MRI-Guided Ultrafocal Salvage High-Dose-Rate Brachytherapy for Localized Radiorecurrent Prostate Cancer: Updated Results of 50 Patients.

PURPOSE: Most patients with local prostate cancer recurrence after radiation therapy undergo palliative androgen deprivation therapy because whole-gland salvage treatments have a high risk of severe toxicity. Focal treatment reduces this risk while offering a second opportunity for cure. We report updated outcomes of ultrafocal salvage high-dose-rate brachytherapy (HDR-BT). METHODS AND MATERIALS: Prospectively collected data from the first 50 treated patients were analyzed. Disease status was assessed by 3T multiparametric magnetic resonance imaging (MRI), 18F-Choline or 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography, and systematic or tumor-targeted biopsies. Ultrafocal salvage HDR-BT (1 × 19 Gy) was performed by implanting the clinical target volume (CTV: gross tumor volume + 5 mm margin) under fused transrectal ultrasound/MRI guidance. Follow-up included toxicity grading (using Common Terminology Criteria for Adverse Events 4.0), quality of life assessment, and prostate-specific antigen (PSA) testing. RESULTS: Median follow-up was 31 months. Median CTV D95% was 18.8 Gy. We observed 2% grade 3 genitourinary toxicity, no grade 3 gastrointestinal toxicity, and 22% newly developed grade 3 erectile dysfunction. Five of 13 patients (38%) with self-reported pretreatment potency (International Index of Erectile Function >17) remained potent. Clinically relevant quality of life deterioration was reported for only 6 of 31 items and was not statistically significant. Biochemical failure (nadir + 2) occurred in 26 patients. Among intraprostatic recurrences, 73% were in field. After 2.5 years, biochemical disease-free survival was 51% (95% confidence interval, 37%-69%), metastases-free survival was 75% (64%-89%), androgen deprivation therapy-free survival was 90% (82%-99%), and overall survival was 98% (94%-100%). Presalvage PSA, CTV size, and stage ≥T3 were significantly associated with biochemical failure. Higher-risk patients (stage ≥T3, PSA ≥10, or PSA double time ≤9 months) had 25% biochemical disease-free survival at 2.5 years versus 71% for lower-risk patients. CONCLUSIONS: At this early stage, MRI-guided ultrafocal HDR-BT seems to be a safe salvage treatment option, with acceptable biochemical control in a well-selected group of patients and potential for effectively postponing androgen deprivation therapy.

MRI-Guided Ultrafocal HDR Brachytherapy for Localized Prostate Cancer: Median 4-Year Results of a feasibility study.

PURPOSE: For the treatment of localized prostate cancer, focal therapy has the potential to cure with fewer side effects than traditional whole-gland treatments. We report an update on toxicity, quality of life (QoL), and tumor control in our magnetic resonance imaging (MRI)-guided ultrafocal high-dose-rate brachytherapy cohort. METHODS AND MATERIALS: Disease status was evaluated by systematic biopsies and 3T multiparametric MRI. The brachytherapy implant procedure under fused transrectal ultrasound/MRI guidance was followed by a 1.5 T MRI for contour adjustments and catheter position verification. A single dose of 19 Gy was delivered to the tumor with a margin of 5 mm. Genitourinary (GU) toxicity, gastrointestinal (GI) toxicity, and erectile dysfunction (ED) were graded with the Common Terminology Criteria for Adverse Events version 4.0. QoL was measured with RAND-36, European Organisation for Research and Treatment of Cancer QLQ-C30 and PR25. International Prostate Symptom Scores and International Index of Erectile Function scores were obtained. Prostate-specific antigen level was monitored, with biochemical recurrence defined as nadir + 2 ng/mL (Phoenix). RESULTS: Thirty patients with National Comprehensive Cancer Network low- (13%) to intermediate-risk (87%) prostate cancer were treated between May 2013 and April 2016. Median follow-up was 4 years. Median age was 71 years (interquartile range, 68-73) and median initial prostate-specific antigen level was 7.3 ng/mL (5.2-8.1). Maximum Gleason score was 4 + 3 = 7 (in 2 patients). All tumors were radiologic (MRI) stage T2. No grade >2 GU or >1 GI toxicity occurred. International Prostate Symptom Scores only deteriorated temporarily. Mild pretreatment ED deteriorated to moderate/severe ED in 50% of patients. Long-term clinically relevant QoL deterioration was seen in sexual activity and tiredness, whereas emotional and cognitive functioning improved. At 4 years, biochemical disease-free survival was 70% (95% confidence interval, 52%-93%), metastases-free survival was 93% (85%-100%), and overall survival was 100%. Of intraprostatic recurrences, 7 of 9 were out of field. CONCLUSIONS: Ultrafocal high-dose-rate brachytherapy conveys minimal GU or GI toxicity and has a marginal effect on QoL. An early decline in erectile function was seen. Tumor control outcomes are poor (biochemical disease-free survival of 70% [52%-93%] at 4 years), most likely as a result of poor patient selection.

Early-Medium-Term Outcomes of Primary Focal Cryotherapy to Treat Nonmetastatic Clinically Significant Prostate Cancer from a Prospective Multicentre Registry.

BACKGROUND: Focal cryotherapy can be used to treat patients with clinically significant nonmetastatic prostate cancer to reduce side effects. OBJECTIVE: Early-medium-term cancer control and functional outcomes. DESIGN, SETTING, AND PARTICIPANTS: A prospective registry-based case series of 122 consecutive patients undergoing focal cryotherapy between October 1, 2013, and November 30, 2016, in five UK centres. Median follow-up was 27.8mo [interquartile range (IQR) 19.5-36.7]. A total of 35 patients (28.7%) had National Comprehensive Cancer Network (NCCN) high risk and 87 (71.3%) had intermediate risk disease. Risk and zonal stratification included multiparametric magnetic resonance imaging (mpMRI) with targeted and systematic biopsies, or transperineal mapping biopsies. INTERVENTION: Focal cryoablation of MR-visible tumours. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Follow-up involved prostate-specific antigen (PSA) monitoring, mpMRI, and for-cause biopsies. Primary outcome was failure-free survival (FFS), defined as transition to radical, whole-gland, or systemic therapy, or metastases/death. Secondary outcomes included adverse events and functional outcomes. RESULTS AND LIMITATIONS: A total of 80 (65.6%) had anterior ablation, 23 (19.7%) combined posterior and anterior ablation, and two (1.6%) posterior ablation alone (SeedNet or Visual-ICE, BTG plc). Median age was 68.7yr (IQR 64.9-73.8) and preoperative PSA 10.8ng/ml (IQR 7.8-15.6). Overall FFS at 3yr was 90.5% [95% confidence interval (CI) 84.2-97.3]. When stratified for the NCCN risk group, 3-yr outcomes were 84.7% (95% CI 71.4-100) in high risk and 93.3% (95% CI 86.8-100) in intermediate risk. At last follow-up, incontinence defined as any pad use was 0/69 (0%) and erectile dysfunction (defined as erections insufficient for penetration) was 5/31 (16.1%). Limitations include lack of long-term outcomes. CONCLUSIONS: Focal cryotherapy primarily for anterior intermediate and high-risk prostate cancer results in good rates of cancer control and low rates of treatment-related side effects. PATIENT SUMMARY: In this multicentre study of 122 patients undergoing focal cryotherapy for medium- to high-risk prostate cancer, at 3yr, no patient died from their cancer whilst failure-free survival, was approximately 90%. None of the patients needed pads for managing urine leakage, although 16% had erection problems.

Second salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer.

PURPOSE: Salvage treatments for localized radiorecurrent prostate cancer can be performed safely when a focal and image guided approach is used. Due to the low toxicity, the opportunity exists to investigate a second salvage treatment when a second locally recurrent prostate cancer occurs. Here, we describe a second salvage treatment procedure of 4 patients. MATERIAL AND METHODS: Four patients with a pathologically proven second local recurrence were treated in an outpatient magnetic resonance imaging (MRI)-guided setting with a single fraction of 19 Gy focal high-dose-rate brachytherapy (HDR-BT). Delineation was performed using choline-PET-CT or a 68Ga-PSMA PET in combination with multiparametric 3 Tesla MRI in all four patients. Toxicity was measured using common toxicity criteria for adverse events (CTCAE) version 4.0. RESULTS: With a median follow-up of 12 months (range, 6-15), there were 2 patients with biochemical recurrence as defined by the Phoenix-definition. There were no patients with grade 3 or more toxicity. In all second salvage HDR-BT treatments, the constraints for rectum, bladder, and urethra were met. Median treatment volume (GTV) was 4.8 cc (range, 1.9-6.6 cc). A median of 8 catheters (range, 6-9) were used, and the median dose to the treatment volume (GTV) was a D95: 19.3 Gy (SD 15.5-19.4 Gy). CONCLUSIONS: Second focal salvage MRI-guided HDR-BT for a select group of patients with a second locally recurrent prostate cancer is feasible. There was no grade 3 or more acute toxicity for these four patients.

Focal MRI-Guided Salvage High-Dose-Rate Brachytherapy in Patients With Radiorecurrent Prostate Cancer.

INTRODUCTION: Whole-gland salvage treatment of radiorecurrent prostate cancer has a high rate of severe toxicity. The standard of care in case of a biochemical recurrence is androgen deprivation treatment, which is associated with morbidity and negative effects on quality of life. A salvage treatment with acceptable toxicity might postpone the start of androgen deprivation treatment, might have a positive influence on the patients' quality of life, and might even be curative. Here, toxicity and biochemical outcome are described after magnetic resonance imaging-guided focal salvage high-dose-rate brachytherapy in patients with radiorecurrent prostate cancer. MATERIALS AND METHODS: Seventeen patients with pathologically proven locally recurrent prostate cancer were treated with focal high-dose-rate brachytherapy in a single 19-Gy fraction using magnetic resonance imaging for treatment guidance. Primary radiotherapy consisted of external beam radiotherapy or low-dose-rate brachytherapy. Tumors were delineated with Ga-68-prostate-specific membrane antigen or F18-choline positron emission tomography in combination with multiparametric magnetic resonance imaging. All patients had a prostate-specific antigen level of less than 10 ng/mL at the time of recurrence and a prostate-specific antigen doubling time of ≥12 months. Toxicity was measured by using the Common Terminology Criteria for Adverse Events version 4. RESULTS: Eight of 17 patients had follow-up interval of at least 1 year. At a median follow-up interval of 10 months (range 3-40 months), 1 patient experienced a biochemical recurrence according to the Phoenix criteria, and prostate-specific membrane antigen testing revealed that this was due to a distant nodal metastasis. One patient had a grade 3 urethral stricture at 2 years after treatment. CONCLUSION: Focal salvage high-dose-rate brachytherapy in patients with radiorecurrent prostate cancer showed grade 3 toxicity in 1 of 17 patients and a distant nodal metastasis in another patient. Whether this treatment option leads to cure in a subset of patients or whether it can successfully postpone androgen deprivation treatment needs further investigation.

Interactions of calix[n]arenes with nucleic acids.

DNA interaction with artificial binders is of great interest, especially in light of the broad range of possible biomedical applications. The growing understanding of replication, transcription and translation opened the path for new approaches to target pathological effects at a very early stage. Meanwhile, the competitive binding to nucleic acids by designed molecules, which, for example, block certain sequences for natural binders, such as transcription factors, has become a promising concept in the context of gene therapy. On the other extreme, the transport of nucleic acids over the cell membrane into the nucleus by transfection agents opens the possibility to reprogram protein biosynthesis within host cells. In the past decades several substance classes have been developed for a noncovalent specific DNA binding with predictable biological effects, such as peptide nucleic acids or polyamide ligands. Calixarenes have not received so much attention, although they consist of a compact aromatic core tuneable in size, and allow the introduction of cationic functionalities at their upper and lower rims. Formerly being utilized as receptor moieties due to the possibility of complexating guests in their cavities, calixarenes are now also used as molecular scaffolds for multivalent ligands and are, therefore, suitable tools for cooperative DNA complexation. This review surveys specific supramolecular interactions between calixarene derivatives and nucleic acids, with an emphasis on structural elements in the calixarenes and the biological consequences of their complex formation with DNA strands.