Is this the swan song of endovascular brachytherapy?

Image guided, adaptive, accelerated, high dose brachytherapy as model for advanced small volume radiotherapy

Brachytherapy has consistently provided a very conformal radiation therapy modality. Over the last two decades this has been associated with significant improvements in imaging for brachytherapy applications (prostate, gynecology), resulting in many positive advances in treatment planning, application techniques and clinical outcome. This is emphasized by the increased use of brachytherapy in Europe with gynecology as continuous basis and prostate and breast as more recently growing fields. Image guidance enables exact knowledge of the applicator together with improved visualization of tumor and target volumes as well as of organs at risk providing the basis for very individualized 3D and 4D treatment planning. In this commentary the most important recent developments in prostate, gynecological and breast brachytherapy are reviewed, with a focus on European recent and current research aiming at the definition of areas for important future research. Moreover the positive impact of GEC-ESTRO recommendations and the highlights of brachytherapy physics are discussed what altogether presents a full overview of modern image guided brachytherapy. An overview is finally provided on past and current international brachytherapy publications focusing on "Radiotherapy and Oncology". These data show tremendous increase in almost all research areas over the last three decades strongly influenced recently by translational research in regard to imaging and technology. In order to provide high level clinical evidence for future brachytherapy practice the strong need for comprehensive prospective clinical research addressing brachytherapy issues is high-lighted.

Patterns of care study for brachytherapy: results of the questionnaire for the years 2002 and 2007 in The Netherlands

Purpose

The goal of the ESTRO Patterns of Care study for Brachytherapy in Europe (PCBE) 2002 was to develop an aid to analyse brachytherapy practices. A 2^nd version of the PCB questionnaire was created for 2007. Data over 2007 were collected at the radiotherapy institutions in The Netherlands and compared with those from 2002. The aim of this study is to describe national brachytherapy practices, to demonstrate trends, and to provide data for rational health care planning.

Material and methods

Data were collected using a web-based questionnaire. For each centre, a local coordinator, responsible for coordinating the questionnaires and support of the further analysis was assigned. Data from the national cancer incidence registry was used for comparison with the data from the 21 Dutch departments.

Results

There was a decrease in low-dose rate equipment in parallel to an increase in both pulsed-dose rate and high-dose rate equipment. The use of 3D CT and MR based imaging techniques showed a slow rise. The most common clinical procedures were for prostate, gynaecological, and oesophageal tumours. A large increase (146%) in permanent implant prostate applications using 125I seeds was observed. The numbers of oesophageal and gynaecological treatments remained stable. There is concern on the low numbers of cases treated in some institutions for a few complex treatment sites. For head and neck, anal canal, paediatrics, bladder and eye interventions it ranged from 3-20 patients per year per institution.

Conclusions

The increase in number of patient treated with brachytherapy is in accordance with the increases in cancer incidence. The percentage of all radiotherapy patients treated with brachytherapy (approximately 5%) remained stable. The survey identified certain trends in resources and techniques, as well as areas of expected improvement and possible gain in clinical outcome. Data reported from this survey can be used for further planning of resources, facilities and concentration of a low-volume specialised and complex treatments.

Results of the 2005-2008 Association of Residents in Radiation Oncology survey of chief residents in the United States: clinical training and resident working conditions

PURPOSE

To document clinical training and resident working conditions reported by chief residents during their residency.

METHODS AND MATERIALS

During the academic years 2005 to 2006, 2006 to 2007, and 2007 to 2008, the Association of Residents in Radiation Oncology conducted a nationwide survey of all radiation oncology chief residents in the United States. Chi-square statistics were used to assess changes in clinical training and resident working conditions over time.

RESULTS

Surveys were completed by representatives from 55 programs (response rate, 71.4%) in 2005 to 2006, 60 programs (75.9%) in 2006 to 2007, and 74 programs (93.7%) in 2007 to 2008. Nearly all chief residents reported receiving adequate clinical experience in commonly treated disease sites, such as breast and genitourinary malignancies; and commonly performed procedures, such as three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. Clinical experience in extracranial stereotactic radiotherapy increased over time (p < 0.001), whereas clinical experience in endovascular brachytherapy (p <0.001) decreased over time. The distribution of gynecologic and prostate brachytherapy cases remained stable, while clinical case load in breast brachytherapy increased (p = 0.006). A small but significant percentage of residents reported receiving inadequate clinical experience in pediatrics, seeing 10 or fewer pediatric cases during the course of residency. Procedures involving higher capital costs, such as particle beam therapy and intraoperative radiotherapy, and infrequent clinical use, such as head and neck brachytherapy, were limited to a minority of institutions. Most residency programs associated with at least one satellite facility have incorporated resident rotations into their clinical training, and the majority of residents at these programs find them valuable experiences. The majority of residents reported working 60 or fewer hours per week on required clinical duties.

CONCLUSIONS

Trends in clinical training and resident working conditions over 3 years are documented to allow residents and program directors to assess their residency training.

The tissue plasminogen activator gene promoter: a novel tool for radiogenic gene therapy of the prostate?

BACKGROUND

Radiation therapy is a treatment modality routinely used in cancer management so it is not unexpected that radiation-inducible promoters have emerged as an attractive tool for controlled gene therapy. The human tissue plasminogen activator gene promoter (t-PA) has been proposed as a candidate for radiogenic gene therapy, but has not been exploited to date. The purpose of this study was to evaluate the potential of this promoter to drive the expression of a reporter gene, the green fluorescent protein (GFP), in response to radiation exposure.

METHODS

To investigate whether the promoter could be used for prostate cancer gene therapy, we initially transfected normal and malignant prostate cells. We then transfected HMEC-1 endothelial cells and ex vivo rat tail artery and monitored GFP levels using Western blotting following the delivery of single doses of ionizing radiation (2, 4, 6 Gy) to test whether the promoter could be used for vascular targeted gene therapy.

RESULTS

The t-PA promoter induced GFP expression up to 6-fold in all cell types tested in response to radiation doses within the clinical range.

CONCLUSIONS

These results suggest that the t-PA promoter may be incorporated into gene therapy strategies driving therapeutic transgenes in conjunction with radiation therapy.