The thermal effect of lasers in urology: a review article.

Lasers as a technology have a leading role in the modern urological treatment armamentarium. In this article, the application of lasers in different areas of urology is described. The major uses are in urolithiasis, benign prostatic enlargement (BPE), and management of many urological malignancies and other benign pathologies. Lasers have become an established treatment modality in urolithiasis, an acceptable alternative with the least side effect profile in BPE patients, and a novel and promising therapy in many other fields of Urology.

COmparing Urolift and Standard Transurethral resection of prostate Ahead of Radiotherapy in men with urinary symptoms secondary to prostate enlargement in Southwest London and North Cumbria (CO-STAR): a study protocol for a randomised feasibility study.

INTRODUCTION: Patients undergoing prostate radiotherapy with an enlarged prostate can have short-term and long-term urinary complications. Currently, transurethral resection of the prostate (TURP) is the mainstay surgical intervention for men with urinary symptoms due to an enlarged prostate prior to radiotherapy. UroLift (NeoTract, Pleasanton, CA, USA) is a recent minimally invasive alternative, widely used in benign disease but is untested in men with prostate cancer. METHODS AND ANALYSIS: A multicentre, two-arm study designed in collaboration with a Patient Reference Group to assess the feasibility of randomising men with prostate cancer and coexisting urinary symptoms due to prostate enlargement to TURP or UroLift ahead of radiotherapy. 45 patients will be enrolled and randomised (1:1) using a computer-generated programme to TURP or UroLift. Recruitment and retention will be assessed over a 12 month period. Information on clinical outcomes, adverse events and costs will be collected. Clinical outcomes and patient reported outcome measures will be measured at baseline, 6 weeks postintervention and 3 months following radiotherapy. A further 12 in-depth interviews will be conducted with a subset of patients to assess acceptability using the Theoretical Framework of Acceptability. Descriptive analysis on all outcomes will be performed using Stata (StataCorp V.2021). ETHICS AND DISSEMINATION: The trial has been approved by the Research Ethics Committee (REC) NHS Health Research Authority (HRA) and Health and Care Research Wales (HCRW). The results will be published in peer-reviewed journals, presented at national meetings and disseminated to patients via social media, charity and hospital websites. TRIAL REGISTRATION NUMBER: NCT05840549.

[Pilot results of prostatic adenoma treatment with diode laser Medilas D UroBeam in the Ukraine].

Pilot results of prostatic adenoma treatment with diode laser (940 nm) in 94 patients showed high efficacy of laser vaporization of the prostate. The effect was achieved in all the patients in minimal number of complications and in satisfactory tolerance of the surgery. Laser vaporization has some advantages over standard treatment (TUR) and is a method of choice in small and middle-size adenomas. In large adenoma good results were obtained in combination of laser vaporization with bipolar TUR.

Permanent interstitial brachytherapy for prostate cancer implementing neoadjuvant prostatic artery embolization.

PURPOSE: Indication for permanent interstitial brachytherapy (PIB) can be limited by prostate volume, commonly decreased using neoadjuvant hormonal therapy. Volume changes and initial clinical results focusing on patients treated with prostatic artery embolization (PAE) were evaluated in this study. METHODS AND MATERIALS: A group of 102 consecutive patients were treated with permanent interstitial brachytherapy (PIB), 13 patients received a neoadjuvant PAE (median 12 weeks before PIB) in case of large prostate volume >60 cm³, and moderate to severe urinary problems. RESULTS: Patients after PAE were treated with significantly larger prostate volumes (52 ± 11 cm³ vs. 39 ± 11 cm³; p < 0.01; 66 ± 17 cm³ before PAE), but larger volume reductions to 44 ± 10 cm³ versus 35 ± 10 cm³ was found at day 30 (p < 0.05). International Prostate Symptom Score (IPSS) decreased significantly from 13 ± 5 before PAE to 7 ± 4 after PAE; p < 0.01. Initial PSA and first PSA after PIB were similar for patients with versus without PAE (5.9 ± 2.9 ng/mL vs. 6.2 ± 2.8 ng/mL and 1.5 ± 0.8 ng/mL vs. 1.9 ± 1.5 ng/mL). However, PSA 12 months after PIB was significantly lower after PAE (0.4 ± 0.3 ng/mL vs. 0.8 ± 0.6 ng/mL; p = 0.03). Four patients without prior PAE needed an intervention after urinary retention - transurethral resection of the prostate (TURP) in three cases and PAE in a single case. Urinary incontinence resulted in two cases after TURP. CONCLUSIONS: PAE could be successfully applied to decrease prostate volume and reduce urinary symptoms before PIB or as a treatment for urinary retention after PIB. A significantly lower PSA is promising for improved long-term cancer control.

Three-dimensional conformal radiation therapy of spontaneous benign prostatic hyperplasia in canines.

The purpose of this study was to determine the effect and possible mechanism of three-dimensional conformal stereotactic radiation therapy (3D-CRT) for the treatment of spontaneous benign prostatic hyperplasia (BPH) in a canine model. Eight canines (7-15 years old) with spontaneous benign prostatic hyperplasia (prostate volume >18 cm3) were used as experimental models. The prostates were directly exposed to 3D-CRT at a total dose of 14 Gy. Serum prostate-specific antigen (PSA) and prostate acid phosphatase (PAP), prostate volume (measured by transrectal ultrasound), apoptosis index [AI, measured by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)], proliferation index [PI, measured by proliferating cell nuclear antigen (PCNA) expression], alpha-SMA, Bax, and bFGF were measured before and after radiation therapy. Histopathology of the prostate, rectum, and bladder tissue was also examined before and after irradiation. 3D-CRT treatment significantly decreased prostate volume, and the PI, PSA, and alpha-SMA, but significantly increased the AI, and had no effect on PAP. There was no evidence of Bax expression before or after irradiation. Irradiation led to no detectable symptoms of diarrhea or changes in stool, but did lead to minor bladder injury, based on light microscopy, scanning electron microscopy, and transmission electron microscopy. In our canine model, 3D-CRT is an effective, noninvasive treatment of BPH that is associated with minimal side effects. Our treatment appeared to reduce prostate size by treatment of the underlying pathological processes.

RADIATION DOSES TO ANAESTHETISTS DURING PROSTATIC ARTERY EMBOLIZATION INTERVENTIONAL PROCEDURES.

The objective of this study was to assess the radiation doses received by anaesthetists from prostatic artery embolization (PAE) procedures. Ten PAE procedures conducted in a reference hospital in the city of Recife, Brazil were investigated. Occupational dosimetry was performed using thermoluminescent dosemeters which were located next to the eyes, close to the thyroid (over the shielding), on the thorax (under the apron), on the wrist and on the feet of the physician's body. The results showed that the anaesthetist's feet received the highest doses followed by the eyes and the hands. In some complex PAE procedures the doses received by anaesthetists on the lens of the eyes and the effective dose were higher than those received by the main operator due to the anaesthetist's close position to the patient's table and the use of oblique projections. The personal dose equivalent Hp(3) per procedure for the anaesthetist's right eyebrow ranged from 20.2 µSv to 568.3 µSv. This result shows that anaesthetists assisting PAE procedures can exceeds the annual eye lens dose limit of 20 mSv recommended by the ICRP with only one procedure per week if radiation protection measures are not implemented during procedures.

UroLift in Place of Fiducial Markers for Patients With Benign Prostatic Hyperplasia Undergoing External Beam Radiation Therapy.

OBJECTIVE: To investigate if using a novel treatment for obstructive benign prostatic hyperplasia (UroLift) to relive lower urinary tract symptoms (LUTS) prior to external beam radiotherapy (EBRT) could also supplant the use of fiducial markers obviating the need for a second transrectal procedure while facilitating symptom-free voiding during and after EBRT a series of patients are reported on. METHODS: The medical records of 7 consecutive patients who underwent placement of UroLift for simultaneous treatment of obstructive LUTS due to benign prostatic hyperplasia and targeting of EBRT for treatment of prostate cancer between September and December of 2015 were reviewed. RESULTS: The UroLift clips were sufficiently radiopaque to make targeting possible for EBRT. All patients were able to complete a full course of radiotherapy without placement of fiducial markers. No patient experienced complications that could be attributed to the UroLift implants or procedure during their course of radiotherapy. None of the patients required additional alpha-blockers during radiation therapy. CONCLUSION: The UroLift system can serve as fiducial markers in patients undergoing EBRT. Although the current clip utilized in the UroLift system is generally radiopaque, it does not project well on the sagittal plane and would be significantly enhanced if a more strongly opaque substance was incorporated. It remains to be proven if the UroLift system can significantly reduce the symptoms of LUTS during and post EBRT.

Safety and Effectiveness of Holmium Laser Enucleation of the Prostate Using a Low-power Laser.

OBJECTIVE: To assess the safety and effectiveness of holmium laser enucleation of the prostate (HoLEP) using a low-power 30-W holmium laser with an en bloc enucleation technique. MATERIALS AND METHODS: We retrospectively analyzed 74 patients with a diagnosis of benign prostatic hyperplasia treated with HoLEP using a 30-W laser set at 1.5 J with a frequency of 20 Hz, as a low-power setting. The enucleation process was performed using the en bloc technique. Forty-four patients were operated on by an experienced surgeon, whereas 30 patients were operated on by 2 less experienced surgeons. We evaluated the surgical parameters and practicality of the low-power laser. RESULTS: All patients underwent successful HoLEP with the low-power setting; it was not necessary to increase the output of the laser in any case. Mean preoperative estimated prostate volume was 94.5 mL (range 22-489 mL). Mean total operating time and enucleation time were 91.9 minutes (range 30-232 minutes) and 45.4 minutes (range 13-101 minutes), respectively. No patient required blood transfusion postoperatively. Other intraoperative complications, including capsular perforation and ureteral orifice injury, did not occur. In 55 patients without preoperative stress urinary incontinence (SUI), postoperative SUI was observed in 7 patients (12.7%) at 1 month postoperatively, and in 3 patients (5.5%) at 3 months postoperatively. CONCLUSION: HoLEP using a low-power 30-W holmium laser can be performed safely and without any technical problems; this low-power setting is thought to be sufficient for performing HoLEP. As the introduction costs can be reduced by using a low-power laser, HoLEP could become widespread.

[Effect and safety of transrectal 137 CS gamma-rays in the treatment of benign prostatic hyperplasia].

OBJECTIVE: To evaluate the effect and safety of transrectal 137Cs gamma-ray therapy for benign prostatic hyperplasia. METHODS: Thirty cases of BPH were treated by transrectal 137Cs gamma-rays. RESULTS: After 6 months there was significant improvement in the maximum urine flow, IPSS and QOL (P < 0.05). But no significant changes were observed in the prostate volume and residual urine (P > 0.05). CONCLUSION: Transrectal 137Cs gamma-ray therapy is safe and effective in the treatment of BPH.

Cell death mechanisms associated with G2 radiosensitivity in patients with prostate cancer and benign prostatic hyperplasia.

Cells respond to genotoxic insults such as ionizing radiation by halting in the G2 phase of the cell cycle. Delayed cell death (mitotic death) can occur when the cell is released from G2, and specific spindle defects form endopolyploid cells (endoreduplication/tetraploidy). Enhanced G2 chromosomal radiosensitivity has been observed in many cancers and genomic instability syndromes, and it is manifested by radiation-induced chromatid aberrations observed in lymphocytes of patients. Here we compare the G2 chromosomal radiosensitivity in prostate patients with benign prostatic hyperplasia (BPH) or prostate cancer with disease-free controls. We also investigated whether there is a correlation between G2 chromosomal radiosensitivity and aneuploidy (tetraploidy and endoreduplication), which are indicative of mitotic cell death. The G2 assay was carried out on all human blood samples. Metaphase analysis was conducted on the harvested chromosomes by counting the number of aberrations and the mitotic errors (endoreduplication/tetraploidy) separately per 100 metaphases. A total of 1/14 of the controls were radiosensitive in G2 compared to 6/15 of the BPH patients and 15/17 of the prostate cancer patients. Radiation-induced mitotic inhibition was assessed to determine the efficacy of G2 checkpoint control in the prostate patients. There was no significant correlation of G2 radiosensitivity scores and mitotic inhibition in BPH patients (P = 0.057), in contrast to prostate cancer patients, who showed a small but significant positive correlation (P = 0.029). Furthermore, there was no significant correlation between G2 radiosensitivity scores of BPH patients and endoreduplication/ tetraploidy (P = 0.136), which contrasted with an extremely significant correlation observed in prostate cancer patients (P < 0.0001). In conclusion, cells from prostate cancer patients show increased sensitivity to the induction of G2 aberrations from ionizing radiation exposure but paradoxically show reduced mitotic indices and aneuploidy as a function of aberration frequency.

Effect of beta radiation on TGF-beta1 and bFGF expression in hyperplastic prostatic tissues.

AIM: To investigate the transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) expressions in benign prostatic hyperplasia (BPH) and the effect of beta-radiation. METHODS: TGF-beta1 and bFGF expression was studied by means of an immunohistochemical method in nine normal prostatic (NP) tissues, 15 hyperplastic prostatic tissues and 35 hyperplastic prostatic tissues treated with 90Sr/90Y. RESULTS: The TGF-beta1 expression in the epithelium and stroma of normal prostatic tissues was 68.2 % +/- 10.5 % and 29.7 % +/- 4.6 %, respectively, while it was 64.8 % +/- 9.3 % and 28.6 % +/- 4.1 %, respectively, in hyperplastic prostatic tissues. Compared with the controls, TGF-beta1 expression in the epithelia and stroma of BPH treated with 90Sr/90Y increased significantly (P <0.01). The bFGF expression in epithelia and stroma of normal prostatic tissues was 17.4 % +/- 3.7 % and 42.5 % +/- 6.8 %, respectively, and was 46.3 % +/- 8.2 % and 73.2 % +/- 12.1 %, respectively, in hyperplastic prostatic tissues. Compared with the controls, expressions of bFGF in the epithelia and stroma of BPH treated with a 90Sr/90Y prostatic hyperplasia applicator decreased significantly (P <0.01). CONCLUSION: Exposure of beta-rays had noticeable effects on BPH tissues, enhancing TGF-beta1 expression and inhibiting bFGF expression.

[Changes in prostatic circulation in response to laser therapy and magnetic therapy in patients with benign prostatic hyperplasia].

The results of preoperative preparation were analysed in 59 patients with prostatic benign hyperplasia (PBH) subjected to TUR. Treatment outcomes were assessed by transrectal ultrasound (color Doppler mapping) in two groups of patients. Group 1 received combined therapy including transrectal laser radiation of the prostate, group 2--transrectal magnetotherapy. The analysis showed that laser radiation reduced insignificantly the size of the prostate and adenomatous node, improved microcirculation and circulation in the prostate. This resulted in relief of inflammation and reduction of the number of postoperative inflammatory complications. Transrectal magnetotherapy has a positive effect on vascularization and hemodynamics of the prostate, local immunity, contamination of the tissues with pathogenic flora.

Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy.

PURPOSE: Larger prostate gland volumes have been associated with long-term urinary morbidity in prostate interstitial radiation therapy utilizing ultrasound image guidance technique. This study was performed to identify the clinical and technical predictors of acute urinary retention following magnetic-resonance (MR)-guided prostate interstitial brachytherapy. METHODS AND MATERIALS: Fifty patients underwent MR-guided prostate brachytherapy between December 1997 and March 1999. Patient selection was limited to men with stage T1cNXM0 disease, PSA of less than10 ng/mL, biopsy Gleason score not more than 3 + 4, and endorectal coil MR stage T2 disease. Dosimetry plans were developed in the operating room and (125)Iodine sources were implanted using MR real-time guidance. The peripheral zone (PZ) of the prostate gland was defined as the clinical target volume (CTV) and the minimum prescribed dose to the CTV was 137 Gy. The volumes of the PZ, transition zone (TZ), and total prostate gland volume were also determined by MR. Individual source strength ranged from 0.35 to 0.54 microGym(2)/h (NIST 99, median 0.46 microGym(2)/h) and the total implanted activity ranged from 17.0 to 43.1 mCi (median, 28.1 mCi) using 43-120 seeds (median, 79). The seeds were placed using MR-compatible biopsy needles (14-28, median, 19). RESULTS: The ability of clinical (MR defined prostate, PZ, and TZ volumes) and technical (number of catheters, number of seeds implanted, and total activity) factors to predict AUR for 50 men undergoing MR-guided prostate interstitial brachytherapy were evaluated using univariable and logistic regression multivariable analyses. Six men (12%) experienced AUR within 24 h after removal of the Foley catheter subsequent to prostate brachytherapy. The total number of seeds (p = 0.05), MR determined prostate volume (p < 0.01), and the MR-determined TZ volume (p < 0.01) were significant predictors of AUR on univariable analysis. Utilizing a multivariable logistic regression analysis, the TZ volume was the only significant predictor of AUR (p < 0.01). The prostate volume is highly correlated to the TZ volume (Spearman correlation coefficient of 0. 91) and was thus significant in the univariable analysis; however, the prostate volume did not add prognostic value in multivariable analysis. CONCLUSION: Benign prostatic hyperplasia (BPH) resulting in an enlarged TZ volume, is the most important predictor of AUR following MR-guided prostate interstitial radiation therapy. Although AUR was significant (60%) in men with moderate BPH (TZ volume >/= 50 cc), it was also self-limiting.

Extensive neodymium-YAG photoirradiation of the prostate in men with obstructive prostatism.

OBJECTIVE: To determine if high-dosage, extensive photoirradiation of the prostate could be used safely in men with large prostate glands and obstruction, coupled with acceptable clinical results. METHODS: Treatment of 25 men consecutively with eight quadrant photoirradiation of the prostate. Treatment of the next 25 men with high-dosage energy up to 109,000 joules. Simultaneous transrectal needle biopsy of the prostate performed on all 50 men after treatment. Patients evaluated with four- to sixteen-month follow-up. RESULTS: Success rate of 86 percent on all patients with mean American Urological Association (AUA) symptom score decreasing by nineteen points and mean peak uroflow rate increasing by 7.9 cc. Needle biopsy after high-dosage laser therapy shows no laser effect on the peripheral zone. CONCLUSIONS: High-dosage laser energy can be used safely, and allows us to treat large prostates with excellent clinical results and minimal complications.

Microwave therapy of benign prostatic hyperplasia.

Thermotherapy of the prostate proves to be a safe and effective treatment for patients with symptomatic prostatism secondary to BPH. Present treatment regimens yield results and side effects intermediate between drug therapy and prostatectomy. Future enhancements of the thermotherapy technique are likely to improve its results to the level of surgery.

Treatment changes in prostatic hyperplasia and cancer, including androgen deprivation therapy and radiotherapy.

Substantial and characteristic changes occur in the microscopic appearance and immunophenotype of the hyperplastic prostate and adenocarcinoma following androgen deprivation therapy and radiotherapy. These changes are rarely seen in untreated cancer, and in the authors' opinion, the combinations of features following therapy are sufficiently distinctive to warrant recognition. Pathologists must be aware of these distinct changes because of the reliance placed on nuclear and nucleolar size in the identification of prostate cancer, particularly in small specimens and lymph node metastases.

Urinary morbidity in brachytherapy patients with median lobe hyperplasia.

PURPOSE: To investigate clinical course of prostate brachytherapy patients with radiographic evidence of median lobe hyperplasia (MLH). METHODS AND MATERIALS: Fifteen patients with median lobe hyperplasia were identified during our routine brachytherapy practice and implanted between June 1998 and March 2000, representing approximately 6% of the 245 brachytherapy patients treated during that time. Each patient was contacted at the time of this report preparation to update postimplant morbidity information, with follow-up ranging from 6 to 30 months (median: 18 months). RESULTS: Three of the 15 patients developed acute, postimplant urinary retention. The preimplant prostate volume, dMLH, and preimplant AUA scores were similar between patients who did or did not develop prolonged urinary retention. Compared with a control group of 62 control patients treated during a similar time interval at the University of Washington, patients with MLH had significantly higher AUA scores at last follow-up. There was no correlation between the change in AUA scores at last follow-up. CONCLUSIONS: Based on the data reported here, we consider MLH to be a weak contraindication to prostate brachytherapy. Considering that even patients with prolonged retention have gradually improved spontaneously, we do not advocate prophylactic prebrachytherapy resection of hypertrophic tissue in MLH patients.

Prostate-specific antigen (PSA) velocity and benign prostate hypertrophy predict for PSA spikes following prostate brachytherapy.

PURPOSE: To evaluate if variants of serum PSA or benign prostatic hypertrophy correlate with the development of a PSA spike following permanent prostate brachytherapy. METHODS AND MATERIALS: Two-hundred-eighteen hormone-naïve patients with clinical T1b-T3a (1997 AJCC) prostate cancer who were treated with brachytherapy between August 1995 and November 1999, with or without supplemental external beam radiation therapy, and who remained free of biochemical failure were analyzed. The median follow-up was 46 months. A PSA spike was defined as a rise > or =0.2 ng/mL followed by a durable decline. Biochemical disease-free survival was defined by the ASTRO Consensus Definition with the additional constraint that the most recent PSA be < or =1.0 ng/mL. In addition, none of the patients possessed equivocal biochemical results (1 or 2 consecutive PSA rises or a declining PSA >1.0 ng/mL). In addition to previously reported clinical, treatment, and dosimetric parameters evaluated for spike, PSA density, transition zone (TZ) PSA density, percent free PSA, PSA velocity, PSA doubling time, TZ volume, and transition zone index (TZI) were included. The PSA kinetics of 18 hormone naïve patients who were implanted during the same time period and subsequently failed were also evaluated. RESULTS: Fifty-two (23.9%) developed a PSA spike. Of the demographic and preimplant clinical parameters, patient age, TZ volume, TZI, TZ PSA density, and 125I were statistically significant predictors for a PSA spike. Of the postimplant parameters, V200, follow-up, first postimplant PSA, and most recent PSA predicted for a PSA spike. In multivariate Cox regression analysis, PSA nadir, TZI, follow-up, age, months to PSA nadir and preimplant PSA velocity were significant predictors for spike. However, when variables only determinable after a PSA spike were included in the multivariate analysis, TZI, age, PSA velocity, and first postimplant PSA were predictors for a spike. Using categorical cutpoints of TZI >0.25, age at implant <62 years, and first postimplant PSA >1.0 ng/mL in the regression analysis, a positive likelihood ratio for a PSA spike of >1.8 was noted for each variable. Patients with PSA progression displayed significantly different PSA kinetics than those with a spike. CONCLUSIONS: In multivariate analysis, PSA nadir, TZI, patient age, months to PSA nadir, follow-up, and preimplant PSA velocity were predictive of a PSA spike. However, when only variables identifiable prior to a spike were evaluated, TZI, patient age, preimplant PSA velocity, and first postimplant PSA were the strongest predictors for a PSA spike.

Transurethral needle ablation of the prostate (TUNA) in the treatment of chronic urinary retention.

The transurethral needle ablation (TUNA) of the prostate was performed in 8 patients in chronic urinary retention, all of whom were a poor surgical risk. A special catheter device was used to deliver low-level radiofrequency energy to heat tissue within the prostate to 100 degrees C. After treatment, uroflowmetry, symptom score and quality of life score were evaluated. Tolerance of the procedure with topical anesthesia was satisfactory. Of the 8 patients, 6 (75%) resumed voiding within a mean time of 9.2 days (range 1-21). The mean maximal flow rate was 9.8 +/- 3.2 ml/s (range 5.9-14). Failure to void was associated with a decompensated detrusor function. We conclude that TUNA is effective for patients with urinary retention due to benign prostatic hyperplasia. It seems particularly suitable for treating elderly patients with a high surgical risk.

[A pilot study of photon therapy for benign prostate hyperplasia (a report of 30 cases)].

OBJECTIVE: To investigate the clinical efficacy and safety of photon therapy for benign prostate hyperplasia (BPH). METHODS: Thirty patients with severe BPH received brachytherapy of prostate photon treatment system irradiation for one month, with the active area of the applicator located in the rectum, and at a dosage of 726-810 cGy. International prostate symptom score (IPSS), quality of life (QOL), volume of prostate gland, maximum flow rate (Qmax), and residual urine were evaluated before and after the treatment. RESULTS: After one-month treatment, 18 cases remarkably improved, 9 slightly improved and 3 had no response. There was significant improvement in IPSS, QOL, volume of prostate gland, Qmax and residual urine (P<0.01, except Qmax P = 0.038). CONCLUSION: Prostate photon treatment system can be used as a safe, effective, micro-invasive, convenient and economical therapy for severe BPH, especially applicable to older and weaker patients.