Proton therapy for the management of localized prostate cancer: Long-term clinical outcomes at a comprehensive cancer center.

BACKGROUND AND PURPOSE: Proton therapy (PT) has emerged as a standard-of-care treatment option for localized prostate cancer at our comprehensive cancer center. However, there are few large-scale analyses examining the long-term clinical outcomes. Therefore, this article aims to evaluate the long-term effectiveness and toxicity of PT in patients with localized prostate cancer. MATERIALS AND METHODS: Review of 2772 patients treated from May 2006 through January 2020. Disease risk was stratified according to National Comprehensive Cancer Network guidelines as low [LR, n = 640]; favorable-intermediate [F-IR, n = 850]; unfavorable-intermediate [U-IR, n = 851]; high [HR, n = 315]; or very high [VHR, n = 116]. Biochemical failure and toxicity were analyzed using Kaplan-Meier estimates and multivariate models. RESULTS: The median patient age was 66 years; the median follow-up time was 7.0 years. Pelvic lymph node irradiation was prescribed to 28 patients (1%) (2 [0.2%] U-IR, 11 [3.5%] HR, and 15 [12.9%] VHR). The median dose was 78 Gy in 1.8-2.0 Gy(RBE) fractions. Freedom from biochemical relapse (FFBR) rates at 5 years and 10 years were 98.2% and 96.8% for the LR group; 98.3% and 93.6%, F-IR; 94.2% and 90.2%, U-IR; 94.3% and 85.2%, HR; and 86.1% and 68.5%, VHR. Two patients died of prostate cancer. Overall rates of late grade ≥ 3 GU and GI toxicity were 0.87% and 1.01%. CONCLUSIONS: Proton therapy for localized prostate cancer demonstrated excellent clinical outcomes in this large cohort, even among higher-risk groups with historically poor outcomes despite aggressive therapy.

Low dose rate brachytherapy for primary treatment of localized prostate cancer: A systemic review and executive summary of an evidence-based consensus statement.

PURPOSE: The purpose of this guideline is to present evidence-based consensus recommendations for low dose rate (LDR) permanent seed brachytherapy for the primary treatment of prostate cancer. METHODS AND MATERIALS: The American Brachytherapy Society convened a task force for addressing key questions concerning ultrasound-based LDR prostate brachytherapy for the primary treatment of prostate cancer. A comprehensive literature search was conducted to identify prospective and multi-institutional retrospective studies involving LDR brachytherapy as monotherapy or boost in combination with external beam radiation therapy with or without adjuvant androgen deprivation therapy. Outcomes included disease control, toxicity, and quality of life. RESULTS: LDR prostate brachytherapy monotherapy is an appropriate treatment option for low risk and favorable intermediate risk disease. LDR brachytherapy boost in combination with external beam radiation therapy is appropriate for unfavorable intermediate risk and high-risk disease. Androgen deprivation therapy is recommended in unfavorable intermediate risk and high-risk disease. Acceptable radionuclides for LDR brachytherapy include iodine-125, palladium-103, and cesium-131. Although brachytherapy monotherapy is associated with increased urinary obstructive and irritative symptoms that peak within the first 3 months after treatment, the median time toward symptom resolution is approximately 1 year for iodine-125 and 6 months for palladium-103. Such symptoms can be mitigated with short-term use of alpha blockers. Combination therapy is associated with worse urinary, bowel, and sexual symptoms than monotherapy. A prostate specific antigen <= 0.2 ng/mL at 4 years after LDR brachytherapy may be considered a biochemical definition of cure. CONCLUSIONS: LDR brachytherapy is a convenient, effective, and well-tolerated treatment for prostate cancer.

The effects of zinc on radiation-induced dysgeusia: a systematic review and meta-analysis.

PURPOSE: Many head and neck cancer patients who receive radiation therapy experience radiation-induced dysgeusia (RID), which has no standard treatment. The only supplement controlled clinical trials have evaluated for the treatment of RID is zinc. However, the results of these and other studies investigating the use of zinc for RID have been inconsistent. To assess the validity of zinc as a treatment for RID, we conducted a systematic literature search and performed a meta-analysis to determine the extent to which zinc affects RID incidence and the degree to which ongoing RID responds to zinc. METHODS: We searched the Ovid MEDLINE, Ovid Embase, PubMed, and Cochrane Library databases to identify studies investigating the use of zinc-based therapy for RID in head and neck cancer patients treated with radiation that were published between January 1, 2003, and November 9, 2017. Using American Society of Clinical Oncology criteria, we selected studies with a high level of evidence for inclusion in the meta-analysis. RESULTS: Of the 32 full-text articles eligible for inclusion, three were included in the final review and meta-analysis. The meta-analysis showed that, compared with placebo, zinc reduces the incidence of RID (risk ratio, 0.72; 95% confidence interval, 0.67-0.92) but does not improve taste acuity more rapidly following radiation therapy (risk ratio, 2.58; 95% confidence interval, 0.97-6.88). CONCLUSION: Our findings indicate that zinc-based therapy reduces the incidence of RID but has a minimal effect on ongoing RID. Our findings also highlight the need for additional evidence-based research on this topic.

Predicting treatment Response based on Dual assessment of magnetic resonance Imaging kinetics and Circulating Tumor cells in patients with Head and Neck cancer (PREDICT-HN): matching 'liquid biopsy' and quantitative tumor modeling.

BACKGROUND: Magnetic resonance imaging (MRI) has improved capacity to visualize tumor and soft tissue involvement in head and neck cancers. Using advanced MRI, we can interrogate cell density using diffusion weighted imaging, a quantitative imaging that can be used during radiotherapy, when diffuse inflammatory reaction precludes PET imaging, and can assist with target delineation as well. Correlation of circulating tumor cells (CTCs) measurements with 3D quantitative tumor characterization could potentially allow selective, patient-specific response-adapted escalation or de-escalation of local therapy, and improve the therapeutic ratio, curing the greatest number of patients with the least toxicity. METHODS: The proposed study is designed as a prospective observational study and will collect pretreatment CT, MRI and PET/CT images, weekly serial MR imaging during RT and post treatment CT, MRI and PET/CT images. In addition, blood sample will be collected for biomarker analysis at those time intervals. CTC assessments will be performed on the CellSave tube using the FDA-approved CellSearch® Circulating Tumor Cell Kit (Janssen Diagnostics), and plasma from the EDTA blood samples will be collected, labeled with a de-identifying number, and stored at - 80 °C for future analyses. DISCUSSION: The primary objective of the study is to evaluate the prognostic value and correlation of weekly tumor response kinetics (gross tumor volume and MR signal changes) and circulating tumor cells of mucosal head and neck cancers during radiation therapy using MRI in predicting treatment response and clinical outcomes. This study will provide landmark information as to the utility of CTCs ('liquid biopsy) and tumor-specific functional quantitative imaging changes during treatment to guide personalization of treatment for future patients. Combining the biological information from CTCs and the structural information from MRI may provide more information than either modality alone. In addition, this study could potentially allow us to determine the optimal time to obtain MR imaging and/ or CTCs during radiotherapy to assess tumor response and provide guidance for patient selection and stratification for future dose escalation or de-escalation strategies. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT03491176 ). Date of registration: 9th April 2018. (retrospectively registered). Date of enrolment of the first participant: 30th May 2017.

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.

Biological responses of human solid tumor cells to X-ray irradiation within a 1.5-Tesla magnetic field generated by a magnetic resonance imaging-linear accelerator.

Devices that combine magnetic resonance imaging with linear accelerators (MRL) represent a novel tool for MR-guided radiotherapy. However, whether magnetic fields (MFs) generated by these devices affect the radiosensitivity of tumors is unknown. We investigated the influence of a 1.5-T MF on cell viability and radioresponse of human solid tumors. Human head/neck cancer and lung cancer cells were exposed to single or fractionated 6-MV X-ray radiation; effects of the MF on cell viability were determined by cell plating efficiency and on radioresponsiveness by clonogenic cell survival. Doses needed to reduce the fraction of surviving cells to 37% of the initial value (D0s) were calculated for multiple exposures to MF and radiation. Results were analyzed using Student's t-tests. Cell viability was no different after single or multiple exposures to MRL than after exposure to a conventional linear accelerator (Linac, without MR-generated MF) in 12 of 15 experiments (all P > 0.05). Single or multiple exposures to MF had no influence on cell radioresponse (all P > 0.05). Cells treated up to four times with an MRL or a Linac further showed no changes in D0s with MF versus without MF (all P > 0.05). In conclusion, MF within the MRL does not seem to affect in vitro tumor radioresponsiveness as compared with a conventional Linac. Bioelectromagnetics. 37:471-480, 2016. © 2016 Wiley Periodicals, Inc.

Proton Beam Therapy for Localized Prostate Cancer: Results from a Prospective Quality-of-Life Trial.

PURPOSE: To report prostate cancer outcomes, toxicity, and quality of life (QOL) in men treated with proton beam therapy (PBT). PATIENTS AND METHODS: Patients were enrolled in a prospective trial. All participants received 75.6 to 78 Gy (RBE). Up to 6 months of luteinizing hormone-releasing hormone agonist therapy was allowed. The Phoenix definition defined biochemical failure. Modified Radiation Therapy Oncology Group criteria defined toxicity. Expanded Prostate Cancer Index Composite questionnaires objectified QOL. Clinically significant QOL decrement was defined as ≥0.5 × baseline standard deviation. RESULTS: In total, 423 men were analyzed. The National Comprehensive Cancer Network risk classification was used (low 43%; intermediate 56%; high 1%). At the 5.2-year median follow-up, overall and disease-specific survival rates were 99.8% and 100%, respectively. Cumulative biochemical failure rate was 5.2% (95% confidence interval [CI] = 3.0%-8.3%); acute grade 2 genitourinary (GU) toxicity was 46.3%; acute grade 2 gastrointestinal (GI) toxicity was 5.0% (95% CI = 3.1%-7.3%). There was no acute grade ≥3 GI or GU toxicity. Cumulative late grade 2 GU and GI toxicity was 15.9% (95% CI = 13%-20%) and 9.7% (95% CI = 6.5%-12%), respectively. There were 2 grade 3 late GI toxicities (rectal bleeding) and no late grade ≥3 GU toxicity. The 4-year mean Expanded Prostate Cancer Index Composite urinary, bowel, sexual, and hormonal summary scores (range; standard deviation) were 89.7 (43.8-100; 11), 91.3 (41.1-94.6; 10), 57.8 (0.0-96.2; 27.1), and 92.2 (25-95.5; 10.5), respectively. Compared with baseline, there was no clinically significant decrement in urinary, sexual, or hormonal QOL after treatment completion. A modest (<10 points), yet clinically significant, decrement in bowel QOL was appreciated throughout follow-up. CONCLUSION: Contemporary PBT resulted in excellent biochemical control, minimal risk of higher-grade toxicity, and modest QOL decrement. Further investigation comparing PBT with alternative prostate cancer treatment strategies are warranted.

Improvement in prostate cancer survival over time: a 20-year analysis.

PURPOSE: This study aimed to evaluate the changes in outcome for men with localized prostate cancer treated with definitive external beam radiation therapy during a 20-year period at a comprehensive cancer center. METHODS: We categorized 2675 men with prostate cancer treated at MD Anderson Cancer Center with definitive external beam radiation therapy with or without androgen deprivation therapy into 3 treatment eras: 1987 to 1993 (n = 722), 1994 to 1999 (n = 828), and 2000 to 2007 (n = 1125). To help adjust for stage migration, patients were stratified according to risk group as defined by the National Comprehensive Cancer Network. Biochemical (Phoenix definition), local, distant, and any clinical failure, prostate-cancer specific survival, and overall survival were analyzed according to the Kaplan-Meier method. RESULTS: Median age was 68.5 years and median follow-up was 6.4 years. Fewer men in the most recent era had high-risk disease, and a higher proportion received 72 Gy or higher (99% vs 4%) and androgen deprivation therapy (60% vs 6%) than the earliest era. All risk groups treated in the modern era experienced improved rates of biochemical, local, and distant failure. In high-risk patients, decreased rates of distant failure and clinical failure led to improved prostate cancer-specific survival and overall survival. Local control was improved for intermediate- and high-risk patients, with a trend toward improvement in low-risk patients. On multivariate analysis, recent treatment era was closely correlated with a dose of 72 Gy or higher and treatment with androgen deprivation therapy and predicted for lower rates of biochemical, local, and distant failure. Androgen deprivation therapy, higher dose, and more recent treatment era predicted for improved prostate cancer-specific survival. DISCUSSION: During the last 20 years of prostate cancer irradiation, disease control outcomes have improved in all patients, leading to improved prostate cancer-specific survival and overall survival for men with high-risk disease. This may reflect advances in workup, staging accuracy, and prostate cancer treatment in the modern era.

Prostate cancer-specific mortality after definitive radiation therapy: who dies of disease?

BACKGROUND: A competing risks analysis was undertaken to identify subgroups at greatest risk of dying from prostate cancer (PC) after definitive external beam radiation therapy (RT)±androgen deprivation therapy (ADT) in the prostate specific antigen (PSA) era. METHODS: Outcomes of 2675 men with localised PC treated with RT±ADT from 1987-2007 were analysed. Prostate cancer-specific mortality (PCSM) and non-PCSM rates were calculated after stratifying patients according to National Comprehensive Cancer Network (NCCN) risk-group, RT dose, use of ADT and age at treatment. RESULTS: Only 0.2% of low-risk men died of PC 10 years after treatment. All of these deaths occurred in patients treated with < 72 Gy, and only one patient ≥ 70 years old who received ≥ 72 Gy died of PC at last follow-up. Likewise, none of the patients with intermediate-risk disease treated with ≥ 72 Gy and ADT died of PC at 10 years, and the highest 10-year rate of PCSM was seen in men ≥ 70 years old treated with < 72 Gy without ADT (5.1%). Among high-risk men < 70 years old, treatment with RT dose < 72 Gy without ADT yielded similar 10-year rates of PCSM (15.2%) and non-PCSM (18.5%), whereas men treated with ≥ 72 Gy and ADT were twice as likely to die from other causes (16.2%) than PC (9.4%). In high-risk men ≥ 70 years old, dose-escalation with ADT reduced 10-year PCSM from 14% to 4%, and most deaths were due to other causes. CONCLUSION: Low- and intermediate-risk patients treated with definitive RT are unlikely to die of PC. PCSM is higher in men with high-risk disease but may be reduced with dose-escalation and ADT, although patients are still twice as likely to die of other causes.

Sexual function and the use of medical devices or drugs to optimize potency after prostate brachytherapy.

PURPOSE: Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center. METHODS AND MATERIALS: Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated. RESULTS: At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested. CONCLUSIONS: Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry.

An assessment of quality of life following radical prostatectomy, high dose external beam radiation therapy and brachytherapy iodine implantation as monotherapies for localized prostate cancer.

PURPOSE: Monotherapy with radical prostatectomy, high dose external beam radiotherapy or a (125)I implant is reported to produce equivalent outcomes. We assessed the health related quality of life associated with these 3 treatment approaches. MATERIALS AND METHODS: Extended Prostate Index Composite surveys were mailed to all 960 patients treated with a (125)I implant, high dose external beam radiotherapy or radical prostatectomy with or without hormonal therapy at our institution from 1998 to 2000. A total of 625 patients (65%) completed the surveys. Nerve sparing radical prostatectomy was performed when appropriate. The (125)I implant consisted of 145 Gy and high dose external beam radiotherapy consisted of 78 Gy. For urinary, rectal and sexual domains mean scores were calculated, compared by treatment modality and compared to normative values. RESULTS: A total of 234 patients with radical prostatectomy, 135 with external beam radiotherapy and 74 with a (125)I implant were treated with a monotherapy approach. Median age was 61 years in the radical prostatectomy group, 68 years in the high dose external beam radiotherapy group and 64 years in the (125)I implant group (p <0.001). Of the patients 97% [corrected] had cT1-2 disease and Gleason score 7 or less [corrected] Median time from treatment was 4.0 years for radical prostatectomy, 4.7 years for high dose external beam radiotherapy and 3.5 years for (125)I implantation. Radiation caused significantly worse bowel bother and bowel function than radical prostatectomy (p < or =0.018). Patients with high dose external beam radiotherapy had significantly better urinary function than patients with radical prostatectomy (p <0.001). While patients with radical prostatectomy had significantly worse urinary incontinence than those with a (125)I implant or high dose external beam radiotherapy (p <0.0001), patients with a (125)I implant had more urinary irritation than those with high dose external beam radiotherapy and radical prostatectomy (p <0.01 and <0.0001, respectively). Patients with a (125)I implant had significantly better sexual function than those with high dose external beam radiotherapy and radical prostatectomy (p = 0.01 and 0.0003, respectively). CONCLUSIONS: Of patients with prostate cancer treated with a monotherapy approach we noted better urinary continence in those who underwent radiation based therapies, and better bowel function and less urinary irritation in those who underwent surgery. Sexual function was impaired across all monotherapies but higher scores were seen in men who selected brachytherapy.