Fiducial markers: can the urologist do better?

INTRODUCTION: Radiotherapy to the bladder has a risk of toxicity to pelvic structures, which can be reduced by using fiducial markers for targeting. Injectable contrast offers an alternative marker to gold seeds, which may fall out or exacerbate scarring. Combining contrast agents with tissue glue can minimize dispersion through tissue, enhancing its utility. We evaluated combinations of contrast agents and tissue glue using porcine bladder, for feasibility and utility as fiducial markers to aid image-guided radiotherapy. METHODS: Different contrast agents (Lipiodol ultra or Urografin) were combined with different tissue glues (Histoacryl, Tisseal or Glubran2). The mixtures were endoscopically injected into porcine bladder submucosa to identify the area of interest with multiple fiducial markers. The porcine bladders were imaged within a phantom porcine pelvis using standard radiation therapy imaging modalities. The feasibility as an injectable fiducial marker and visibility of each fiducial marker on imaging were scored as binary outcomes by two proceduralists and two radiation therapists, respectively. RESULTS: Lipiodol-glue combinations were successfully administered as multiple fiducials that were evident on CT and CBCT. Lipiodol with Histoacryl or Glubran2 was visible on kV imaging. The Lipiodol Glubran2 combination was deemed subjectively easiest to use at delivery, and a better fiducial on KV imaging. CONCLUSION: This study demonstrates the feasibility of mixing contrast medium Lipiodol with Histoacryl or Glubran2 tissue glue, which, injected endoscopically, provides discrete and visible fiducial markers to aid image-guided radiotherapy. Although promising, further study is required to assess the durability of these markers through a course of radiotherapy.

Short-Term Complications Associated With Acellular Dermal Matrix-Assisted Direct-to-Implant Breast Reconstruction.

BACKGROUND: Although direct-to-implant breast reconstruction is a more concise procedure than 2-stage expander/implant reconstruction, it is less frequently performed. Skeptics of direct-to-implant reconstruction cite risk of postoperative complications as a reason for its rejection. To determine whether these perceptions are valid, we evaluated our 13-year experience of acellular dermal matrix (ADM)-assisted, direct-to-implant breast reconstruction. We report complication and reoperation rates associated with this technique as well as predictors for these outcomes. METHODS: This retrospective study included all patients who underwent immediate, ADM-assisted, direct-to-implant, breast reconstruction from December 2001 to May 2014 at 2 practices. Postoperative complications, defined as those occurring within the first 12 months after reconstructive surgery, were evaluated. Univariate/multivariate analyses were performed to determine the influence of patient-, breast-, and surgery-related characteristics on the development of complications. RESULTS: A total of 1584 breast reconstructions (721 bilateral, 142 unilateral) in 863 patients were performed; 35% were oncologic, and 65% were prophylactic reconstructions. Complication rate was 8.6% and included skin necrosis (5.9%), infection (3.0%), implant loss (2.9%), seroma (1.1%), and hematoma (0.9%). Reoperative rate in breasts with complications was 3.2%. Age 50 years or older, smoking, nonnipple-sparing mastectomy, and implant size of 600 mL or greater strongly predicted the development of complications (P < 0.001). CONCLUSIONS: Our cumulative 13-year experience demonstrates that immediate, ADM-assisted, direct-to-implant breast reconstruction is safe, effective, and reliable. Complication and reoperation rates are less than 10% and are comparable to those reported for 2-stage procedures in the published literature.

A clinical study comparing polymer and gold fiducials for prostate cancer radiotherapy.

Introduction: Image guidance with gold fiducials improves outcomes of prostate radiotherapy. However, gold produces artefact on CT imaging, interfering with contouring and verification. The purpose of this study was to compare polymer to standard gold fiducials using radiotherapy imaging modalities to assess the visibility and artefact. Methods: Twenty eight patients with locally advanced prostate cancer were enrolled, half had three polymer fiducials implanted into the prostate and half underwent insertion of gold fiducials. Patients were imaged with CT, T2 weighted MRI, cone-beam CT (CBCT) and planar KV images. Fiducials were scored for visibility and assessed for CT artefact in surrounding prostate tissue. The artefact was quantified from Hounsfield number histograms and separated into percentile ranges and proportion of voxels in HU normal tissue range of a 2cm sphere surrounding the fiducial. Results: Gold and polymer fiducials were sufficiently visible for CT and CBCT verification. The gold fiducials could be visualized well on KV planar imaging; however, the polymer markers were obscured by pelvic bones. Neither polymer nor gold fiducials could be visualized on MRI. The polymer fiducial produced less artefact than gold on CT, having less voxel spread for the HU percentile ranges and a greater proportion of voxels in the normal tissue range. Conclusions: Polymer fiducials are a more suitable fiducial than gold for CT/CBCT in prostate cancer radiotherapy, demonstrating minimal artefact and good visibility on CT. However, they were not well seen on MRI or KV imaging and thus not suitable for co-registration or planar KV verification.

Exploratory models comparing ethiodized oil-glue and gold fiducials for bladder radiotherapy image-guidance.

BACKGROUND AND PURPOSE: Image-guidance with fiducials has been shown to improve pelvic radiotherapy outcome. However, bladder fiducials using ethiodized oil (EO) alone can disperse widely, and gold causes Computed Tomography scan (CT) metal artifacts. The study's purpose was to investigate the ability to deliver EO-tissue glue fiducials and compare them to gold for bladder radiotherapy image guidance. MATERIALS AND METHODS: A fluid-filled porcine bladder model was used to assess the ability to cystoscopically inject visible EO glue fiducials into the submucosa. We then transferred the bladders into a porcine pelvis for imaging and compared them to gold fiducials using CT, Cone Beam CT (CBCT), and kilovoltage (KV) planar views. A tissue-equivalent phantom was utilized to analyze the CT number Hounsfield Unit (HU) characteristics and artifacts of the glue and gold fiducials. Percentile ranges and normal tissue voxel percentages of the subsequent CT number voxel histogram from a 2 cm sphere surrounding the fiducial was used to characterize the artifact. RESULTS: We successfully delivered all EO glue fiducials into the porcine bladders as discrete fiducials. They were well seen on CT, CBCT, and KV imaging. The glue fiducials had lower CT number values, but less CT number spread of the voxel percentile ranges consistent with the diminished contrast and less artifact than gold. The glue fiducial types had similar CT number characteristics. CONCLUSION: This study has shown that EO glue fiducials can be delivered with online visualization qualities comparable to gold fiducials without metal-related artifacts.

Efficacy of Vancomycin-based Continuous Triple Antibiotic Irrigation in Immediate, Implant-based Breast Reconstruction.

BACKGROUND: Single irrigation of the peri-implant space with a cefazolin-based triple antibiotic solution is a routine antibiotic prophylaxis measure during implant-based breast augmentation and reconstruction. Cefazolin, however, is less efficacious against resistant Staphylococcus species, which are the predominant bacterial species isolated from the peri-implant space. Vancomycin is effective against resistant Staphylococcus species and may be a more appropriate prophylactic agent. The availability of single-injection long-acting anesthetic agents allows the novel use of the elastomeric infusion pump for continuous irrigation of antibiotic solution into the peri-implant space. The efficacy of continuous irrigation with a vancomycin-based solution is evaluated here. METHODS: Study patients (N = 163; group 1) who underwent immediate, direct-to-implant breast reconstruction received continuous infusion of a vancomycin-based triple antibiotic solution. Patients also received a single injection of liposomal bupivacaine in the pectoralis major/minor muscles for pain control. A historic control group (N = 113; group II) received ropivacaine local anesthetic via the infusion pump and a single intraoperative irrigation of the peri-implant space with the vancomycin-based triple antibiotic solution. Incidence of postsurgical infection during the 6 weeks after surgery was compared between the groups. RESULTS: Group I patients had a statistically significant lower incidence of infections (1.9%) than group II patients (6.4%) (P = 0.007). There were no vancomycin-related adverse effects. CONCLUSIONS: Continuous breast irrigation with a vancomycin-based triple antibiotic solution is a safe and effective accompaniment for immediate implant reconstruction. Use of intramuscular anesthetic injection for postoperative pain control allows the elastomeric infusion pump to be available for local tissue antibiotic irrigation.

Acellular Dermal Matrix-Assisted Direct-to-Implant Breast Reconstruction and Capsular Contracture: A 13-Year Experience.

BACKGROUND: Use of acellular dermal matrix for implant-based breast reconstruction appears to be associated with a lower incidence of capsular contracture compared with standard reconstruction. The majority of acellular dermal matrix studies were, however, of short duration; thus, long-term incidence of capsular contracture with acellular dermal matrix use is unknown. METHODS: Patients undergoing acellular dermal matrix-assisted breast reconstruction from December of 2001 to May of 2014 at two institutions were evaluated. Cumulative incidence of capsular contracture was determined by the performing surgeon. A retrospective chart review was performed on prospectively gathered data on patient-, breast-, surgery-, and implant-related characteristics that were analyzed as potential risk factors for the development of capsular contracture. RESULTS: A total of 1584 breast reconstructions in 863 patients were performed. Mean follow-up of patients was 4.7 years; 45 percent of patients had greater than or equal to 5 years of follow-up. The cumulative incidence of capsular contracture was 0.8 percent. Smaller implant size (<400 ml) and postoperative radiotherapy were significantly associated with an increased risk of capsular contracture, but the incidence of capsular contracture was 1.9 percent in irradiated breasts. All capsular contractures developed within the first 2 years, with no new events with longer follow-up. CONCLUSIONS: In this long-term study, the cumulative incidence of capsular contracture with acellular dermal matrix-assisted reconstruction remains low, even in irradiated breasts. Capsular contracture appears to be an early event, and longer follow-up does not appear to increase the incidence, suggesting that acellular dermal matrix may truly mitigate the development of capsular contracture as opposed to delaying its occurrence. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Rehabilitation of the child with lower limb loss.

Care for the child with limb deficiency or amputation is optimized when provided by an interdisciplinary team. A center specializing in the care of children with limb loss is typically the best choice and has the most experience in providing up to date, evidence based practice. The child and his/her family must be integral members of the team and optimal functional outcome requires recognizing and addressing their expectations and goals. We present an overview of rehabilitation strategies, including prosthetic management, for children with lower extremity limb loss.