High-field MRSI of the prostate using a transmit/receive endorectal coil and gradient modulated adiabatic localization

PURPOSE

To demonstrate in vivo magnetic resonance spectroscopic imaging (MRSI) of the human prostate at 4.0T using a transmit/receive endorectal coil and a pulse sequence designed specifically for this application.

MATERIALS AND METHODS

A solid, reusable endorectal probe was designed for both radiofrequency transmission and reception. Finite difference time domain (FDTD) simulations were performed to characterize the coil's electric field distribution, and temperature measurements were performed in a beef tissue phantom to determine the coil's safe operating limit. The localization by selective adiabatic refocusing (LASER) pulse sequence was implemented using six gradient modulated offset independent adiabatic (GOIA) pulses for very sharp, B(1)-insensitive voxel localization.

RESULTS

Based on the simulations and temperature measurements, the coil's safe operating limit was conservatively estimated to be 1.0W for 15 minutes. The transition width of the GOIA pulse selection profiles was only 6% of the bandwidth, compared with 22% for a specific absorption rate (SAR)-matched conventional adiabatic pulse. Using the coil and pulse sequence described here, MRSI data were successfully acquired from a patient with biopsy-proven prostate cancer, with a nominal voxel size of 0.34 cc in a scan time of 15 minutes.

CONCLUSION

This work demonstrates the safe and effective use of a transmit/receive endorectal coil for in vivo MRSI of the prostate.

Molecular biomarkers in prostate cancer

BACKGROUND

After more than two decades of clinical use, serum prostate-specific antigen (PSA) has increased the early diagnosis of prostate cancer, detecting the disease even when small volumes are present. Although stage migration of prostate cancer has occurred, PSA has well-known limitations, despite attempts at refinement and modification, such as the use of PSA velocity, which have been used to improve it. New biomarkers for prostate cancer have been discovered, with promising early results.

OBJECTIVE/METHODS

This article reviews the ubiquitous current literature on biomarkers in prostate cancer. A search using MEDLINE and EMBASE databases was performed and those articles reporting biomarkers in prostate cancer with clinically significant findings in terms of detection were analyzed. Immunohistochemical markers were not considered for this review.

RESULTS/CONCLUSION

Despite many markers being promising, no single marker has satisfied the criteria as a perfect candidate. Limited clinical use of IL-6, TGF-β1 and PCA3 has commenced, and further widespread availability of these tests is expected in the coming years. The future lies in artificial neural networks and panels of markers instead of individual assays. Although PSA has some well-known limitations, it is at present the best marker available for prostate cancer when used in conjunction with nomograms or risk calculators.

Coping with Loneliness when Death is Near

The study compared the manner in which the dying, their caregivers, and the general population cope with loneliness. The patients were recruited in an oncological hospice in Israel, and despite being on their deathbed agreed to participate in the study. Thirty-seven cancer stricken patients, 78 caregivers, and 128 participants from the general population volunteered to partake in the study. They answered, anonymously, a 34-item yes/no questionnaire and were asked to endorse those items that described their strategies of successfully coping with loneliness. The dimensions of the coping strategies included: Reflection and acceptance which was defined as being by one's self and becoming acquainted with one's fears, wishes, and needs; Self-development and understanding, was defined as the increased self-intimacy, renewal, and growth; Social support network; Distancing and denial which was defined as denial of the experience and pain of loneliness through the use of alcohol or street drugs; Religion and faith; and Increased activity, the active pursuit of daily responsibilities. Results suggested the dying patient, his or her caregiver, and the general population cope with loneliness differently. Dying patients scored significantly lower than the general population on the Social support network and on the Increased activity subscales. The trend was reversed on the Religion and faith subscale. The present may be the first study to examine the manner in which the dying and their caregivers cope with loneliness. As such, more research is needed to replicate the present study, using larger samples.

Design and evaluation of a 3D transrectal ultrasound prostate biopsy system

Biopsy of the prostate using ultrasound guidance is the clinical gold standard for diagnosis of prostate adenocarcinoma. The current prostate biopsy procedure is limited to using 2D transrectal ultrasound (TRUS) images to target biopsy sites and record biopsy core locations for postbiopsy confirmation. Localization of the 2D image in its actual 3D position is ambiguous and limits procedural accuracy and reproducibility. We have developed a 3D TRUS prostate biopsy system that provides 3D intrabiopsy information for needle guidance and biopsy location recording. The system conforms to the workflow and imaging technology of the current biopsy procedure, making it easier for clinical integration. In this paper, we describe the system design and validate the system accuracy by performing mock biopsies on US/CT multimodal patient-specific prostate phantoms. Our biopsy system generated 3D patient-specific models of the prostate with volume errors less than 3.5% and mean boundary errors of less than 1 mm. Using the 3D biopsy system, needles were guided to within 2.3 +/- 1.0 mm of 3D targets and with a high probability of biopsying clinically significant tumors. The positions of the actual biopsy sites were accurately localized to within 1.5 +/- 0.8 mm.

Diagnostic screening of mitochondrial DNA mutations in Australian adults 1990-2001

BACKGROUND

Many diverse pathogenic mitochondrial DNA (mtDNA) mutations have been described since 1988. The Melbourne Neuromuscular Research Institute (MNRI) has undertaken diagnostic detection of selected mtDNA mutations since 1990. MtDNA mutations screened have included point mutations associated with Leber's hereditary optic neuropathy (LHON; G3460A, G11778A and T14484C), mitochondrial encephalopathy lactic acidosis and stroke-like episodes (MELAS; A3243G), myoclonus epilepsy and ragged red fibres (MERRF; A8344G) and Leigh's syndrome/neuropathy ataxia retinitis pigmentosa (LS/NARP; T8993C/G). Samples have also been screened for deletions/ rearrangements associated with Kearns-Sayre syndrome (KSS) and chronic progressive external ophthalmoplegia (CPEO).

AIMS

To present an audit of the MNRI mtDNA diagnostic service between 1990 and 2001, encompassing 1725 referred patients.

METHODS

The detection techniques carried out included polymerase chain reaction amplification of mtDNA combined with restriction fragment length polymorphism analysis for mtDNA point mutation detection, supplemented with selected sequence analysis and Southern blots for the detection of deletions/ rearrangements. Tissues tested included blood, hair and skeletal muscle.

RESULTS

Of the 1184 patients screened for MELAS A3243G, 6.17% were positive for the mutation, whereas for MERRF A8344G, 2.21% carried the mutation and for LS/NARP T8993C/G, 0.32% carried the mutation. The outcomes for the LHON mutations were G11778A, 6.60%, T14484C, 5.76% and G3460A, 0.29%. Of the patients referred for KSS and CPEO, 17.72% had deletions/rearrangements.

CONCLUSIONS

Overall, the detection rate of mtDNA point mutations was low. The protean clinical features of mitochondrial disorders and the frequency of partial phenotypes lead to requests for tests in many patients with a relatively low likelihood of mtDNA mutations. An improved algorithm could involve mutation screening appropriate to the phenotype using sequencing of selected mtDNA regions in patients with a high likelihood of mtDNA disease. Features increasing the likelihood of mtDNA mutations include the following: (i) a typical phenotype, (ii) a maternal inheritance pattern and (iii) histochemical evidence of mitochondrial abnormality in the muscle biopsy. Efficient laboratory diagnosis of mtDNA disease involves good communication between the physician and laboratory scientists, coupled with screening of the appropriate tissue.

In vitro validation of a 3-dimensional transrectal ultrasound system for prostate biopsiess

Introduction: Transrectal ultrasound (TRUS) prostate biopsy (Bx) is currently confined to 2D information to both target and record 3D Bx locations. Accurate placement of Bx needles cannot be verified without 3D information, and recording Bx sites in 2D does not provide sufficient information to accurately guide the high incidence of repeat Bx. We have designed a 3D TRUS prostate Bx system that augments the current 2D TRUS system and provides tools for biopsy-planning, needle guidance, and recording of the biopsy core locations entirely in 3D. Methods: Our Bx system displays a 3D model of the patient’s prostate, which is generated intra-procedure from a collection of 2D TRUS images, representative of the particular prostate shape. Bx targets are selected, needle guidance is facilitated, and 3D Bx sites are recorded within the 3D context of the prostate model. The complete 3D Bx system was validated, in vitro, by performing standard ten-core Bx on anatomical phantoms of two patient’s prostates. The accuracy of the needle-guidance, Bx location recording, and 3D model volume and surface topology were validated against a CT gold standard. Results: The Bx system successfully reconstructed the 3D patient prostate models with a mean volume error of 3.2 ± 7.6%. Using the 3D system, needles were accurately guided to the pre-determined targets with a mean error of 2.26 ± 1.03 mm and the 3D locations of the Bx cores were accurately recorded with a mean distance error of 1.47 ± 0.79 mm. Conclusion: We have successfully developed a 3D TRUS prostate biopsy system and validated the system in vitro. A pilot study has been initiated to apply the system clinically.

Multicenter phase II study of combined neoadjuvant docetaxel and androgen ablation (ADT) prior to radical prostatectomy (RP) for patients (pts) with high risk localized prostate cancer (LCaP): Pathologic outcomes and 3-year follow-up analyses

5002

Background: Pts with high risk LCaP (cT3, Gleason score > 7 &/or PSA > 20) have an increased risk of relapse with a biochemical failure rate of >50% at 3 years after RP. Docetaxel is active in hormone refractory prostate cancer & potentially beneficial if combined with ADT for treatment naïve disease. The objectives of this trial were to assess the pathologic outcomes & feasibility of docetaxel + ADT in men with LCaP prior to RP. Methods: A phase II multi-center study of newly diagnosed previously untreated pts with clinically LCaP with high-risk features. All pts received ADT (buserelin acetate 6.3 mg q8 weeks x 3 and anti-androgen for 4 weeks) plus docetaxel (35 mg/m2 weekly for 6 out of 8 weeks for 3 cycles) prior to RP. Results: 72 men with a median age of 59 years (range 46–78) were enrolled at 6 sites. Baseline characteristics included: clinical stage T1C, T2 & T3 in 14%, 47% & 39%; and Gleason score <7, 7 & >7 in 10%, 30% & 60% of pts; respectively. Median baseline PSA was 10.8 μg/L (range 1.6–65.6) with PSA < 10 in 47%, 10–20 in 24% & >20 in 29% of pts. Eight pts did not complete protocol therapy because of toxicity (n=4), withdrawal of consent (n=1), or other reasons (n=3). 1 pt had myocardial infarction day 1 post-operatively & 1 pt had DVT 1.5 months after RP. No other major post-operative complications were reported. Of the 64 pts completing protocol therapy, 2 had a complete pathologic response and pathologic stage was T2 in 34 (53%) and T3 in 28 (44%) pts. Four pts had N1 disease & positive surgical margins were identified in 17 (27%). On multivariate Cox regression analysis only baseline Gleason score (=7 vs. >7) was associated with PSA recurrence-free survival (hazard ratio 4.58, 95% CI 1.32–15.93). At a median follow-up of 42.7 months (range 25.6–65.6), 19 (30%) pts have relapsed. Three pts have died at 32.0, 40.0 & 40.3 months, with all deaths attributed to prostate cancer. Conclusions: Combined ADT and docetaxel prior to RP was feasible and resulted in encouraging pathologic outcomes and PSA- recurrence free survival. These data further support the rationale for randomized trials determining the efficacy of chemo-hormonal therapy in pts with clinically LCaP.

[Table: see text]

Predominant treatment failure in postprostatectomy patients is local: analysis of patterns of treatment failure in SWOG 8794

PURPOSE

Southwest Oncology Group (SWOG) trial 8794 demonstrated that adjuvant radiation reduces the risk of biochemical (prostate-specific antigen [PSA]) treatment failure by 50% over radical prostatectomy alone. In this analysis, we stratified patients as to their preradiation PSA levels and correlated it with outcomes such as PSA treatment failure, local recurrence, and distant failure, to serve as guidelines for future research.

PATIENTS AND METHODS

Four hundred thirty-one subjects with pathologically advanced prostate cancer (extraprostatic extension, positive surgical margins, or seminal vesicle invasion) were randomly assigned to adjuvant radiotherapy or observation.

RESULTS

Three hundred seventy-four eligible patients had immediate postprostatectomy and follow-up PSA data. Median follow-up was 10.2 years. For patients with a postsurgical PSA of 0.2 ng/mL, radiation was associated with reductions in the 10-year risk of biochemical treatment failure (72% to 42%), local failures (20% to 7%), and distant failures (12% to 4%). For patients with a postsurgical PSA between higher than 0.2 and <or = 1.0 ng/mL, reductions in the 10-year risk of biochemical failure (80% to 73%), local failures (25% to 9%), and distant failures (16% to 12%) were realized. In patients with postsurgical PSA higher than 1.0, the respective findings were 94% versus 100%, 28% versus 9%, and 44% versus 18%.

CONCLUSION

The pattern of treatment failure in high-risk patients is predominantly local with a surprisingly low incidence of metastatic failure. Adjuvant radiation to the prostate bed reduces the risk of metastatic disease and biochemical failure at all postsurgical PSA levels. Further improvement in reducing local treatment failure is likely to have the greatest impact on outcome in high-risk patients after prostatectomy.

Characterization of mesophilic bacilli in faeces of feedlot cattle

AIMS

To determine the identity and composition of mesophilic Bacillus spp. in faeces sampled from feedlot cattle.

METHODS AND RESULTS

Faecal samples from 10 feedlot cattle were analysed. The total aerobic spore count increased from 4.6 x 10(4) CFU g(-1) (before feedlotting, day 0) to 1.6 x 10(6) CFU g(-1) (feedlot for day 76). A total of 150 randomly selected spore isolates (60 each from days 0 and 76 cattle, 30 from feed) were speciated using a Bacillus group-specific PCR-amplified ribosomal DNA restriction analysis technique (Wu et al. 2006). At day 0, Bacillus subtilis and Bacillus cereus predominated with a prevalence of 58.3% and 26.7%, respectively, whereas three species, B. subtilis (50.0%), Bacillus licheniformis (27.6%) and Bacillus clausii (20.0%) predominated in day 76 faecal samples. Of these, only the first two species were present in feed samples at a frequency of 70% and 30% respectively. All B. cereus isolates on day 0, possessed at least one of three enterotoxin genes (nheA, nheB and nheC) but these were completely eliminated after a period of feedlotting. All isolates of B. licheniformis were genotypically heterogeneous according to pulsed-field gel electrophoresis analysis.

CONCLUSIONS

Cattle faeces contain large numbers of Bacillus spores representing different mesophilic species. Stable faecal populations of particular Bacillus spp. mimicking those found in feed, were subsequently established by feedlotting.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results obtained and methods used in this study will help to investigate the indigenous Bacillus composition in the gastrointestinal tract of cattle and will further guide the administration of Bacillus probiotics.

3D prostate model formation from non-parallel 2D ultrasound biopsy images

Biopsy of the prostate using 2D transrectal ultrasound (TRUS) guidance is the current gold standard for diagnosis of prostate cancer; however, the current procedure is limited by using 2D biopsy tools to target 3D biopsy locations. We propose a technique for patient-specific 3D prostate model reconstruction from a sparse collection of non-parallel 2D TRUS biopsy images. Our method conforms to the restrictions of current TRUS biopsy equipment and could be efficiently incorporated into current clinical biopsy procedures for needle guidance without the need for expensive hardware additions. In this paper, the model reconstruction technique is evaluated using simulated biopsy images from 3D TRUS prostate images of 10 biopsy patients. All reconstructed models are compared to their corresponding 3D manually segmented prostate models for evaluation of prostate volume accuracy and surface errors (both regional and global). The number of 2D TRUS biopsy images used for prostate modeling was varied to determine the optimal number of images necessary for accurate prostate surface estimation.

Adjuvant radiotherapy for pathologically advanced prostate cancer: a randomized clinical trial

CONTEXT

Despite a stage-shift to earlier cancer stages and lower tumor volumes for prostate cancer, pathologically advanced disease is detected at radical prostatectomy in 38% to 52% of patients. However, the optimal management of these patients after radical prostatectomy is unknown.

OBJECTIVE

To determine whether adjuvant radiotherapy improves metastasis-free survival in patients with stage pT3 N0 M0 prostate cancer.

DESIGN, SETTING, AND PATIENTS

Randomized, prospective, multi-institutional, US clinical trial with enrollment between August 15, 1988, and January 1, 1997 (with database frozen for statistical analysis on September 21, 2005). Patients were 425 men with pathologically advanced prostate cancer who had undergone radical prostatectomy.

INTERVENTION

Men were randomly assigned to receive 60 to 64 Gy of external beam radiotherapy delivered to the prostatic fossa (n = 214) or usual care plus observation (n = 211).

MAIN OUTCOME MEASURES

Primary outcome was metastasis-free survival, defined as time to first occurrence of metastatic disease or death due to any cause. Secondary outcomes included prostate-specific antigen (PSA) relapse, recurrence-free survival, overall survival, freedom from hormonal therapy, and postoperative complications.

RESULTS

Among the 425 men, median follow-up was 10.6 years (interquartile range, 9.2-12.7 years). For metastasis-free survival, 76 (35.5%) of 214 men in the adjuvant radiotherapy group were diagnosed with metastatic disease or died (median metastasis-free estimate, 14.7 years), compared with 91 (43.1%) of 211 (median metastasis-free estimate, 13.2 years) of those in the observation group (hazard ratio [HR], 0.75; 95% CI, 0.55-1.02; P = .06). There were no significant between-group differences for overall survival (71 deaths, median survival of 14.7 years for radiotherapy vs 83 deaths, median survival of 13.8 years for observation; HR, 0.80; 95% CI, 0.58-1.09; P = .16). PSA relapse (median PSA relapse-free survival, 10.3 years for radiotherapy vs 3.1 years for observation; HR, 0.43; 95% CI, 0.31-0.58; P<.001) and disease recurrence (median recurrence-free survival, 13.8 years for radiotherapy vs 9.9 years for observation; HR, 0.62; 95% CI, 0.46-0.82; P = .001) were both significantly reduced with radiotherapy. Adverse effects were more common with radiotherapy vs observation (23.8% vs 11.9%), including rectal complications (3.3% vs 0%), urethral strictures (17.8% vs 9.5%), and total urinary incontinence (6.5% vs 2.8%).

CONCLUSIONS

In men who had undergone radical prostatectomy for pathologically advanced prostate cancer, adjuvant radiotherapy resulted in significantly reduced risk of PSA relapse and disease recurrence, although the improvements in metastasis-free survival and overall survival were not statistically significant. Trial Registration clinicaltrials.gov Identifier: NCT00394511.

The effects of the dual 5alpha-reductase inhibitor dutasteride on localized prostate cancer--results from a 4-month pre-radical prostatectomy study

BACKGROUND

As dihydrotestosterone (DHT) is the most potent androgen in the prostate, inhibition of the 5alpha-reductase isoenzymes, which convert testosterone to DHT, could be an appropriate target for the treatment of prostate cancer.

METHODS

Eighty-one men with clinically localized prostate cancer received daily dutasteride 3.5 or 0.5 mg, or no therapy for 4 months before radical prostatectomy. Histopathological assessments were conducted on prostatectomy specimens.

RESULTS

Treatment with dutasteride was associated with reductions in serum and intraprostatic DHT of >or=90%, and a decrease in total prostate and tumor volumes. No effect of dutasteride was noted on Gleason grade. Histopathological effects on benign tissue were similar but less prominent than those seen with androgen ablation, whereas there was no significant difference in cancer histology among the groups.

CONCLUSIONS

Dutasteride treatment results in similar but less marked changes compared with androgen ablation.

Mobilization of iron from cells by hydroxyquinoline-based chelators

With the aim of identifying an iron (Fe) chelator which is effective at mobilizing intracellular Fe, two novel ligands were synthesized and tested. Hydroxyquinoline is known to possess a high affinity for Fe and was thus chosen as the Fe binding motif for the hexadentate chelators, C1 (2,2'-[ethane-1,2-diylbis(iminomethylene)]diquinolin-8-ol) and C2 (2,2'-[cyclohexane-1,2-diylbis(iminomethylene)]diquinolin-8-ol). Both chelators are lipophilic, with Fe3+ complexes slightly more hydrophilic than the free ligands. C1 and C2 were equally toxic to K562 cells, and partial protection was afforded by supplementing the culture medium with human holotransferrin, suggesting that some of the toxicity of the ligands is due to cellular Fe depletion. Micromolar concentrations of both ligands effectively mobilized 59Fe from reticulocytes and K562 cells. In reticulocytes, 50 microM C1 caused the release of 60% of the cells' initial 59Fe uptake after a 4h incubation. Under the same conditions, C2 revealed a release of 50% of the 59Fe. Overall, both ligands merit in vivo study for oral activity. Their effectiveness at low concentrations makes them candidates for therapeutic use.

Selected culturable enteric bacterial populations are modified by diet acidification and the growth promotant Tylosin

AIMS

To determine the effect of diet acidification and an in-feed antibiotic growth promotant (Tylosin, Ty) on selected culturable bacterial populations in the gastrointestinal tract (GIT) of mice.

METHODS AND RESULTS

Female C57Bl mice were given a standard diet supplemented with Acid Pak (AP) or Ty in the drinking water. After 21 days, lumen and adherent populations of Enterobacteriaceae, enterococci/streptococci, and lactic acid bacteria (LAB) from the ileum, caecum, colon and faeces were enumerated. General intestinal health was assessed by the frequency of haemolytic bacteria in the different intestinal compartments. Contrary to expectations, AP and Ty significantly increased haemolytic bacteria in the lumen of the caecum and colon (P<0.05). The small but significant growth-enhancing effect of Ty (P<0.05) was associated with decreases in enterococci/streptococci and surprisingly, LAB, as well as increases in coliforms. AP, which failed to improve growth rates, reduced coliforms, had limited effects on enterococci/streptococci, and specifically failed to promote the growth of LAB populations in all intestinal compartments. Ty supplementation was also associated with a significant increase in macrolide-resistant enterococci throughout the GIT.

CONCLUSIONS

Dietary acidification is less effective than Ty in modulating the population dynamics of selected culturable populations of enteric bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

The mouse can provide a useful experimental model to examine the effects of new dietary supplements, formulations or regimes on changes in microbial population dynamics, including monitoring for antibiotic resistance.