRODUCTION: The German Society of Radiation Oncology initiated a multicenter trial to evaluate core processes and subprocesses of radiotherapy by prospective evaluation of all important procedures in the most frequent malignancies treated by radiation therapy. The aim of this analysis was to assess the required resources for interstitial high-dose-rate (HDR) and low-dose-rate (LDR) prostate brachytherapy (BRT) based on actual time measurements regarding allocation of personnel and room occupation needed for specific procedures. PATIENTS AND METHODS: Two radiotherapy centers (community hospital of Offenbach am Main and community hospital of Eschweiler) participated in this prospective study. Working time of the different occupational groups and room occupancies for the workflow of prostate BRT were recorded and methodically assessed during a 3-month period. RESULTS: For HDR and LDR BRT, a total of 560 and 92 measurements, respectively, were documented. The time needed for treatment preplanning was median 24 min for HDR (n = 112 measurements) and 6 min for LDR BRT (n = 21). Catheter implantation with intraoperative HDR real-time planning (n = 112), postimplantation HDR treatment planning (n = 112), and remotely controlled HDR afterloading irradiation (n = 112) required median 25, 39, and 50 min, respectively. For LDR real-time planning (n = 39) and LDR treatment postplanning (n = 32), the assessed median duration was 91 and 11 min, respectively. Room occupancy and overall mean medical staff times were 194 and 910 min respectively, for HDR, and 113 and 371 min, respectively, for LDR BRT. CONCLUSION: In this prospective analysis, the resource requirements for the application of HDR and LDR BRT of prostate cancer were assessed methodically and are presented for first time.

A gEUD-based inverse planning technique for HDR prostate brachytherapy: feasibility study.

PURPOSE: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. METHODS: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. RESULTS: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D10 or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. CONCLUSIONS: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

Bone metastases: assessment of therapeutic response through radiological and nuclear medicine imaging modalities.

Radiological and nuclear medicine imaging modalities used for assessing bone metastases treatment response include plain and digitalised radiography (XR), skeletal scintigraphy (SS), dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), magnetic resonance imaging (MRI), [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET) and PET/CT. Here we discuss the advantages and disadvantages of these assessment modalities as evident through different clinical trials. Additionally, we present the more established response criteria of the International Union Against Cancer and the World Health Organization and compare them with newer MD Anderson criteria. Even though serial XR and SS have been used to assess the therapeutic response for decades, several months are required before changes are evident. Newer techniques, such as MRI or PET, may allow an earlier evaluation of response that may be quantified through monitoring changes in signal intensity and standard uptake value, respectively. Moreover, the application of PET/CT, which can follow both morphological and metabolic changes, has yielded interesting and promising results that give a new insight into the natural history of metastatic bone disease. However, only a few studies have investigated the application of these newer techniques and further clinical trials are needed to corroborate their promising results and establish the most suitable imaging parameters and evaluation time points. Last, but not least, there is an absolute need to adopt uniform response criteria for bone metastases through an international consensus in order to better assess treatment response in terms of accuracy and objectivity.

In vivo thermoluminescence dosimetry dose verification of transperineal 192Ir high-dose-rate brachytherapy using CT-based planning for the treatment of prostate cancer.

PURPOSE: To evaluate the potential of in vivo thermoluminescence dosimetry to estimate the accuracy of dose delivery in conformal high-dose-rate brachytherapy of prostate cancer. METHODS AND MATERIALS: A total of 50 LiF, TLD-100 cylindrical rods were calibrated in the dose range of interest and used as a batch for all fractions. Fourteen dosimeters for every treatment fraction were loaded in a plastic 4F catheter that was fixed in either one of the 6F needles implanted for treatment purposes or in an extra needle implanted after consulting with the patient. The 6F needles were placed either close to the urethra or in the vicinity of the median posterior wall of the prostate. Initial results are presented for 18 treatment fractions in 5 patients and compared to corresponding data calculated using the commercial treatment planning system used for the planning of the treatments based on CT images acquired postimplantation. RESULTS: The maximum observed mean difference between planned and delivered dose within a single treatment fraction was 8.57% +/- 2.61% (root mean square [RMS] errors from 4.03% to 9.73%). Corresponding values obtained after averaging results over all fractions of a patient were 6.88% +/- 4.93% (RMS errors from 4.82% to 7.32%). Experimental results of each fraction corresponding to the same patient point were found to agree within experimental uncertainties. CONCLUSIONS: Experimental results indicate that the proposed method is feasible for dose verification purposes and suggest that dose delivery in transperineal high-dose-rate brachytherapy after CT-based planning can be of acceptable accuracy.

Effects of strain, behavior and age on the self-administration of ethanol, nicotine, cocaine and morphine by two rat strains.

Two genetically different strains, Brown Norway rats (BNR) and Wistar Kyoto rats (WKR), with the latter showing higher emotionality and lower plasma stress catecholamine responses, were compared for their voluntary intake of ethanol, nicotine, cocaine and morphine. Younger BNR self-administered the same amounts of all 4 substances as did the younger WKR suggesting a similar genetic basis for all drugs at this age. Older BNR consumed less ethanol and nicotine but equal amounts of cocaine and morphine as compared to older WKR, and older BNR were more sensitive to the effects of ethanol than WKR suggesting a different genetic basis for different drugs at an older age. Forcing both strains to consume one of the drugs did not affect a subsequent voluntary consumption of ethanol and morphine but reduced nicotine intake in WKR and decreased cocaine intake in both strains suggesting that drug use is determined by individual preferences and not drug exposure per se. The behavioral characteristics of both strains coincide only with the self-administration of ethanol and nicotine supporting a possible genetic linkage between anxiety/stress and ethanol and nicotine use.