Intraoperative Neurovascular Bundle Preservation with Hyaluronic Acid during Radical Brachytherapy for Localized Prostate Cancer: Technique and MicroMosfet In Vivo Dosimetry

Purpose: To evaluate the reduction in the absorbed dose delivered to the neurovascular bundle (NB) in patients with localized prostate cancer treated with only HDR brachytherapy and NB protection with hyaluronic acid (HA) on the side of the prostate to increase the distance from NB to the radioactive sources. Methods: This is the first published report in the medical literature that studies a new approach to decrease neurovascular bundle toxicity and improve quality of life for patients with prostate cancer treated with radical brachytherapy as monotherapy. Transperineal HA injection on the side of the prostate into the lateral aspect of the prostate fat was used to consistently displace several autonomic fibers and vessels on the lateral wall of the prostate away from radiation sources. Results: When a protection in the form of an HA layer is placed, the reduction effect at the maximum dose is between 46% and 54% (calculated values), which means that the method for protection is highly recommended. The values of the absorbed dose calculated in this project have been compared with the ones given by the treatment planning system. Conclusions: This newly created space decreases absorbed dose in the NB, calculated with the TPS and measured by microMOSFET due to the thickness of HA.

Late vascular complications after cranial radiotherapy: A report of two illustrative cases

Cranial radiotherapy (CRT) is used to treat a large variety of benign and malignant disorders. We present two cases of late neurological complications after CRT and briefly discuss its diagnosis and their shared pathophysiological aspects. The first case is a patient with cognitive impairment associated to mineralizing microangiopathy ten years after CRT for nasopharyngeal carcinoma and the second one is a woman with Stroke-like Migraine Attacks after Radiation Therapy (SMART) syndrome two years after CRT for anaplastic meningioma. Nowadays, higher survival rates might cause an increase in appearance of late neurological complications after CTR. These reported cases show that late complications can mimic a wide variety of neurological conditions and the importance of magnetic resonance image (MRI) to get a diagnosis.

Characterization of microMOSFET detectors for in vivo dosimetry in high-dose-rate brachytherapy with 192 Ir

PURPOSE

The objective of this study was to characterize the Best Medical Canada microMOSFET detectors for their application in in vivo dosimetry for high-dose-rate brachytherapy (HDRBT) with ¹⁹² Ir. We also developed a mathematical model to correct dependencies under the measurement conditions of these detectors.

METHODS

We analyzed the linearity, reproducibility, and interdetector variability and studied the microMOSFET response dependence on temperature, source-detector distance, and angular orientation of the receptor with respect to the source. The correction model was applied to 19 measurements corresponding to five simulated treatments in a custom phantom specifically designed for this purpose.

RESULTS

The detectors (high bias applied in all measurements) showed excellent linearity up to 160 Gy. The response dependence on source-detector distance varied by (8.65 ± 0.06)% (k = 1) for distances between 1 and 7 cm, and the variation with temperature was (2.24 ± 0.05)% (k = 1) between 294 and 310 K. The response difference due to angular dependence can reach (10.3 ± 1.3)% (k = 1). For the set of measurements analyzed, regarding angular dependences, the mean difference between administered and measured doses was -4.17% (standard deviation of 3.4%); after application of the proposed correction model, the mean difference was -0.1% (standard deviation of 2.2%). For the treatments analyzed, the average difference between calculations and measures was 4.7% when only the calibration coefficient was used, but it is reduced to 0.9% when the correction model is applied.

CONCLUSION

Important response dependencies of microMOSFET detectors used for in vivo dosimetry in HDRBT treatments, especially the angular dependence, can be adequately characterized by a correction model that increases the accuracy of this system in clinical applications.

Focal high-dose-rate brachytherapy for localized prostate cancer: toxicity and preliminary biochemical results

BACKGROUND

This study aimed to evaluate the outcomes and the toxicity of focal high-dose-rate (HDR) brachytherapy in selected localized prostate cancer patients.

METHODS

Fifty patients were treated with focal high-dose-rate brachytherapy between March 2013 and November 2017, representing 5% of the cases treated by our group during this period. Only patients with very limited and localized tumors, according to strict criteria, were selected for the procedure. The prescribed dose for the focal volume was 24 Gy.

RESULTS

The treated volume corresponded to a mean value of 32% of the total prostatic volume. The mean focal D₉₀ in our series was 23 Gy (range 16-26 Gy). The mean initial IPSS was 8.2 (range 0-26), at 6 months 7.5 (range 0-23), and at 24 months 6.7 (range 0-18). No acute or late urinary retention was seen. When the ICIQ-SF score was 0 at the end of treatment, it remained nil thereafter at 1 and 2 years for all patients. No intraoperative or perioperative complications occurred. No rectal toxicity was reported after treatment. Of the total patients identified as potent, only three patients had a very slight decrease of the mean IIEF5. The mean initial PSA was 6.9 ng/mL (range 1.9-13.4). At the last follow-up visit, the mean PSA was 3 ng/ml (range 0.48-8.11).

CONCLUSION

HDR focal brachytherapy in selected patients with low intermediate-risk prostate cancer could achieve the same satisfactory results in terms of relapse-free survival as conventional whole prostate brachytherapy with less toxicity.

Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer. Longterm results

Objectives

We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy.

Methods and Materials

From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the “Phoenix consensus”. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition.

Results

The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function.

Conclusions

The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer.

Adaptation and validation of the Spanish version of the Patient-Oriented Prostate Utility Scale (PORPUS)

OBJECTIVE

The Patient-Oriented Prostate Utility Scale (PORPUS) is a combined profile and utility-based quality of life measure for prostate cancer patients. Our objectives were to adapt the PORPUS into Spanish and to assess its acceptability, reliability, and validity.

METHODS

The PORPUS was adapted into Spanish using forward and back translations and cognitive debriefing. PORPUS was administered jointly with the SF-36 and the Expanded Prostate Index Composite (EPIC) to 480 Spanish prostate cancer patients treated with radical prostatectomy or radiotherapy. The Spanish PORPUS scores' distribution and reliability were examined and compared with the original instrument. To evaluate construct validity, relationships were assessed between PORPUS and other instruments (testing hypotheses of the original PORPUS study), and among known groups defined by side effect severity.

RESULTS

Reliability coefficient was 0.76 (similar to the original PORPUS' 0.81). Spanish PORPUS items presented correlations ranging 0.57-0.88 with the corresponding EPIC domains, as in the original PORPUS study (0.60-0.83). Both PORPUS-P and PORPUS-U showed significant differences and large effect sizes (0.94-1.90) when comparing severe versus no problem groups on urinary, bowel, sexual and hormonal side effects defined by EPIC.

CONCLUSIONS

A conceptually equivalent Spanish version was obtained, with high reliability and good construct validity, similar to the original Canadian PORPUS version. It can therefore be used to measure health-related quality of life and utilities in Spanish prostate cancer patients.

Long-term biochemical results after high-dose-rate intensity modulated brachytherapy with external beam radiotherapy for high risk prostate cancer

Background

Biochemical control from series in which radical prostatectomy is performed for patients with unfavorable prostate cancer and/or low dose external beam radiation therapy are given remains suboptimal.

The treatment regimen of HDR brachytherapy and external beam radiotherapy is a safe and very effective treatment for patients with high risk localized prostate cancer with excellent biochemical control and low toxicity.

Biochemical outcome after high-dose-rate intensity modulated brachytherapy with external beam radiotherapy: 12 years of experience

Study Type - Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Biochemical control from series in which radical prostatectomy is performed for patients with unfavorable prostate cancer and/or low dose external beam radiation therapy are given remains suboptimal. The treatment regimen of HDR brachytherapy and external beam radiotherapy is a safe and very effective treatment for patients with high risk localized prostate cancer with excellent biochemical control and low toxicity.

OBJECTIVE

• To investigate the long-term oncological outcome, during the PSA era, of patients with prostate cancer who were treated using high-dose-rate (HDR) brachy therapy (BT) combined with external beam radiation therapy (EBRT).

PATIENTS AND METHODS

• From June 1998 to April 2007, 313 patients with localized prostate cancer were treated with 46 Gy of EBRT to the pelvis with a HDR-BT boost. • The mean (median) follow-up was 71 (68) months. • Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, V.4.

RESULTS

• The 10-year actuarial biochemical control was 100% for patients with no high-risk criteria, 88% for patients with two intermediate-risk criteria, 91% with one high-risk criterion and 79% for patients with two to three high-risk criteria (P= 0.004). • The 10-year cancer-specific survival was 97% (standard deviation ± 1%). • The multivariate Cox regression analyses identified, Gleason score and T stage as independent prognostic factors for biochemical failure. • Gleason score was the only factor to significantly affect distant metastases. • Grade ≥ 3 late toxicity was not detected.

CONCLUSION

• The 10-year results confirm the feasibility and effectiveness of EBRT with conformal HDR-BT boost for patients with localised prostate cancer.

High-dose-rate interstitial brachytherapy as monotherapy in one fraction and transperineal hyaluronic acid injection into the perirectal fat for the treatment of favorable stage prostate cancer: treatment description and preliminary results

PURPOSE

To evaluate the technical feasibility, acute and late genitourinary (GU) toxicity, and gastrointestinal toxicity after high-dose-rate (HDR) brachytherapy as monotherapy in one fraction with transperineal hyaluronic acid injection into the perirectal fat to displace the rectal wall away from the radiation sources to decrease rectal toxicity.

METHODS AND MATERIALS

Between April 2008 and January 2010, 40 consecutive patients were treated with favorable clinically localized prostate cancer; the median followup was 19 months (range, 8-32). No patients received external beam radiation, and 35% received hormone therapy before brachytherapy. All patients received one implant and one fraction of HDR. Fraction dose was 19 Gy. Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, Version 4.0.

RESULTS

All patients tolerated the implantation procedure very well with minimal discomfort. No intraoperative or perioperative complications occurred. Acute toxicity Grade 2 or more was not observed in any patients. No chronic toxicity has been observed after treatment. Logistic regression showed that the late Grade 1 GU toxicity was associated with D(90) (p=0.050). The 32-month actuarial biochemical control was 100% and 88%, respectively (p=0.06) for low- and intermediate-risk groups.

CONCLUSIONS

This is the first published report of the use of HDR brachytherapy as monotherapy in one fraction for patients with favorable-risk prostate cancer. This protocol is feasible and very well tolerated with low GU morbidity, no gastrointestinal toxicity, and the same level of low-dose-rate biochemical control at 32 months.

Prostate-specific antigen relapse-free survival and side-effects in 734 patients with up to 10 years of follow-up with localized prostate cancer treated by permanent iodine implants

STUDY TYPE

Therapy (case series) Level of Evidence 4.

OBJECTIVE

To report our analysis of the oncological outcome, side-effects and complications after (125)I-brachytherapy, based on 10 years of experience, as low dose-rate (LDR) prostate brachytherapy is an accepted, effective and safe therapy for localized prostate cancer.

PATIENTS AND METHODS

Between April 1999 and December 2006, 734 consecutive patients were treated with clinically localized prostate cancer with a follow-up of >or=30 months. No patients received external beam radiotherapy and 43% received hormonal therapy before brachytherapy; this therapy was given for 3-4 months. All patients had LDR prostate brachytherapy administered by one radiation oncologist. Biochemical failure was defined according to the 'Phoenix consensus'.

RESULTS

The median follow-up for the 734 patients was 55 months; 26 had a clinical relapse and 11 died from prostate cancer; 20 patients died from other illnesses. The 10-year actuarial biochemical control was 92%, 84% and 65%, respectively (P < 0.001) for the low-, intermediate- and high-risk groups. Multivariate Cox regression analyses identified Gleason score and prostate-specific antigen (PSA) level as independent prognostic factors for biochemical failure. The actuarial biochemical control with Gleason score was 88%, 76% and 67% for patients with a Gleason score of <or=6, 7 and >7, respectively (P < 0.001). The biochemical control was 90%, 80% and 42% for patients with a PSA level of <or=10, 10.1-20 and >20 ng/mL, respectively (P < 0.001). No patients reported incontinence after treatment. There was acute urinary retention in 22 (2.9%) patients. Logistic regression showed that the most significant factors correlating with the probability of catheterization were the pretreatment prostate volume and hormonal therapy.

CONCLUSIONS

The excellent long-term results and low morbidity, and the many advantages of prostate brachytherapy over other treatments, show that brachytherapy is an effective treatment for clinically organ-confined prostate cancer.

Transperineal injection of hyaluronic acid in the anterior perirectal fat to decrease rectal toxicity from radiation delivered with low-dose-rate brachytherapy for prostate cancer patients

PURPOSE

Monitored rectal late morbidity using proctoscopy and a modified radiation therapy oncology group rectal bleeding scoring scale, in patients treated with permanent implant of I-125 and submitted to rectal protection with hyaluronic acid (HA) injecting in the perirectal fat to increase the distance between the prostate and the anterior rectal wall to decrease rectal toxicity. This is the first article looking at such injections in low-dose-rate brachytherapy patients and subsequent rectal toxicity.

METHODS AND MATERIALS

Between January 2005 and July 2006, a total of 69 consecutive outpatients with low- and intermediate-risk prostate cancer were enrolled in a clinical trial. First group received brachytherapy alone with I-125 and the second group received brachytherapy I-125 and protection of the rectal wall with HA. We injected 6-8cc of HA in the perirectal fat, to increase the distance between the prostate and the anterior rectal wall. Proctoscopic examinations with scoring of mucosal damage were performed according to a descriptive scale, described by Wachter et al. The median follow-up at time of endoscopy was 18 months. Toxicity measures included modified radiation therapy oncology group late bleeding toxicity grading.

RESULTS

The hyaluronic and non-hyaluronic groups were similar for most patients, in tumor, treatment, and dosimetric characteristics. Patients treated with brachytherapy I-125 and rectal protection with HA had significantly smaller incidence of mucosal damage at the proctoscopic examinations (5% vs. 36%, p=0.002) and no macroscopic rectal bleeding (0% vs. 12%, p=0.047) than those treated with brachytherapy I-125 alone without HA. No toxicity was produced from the HA or its injection.

CONCLUSIONS

The increased distance between the rectal wall and the prostate, as a result from the injection of HA in the perirectal fat, has significantly decreased the rectal dose from low-dose-rate brachytherapy. Patients treated with brachytherapy I-125 and protection rectal with HA had significantly smaller incidence of mucosal damage at the proctoscopic examinations and no macroscopic rectal bleeding than those treated with brachytherapy I-125 alone without HA.

Transperineal injection of hyaluronic acid in anterior perirectal fat to decrease rectal toxicity from radiation delivered with intensity modulated brachytherapy or EBRT for prostate cancer patients

PURPOSE

Rectal toxicity remains a serious complication affecting quality of life for prostate cancer patients treated with radiotherapy. We began an investigational trial injecting hyaluronic acid (HA) in the perirectal fat to increase the distance between the prostate and the anterior rectal wall. This is the first report using HA injection in oncology.

METHODS AND MATERIALS

This is a trial of external beam radiation therapy with HDR brachytherapy boosts in prostate cancer. During the two high-dose-rate (HDR) fractions, thermoluminescent dosimeter dosimeters were placed in the urethra and in the rectum. Before the second HDR fraction, 3-7 mL (mean, 6 mL) of HA was injected under transrectal ultrasound guidance in the perirectal fat to systematically create a 1.5-cm space. Urethral and rectal HDR doses were calculated and measured. Computed tomography and magnetic resonance imaging were used to assess the stability of the new space.

RESULTS

Twenty-seven patients enrolled in the study. No toxicity was produced from the HA or the injection. In follow-up computed tomography and magnetic resonance imaging, the HA injection did not migrate or change in mass/shape for close to 1 year. The mean distance between rectum and prostate was 2.0 cm along the entire length of the prostate. The median measured rectal dose, when normalized to the median urethral dose, demonstrated a decrease in dose from 47.1% to 39.2% (p < 0.001) with or without injection. For an HDR boost dose of 1150 cGy, the rectum mean Dmax reduction was from 708 cGy to 507 cGy, p < 0.001, and the rectum mean Dmean drop was from 608 to 442 cGy, p < 0.001 post-HA injection.

CONCLUSION

The new 2-cm distance derived from the HA injection significantly decreased rectal dose in HDR brachytherapy. Because of the several-month duration of stability, the same distance was maintained during the course of external beam radiation therapy.

[Brachyterapy in localized prostate cancer]

INTRODUCTION AND OBJECTIVES

Considering the high frequency of localized prostate cancer in stages, at the moment there are minimally invasive techniques that compete with the classic surgery. One of them is the Low Dose Rate (LDR) Brachytherapy with permanent implants of 1125 seeds. The objective of the present study is to expose our experience from the year 1998, when we made the first treatment, until today. The results and the morbidity of the patients over a 7 and a half years period are analyzed.

MATERIAL AND METHODS

A total of 800 patients were treated with LDR brachytherapy, with average age of 68 years and range between 48 and 83 years. In all patients the 1125 seeds were used with Rapid-Strand and peripheral load by means of intraoperative planning.

RESULTS

The urinary rate of complications was of 3% of AUR, and 0.2% of urinary incontinence. The morbidity on the digestive apparatus was of a 12% intermittent bleeding, 2% of proctitis, and a 0.3% of rectal fistulas.

Conformal prostate brachytherapy guided by realtime dynamic dose calculations using permanent 125iodine implants: technical description and preliminary experience

OBJECTIVE

Low dose rate (LDR) prostate brachytherapy (permanent 125I or 103Pd seeds) is an accepted treatment option for low risk prostate cancer patients. However, differences in prostate spatial location, volume and gland deformation between the images obtained during pre-planning and later on during the implant procedure prevent the pre-planned intended dose to be accurately delivered. We are reporting on a new technique based on interactive real-time dynamic intra-operative dose calculation with avoidance of postimplant CT for final dosimetry. The reasons leading us to implementing this new technique are discussed and preliminary results reported. 47-78 years). For the real time intra-operative dosimetric analysis the following values were obtained: a median of 98% (90%-100%) for V90, of 60% (22%-76%) for V150 and 24% (9%-34%) for V200. The median intro-operative D90 obtained was 16,817 cGy with a range of 13,743 to 19,553 cGy. The median dose point calculation to the rectum maximum was 12,936 cGy and for the maximum in urethra was 21,880 cGy. For the real-time dynamic planning, the acute GU grade 1&2 toxicity was reduced from 28% and 2 1% to 16% and 6% respectively. Acute urinary retention was seen in 2/63 or 3% requiring a temporary post-implant bladder catheter. In addition, a decrease in chronic GU grade 1-2 toxicity was also seen from 16% and 17% to 1 1% and 2% respectively. No change in GI toxicity pattern was noted. No severe grade 3-4 intra-operative complications were noted.

CONCLUSION

Real-time intra-operative planning was successfully implemented in our center. It avoids the possible implant quality and dose delivery disadvantages of the standard post-implant CT-based dosimetry by improving the accuracy of seed placement on real time, which was translated in lower rates of acute and chronic GU morbidity. In addition, avoids the unnecessary time, effort and cost of post-implant CT-based dosimetry.

[I125 low dose rate brachytherapy in localized prostate cancer. Preliminary results after 5 years]

OBJECTIVES

Prostatic brachytherapy by permanent implant of I125 or Pd103 is a therapeutic option in the treatment of organ confined prostate cancer We analyze preliminary results and complications after five years in the group of patients who received I125 low dose rate brachytherapy as the only intention-to-cure treatment and evaluate the differences with the standard treatment (surgery).

METHODS

From a case series of more than 400 patients treated with brachytherapy as radical intention-to-cure monotherapy for organ-confined prostate cancer we excluded patients with less than 12 months of follow-up for statistical analysis; the study group includes 275 patients enrolled between april 1999 and December 2003. Mean follow-up is 31 months (12-68). Biochemical failure was defined in accordance to the ASTRO criteria. Statistical survival analysis was carried out with the SPSS statistical software using the Kaplan Meyer method. Urinary and gastrointestinal complications were evaluated in accordance to the RTOG criteria.

RESULTS

Mean age was 68 years (range 49-83 years). 93% of the patients presented a clinical stage < or ='3dT2a and 7% T2b, with 60 8% of the cases having a PSA < or ='3d 10 ng/ml. Gleason score was < or ='3d 6 in 94% of the cases. 9% of the cases had a prostate volume > 50 cc. Overall 5 year survival was 96%, with a 97% disease-free survival and a 99% biochemical failure-free survival. Figure 3 and tables II-VI summarize the complications in various series including this.

CONCLUSIONS

Multiple published series seem to show similar results on biochemical control of the disease when comparing surgery and low dose rate brachytherapy in organ-confined disease. In comparison to surgery, brachytherapy has the advantage of having a lower percentage of immediate postoperative complications, lower incontinence rate, and a higher number of patients preserving erectile function.