Joshua M. Stern

Intermediate comparison of partial nephrectomy and radiofrequency ablation for clinical T1a renal tumours

To compare the intermediate‐term outcomes of patients with clinical T1a renal tumours who were treated with nephron‐sparing surgery by partial nephrectomy (PN), the preferred approach for small (cT1a) renal tumours, or radiofrequency ablation (RFA), recently offered to selected patients as an alternative, less morbid technique.

YouTube as source of prostate cancer information.

OBJECTIVES Patients can search the Internet for prostate cancer information, and YouTube is a popular Web site that they may consult. We analyzed the prostate cancer videos on YouTube for information content and the presence of bias. METHODS YouTube was searched for videos about prostate-specific antigen (PSA) testing, radiotherapy, and surgery for prostate cancer. The included videos were in English and <10 minutes long. Two physician viewers watched each video and assigned a score for information content (excellent, fair, poor) and bias (for, against, neutral, or balanced). A third viewer arbitrated any discrepancies. The kappa statistic was used to measure interobserver variability, and Pearsons test was used to assess correlation. RESULTS A total of 14 PSA videos, 5 radiotherapy videos, and 32 surgery videos were analyzed. The PSA testing videos averaged 1480 +/- 2196 views and 146 +/- 174 s long and had an average viewer rating of 3.1 +/- 2.1 (viewer rating scale 0-5). The surgery videos averaged 2044 +/- 3740 views and 172 +/- 122 s long and had an average viewer rating of scored 3 +/- 2.2. The radiotherapy videos averaged 287 +/- 255 views and 97 +/- 45 s long and had a score of 1.8 +/- 2.5. The information content was fair or poor for 73% of all videos. The bias for surgery, radiotherapy, or PSA testing was present in 69% of videos; 0% of videos were biased against treatment or PSA testing. The interobserver variability was well above than expected by chance alone. CONCLUSIONS The results of our study have shown that although some videos are robust sources of information, given the preponderance of modest and unbalanced information among reviewed videos, YouTube is an inadequate source of prostate cancer information for patients.

Absence of Viable Renal Carcinoma in Biopsies Performed More Than 1 Year Following Radio Frequency Ablation Confirms Reliability of Axial Imaging

PURPOSE Radio frequency ablation is an emerging nephron sparing treatment option in select patients with small renal tumors. Some have questioned the completeness of cell death and the reliability of axial imaging for radio frequency ablation followup. We present results in patients with no evidence of radiographic active disease who underwent biopsy more than 1 year following ablation. MATERIALS AND METHODS Patients who had no clinical evidence of disease, defined as absent lesion growth and contrast enhancement on computerized tomography, 1 year or more following radio frequency ablation underwent percutaneous renal biopsy to evaluate cell viability in the ablative zone. A total of 19 patients (20 lesions) were included in the study. Histological comparison of pre-ablation and post-ablation specimens was performed using hematoxylin and eosin staining. RESULTS Pre-ablation biopsies confirmed that 17 of 20 tumors were renal cell carcinoma, while the remaining 3 were oncocytoma. Following ablation at a mean followup of 26.9 months (range 13.1 to 58.0) all 20 lesions were stable in size without evidence of contrast enhancement on computerized tomography. At repeat biopsy all histology specimens showed unequivocal tumor eradication with no evidence of cellular viability. Histological changes beyond 1 year demonstrated coagulative necrosis, hyalinization, inflammatory cell infiltration and residual ghost cells. CONCLUSIONS Pathological examination of radiographically negative lesions biopsied more than 1 year following radio frequency ablation confirmed no evidence of disease in all specimens. Therefore, axial imaging can reliably monitor treatment efficacy in the long term. Chronic changes after radio frequency ablation demonstrate coagulative necrosis and nonviable cells. This suggests an evolution of pathological changes that renders early post-ablative biopsy unreliable.

General anesthesia and contrast-enhanced computed tomography to optimize renal percutaneous radiofrequency ablation: Multi-institutional intermediate-term results

INTRODUCTION Percutaneous renal ablation is often performed under conscious sedation and without contrast-enhanced imaging. We evaluated intermediate-term outcomes of patients undergoing percutaneous contrast-enhanced computed tomography (CT)-guided radiofrequency ablation (RFA) under general anesthesia (GA) at two high-volume centers. MATERIALS AND METHODS Prospectively maintained Institutional Regulatory Board-approved databases were searched to identify patients treated with percutaneous RFA using contrast-enhanced CT under GA. A total of 163 masses in 151 patients were treated. Enhancement on imaging or a positive biopsy at 4 to 6 weeks was considered incomplete ablation. Positive findings beyond this interval were defined as local recurrence. RESULTS The median follow-up was 18 months (range, 1.5-70). Median tumor size was 2.3 cm (range, 1-5.4). Of the 130 (80%) masses with definitive pathology, 70% were renal cell cancer. Five masses had evidence of viable tumor at 4 to 6 weeks posttreatment for a complete initial ablation rate of 97%. Three of these five lesions were endophytic. Five masses (3.3%) showed evidence of local recurrence, and metastases developed in two patients (1.3%). Overall 1- and 3-year recurrence-free survival was 97% and 92%, respectively. Masses that were in the central region and were endophytic had the highest risk for recurrence (hazard ratio, 6.3; p = 0.016). CONCLUSIONS Intermediate-term outcomes of percutaneous RFA are excellent. GA-assisted, contrast-enhanced CT-guided percutaneous RFA demonstrates a high initial ablation success rate. However, endophytic and interpolar lesions are at higher risk for recurrence.

Development of quantum dot-mediated fluorescence thermometry for thermal therapies

As thermal therapies are frequently employed for management of tumors in various organs, there are growing demands for reliable and accurate intraoperative monitoring techniques of the thermal lesion. However, current monitoring techniques have limited accuracy, accessibility and are not capable of monitoring the thermal lesion in real-time during the procedure. In the present study, quantum dot-mediated fluorescence thermometry was developed and its performance was characterized to demonstrate the feasibility of spatiotemporal monitoring of thermal lesions. First, the temperature dependency of two different types of CdTe/ZnS quantum dots (QDs) were characterized in a temperature range relevant to hyperthermic therapies, and a temperature–intensity relationship was established for each QD. The spatial and temporal resolutions of the system were characterized by exposing QDs to a pre-determined spatial temperature gradient, and by monitoring the spatiotemporal temperature during gold nanoshell-mediated heating. The results demonstrated that QD-mediated thermometry is capable of measuring spatiotemporally varying temperature fields relevant for hyperthermic thermal therapies. Its implication for intraoperative image-guidance of thermal therapy was also discussed.

Intravesical Nanocrystalline Silver Decreases Experimental Bladder Inflammation

PURPOSE Interstitial cystitis is a sterile bladder inflammatory disease characterized by pelvic pain, urinary urgency and frequency. Nanocrystalline silver has anti-inflammatory properties, prompting us to investigate its effect in experimental bladder inflammation. MATERIALS AND METHODS Nanocrystalline silver (0.01%, 0.05%, 0.1%, 0.5% or 1%) or phosphate buffered saline (Invitrogen) (0.5 ml) was introduced intravesically in Sprague-Dawley female rat (Charles River Laboratories, Wilmington, Massachusetts) bladders for 20 minutes, followed by vehicle or protamine sulfate (10 mg/ml for 30 minutes) and lipopolysaccharide (Sigma) (2 mg/ml for 45 minutes). Urine was collected throughout for histamine assay. The catheter was removed, the rat was returned to its cage and 4 hours later it was sacrificed. The bladder was harvested, minced and cultured overnight. The medium was collected for tumor necrosis factor-alpha assay. RESULTS Mean +/- SD total urine histamine increased from 270 +/- 190 ng in 4 controls to 842 +/- 239 ng after protamine sulfate/lipopolysaccharide and it decreased to 505 +/- 187 ng in 6 animals after pretreatment with 1% nanocrystalline silver (p = 0.036). Tumor necrosis factor-alpha release in explant medium increased from 0.02 +/- 0.03 pg/mg in 6 controls to 0.28 +/- 0.15 pg/mg in 14 animals after treatment with protamine sulfate/lipopolysaccharide and it decreased to 0.12 +/- 0.11 pg/mg in 10 animals pretreated with nanocrystalline silver (p = 0.009). Nanocrystalline silver was not effective at less than 1% and at 1% alone it released 0.05 +/- 0.07 pg/mg tumor necrosis factor-alpha in 7 rats (vs phosphate buffered saline in 6, p = 0.387). Nanocrystalline silver (1%) significantly decreased bladder inflammation and mast cell activation. These effects were apparent even 4 days later. CONCLUSIONS Intravesical administration of nanocrystalline silver (1%) decreased urine histamine, bladder tumor necrosis factor-alpha and mast cell activation without any toxic effect. This action may be useful for interstitial cystitis.

Radiofrequency ablation of small renal cortical tumours in healthy adults: renal function preservation and intermediate oncological outcome

To present the glomerular filtration rate (GFR) and oncological outcomes in a series of patients with cT1a renal cortical tumours treated with radiofrequency ablation (RFA), a non‐ischaemic minimally invasive ablative method, as nephron‐sparing surgery gives excellent oncological outcomes and preserves renal function.

Emerging use of nanoparticles for the therapeutic ablation of urologic malignancies

Metal nanoshells are a new class of nanoparticle with highly tunable optical properties. Gold nanoshells (GNS) are particularly suitable for use in the surgical arena as their outer shell is composed of a commonly used reduced inert gold. When activated by near infrared light, GNS can raise surrounding temperatures to levels sufficient for cellular ablation. As such, investigators have established both in vitro and in vivo models to examine the role of GNS as a therapeutic modality for the thermal ablation of solid organ tumors.

The Screening for Occult Renal Disease (SCORED) value is associated with a higher risk for having or developing chronic kidney disease in patients treated for small, unilateral renal masses

Patients with renal masses are at risk for having or developing chronic kidney disease (CKD) stage 3 (glomerular filtration rate [GFR] <60 mL per minute/1.73 m2). In this study, the authors investigated whether the Screening for Occult Renal Disease (SCORED) model could identify patients with renal masses who were at risk for having or developing CKD.

Phase One Pilot Study Using Magnetic Resonance Spectroscopy to Predict the Histology of Radiofrequency-Ablated Renal Tissue

INTRODUCTION AND OBJECTIVE Recent advances in magnetic resonance (MR) technology have allowed for high-resolution ex vivo spectroscopy on small, intact tissue samples. We examined the capability of (1)H magnetic resonance magic angle spinning (MR-MAS) to correctly characterize post-radiofrequency ablation (RFA) renal biopsies from human samples, compared with standard histology and cross-sectional imaging. METHODS A minimum of two, 18G, percutaneous renal biopsies were obtained from ten biopsy-confirmed renal tumors at a mean 26.6 mo (range, 15-48) post-RFA. All patients were considered free of disease by computed tomography criteria. A portion of each sample was immediately frozen at -80 degrees C for spectroscopy and the remainder used for pathological analysis. (1)H MR-MAS was performed blinded with a 14.1-tesla field strength. Prior renal biopsies from nonablated tissue were used as positive controls for the spectral analysis. Concordance between, computed tomography, histology, and MR-MAS was analyzed. All spectroscopy was processed with VNMR software. RESULTS Histological analysis of all ten post-RFA biopsies demonstrated no cancer or viable tissue. All MR-MAS spectral peaks for each biopsy were consistent with necrosis and, more importantly, indicated an absence of small molecule metabolites characteristic of both normal and malignant renal tissue. Both MR-MAS and histology confirmed, in each case, the conventional computed tomography determination of complete ablation. CONCLUSIONS MR spectroscopy can correctly diagnose the molecular absence of disease in post-RFA tissue biopsies. This proof of principle study warrants in vivo evaluation to confirm the clinical correlates of this modality.