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G Jozsef

Publications and source records attributed to G Jozsef.

18 recordsLinked to original sources

Radiotherapy for carcinoma of the bladder: a review.

Carcinoma of the bladder (CaB) is a common and important tumor in North America and Western Europe. There has been a steady increase in the incidence of CaB during the past 25 years in both of these regions with a simultaneous decrease in the mortality rates. The decrease in mortality is primarily due to an earlier diagnosis and the availability of more effective therapeutic interventions resulting from major advances in surgery and a wide use of multimodality bladder preservation therapy.The use of radiotherapy in the management of muscle-invasive CaB has undergone a major evolution. External beam radiotherapy alone is used infrequently in carefully selected patients. The same applies to the use of preoperative irradiation. Brachytherapy alone or combined with external beam radiotherapy has been used successfully in Europe but is used infrequently in North America. External beam radiotherapy is an essential component of a multimodality therapy consisting of cytoreductive surgery via transurethral resection of a bladder tumor followed by a planned combination of radiotherapy and chemotherapy. The outcomes of this bladder preservation therapy are similar to those reported in a like patient population treated with radical cystectomy. The main benefit of conservatively treated patients is functioning bladder in about 50% of those receiving conservative therapy. Radiotherapy alone or in a combination with chemotherapy remains an important and effective palliative therapy for patients with recurrent and/or metastatic CaB. Current research efforts are directed toward a better identification of important pretreatment risk factors predicting failure thus helping in a more optimal selection of patients who would benefit most from radical cystectomy or from the application of bladder preservation therapy.

Brachytherapy↗

Calculation of mean central dose in interstitial brachytherapy using Delaunay triangulation.

In 1997 the ICRU published Report 58 "Dose and Volume Specification for Reporting Interstitial Therapy" with the objective of addressing the problem of absorbed dose specification for reporting contemporary interstitial therapy. One of the concepts proposed in that report is "mean central dose." The fundamental goal of the mean central dose (MCD) calculation is to obtain a single, readily reportable and intercomparable value which is representative of dose in regions of the implant "where the dose gradient approximates a plateau." Delaunay triangulation (DT) is a method used in computational geometry to partition the space enclosed by the convex hull of a set of distinct points P into a set of nonoverlapping cells. In the three-dimensional case, each point of P becomes a vertex of a tetrahedron and the result of the DT is a set of tetrahedra. All treatment planning for interstitial brachytherapy inherently requires that the location of the radioactive sources, or dwell positions in the case of HDR, be known or digitized. These source locations may be regarded as a set of points representing the implanted volume. Delaunay triangulation of the source locations creates a set of tetrahedra without manual intervention. The geometric centers of these tetrahedra define a new set of points which lie "in between" the radioactive sources and which are distributed uniformly over the volume of the implant. The arithmetic mean of the dose at these centers is a three dimensional analog of the two-dimensional triangulation and inspection methods proposed for calculating MCD in ICRU 58. We demonstrate that DT can be successfully incorporated into a computerized treatment planning system and used to calculate the MCD.

Biophysical Phenomena↗

Application of radiosurgery principles to a target in the breast: a dosimetric study.

PURPOSE: To investigate the technical and physical feasibility of using a radiosurgery-like technique to irradiate a small target within the breast with a single fraction. MATERIAL AND METHODS: During diagnostic biopsy, a tantalum surgical clip is placed in the lesion identified at mammography. Transverse CT scans over the entire breast are obtained, as the patient lies prone on a special table that allows the breast to hang down. The clip is used as a reference point to define the isocenter of the radiation treatment. RESULTS: The clip is visible on port films taken with a 4 MV beam, allowing the isocenter to be set to its planned location. No movement of the hanging breast is visually detected. The possible beam directions are enclosed by a 220 degrees horizontal x 180 degrees vertical angular interval. Dosimetry of two "radiosurgical" examples, (A) seven fixed horizontal beams and (B) six 45 degrees arcs and a 90 degrees sagittal arc using a 4 MV x-ray beam with a 32 mm diameter collimator, are discussed. Both field arrangements produce adequate tumor coverage: the minimum target dose is 83% of the dose maximum in the fixed beam arrangement and 86% in the multiarc setup. In arrangement A the lung and other tissues external to the breast receive dose only from scattered radiation. In arrangement B the maximum lung dose is less than 5% of the dose to isocenter. CONCLUSION: From a dosimetric point of view both described techniques are feasible, and the radiosurgery-like treatment is executable.

Biophysical Phenomena↗

Unresectable primary and recurrent head and neck tumors: effect of hyperthermia and carboplatin--preliminary experience.

PURPOSE: To perform a single-arm study to determine the effectiveness of and potential toxic reactions to local hyperthermia and systemic carboplatin (cis-diammine-1,1-cyclobutane dicarboxylate platinum II) for the treatment of advanced or recurrent squamous cell carcinomas of the head and neck. MATERIALS AND METHODS: Eight patients with squamous cell carcinoma of the head and neck and stage IV disease (N2 or N3 neck adenopathy) or recurrent local-regional disease and who were previously and definitively treated were included in the study. Thermochemotherapy was administered every 4 weeks. Recorded end points were tumor response, duration of response, incidence of distant metastases, survival, cause of death, and toxic reactions. RESULTS: One patient had a complete response to therapy, and two had a partial response. Five patients had no response or developed progressive disease during therapy. Six patients died after 4-13 months of progressive disease. Two long-term survivors received radiation therapy; one also underwent surgical resection for residual neck disease. Each thermochemotherapeutic session was well tolerated, with minimal discomfort. Toxic reactions included hypotension, vomiting, hyponatremia, anemia, thrombocytopenia, and infection at the site of administration. There were no life-threatening toxic reactions. CONCLUSION: The combined use of hyperthermia and carboplatin shows potential in the management of unresectable head and neck tumors and is safe and well tolerated. Further studies on thermochemotherapy are warranted to assess its potential.

Aged↗

Dosimetric comparison of three photon radiosurgery techniques for an elongated ellipsoid target.

PURPOSE: To examine the dosimetric differences among three radiosurgery techniques: gamma knife, linac multiple arcs, and conformally-shaped static fields. METHODS AND MATERIALS: A simulated target was taken to be a prolate ellipsoid, 25 mm in diameter, 35 mm in length, centrally located in a three-dimensional (3D) model of a patient head taken from MR images. Single isocenter linac treatment plans were developed, 9 portals for the static shaped field technique, and a 7-arc plan for the multiple arc method. A total of 13 isocenters with 3 different collimators were used in the gamma knife plan. RESULTS: At dose levels from 25% to 50% of the reference dose, multiple arc and shaped-field plans treated a greater volume than the gamma knife plan. The linac plans, however, delivered the dose more homogeneously across the target volume as compared to the gamma knife plan. For the dose levels between 50-100%, the shaped fields and gamma knife plan have a similar dose distribution, and treated slightly less volume than the multiple arc plan. CONCLUSION: For a target of limited volume and essentially any shape, one can obtain closely conformal dosimetry with the gamma knife. For a regular-shaped target, the single isocenter multiple arc technique gives a more homogenous dose distribution within the target. Static shaped fields offer an alternative radiosurgery technique, with dosimetry similar to the multiple arc method, applicable to targets of any shape.

Head↗

Radial dose distribution, dose to water and dose rate constant for monoenergetic photon point sources from 10 keV to 2 MeV:EGS4 Monte Carlo model calculation.

A comprehensive set of dose distributions from monoenergetic photon-emitting isotropic point sources in a medium can be used as a reference database for the dosimetry of photon emitter sources in that medium. Data of this type for water over the photon energy range from 15 keV to 2 MeV have been published based on calculations using a one-dimensional photon transport model. The present work, based on a previously published EGS4 Monte Carlo code, updates the classic data set of Berger and provides more extensive calculations than previously available. Air kerma strength per unit photon emission rate from an isotropic point emitter is obtained as a function of energy using published data for mass energy absorption coefficients. The TG-43 dose rate constant for water as a function of energy is calculated for monoenergetic photon emitters as the ratio of dose rate to water at 1 cm to air kerma strength for unit photon emission rate. Results for the radial dose distribution agree well with the data of Berger between 40 and 400 keV. For energies > or =500 keV, a previously undescribed buildup region for the radial dose function is identified. Thickness of the buildup region ranges from 1 mm at 500 keV to 8 mm at 2 MeV. Between 15 and 30 keV, the radial dose function within a few millimeters of the emitter is calculated to be 4%-5% higher than values derived from Berger's data. The maximum dose rate constant for monoenergetic photon emitters occurs at an energy of 60 keV, and has the value 1.355 cGy h(-1)U(-1), where U is the unit of air kerma strength, 1 microGy m2 h(-1). This would correspond to the maximum hypothetical dose rate constant for a brachytherapy photon source emitting photons of energy < or =2 MeV.

Dose-Response Relationship, Radiation↗

Abdomino-pelvic hyperthermia and intraperitoneal carboplatin in epithelial ovarian cancer: feasibility, tolerance and pharmacology.

PURPOSE: To investigate the feasibility, toxicity, and pharmacokinetics of intraperitoneal (i.p.) carboplatin (CB) with concomitant abdomino-pelvic hyperthermia (HT) in advanced ovarian cancer patients. METHODS AND MATERIALS: Patients with residual disease mainly confined to the peritoneal cavity after platinum based chemotherapy received an initial course of i.p. CB for baseline pharmacokinetics followed by three cycles of i.p. CB with concomitant regional hyperthermia. The goal of HT was to achieve at least 45 min of intraperitoneal temperature > 42 degrees but < 50 degrees C while maintaining normal tissue temperatures < 43 degrees C and systemic body temperatures < 38 degrees C. No analgesic premedication was used. Thermometry was recorded by multisensor fiberoptic probes placed within the peritoneal cavity, bladder, vagina, and oral cavity. RESULTS: Thirteen patients received a total of 31 sessions. Our intraperitoneal temperature goal could not be achieved because of patient intolerance. At best, we could maintain intraperitoneal temperatures > 40 degrees C, for more than 40 min in 7 of 31 sessions. The average values of thermal variables were T90 = 40 degrees C, TAVE = 41 degrees C, TMIN = 38.2 degrees C, and TMAX = 42.9 degrees C. The mean maximum systemic temperature was 38 degrees C. Acute thermal toxicities requiring early interruption of hyperthermia were systemic temperature exceeding 38 degrees C (11 of 31), abdominal pain or generalized distress (20 of 31), and vomiting (2 of 31). Hematological toxicities were not increased by hyperthermia. Pharmacokinetics were consistent with enhanced clearance of CB by HT. Lower radio frequencies (< 75 MHz) achieved better heat deposition in the peritoneal cavity than higher frequencies (> 75 MHz). Two of the 13 patients (a Stage III and a Stage IV patient) are alive with no evidence of disease at 40 and 43 months from treatment. CONCLUSIONS: Intraperitoneal temperatures in the range of 40 degrees C maintained for approximately 40 min can be achieved within the described setting. The probability of successful induction of therapeutic intraperitoneal temperatures appears to be higher when frequencies below 75 MHz are used. Patients who are potentially platinum sensitive and have minimal residual disease could potentially benefit from the combined treatment under the conditions studied. However, this temperature-time range appears inadequate against platinum resistant disease, and/or bulky residual pelvic disease. Alternative approaches such as whole body hyperthermia and carboplatin are warranted to overcome some of the obstacles observed.

Adult↗

Single isocenter treatment planning for homogeneous dose delivery to nonspherical targets in multiarc linear accelerator radiosurgery.

PURPOSE: Conventional radiosurgery refers to single isocenter focused beam irradiation of small intracranial targets with a single collimator. Conventional radiosurgery is characterized by spherical-shaped isodose surfaces. Nonspherical targets require a different approach to avoid exposing a large volume of nontarget brain tissue to high dose, particularly for lesions larger than 25 mm. Multiple isocenters are frequently used to treat nonspherical large targets, but multiple isocenter treatments are associated with a relative dose inhomogeneity of approximately 100% within the target volume, and may be correlated with an increased rate of complications. The feasibility of conformally treating elongated targets to an approximately homogeneous dose using a single isocenter methodology will be demonstrated. METHODS AND MATERIALS: A prolate ellipsoid of revolution, 25 mm in diameter, 35 mm in length, positioned at five representative locations in a head phantom, was used as a target model. The alignment of the target was taken to be parallel in turn to each of the three principal axes of the head model (A/P, R/L, and C/C). Dose conformation is achieved by nonuniform arc weighting, selective limitation of the extent of individual arcs, and the use of different collimator apertures for the different arcs in accordance with the aperture size required to encompass the target for that arc. Treatment plans were selected based on considerations of dose-volume histograms and conformation of the 80% dose surface with the surface of the target. The goal was that the minimum target dose would not be less than 80% of the maximum dose. RESULTS: Practical treatment plans for which the minimum target dose exceeded 80% were obtained for the three orthogonal orientations of the target for the five target locations. Plan parameters were essentially independent of the target position, dependent only on target orientation. The 80% isodose contour surface enclosed on average 2.8 cm3 larger volume (range: 2.1-3.9 cm3) than the prescribed 11.45 cm3 target. The minimum dose to the target ranged from 80.1 to 84.5%, and the average dose to the target was 94.26%. The 80-to-50% dose volume enclosed an average of 14.8 cm3 of nontarget volume (range: 12.7-15.9 cm3). Average deviation in the principal planes of the 80% isodose lines from the surface of the target volume was 0.95 mm for the 25 mm dimension (range 0.0 to +1.9 mm) and 0.86 mm (range 0.0 to + 2.4 mm) for the 35 mm dimension. CONCLUSION: Standardized single isocenter treatment plans with the isocenter at the center of the target can achieve good conformation of the dose distribution to targets elongated along any of the principal axes, and located anywhere in the brain.

Humans↗

Stereotactic radiosurgery: principles and comparison of treatment methods.

Methods of stereotactic radiosurgery are reviewed and compared with respect to technical factors and published clinical results. Heavy-ion beams, the Leksell cobalt-60 gamma knife, and the conventional linear accelerator (linac) are compared with respect to dosimetry, radiobiology, treatment planning, cost, staffing requirements, and ease of use. Clinical results on the efficacy of treatment of arteriovenous malformations are tabulated, and other applications of radiosurgery are described. It is concluded that although there are dosimetric and radiobiological advantages to charged-particle beams that may ultimately prove critical in the application of radiosurgery to large (> 30 mm) lesions, these advantages have not yet demonstrated clinical effect. On the other hand, equally excellent clinical results are obtained for small lesions with photon beams--the gamma knife and the linac. There are only minor differences between gamma and x-ray beam dose distributions for small, spherical-shaped targets. Mechanical precision is superior for the gamma knife as compared with the linac. The superior mechanical precision is of limited importance for most clinical targets, because inaccuracy of cranial target localization based on radiological imaging is greater than the typical linac imprecision of +/- 1 mm. Treatment planning for the linac is not standardized, but existing systems are based on well-known algorithms. The linac allows flexible, ready access to individualized beam control, without intrinsic field size limitations. Thus, it is more readily possible to achieve homogeneous dose distributions for nonspherical targets with one or more dimensions greater than 25 mm, as compared with that achieved with the gamma unit.(ABSTRACT TRUNCATED AT 250 WORDS)

Equipment Design↗

Radiotherapy following radical prostatectomy in patients with adenocarcinoma of the prostate.

From 1973 to 1986, 160 patients with adenocarcinoma localized to the prostate were treated with radical prostatectomy and pelvic lymphadenectomy. In 78 (49%) patients more advanced stage of disease was found at surgery and they received local pelvic irradiation (RT). This consisted of 45 Gy for microscopic and 55 Gy for macroscopic residual disease. RT was given at 1.8 Gy a day, using the four-field "box" technique with the 23 MV X ray beam. Pelvic lymph node metastases were found in 28 (36%) patients who, in addition to RT, received systemic therapy: 20 with cyclophosphamide alone, 4 combined with 5-Fluorouracil, and 4 patients received DES. The 5- and 10-year overall actuarial survival was 95 and 77%, respectively, and the 5- and 10-year disease-free survival was 58 and 43%, respectively. Recurrent tumor was found in 34 (44%) patients. Of these 34 patients, 32 (94%) had distant metastatic tumor and 2 (6%) had local recurrence in the pelvis. The presence of metastatic disease in pelvic lymph nodes had clinical significance since it influenced disease-free survival and the incidence of tumor recurrence. The 10-year disease-free survival for the 50 patients with no lymph node metastases was 51%, as compared to 28% for the 28 patients with such metastases, p = 0.001. Similarly, recurrent tumor was found in 28% of the former and 68% of the latter patients, p = 0.002. Other important parameters predicting recurrence were: clinical stage, p = 0.018, histological grade, p = 0.013, and Gleason's grade, p = 0.002. This treatment program was very well tolerated and of low toxicity. There was no surgical mortality. Surgical complications were seen in 10 (13%) patients including: minor in 5 and major in 5. At 1 year, 77% of the patients remained continent, while 10% had mild stress incontinence. Of the remaining 13% only 3 (4%) patients had severe incontinence (greater than 5 pads daily). RT toxicity was mild with 38% experiencing diarrhea. Severe toxicity was seen in 2 (3%) patients who, early in the study, developed scrotal and lower extremity edema. Severe chemotherapy complications were seen in 1 (4%) patient who had severe neutropenic sepsis. Postoperative radiotherapy is a well tolerated, safe and effective treatment in patients who have microscopic or macroscopic residual tumor following radical prostatectomy.

Adenocarcinoma↗

An interactive treatment planning system for ophthalmic plaque radiotherapy.

Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system.

Brachytherapy↗

Transurethral hyperthermia for benign prostatic hyperplasia: preliminary clinical results.

A total of 21 patients with biopsy proved benign prostatic hyperplasia underwent treatment on a pilot protocol involving intracavitary transurethral radiating microwave (630 or 915 MHz.) antenna hyperthermia. Acute and subacute toxicity was mild and consisted primarily of bladder spasm (26% of the patients), hematuria (23%) and dysuria (9%), none of which significantly limited the achievement of desired temperatures during the treatment sessions. No chronic treatment-related morbidity or mortality was observed. Detailed thermal mapping, performed along the course of the prostatic urethra, recorded temperatures of 43C or more at greater than 75% of the loci. Highly significant increases in urine flow rate, decrease in post-void residual urine capacity and decrease in frequency of nocturia were observed. A marginally significant decrease in prostate volume was noted and, with a median followup of 12.5 months, only 3 patients have required subsequent prostatic resection. Transurethral hyperthermia represents a safe and promising outpatient approach to treatment of benign prostatic hyperplasia, particularly for patients who are not candidates for conventional surgical approaches because of medical or personal reasons. Further studies with the goal of optimizing the technique appear to be warranted, although long-term results would be best evaluated with prospective phase 3 trials.

Aged↗

Optimization of 125I ophthalmic plaque brachytherapy.

Episcleral plaques containing 125I sources are often used in the treatment of ocular melanoma. Within four years post-treatment, however, the majority of patients experience some visual loss due to radiation retinopathy. The high incidence of late complications suggests that careful treatment optimization may lead to improved outcome. The goal of optimization would be to reduce the magnitude of vision-limiting complications without compromising tumor control. We have developed a three-dimensional computer model for ophthalmic plaque therapy which permits us to explore the potential of various optimization strategies. One simple strategy which shows promise is to maximize the ratio of dose to the tumor apex (T) compared to dose to the macula (M). By modifying the parameters of source location, activity distribution, source orientation, and shielding we find that the calculated T:M ratio can be varied by a factor of 2 for a common plaque design and posterior tumor location. Margins and dose to the tumor volume remain essentially unchanged.

Biophysical Phenomena↗

Algorithm for dosimetry of multiarc linear-accelerator stereotactic radiosurgery.

Treatment planning for multiarc radiosurgery is an inherently complex three-dimensional dosimetry problem. Characteristics of small-field x-ray beams suggest that major simplification of the dose computation algorithm is possible without significant loss of accuracy compared to calculations based on large-field algorithms. The simplification makes it practical to efficiently implement accurate multiplanar dosimetry calculations on a desktop computer. An algorithm is described that is based on data from fixed-beam tissue-maximum-ratio (TMR) and profile measurements at isocenter. The profile for each fixed beam is scaled geometrically according to distance from the x-ray source. Beam broadening due to scatter is taken into account by a simple formula that interpolates the full width at half maximum (FWHM) between profiles at isocenter at different depths in phantom. TMR and profile data for two representative small-field collimators (10- and 25-mm projected diameter) were obtained by TLD and film measurements in a phantom. The accuracy of the calculational method and the associated computer program were verified by TLD and film measurements of noncoplanar multiarc irradiations from these collimators on a 4-MV linear accelerator. Comparison of film measurements in two orthogonal planes showed close agreement with calculations in the shape of the dose distribution. Maximal separation of measured and calculated 90%, 80%, and 50% isodose curves was less than or equal to 0.5 mm for all planes and collimators. All TLD and film measurements of dose to isocenter agreed with calculations to within 2%.

Algorithms↗

Heating characteristics of a helical microwave applicator for transurethral hyperthermia of benign prostatic hyperplasia.

A new applicator for intraurethral hyperthermic treatment of benign prostatic hyperplasia is described. The applicator uses an insulated helical antenna wound on the outer surface of a silicone urological (Foley) balloon catheter. The balloon catheter assures rapid and reproducible localization of the antenna in the prostatic urethra. Two small cannulae are fixed to the exterior surface of the applicator. One holds a temperature control sensor at a fixed location, the other is used to map temperature along the applicator. Two-dimensional SAR and steady-state temperature distributions measured in a plane tangent to the applicator in a tissue-equivalent phantom are presented, as well as longitudinal temperature distributions measured in situ at the applicator-urethral interface. Prostatic temperatures were also measured intraoperatively. The applicator appears to be capable of elevating temperature to greater than 42 degrees C in a cylindrically symmetric volume of about 4 cm length and about 0.5 cm radial penetration surrounding the antenna. The heating characteristics of this applicator are similar to an earlier design that employed an array of three dipoles. The helical applicator is narrower, more flexible and simpler to use than the earlier design.

Biomedical Engineering↗

Transurethral hyperthermia for benign prostatic hyperplasia: long term results.

Transurethral resection of the prostate (TURP) is the only recognized treatment in patients with benign prostatic hyperplasia (BPH). Transurethral hyperthermia (TUHT) was used as an alternative treatment in patient who refused TURP. From 1987 to 1988, 21 BPH patients with moderate to severe symptoms and signs of prostatism were treated with TUHT in a phase I trial. Mean pre-treatment subjective and objective values were: total symptom score (TSS) 13.5, obstructive symptom score (OSS) 6.5, irritative symptom score (TSS) 7.0, peak flow rate (PFR) 11.6 cc/sec, post-voiding residual volume (PRV) 187 cc, and prostate volume (PV) 93 cc. TUHT was given for a total of 177 sessions (mean 8.4), each of 60 min duration at a steady state. Temperature was recorded continuously on the urethral surface, in all treatments. It ranged from Tmin 40.3 degrees C to Tmax = 49.2 degrees C and Tmean = 44.1 degrees C. The mean minimum temperature of > or = 42 degrees C was obtained in 98% of the TUHT sessions. Treatments were given on an outpatient basis without sedation or anaesthesia. Treatment tolerance was excellent with minor acute toxicity common (71% of patients), of no clinical importance and with no late complications. Of the 21 patients treated, 17 (81%) had an objective and 15 (71%) a subjective improvement recorded at 6 months post-treatment. This statistically highly significant improvement included: 61% decrease in TSS; 66% decrease in OSS; 55% decrease in ISS; 42% increase in PFR; 55% decrease in PRV; and 21% decrease in PV. Of the 17 patients with objective improvement, nine have maintained their response to TUHT for a minimum period of over six years, two relapsed at 11 and 40 months, respectively, and six patients died of cardiovascular causes maintaining their response to death. This study has demonstrated TUHT treatment efficacy with no major or clinically important toxicity in BPH patients. A relative weakness of this report is a lack of verification of objective study parameters in the patients at seven years post-treatment. Prospective randomized trials are needed to define the role of TUHT in the management of BPH patients.

Aged↗