Imaging after GliaSite brachytherapy: prognostic MRI indicators of disease control and recurrence.

PURPOSE: In this study, we analyzed the magnetic resonance imaging (MRI) changes in patients after GliaSite treatment and characterized the prognostic MRI indicators in these patients. METHODS AND MATERIALS: A total of 25 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System. Patients at the Johns Hopkins Hospital with recurrent glioblastoma multiforme underwent surgical resection followed by GliaSite balloon implantation. Available MRI scans for 20 patients were obtained throughout the post-GliaSite treatment course. These were reviewed and analyzed for prognostic significance. RESULTS: After GliaSite treatment, all patients developed some degree of T(1)-weighted contrast and T(2)-weighted hyperintensity around the resection cavity. The development of enhancement on T(1)-weighted contrast-enhanced imaging and the size of these lesions, in the absence of increasing T(2)-weighted hyperintensity, before clinical progression was not associated with decreased survival. Patients with T(1)-weighted enhancement >1 cm had a median survival of 13.6 months and those with T(1)-weighted lesions

Storage, transmission, and retrieval of digital mammography, including recommendations on image compression.

This paper on digital mammography image storage, retrieval, and transmission is 1 of 3 papers written as part of an intersociety effort to establish image quality standards for digital mammography. The information included in this paper is intended to support the development of an American College of Radiology (ACR) guideline on image quality for digital mammography. The topics of the other 2 papers are digital mammography image acquisition and digital mammography image display. The societies that were represented in compiling this document were the Radiological Society of North America, the ACR, the American Association of Physicists in Medicine, and the Society for Computer Applications in Radiology. These papers describe in detail what is known to improve image quality for digital mammography and make recommendations about how digital mammography should be performed to optimize the visualization of breast cancers using this imaging tool. Through the publication of these papers, the ACR is seeking input from industry, radiologists, and other interested parties on their contents so that the final ACR guideline for digital mammography will represent the consensus of the broader community interested in these topics.

Treatment of recurrent glioblastoma multiforme with GliaSite brachytherapy.

PURPOSE: In this study, we assess the efficacy of GliaSite brachytherapy in the treatment of patients with recurrent glioblastoma multiforme (GBM). METHODS AND MATERIALS: Between 1999 and 2004, 24 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System (RTS). The GliaSite is an inflatable balloon catheter that is placed in the resection cavity at the time of surgical resection. Low-dose-rate radiation is then delivered locally by temporarily inflating the balloon with an aqueous solution of organically bound (125)I (Iotrex [sodium 3-((125)I)-iodo-4-hydroxybenzenesulfonate]). Patients at the Johns Hopkins Hospital with recurrent GBM, who were previously treated with surgery and external beam radiotherapy, underwent surgical resection followed by GliaSite balloon implantation. Subsequently, the patients received radiation therapy using the GliaSite to a mean dose of 53.1 Gy. Ten patients were male, and 14 patients were female. The mean age was 48.1 years. All patients had pathologically confirmed recurrent GBM. The median Karnofsky performance status (KPS) was 80. Median follow-up time was 21.8 months. RESULTS: At the time of analysis, 18 patients (75%) had died; 6 patients (25%) were alive. Median survival from diagnosis for all patients was 23.3 months. Median survival after GliaSite brachytherapy was 9.1 months. Patients with a KPS > or =70 had a median survival of 9.3 months, whereas patients with a KPS <70 had a median survival of 3.1 months (p < 0.003). Survival was not significantly different between patients receiving 45 Gy and patients receiving a dose greater than 45 Gy. Acute side effects were minor, consisting of mild nausea and/or headache. One patient developed a wound infection. No incidents of meningitis were observed. Late sequelae were rare, but 2 incidents of symptomatic radiation necrosis were observed. One patient developed transient expressive aphasia. CONCLUSIONS: GliaSite radiotherapy confers a prolongation of survival in patients with recurrent glioblastoma multiforme compared to historical controls with recurrent GBM. GliaSite therapy leads to a favorable survival outcome of 9.3 months in patients with KPS > or =70, but only 3.1 months in patients with KPS <70. Favorable survival is observed for patients within each recursive partitioning analysis class. Treatment with GliaSite is safe and generally well tolerated. Additional data are needed to fully assess the therapeutic benefit of GliaSite brachytherapy for recurrent GBM.

Fiducial markers implanted during prostate brachytherapy for guiding conformal external beam radiation therapy.

Prostate movement imposes limits on safe dose-escalation with external beam radiation therapy. If the precise daily location of the prostate is known, dose escalation becomes more feasible. We have developed an approach to dose escalation using a combination of prostate brachytherapy followed by external beam radiation therapy in which fiducial markers are placed along with (125)I seeds during transperineal interstitial permanent prostate brachytherapy. These markers serve to verify daily prostate location during the subsequent external beam radiotherapy. Prior to implementing this approach, preliminary studies were performed to test visibility of the markers. Three different (125)I seed models, as well as gold and silver marker seeds were placed within tissue-equivalent phantoms. Images were obtained with conventional x-rays (75-85 kV) and 6 MV photons from a linear accelerator. All (125)I seed models were clearly visible on conventional x-rays but none were seen with 6 MV photons. The gold markers were visible with both energies. The silver markers were visible with conventional x-rays and 6 MV x-rays, but not as clearly as the gold seeds at 6 MV. Subsequently, conventional x-rays, CT scans, and 6 MV port films were obtained in 29 patients in whom fiducial gold marker seeds were implanted into the prostate during (125)I prostate brachytherapy. To address the possibility of "seed migration" within the prostate, CT scans were repeated 5 weeks apart in 14 patients and relative positions of the gold seeds were evaluated. The repeated CT scans showed no change in intraprostatic gold marker location, suggesting minimal migration. The gold seeds were visible with conventional x-rays, CT, and 6 MV port films in all patients. During the course of external beam radiation therapy, the gold markers were visible on routine 6 MV port films and were seen in different locations from film to film suggesting prostate motion. Mean daily displacement was 4-5 mm in the anterior-posterior, and 4-5 mm in superior-inferior dimensions. Left-right displacement appeared less, averaging 2-3 mm. We conclude that implantation of gold marker seeds during prostate brachytherapy represents an easily implemented and practical means of prostate localization during subsequent image-guided external beam radiotherapy. With such markers, conformality of the external beam component can be confidently improved without expensive new equipment.

Dosimetric and technical considerations for interstitial adenoviral gene therapy as applied to prostate cancer.

PURPOSE: To introduce a simple and specific dosimetric model and an adenoviral delivery technique for interstitial adenoviral gene therapy of prostate cancer. METHODS AND MATERIALS: CG7060, a PSA-specific, replication-competent adenovirus, was used in a Phase I study in the treatment of 20 patients with locally recurrent prostate cancer. The virus was delivered directly into the prostate via transperineal needles under real-time transrectal ultrasonography guidance. Up to 80 aliquots of 0.1-mL viral solution were injected into the prostate. The injection pattern, effective treatment volume (V(eff)), and viral dose distribution were determined according to a simple dosimetric model in which the local dose of virus was defined as the concentration of the delivered virion uniformly distributed in a sphere of 5-mm radius per injection. The initial dosimetric parameters were measured through scans of contrast solutions in dog prostate glands. The biochemical response (the reduction of serum PSA) as a function of the viral dose and tumor volume coverage was analyzed. RESULTS: A 0.1-mL solution injected into the dog prostate gland spreads via 4-mm mechanical flow plus 1-mm molecular diffusion. Multiple injections into the prostate of patients resulted in considerable enlargement of the prostate gland. The biochemical response probability for patients treated with CG7060 may be estimated by 1 - alpha * exp[-[beta + gamma (PTV/V(eff)) P/A] * P], where alpha, beta, and gamma are constants; A is the number of aliquots, and P is the integral dose of initial viruses. CONCLUSION: A simple dosimetric model based on results from our recently reported Phase I study can quantify the biochemical response of patients treated with CG7060 adenoviral therapy. The model predicts that outcome is influenced by the integral dose of delivered virus and the target volume coverage. This first dosimetric model for interstitial adenoviral therapy will serve as a basis for quantitative analysis for ongoing and future studies.