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Biomedical subjects

B J Donnelly

Publications and source records attributed to B J Donnelly.

At least 19 recordsLinked to original sources
PubMed2005

Role of transrectal ultrasound guided salvage cryosurgery for recurrent prostate carcinoma after radiotherapy.

Despite improvements in treatment of localized prostate cancer, local recurrence remains a significant problem. A total of 46 patients with proven local cancer recurrence following external beam radiotherapy entered a prospective clinical trial using ultrasound-guided cryosurgery to ablate the residual prostate gland. Persistent complications included one urethra-rectal fistula, incontinence (2), retention (3), and treatment induced erectile dysfunction (7). Using the PSA definitions for biochemical failure as PSA>or=0.3 ng/ml, the Kaplan-Meier plots showed the incidence of patients to be free of biochemical recurrence at 51 and 44% at 1 and 2 y, respectively. For a PSA>or=1.0, the values at 1 and 2 y were 72 and 58%.

Aged↗
PubMed2002

Prospective trial of cryosurgical ablation of the prostate: five-year results.

OBJECTIVES: To determine in a prospective pilot study the safety and efficacy of cryosurgical ablation for localized prostate carcinoma. METHODS: A total of 87 cryosurgical procedures were performed on 76 consecutive patients between December 1994 and February 1998. All patients had histologically proved adenocarcinoma of the prostate, with prostate-specific antigen (PSA) readings of less than 30 ng/mL. Clinical evaluations, PSA determinations, and patient self-reported quality-of-life questionnaires (functional assessment of cancer treatment-prostate; FACT-P) were used to determine biochemical and clinical disease-free status and complications. Patients had a mean follow-up of 50 months (minimum 36). RESULTS: Follow-up biopsies were performed in 73 patients, and 72 were negative for malignancy after one or more treatments. Ten patients required two treatments and 1 patient required three treatments. The 5-year overall and cancer-specific survival rate was 89% (95% confidence interval, 83% to 97%) and 98.6% (95% confidence interval, 96% to 100%), respectively. The undetectable PSA rate (less than 0.3 ng/mL) for low-risk patients (n = 13) was 60% at 5 years; for moderate-risk patients (n = 23), it was 77%, and for high-risk patients (n = 40), 48%. The corresponding percentage of patients with a PSA level less than 1.0 ng/mL at 5 years was 75%, 89%, and 76%. Sloughing occurred in 3 patients (3.9%), incontinence in 1 (1.3%), and testicular abscess in 1 (1.3%). At 3 years, 18 (47%) of 38 patients capable of unassisted intercourse at the time of cryosurgery had resumed sexual intercourse, 5 spontaneously and 13 with sildenafil or prostaglandin. CONCLUSIONS: The results of this prospective evaluation show cryosurgery to be both a safe and an effective option in the treatment of localized prostate cancer.

Adenocarcinoma↗
PubMed2001

Flounder antifreeze peptides increase the efficacy of cryosurgery.

Type I antifreeze protein (AFP) from the winter flounder (Pseudopleuronectes americanus) was used as an adjuvant to cryosurgery of subcutaneous tumors of Dunning AT-1 rat prostate cells grown in Copenhagen rats. The cryosurgical procedure was performed with a commercially available cryosurgery device (CRYO-HIT, Galil Medical) with clinically relevant single- and double-freeze protocols. Injury was assessed with the alamar blue indicator of metabolic activity. The assay gave anomalous results when used to assess the extent of injury immediately following the procedure, underestimating the extent of injury. However, a double-freeze procedure with antifreeze protein present was found to give significantly better ablation than a double-freeze without AFP or a single-freeze with or without AFP.

Animals↗
PubMed2001

A model for the time dependent three-dimensional thermal distribution within iceballs surrounding multiple cryoprobes.

A time dependent three-dimensional finite difference model of iceball formation about multiple cryoprobes has been developed and compared to experimental data. Realistic three-dimensional probe geometry is specified and the number of cryoprobes, the cryoprobe cooling rates, and the locations of the probes are arbitrary inputs by the user. The simulation accounts for observed longitudinal thermal gradients along the cryoprobe tips. Thermal histories for several points around commercially available cryoprobes have been predicted within experimental error for one, three, and five probe configurations. The simulation can be used to generate isotherms within the iceball at arbitrary times. Volumes enclosed by the iceball and any isotherms may also be computed to give the ablative ratio, a measure of the iceball's killing efficiency. This ratio was calculated as the volume enclosed by a critical isotherm divided by the total volume of the iceball for assumed critical temperatures of -20 and -40 degrees C. The ablative ratio for a single probe is a continuously decreasing function of time but when multiple probe configurations are used the ablative ratio increases to a maximum and then essentially plateaus. Maximum values of 0.44 and 0.55 were observed for three and five probe configurations, respectively, with an assumed critical temperature of -20 degrees C. Assuming a critical temperature of -40 degrees C, maximum ablative ratios of 0.21 and 0.3 for three and five probe configurations, respectively, were observed.

Biophysical Phenomena↗
PubMed2001

Histological findings in the prostate two years following cryosurgical ablation.

We examined the pathological findings from prostatic whole mounts obtained at post-mortem, 2 years following cryosurgical ablation of the prostate (CSAP), to evaluate the presence or absence of residual benign or malignant tissue. Whole prostates were obtained from two patients at post-mortem, in which the cause of death was not related to prostate cancer. The patients had received CSAP 24 and 30 months earlier, as the primary treatment for prostate cancer. Complete ablation of the gland was demonstrated in one case, with some residual viable benign glands in the transitional zone in the second case. These results suggest that localized prostate cancer can be successfully eradicated by CSAP.

Autopsy↗
PubMed2000

A semi-empirical treatment planning model for optimization of multiprobe cryosurgery.

A model is presented for treatment planning of multiprobe cryosurgery. In this model a thermal simulation algorithm is used to generate temperature distribution from cryoprobes, visualize isotherms in the anatomical region of interest (ROI) and provide tools to assist estimation of the amount of freezing damage to the target and surrounding normal structures. Calculations may be performed for any given freezing time for the selected set of operation parameters. The thermal simulation is based on solving the transient heat conduction equation using finite element methods for a multiprobe geometry. As an example, a semi-empirical optimization of 2D placement of six cryoprobes and their thermal protocol for the first freeze cycle is presented. The effectiveness of the optimized treatment protocol was estimated by generating temperature-volume histograms and calculating the objective function for the anatomy of interest. Two phantom experiments were performed to verify isotherm locations predicted by calculations. A comparison of the predicted 0 degrees C isotherm with the actual iceball boundary imaged by x-ray CT demonstrated a spatial agreement within +/-2 mm.

Algorithms↗
PubMed2000

Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy.

Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.

Biophysical Phenomena↗
PubMed2000

Extraprostatic biopsy improves the staging of localized prostate cancer.

OBJECTIVE: To evaluate the role and safety of biopsy of the seminal vesicles and neurovascular bundles in determining the pathologic stage of prostatic carcinoma. METHODS: Eighty-one consecutive patients were enrolled in a comprehensive cryosurgical biopsy protocol that included sextant intraprostatic plus extraprostatic biopsy. The pathologic stage, determined after biopsy, was compared with the clinical stage, determined by digital rectal examination (DRE) and transrectal ultrasonographic (TRUS) evaluation. As well, complication rates for these patients were compared with rates for a separate group that underwent sextant intraprostatic biopsy alone. RESULTS: Of the 81 patients, 61 (75%) were confirmed to have cancer by biopsy. None of these patients was considered to have extraprostatic extension by clinical evaluation (DRE and TRUS), but 16 of 61 (26%) were identified to have extraprostatic cancer in the seminal vesicles (8 of 61, 13%) or in the neurovascular bundles (8 of 61, 13%) by extraprostatic biopsy. There was no significant difference in the complication rates between sextant intraprostatic biopsy and sextant intraprostatic plus extraprostatic biopsy (p>0.97). CONCLUSIONS: Extraprostatic biopsy identifies extension of carcinoma in a large proportion of patients in whom clinical evaluation by DRE and TRUS indicates organ-confined disease. Extraprostatic biopsy is therefore warranted as routine evaluation before surgery in order to correctly stage prostatic carcinoma and select appropriate therapy.

Adult↗
PubMed1999

Quality-of-life outcomes for men treated with cryosurgery for localized prostate carcinoma.

BACKGROUND: Cryosurgery was introduced as an alternative to radiotherapy or radical prostatectomy in the mid-1960s. Although it met the primary objective of achieving local control, it was largely abandoned due to a high incidence of complications. Technologic advances in the areas of imaging and urethral warming have renewed interest in this treatment methodology. The aim of the current study was to determine the quality of life of men enrolled in a Phase II clinical trial of cryosurgery for the treatment of localized prostate carcinoma. METHODS: Men were administered the Functional Assessment of Cancer Treatment-Prostate (FACT-P) prior to their treatment and at 6 weeks and 3, 6, and 12 months posttreatment. RESULTS: By 12 months after cryosurgery, most of the FACT-P subscales had returned to pretreatment levels, following a decline in well-being immediately after cryosurgery. There were two exceptions to this general trend: At 12 months, impairments in social/family well-being and sexual function still remained. The average time to return to work after therapy was 3 weeks. Stay in hospital after treatment was limited to 1 day for 94% of the participants. Compared with men who received the standard treatments of radical prostatectomy and radical radiotherapy, men treated with cryosurgery appeared to have a similar quality of life, with perhaps the exception of decreased sexual function. CONCLUSIONS: The quality-of-life outcomes of this study support the current renewed interest in cryosurgery. The severe impairments reported in other studies were not seen in this sample. In fact, it appeared that all aspects of the participants' well-being had returned to pretreatment levels by 12 months, with the exception of sexual function.

Aged↗
PubMed1999

Considerations during clinical operation of two commercially available cryomachines.

BACKGROUND AND OBJECTIVES: Advances in the technology of cryomachines in the last 10 years have led to the development of both liquid nitrogen and argon-based Joule-Thompson cryomachines. Theoretical and practical evaluation of the CMS Accuprobe and the ENDOcare CRYOcare was performed as respective examples of these technologies. METHODS: Thermal gradients were calculated about both probes for the best case scenario of probe surface temperature equaling that of the cryogen used. Also, experimental evaluation in gelatin phantoms was performed with five probe arrays. RESULTS: Theoretically, a liquid nitrogen-cooled probe provides only a slight advantage over one cooled with liquid argon. However, the experimental performance evaluation demonstrated that the CRYOcare system creates an iceball faster with steeper internal temperature gradients than the Accuprobe. Further, temperature outputs from the Accuprobe were shown to be in error, likely due to the position of the thermocouple within the probe. CONCLUSIONS: Cryomachine performance is determined more by technological innovations than by cryogen temperature. Thermocouple monitoring is urged for users of the Accuprobe.

Argon↗
PubMed1999

Outcome and safety of transrectal US-guided percutaneous cryotherapy for localized prostate cancer.

OBJECTIVES: To assess the effectiveness and safety of ultrasound (US)-guided cryotherapy as a primary treatment for localized prostate cancer. MATERIALS AND METHODS: A prospective study of percutaneous transrectal US (TRUS)-guided cryotherapy was performed on 71 patients with T1-T3, N0, M0 prostatic cancer: 10 patients underwent two or more procedures. All cases were newly diagnosed and patients had no previous treatment for cancer. For all patients, TRUS biopsies were performed at 5-6 months. Patients were monitored at 6 weeks; 3, 6, 9, and 12 months; and twice yearly thereafter for prostate specific antigen (PSA) levels, complications, and clinical evidence of residual disease. RESULTS: Follow-up from 10 to 36 months was available for 70 of 71 patients; one patient died of unrelated disease. Initially, 10 of 69 patients had positive postcryotherapy biopsy results. After repeated treatment, nine of these 10 patients had negative biopsy results and one patient had no follow-up. Overall, 68 of 69 patients had negative biopsy results. At 1 year, 43 of 64 (67%) had an undetectable PSA level. Two patients had proven metastases. Complications include three cases with urethral sloughing requiring transurethral resection of the prostate (TURP). One patient had orchitis. Two patients had persistent incontinence, one as the result of a TURP. There was no death, acute serious morbidity, or fistula formation. Impotence was universal at 6 months, but many patients demonstrated late recovery. CONCLUSION: Cryoablation is an imaging-guided percutaneous intervention for prostate cancer that can safely yield disease-free status in a high percentage of patients with localized disease.

Adenocarcinoma↗
PubMed1999

Transrectal ultrasound-guided biopsy of the prostate: relation between ASA use and bleeding complications.

OBJECTIVE: To determine the relation between ASA ingestion and the incidence of bleeding complications after transrectal ultrasound (TRUS)-guided biopsy of the prostate. METHODS: Overall, 1810 patients with suspected prostate disease were followed after biopsy. ASA use was determined before the procedure. A TRUS-guided sextant biopsy was performed and patients were contacted immediately and by follow-up telephone call to determine whether there were any immediate or delayed bleeding complications. RESULTS: Overall, 46 subjects (2.5%) had bleeding complications. Of the 54 subjects reporting current use of ASA, 2 (3.7%) had such complications. This difference was not significant. CONCLUSION: There was no evidence of an association between the use of ASA and postbiopsy bleeding complications.

Adult↗
PubMed1998

X-ray CT monitoring of iceball growth and thermal distribution during cryosurgery.

X-ray CT is able to image the internal architecture of frozen tissue. Phantoms of distilled water, a saline-gelatin mixture, lard and a calf liver-gelatin suspension cooled by a plastic tube acting as a long liquid nitrogen cryoprobe were used to study the relationship between Hounsfield unit (HU) values and temperature. There is a signature change in HU value from unfrozen to completely frozen tissue. No discernible relation exists between temperature in a completely frozen tissue and its HU value for the temperature range achieved with commercial cryoprobes. However, such a relation does exist in the typically narrow region of phase change and it is this change in HU value that is the parameter of concern for quantitative monitoring of the freezing process. Calibration of temperature against change in HU value allows a limited set of isotherms to be generated in the phase change region for direct monitoring of iceball growth. The phase change temperature range, mid-phase change temperature and the absolute value of HU change from completely frozen to unfrozen tissue are shown to be sensitive to the medium. Modelling of the temperature distribution within the region of completely frozen phantom using the infinite cylinder solution to the Fourier heat equation allows the temperature history of the phantom to be predicted. A set of isotherms, generated using a combination of thermal modelling and calibrated HU values demonstrates the feasibility of routine x-ray CT assisted cryotherapy. Isotherm overlay will be a major aid to the cryosurgeon who adopts a fixed target temperature as the temperature below which there is a certainty of ablation of the diseased tissue.

Animals↗
PubMed1998

A model for the time-dependent thermal distribution within an iceball surrounding a cryoprobe.

The optimal cooling parameters to maximize cell necrosis in different types of tissue have yet to be determined. However, a critical isotherm is commonly adopted by cryosurgeons as a boundary of lethality for tissue. Locating this isotherm within an iceball is problematic due to the limitations of MRI, ultrasound and CT imaging modalities. This paper describes a time-dependent two-dimensional axisymmetric model of iceball formation about a single cryoprobe and extensively compares it with experimental data. Thermal histories for several points around a CRYOprobe are predicted to high accuracy (5 degrees C maximum discrepancy). A realistic three-dimensional probe geometry is specified and cryoprobe temperature may be arbitrarily set as a function of time in the model. Three-dimensional temperature distributions within the iceball, predicted by the model at different times, are presented. Isotherm locations, as calculated with the infinite cylinder approximation, are compared with those of the model in the most appropriate region of the iceball. Infinite cylinder approximations are shown to be inaccurate when applied to this commercial probe. Adopting the infinite cylinder approximation to locate the critical isotherm is shown to lead the user to an overestimate of the volume of target tissue enclosed by this isotherm which may lead to incomplete tumour ablation.

Computer Simulation↗
PubMed1998

Phase III trial of neoadjuvant chemotherapy in patients with invasive bladder cancer treated with selective bladder preservation by combined radiation therapy and chemotherapy: initial results of Radiation Therapy Oncology Group 89-03.

PURPOSE: To assess the efficacy of neoadjuvant methotrexate, cisplatin, and vinblastine (MCV) chemotherapy in patients with muscle-invading bladder cancer treated with selective bladder preservation. PATIENTS AND METHODS: One hundred twenty-three eligible patients with tumor, node, metastasis system clinical stage T2 to T4aNXMO bladder cancer were randomized to receive (arm 1, n=61 ) two cycles of MCV before 39.6-Gy pelvic irradiation with concurrent cisplatin 100 mg/m2 for two courses 3 weeks apart. Patients assigned to arm 2 (n=62) did not receive MCV before concurrent cisplatin and radiation therapy. Tumor response was scored as a clinical complete response (CR) when the cystoscopic tumor-site biopsy and urine cytology results were negative. The CR patients were treated with an additional 25.2 Gy to a total of 64.8 Gy and one additional dose of cisplatin. Those with less than a CR underwent cystectomy. The median follow-up of all patients who survived is 60 months. RESULTS: Seventy-four percent of the patients completed the protocol with, at most, minor deviations; 67% on arm 1 and 81% on arm 2. The actuarial 5-year overall survival rate was 49%; 48% in arm 1 and 49% in arm 2. Thirty-five percent of the patients had evidence of distant metastases at 5 years; 33% in arm 1 and 39% in arm 2. The 5-year survival rate with a functioning bladder was 38%, 36% in arm 1 and 40% in arm 2. None of these differences are statistically significant. CONCLUSION: Two cycles of MCV neoadjuvant chemotherapy were not shown to increase the rate of CR over that achieved with our standard induction therapy or to increase freedom from metastatic disease. There was no impact on 5-year overall survival.

Aged↗
PubMed1997

Correlation between thermosensor temperature and transrectal ultrasonography during prostate cryoablation.

OBJECTIVE: To determine if the adequacy of freezing in the neurovascular bundle region of the prostate during prostate cryotherapy can be monitored by transrectal ultrasonography (TRUS). PATIENTS AND METHODS: The study group consisted of 11 patients undergoing TRUS-guided prostate cryotherapy. The actual temperature in the gland was monitored with thermosensors placed in each prostatic neurovascular bundle. The 2 cryo-operators, working together and blinded to the actual temperature, used sonographic observations to estimate the temperature at the neurovascular bundles every 2 minutes until they believed that the gland was adequately frozen. The congruity between the estimated and measured temperatures was analyzed to determine if the operators could accurately monitor the progress of cryoablation by ultrasonography. RESULTS: There were a total of 85 data points for which the operators thought tumoricidal cryo-injury had been achieved at the neurovascular bundles (temperature -20 degrees C or below). For these points the measured temperature was on average 6.0 degrees C warmer than the estimated temperature (standard deviation, 22). For operator estimates of -20 degrees C or below, the measured temperature was -20 degrees C or below for 37 (44%) data points, between -19 degrees C and 0 degree C for 32 (38%) and greater than 0 degree C for 16 (19%). CONCLUSIONS: The operators were not able to accurately predict subzero temperatures at the neurovascular bundle region by TRUS evaluation. Moreover, the bias and magnitude of the error were significant and might lead to inadequate freezing of the prostate during attempted cryoablation.

Body Temperature↗
PubMed1995

Complaints management--in-depth review.

Introduces the Complaints Manager program from Health-TEC to address the problems involved in complaints management and control in the health service. Shows the main screens available for data input. Demonstrates the wide range of reports which can be generated. Suggests that the Complaints Manager program provides an efficient and low-cost means of keeping complaints under control.

Cost-Benefit Analysis↗