12-Year Outcomes Following Permanent Prostate Brachytherapy in Patients with Clinically Localized Prostate Cancer

Trends in Androgen Deprivation Use in Men with Intermediate Risk Prostate Cancer Who Underwent Radiotherapy

Purpose

Until 2018, National Cancer Comprehensive Network guidelines recommended androgen deprivation therapy (ADT) for all men with intermediate-risk prostate cancer who had undergone radiation therapy. Intermediate risk was stratified as favorable and unfavorable in 2018, and ADT recommendation was limited to men with unfavorable intermediate-risk prostate cancer. Data suggesting this stratification and treatment deintensification were first published in December 2013. This study characterizes US national trends for demographic, clinical, and socioeconomic factors associated with ADT use in men with intermediate-risk prostate cancer who have undergone definitive radiation therapy.

Methods and Materials

This retrospective cohort study examined 108,185 men in the National Cancer Database who were diagnosed with intermediate-risk prostate cancer from 2004 to 2016. Temporal trends in demographic, clinical, and socioeconomic factors among men with intermediate-risk prostate cancer and associations with the use of ADT were characterized.

Results

In total, 108,185 men diagnosed with intermediate-risk prostate cancer underwent radiation therapy from 2004 to 2016. Of these men, 41.09% received ADT. Among the 60,705 men with favorable intermediate-risk prostate cancer, 32.06% received ADT. Among the 47,480 men with unfavorable intermediate-risk prostate cancer, 52.64% received ADT. On multivariate analysis, use of ADT was associated with age and year of diagnosis; being a race other than White; having government-based insurance; having a higher prostate-specific antigen level, tumor stage, and Gleason score; receiving treatment at a nonacademic center; and receiving external beam radiation therapy alone.

Conclusions

The findings highlight that ADT use is variable in men undergoing definitive radiation therapy for intermediate-risk prostate cancer, with the data suggesting that several clinical and socioeconomic disparities influence its use. The findings suggest that a significant proportion of men with favorable intermediate-risk prostate cancer receive ADT and remain candidates for treatment de-escalation, whereas a significant proportion of men with unfavorable intermediate-risk prostate cancer may be undertreated when ADT is omitted.

PD-1 Inhibitor Maintenance Therapy Combined Iodine-125 Seed Implantation Successfully Salvage Recurrent Cervical Cancer after CCRT: A Case Report

Cervical cancer is the fourth most common cancer in females worldwide. Patients with stage III and IV cervical cancer based on the Federation of Gynecology and Obstetrics (FIGO) classification have higher recurrence rates. Because of organs at risk (OAR) protection and the low indication rate of salvage surgery, the choice of treatment is always challenging. Systemic chemotherapy is palliative and can be performed in conjunction with surgery or radiotherapy; however, it has no significant benefit to survival. Brachytherapy and stereotactic body radiotherapy (SBRT) are characterized by extremely high radiation doses applied to tumor cells while sparing the normal tissues. Several studies have investigated the efficacy of these technologies in recurrent cervical cancer and showed promising results. The immune checkpoint inhibitors approach was also investigated and showed promising results too. Herein, we report a case of a patient with cervical cancer that recurred five months after adjuvant chemotherapy and concurrent chemoradiotherapy. The disease prognosis after interstitial implantation brachytherapy (IIB) was determined. Then, the patient underwent radioactive 125I-seed implantation combined with PD-1 inhibitor treatment. The patient exhibited a partial response after seed implantation, and up to now, the duration of this partial response was 24 months.

A review on permanent implants for prostate brachytherapy with comparison between stranded and loose seeds

A systematic literature review to validate the conclusions with regard to stranded seeds versus loose seeds. Published data for this review were identified by searching the PubMed databases. PD90, PV100, PV150, UD30, and RV100 acquired during the perioperative period and the postoperative period were analyzed by meta-analysis. Based on these studies, in addition to the reduction of migration and displacement, stranded seeds had some dosimetric advantages, especially in dose homogeneity and coverage of target area due to its connection characteristics. We also noticed implanted seeds usually excessive both in stranded seeds group and loose seed group. Intraoperatively built custom links will prolong operation time, with the proficiency of technology, the prolonged time gradually decreases.

The one hundred most cited publications in prostate brachytherapy

PURPOSE

The aim of this study is to identify the leaders in research on prostate brachytherapy through a bibliometric analysis of the top 100 most cited publications in the field.

METHODS AND MATERIALS

A broad search was performed with the term "prostate brachytherapy" using the Web of Science database to generate wide-ranging results that were reviewed by reading the abstracts and, if necessary, the articles to select the top 100 most cited publications.

RESULTS

The median of the total citation count was 187 (range 132-1464). The median citation per year index (citations/year since publication) was 13.5 (range 6.3-379.0). In all publications, the first author was also the corresponding author. The top publishing countries of the first author included the United States (n = 78), Canada (n = 6), the UK (n = 5), and Germany (n = 4). The journal with the most publications was the International Journal of Radiation Oncology Biology Physics (n = 38). There were 27 more publications on low-dose-rate (LDR) than on high-dose-rate (HDR) (43 vs 16) among the top 100. HDR publications had only one first author that had three articles in comparison to LDR publications, which had four first authors, each with three articles on LDR. The United States was the leading country in 43.8% of HDR publications (n = 7) and 88.4% of LDR publications (n = 38).

CONCLUSIONS

Our bibliometric analysis of the top 100 most cited publications clearly demonstrates the North American dominance in the publications of prostate brachytherapy, especially in LDR. However, European first authors were more frequent in HDR publications.

Prostate Cancer, Version 2.2019, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Prostate Cancer include recommendations regarding diagnosis, risk stratification and workup, treatment options for localized disease, and management of recurrent and advanced disease for clinicians who treat patients with prostate cancer. The portions of the guidelines included herein focus on the roles of germline and somatic genetic testing, risk stratification with nomograms and tumor multigene molecular testing, androgen deprivation therapy, secondary hormonal therapy, chemotherapy, and immunotherapy in patients with prostate cancer.

Tumor burden and location as prognostic factors in patients treated by iodine seed implant brachytherapy for localized prostate cancers

Background

Iodine seed implant brachytherapy is indicated for low risk and selected favorable intermediate risk prostate cancers. A percentage of positive biopsies > 50% is usually considered as a contra-indication, and the tumor location could also influence the treatment efficacy. We studied the association of the percentage of positive biopsy cores, and tumor location, with progression-free survival.

Methods

Among the 382 patients treated at our center by permanent implant iodine seed brachytherapy for a localized prostate cancer between 2006 and 2013, 282 had accessible detailed pathology reports, a minimum follow-up of 6 months, and were included. Progression was defined as a biochemical, local, nodal, or distant metastatic relapse. We studied cancer location on biopsies (base, midgland or apex of the prostate) and percentage of positive biopsy cores, as well as potential confounders (pre-treatment PSA, tumor stage, Gleason score, risk group according to D’Amico’s classification modified by Zumsteg, adjunction of androgen deprivation therapy, and dosimetric data).

Results

Most patients (197; 69.9%) had a low risk, 67 (23.8%) a favorable intermediate risk, 16 (5.7%) an unfavorable intermediate risk, and 1 (0.3%) a high-risk prostate cancer. An involvement of the apex was found for 131 patients (46,5%), of the midgland for 149 (52,8%), and of the base for 145 (51,4%). The median percentage of positive biopsy cores was 17% [3–75%]. The median follow-up was 64 months [12–140]. Twenty patients (7%) progressed: 4 progressions (20%) were biochemical only, 7 (35%) were prostatic or seminal, 6 (30%) were nodal, and 3 (15%) were metastatic. The median time to failure was 39.5 months [9–108]. There were more Gleason scores ≥7 among patients who progressed (40% vs 19%; p = 0.042). None of the studied covariates (including tumor location, and percentage of positive biopsy cores), were significantly associated with progression-free survival. The risk group showed a trend towards an association (p = 0.055).

Conclusions

Brachytherapy is an efficient treatment (5-year control rate of 93%) for patients carefully selected with classical criteria. The percentage and location of positive biopsies were not significantly associated with progression-free survival. A Gleason score ≥ 7 was more frequent in case of progression.

Dose to the dominant intraprostatic lesion using HDR vs. LDR monotherapy: A Phase II randomized trial

PURPOSE

To present the dosimetric results of a Phase II randomized trial comparing dose escalation to the MRI-defined dominant intraprostatic lesion (DIL) using either low-dose-rate (LDR) or high-dose-rate (HDR) prostate brachytherapy.

MATERIAL AND METHODS

Patients receiving prostate brachytherapy as monotherapy were randomized to LDR or HDR brachytherapy. Prostate and DILs were contoured on preoperative multiparametric MRI. These images were registered with transrectal ultrasound for treatment planning. LDR brachytherapy was preplanned using I-125 seeds. HDR brachytherapy used intraoperative transrectal ultrasound-based planning to deliver 27 Gy/2 fractions in separate implants. DIL location was classified as peripheral, central, or anterior. A student t-test compared DIL D₉₀ between modalities and DIL locations.

RESULTS

Of 60 patients, 31 underwent LDR and 29 HDR brachytherapy. Up to three DILs were identified per patient (100 total) with 74 peripheral, six central, and 20 anterior DILs. Mean DIL volume was 1.9 cc (SD: 1.7 cc) for LDR and 1.6 cc (SD 1.3 cc) for HDR (p = 0.279). Mean DIL D₉₀ was 151% (SD 30%) for LDR and 132% (SD 13%) for HDR. For LDR, mean peripheral DIL D₉₀ was 159% (SD 27%) and central or anterior 127% (SD 13%). HDR peripheral DILs received 137% (SD 12%) and central or anterior 119% (SD 7%). DIL D₉₀ for peripheral lesions was higher than anterior and central (p < 0.001).

CONCLUSIONS

DIL location affects dose escalation, particularly because of urethral proximity, such as for anterior and central DILs. HDR brachytherapy may dose escalate better when target DIL is close to critical organs.

Acute and late toxicities in localized prostate cancer patients treated with low-dose 125I brachytherapy (110 Gy) in combination with external beam radiation therapy versus brachytherapy alone (160 Gy)

Purpose

The aim of this analysis was to compare acute and late toxicities between low-dose-rate brachytherapy (LDR-BT) (110 Gy) in combination with 45 Gy in 25 fractions external beam radiation therapy (EBRT) and LDR-BT (160 Gy) alone for localized prostate cancer.

Material and methods

One hundred five consecutive patients with localized prostate cancer treated from May 2014 to May 2017 were included in this retrospective analysis. Sixty patients received combination therapy and 45 patients received BT monotherapy. The LDR-BT procedure was performed using ¹²⁵I seeds.

Results

The median follow-up time was 28 months in both groups. Three-year effect rates were overall survival: 100% in both groups. The biochemical failure rate was 2.3% in the combination group and 0% in the monotherapy group (p = 0.373). No patients died during the study period. In both groups, almost all the patients experienced acute urethritis. There was a significant difference between the combination therapy group (8.3%) and BT monotherapy group (11.1%) in late genitourinary (GU) toxicities ≥ grade 2 (p = 0.035). Only 2 patients (3.3%) in the combination therapy group developed late ≥ grade 2 rectal hemorrhage. There were no significant differences between two groups in hematuria ≥ grade 2 (p = 0.068) or rectal hemorrhage ≥ grade 2 (p = 0.206).

Conclusions

To our knowledge, this is the first report to compare the GU and gastrointestinal toxicities between the combination therapy and BT monotherapy (160 Gy) for localized prostate cancer. Unexpectedly, there were more late GU toxicities (except for hematuria) in the BT monotherapy group.

Recurrence of prostate cancer after HIFU. Proposal of a novel predictive index

Background and aim of the work: Prostate cancer is one of the most common cancers in men over 50 years of age. Surgery, radiotherapy and hormonal manipulation represent its typical treatment. High-Intensity Focused Ultrasound (HIFU) is an alternative choice in localized prostate cancer. To date, an index for prediction of recurrence in patients treated with HIFU is not availabe. Our study proposes a novel index for the predition of recurrence able to determine if a candidate is fit for this tratment. methods: 107 patients underwent HIFU fram 2010 to 2015. A total of 12 variables were considered for the analysis. The final predictive model was obtained through a stepwise forward selection method. Results: The final model used a total of 6 variables, all correlated to the response variable. The Index is able to predict the recurrence after HIFU tratment in the most majority of candidates to treatment. The index may be used to make a more scientific decision with regard to choosing optimal candidates for HIFU. (www.actabiomedica.it)

The evolution of brachytherapy for prostate cancer

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

Prostate-specific antigen nadir concentration, hypertension and diabetes as risk factors for biochemical failure after permanent 125I seed brachytherapy for prostate cancer

The aim of this study was to evaluate risk factors for biochemical failure (BF) following permanent prostate seed ¹²⁵I brachytherapy for prostate cancer. The study reviewed the medical records of 607 patients with biopsy-proven prostate adenocarcinoma who were treated at Oulu University Hospital between 2001 and 2014. Clinical characteristics at diagnosis, treatment-related data and follow-up data were collected to identify potential risk factors for BF, which was defined using the Phoenix criteria [prostate-specific antigen (PSA) increase >2 µg/l from the PSA nadir concentration, which defined as the lowest PSA concentration observed after BT]. The median follow-up was 81 months. BF was detected in 117 (19.3%) patients. The PSA nadir concentration was associated with BF. The mean times to BF were 114 [95% confidence interval (CI): 112-116] and 55 (95% CI: 47-63) months for patients with PSA nadir concentrations <0.5 and ≥0.5 µg/l, respectively (P<0.001). Patients with underlying hypertension or diabetes tended to develop BF more rapidly. For patients without and with hypertension, the mean times to BF were 104 (95% CI: 100-107) and 98 (95% CI: 93-103) months, respectively (P=0.035). For patients without and with diabetes, the mean times to BF were 103 (95% CI: 100-106) and 89 (95% CI: 77-102) months, respectively (P=0.006). The overall survival and prostate cancer-specific survival rates were 90.3 and 98.0%, respectively. The mean overall survival and prostate-cancer specific survival times were 147 and 158 months, respectively. Therefore, PSA nadir level was identified as a clear risk factor for BF. In addition, BF tended to develop more rapidly among patients with underlying hypertension or diabetes. These risk factors should be considered, and individually tailored follow-up may be useful for identifying patients requiring more intense follow-up for early BF detection.

Radiation-induced erectile dysfunction: Recent advances and future directions

Prostate cancer is one of the most prevalent cancers and the second leading cause of cancer-related deaths in men in the United States. A large number of patients undergo radiation therapy (RT) as a standard care of treatment; however, RT causes erectile dysfunction (radiation-induced erectile dysfunction; RiED) because of late side effects after RT that significantly affects quality of life of prostate cancer patients. Within 5 years of RT, approximately 50% of patients could develop RiED. Based on the past and current research findings and number of publications from our group, the precise mechanism of RiED is under exploration in detail. Recent investigations have shown prostate RT induces significant morphologic arterial damage with aberrant alterations in internal pudendal arterial tone. Prostatic RT also reduces motor function in the cavernous nerve which may attribute to axonal degeneration may contributing to RiED. Furthermore, the advances in radiogenomics such as radiation induced somatic mutation identification, copy number variation and genome-wide association studies has significantly facilitated identification of biomarkers that could be used to monitoring radiation-induced late toxicity and damage to the nerves; thus, genomic- and proteomic-based biomarkers could greatly improve treatment and minimize arterial tissue and nerve damage. Further, advanced technologies such as proton beam therapy that precisely target tumor and significantly reduce off-target damage to vital organs and healthy tissues. In this review, we summarize recent advances in RiED research and novel treatment modalities for RiED. We also discuss the possible molecular mechanism involved in the development of RiED in prostate cancer patients. Further, we discuss various readily available methods as well as novel strategies such as stem cell therapies, shockwave therapy, nerve grafting with tissue engineering, and nutritional supplementations might be used to mitigate or cure sexual dysfunction following radiation treatment.

Saudi oncology society and Saudi urology association combined clinical management guidelines for prostate cancer

This is an update to the previously published Saudi guidelines for the evaluation, medical, and surgical management of patients diagnosed with prostate cancer. It is categorized according to the stage of the disease using the tumor node metastasis staging system 7(th) edition. The guidelines are presented with supporting evidence level, they are based on comprehensive literature review, several internationally recognized guidelines, and the collective expertise of the guidelines committee members (authors) who were selected by the Saudi oncology society and Saudi urological association. Considerations to the local availability of drugs, technology, and expertise have been regarded. These guidelines should serve as a roadmap for the urologists, oncologists, general physicians, support groups, and health care policy makers in the management of patients diagnosed with adenocarcinoma of the prostate to.

Injectable polypeptide micelles that form radiation crosslinked hydrogels in situ for intratumoral radiotherapy

Intratumoral radiation therapy - 'brachytherapy' - is a highly effective treatment for solid tumors, particularly prostate cancer. Current titanium seed implants, however, are permanent and are limited in clinical application to indolent malignancies of low- to intermediate-risk. Attempts to develop polymeric alternatives, however, have been plagued by poor retention and off-target toxicity due to degradation. Herein, we report on a new approach whereby thermally sensitive micelles composed of an elastin-like polypeptide (ELP) are labeled with the radionuclide (131)I to form an in situ hydrogel that is stabilized by two independent mechanisms: first, body heat triggers the radioactive ELP micelles to rapidly phase transition into an insoluble, viscous coacervate in under 2 min; second, the high energy β-emissions of (131)I further stabilize the depot by introducing crosslinks within the ELP depot over 24h. These injectable brachytherapy hydrogels were used to treat two aggressive orthotopic tumor models in athymic nude mice: a human PC-3 M-luc-C6 prostate tumor and a human BxPc3-luc2 pancreatic tumor model. The ELP depots retained greater than 52% and 70% of their radioactivity through 60 days in the prostate and pancreatic tumors with no appreciable radioactive accumulation (≤ 0.1% ID) in off-target tissues after 72h. The (131)I-ELP depots achieved >95% tumor regression in the prostate tumors (n=8); with a median survival of more than 60 days compared to 12 days for control mice. For the pancreatic tumors, ELP brachytherapy (n=6) induced significant growth inhibition (p=0.001, ANOVA) and enhanced median survival to 27 days over controls.

Dosimetric variations due to interfraction organ deformation in cervical cancer brachytherapy

We quantitatively estimated dosimetric variations due to interfraction organ deformation in multi-fractionated high-dose-rate brachytherapy (HDRBT) for cervical cancer using a novel surface-based non-rigid deformable registration. As the number of consecutive HDRBT fractions increased, simple addition of dose-volume histogram parameters significantly overestimated the dose, compared with distribution-based dose addition.

Is it necessary to perform week three dosimetric analysis in low-dose-rate brachytherapy for prostate cancer when day 0 dosimetry is done? A quality assurance assessment

PURPOSE

To determine whether computed tomography/magnetic resonance imaging-based day 0 (d0) dosimetry is a meaningful predictor of day 21 (d21) dosimetry in low-dose-rate brachytherapy for localized prostate cancer.

METHODS AND MATERIALS

The study population consisted of 277 men with localized (T1-2 N0 M0), low-/intermediate-risk prostate cancer treated with low-dose-rate brachytherapy. Computed tomography/magnetic resonance imaging fusion was used for postimplant dosimetry at d0 and d21. Logistic regression was used to construct receiver operating characteristic curves for achieving each constraint at d21, based on d0 D90 and V100, and Youden's index was used to evaluate cutpoints. Freedom from biochemical failure (FBCF) was estimated with the Kaplan-Meier method.

RESULTS

The median d0 D90 increased from 133 to 150 Gy at d21, and median d0 V100 increased from 87% to 91%. For achieving the D90 constraint at d21, the optimal cut-point for d0 D90 was 135 Gy, with 84% of these patients maintaining a d21 D90 > 145 Gy. For achieving the D90 constraint at d21, the optimal cut-point for d0 V100 was 87%, with 83% of these patients maintained a d21 V100 > 90%. There was no improvement in FBCF in patients with a d0 D90 > 135 Gy or D90 > 145 Gy. Similarly, there was no improvement in FBCF in patients with a d0 V100 > 87% or V100 > 90%.

CONCLUSIONS

Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis. Constraints used for dose prescriptions on d0 are not the ideal predictors of d21 dosimetry.

Influence of zonal dosimetry on prostate brachytherapy outcomes

Purpose

To examine the influence of zone-specific dosimetry on outcomes during permanent prostate implantation (PI), where the peripheral zone (PZ) and transitional zone (TZ) may receive varying radiation doses.

Material and methods

Four hundred and sixteen patients treated with I-125 PI (target dose: 144 Gy) between 1996 and 2003 were included in this Institutional Review Board (IRB) approved, retrospective analysis. Whole prostate (WP), TZ, and PZ were contoured, and zone-specific D₉₀ and V₁₀₀ were computed. Their influence on biochemical failure (BF) was evaluated using Cox proportional hazards analysis.

Results

The median age and initial prostate-specific antigen (PSA) was 68 years and 6.1 ng/ml, respectively, and the median follow-up time was 8.8 years. There were 329 subjects with Gleason score (GS) 6 disease (79.1%), and 82 subjects had GS 7 disease (19.7%). Androgen deprivation therapy (ADT) was used in 20.4% of patients. Median D₉₀ and V_100% in the WP, PZ, and TZ were 141.2 Gy, 156.1 Gy, and 134.5 Gy; and 88.8%, 93.3%, and 84.2%, respectively. Ten-year rates for biochemical recurrence-free survival, distant metastasis-free survival, and prostate cancer-specific mortality were 82.4%, 92.4%, and 0.97% respectively. Only initial PSA, GS7+ disease, ADT, and PSA frequency were significant on multivariate analysis. Ten-year rates of grade 3 or higher GU and GI toxicity was 10.9% and 1.8%, respectively. TZ V₂₀₀ and TZ V₃₀₀ were significantly associated with late genitourinary toxicity.

Conclusions

The TZ received significantly lower doses of radiation compared to the PZ. On multivariate analysis, no dosimetric parameter was associated with efficacy. Higher TZ doses may be associated with higher late GU toxicity without improving efficacy.

Permanent seed brachytherapy for clinically localized prostate cancer: long-term outcomes in a 700 patient cohort

PURPOSE

Few large European studies have evaluated long-term outcomes for permanent prostate brachytherapy (PPB) as monotherapy for clinically localized prostate cancer. The objective of the present study was to evaluate long-term survival in this patient profile.

METHODS AND MATERIALS

Retrospective study of 700 patients who underwent transperineal ultrasound-guided iodine-125 PPB (145 Gy) between January 2000 and July 2012. Median age was 64.8 years (range, 35-79). Most patients (638 of 700; 91%) had low-risk disease (D'Amico criteria). Eighty-five patients (12%) received hormonal treatment. Overall survival, cause-specific survival, and biochemical relapse-free survival were calculated and estimated using actuarial and Kaplan-Meier methods. Differences between groups were assessed using the log-rank test.

RESULTS

Median followup was 63 months (range, 6-164). At 5- and 10-year followup, respectively, overall survival was 94% (95% confidence interval [CI], 92-96) and 84% (95% CI, 78-90); cause-specific survival was 100% and 97% (95% CI, 95-99); and biochemical relapse-free survival was 95% (95% CI, 93-97) and 85% (95% CI, 79-91).

CONCLUSIONS

The long-term results presented in this report confirm previous studies and provide additional support for the use of PPB in patients with favorable-risk prostate cancer. Seed brachytherapy provides excellent long-term results in this patient profile.

Saudi oncology society and Saudi urology association combined clinical management guidelines for prostate cancer

In this report, updated guidelines for the evaluation, medical, and surgical management of prostate cancer are presented. They are categorized according the stage of the disease using the tumor node metastasis staging system 7(th) edition. The recommendations are presented with supporting evidence level.

Sexual potency preservation and quality of life after prostate brachytherapy and low-dose tadalafil

PURPOSE

To prospectively determine sexual function, bother, and potency preservation in men treated with prostate brachytherapy and twice-weekly tadalafil.

METHODS AND MATERIALS

From 2005 to 2011, men treated with low-dose-rate prostate brachytherapy were treated on a prospective registration study. All patients were prescribed tadalafil 10mg twice weekly. The expanded prostate cancer index composite questionnaire was administered before treatment and at each followup. A subgroup analysis of men with sexual potency at baseline was performed.

RESULTS

A total of 237 men were analyzed. Median age was 64 years (range, 44-86). Median followup was 24.8 months (range, 1-60). At baseline, 175 men (74%) reported erections firm enough for sexual activity and 148 (62%) were potent (erections firm enough for intercourse). Statistically significant changes in sexual function/bother were appreciated from baseline throughout the analysis period, although absolute changes were relatively small and did not meet criteria for clinical significance. At 24-months followup, 72% reported erections firm enough for sexual activity and 56% were potent. Of men with potency at baseline, 89% had erections firm enough for sexual activity and 76% remained potent 24 months after treatment.

CONCLUSIONS

Peri-procedural tadalafil and prostate brachytherapy resulted in high rates of sexual potency preservation and no clinically significant effect on sexual quality of life.

Do theoretical potential and advanced technology justify the use of high-dose rate brachytherapy as monotherapy for prostate cancer?

Low-dose rate brachytherapy (LDR-BT), involving implantation of radioactive seeds into the prostate, is an established monotherapy for most low-risk and select intermediate- and high-risk prostate cancer patients. High-dose rate brachytherapy (HDR-BT) is an advanced technology theorized to be more advantageous than LDR-BT from a radiobiological and radiophysics perspective, to the patient himself, and in terms of resource allocation. Studies of HDR-BT monotherapy have encouraging results in terms of biochemical control, patient survival, treatment toxicity and erectile preservation. However, there are still certain limitations that preclude recommending HDR-BT monotherapy for prostate cancer outside the setting of a clinical trial. HDR-BT monotherapy should be considered experimental at present.

Long-term outcome of early stage prostate cancer treated with brachytherapy analysis after a mean follow-up of 7 years

Purpose

To investigate the long-term efficacy of ¹²⁵I brachytherapy in early-stage prostate cancer and to identify correlating factors.

Methods

This study included 117 cases of early stage prostate cancer. The patients ranged in age from 51 to 84 years, with a mean of 73 years. The features of the study population were as follows: the PSA ranged from 0.4 to 47.6 ng/ml (median, 14.7); the Gleason score ranged from 4 to 9 (mean, 6.4); the clinical stage ranged from T1b to T2c; and the positive biopsy rate ranged from 0.08 to 1.0 (mean, 0.45). The mean D90 was 142 Gy and ranged from 106 Gy to 170 Gy. The numbers of low-risk, intermediate-risk and high-risk prostate cancer cases were 22, 29 and 66, respectively. The biochemical no evidence of disease (bNED) rate and overall survival were recorded. Factors that correlated with the outcomes were evaluated.

Results

With a mean follow up of 84 months, 33 cases had biochemical recurrence, with a bNED rate of 72%. The overall survival rate was 90%, and the cancer-specific survival rate was 97%. The bNED rates in the low-risk, intermediate-risk and high-risk groups were 86%, 79% and 64%, respectively (P = 0.040). The patients with PSA <20 ng/ml, a positive biopsy rate lower than 0.5, and D90 ≥ 140 Gy had lower biochemical recurrence (P = 0.028, 0.006, 0.009, respectively).

Conclusions

The long-term efficacy of ¹²⁵I brachytherapy in early stage prostate cancer was shown. bNED is related to risk stratification, PSA level, positive biopsy rate and D90.

Combining theoretical potential and advanced technology in high-dose rate brachytherapy boost therapy for prostate cancer

External beam radiation therapy (EBRT) combined with brachytherapy (BT) is an attractive treatment option for select patients with clinically localized prostate cancer. Either low- or high-dose rate BT may be combined with EBRT ('LDR-BT boost,' 'HDR-BT boost,' respectively). HDR-BT boost has potential theoretical benefits over LDR-BT boost or external beam radiation therapy monotherapy in terms of radiobiology, radiophysics and patient convenience. Based on prospective studies in this review, freedom from biochemical failure (FFBF) rates at 5 years for low-, intermediate- and high-risk patients have generally been 85-100%, 68-97%, 63-85%, respectively; late Radiotherapy and Oncology Group Grades 3 and 4 genitourinary and gastrointestinal toxicities are seen in <8% of patients. HDR-BT boost is now a relatively well-established treatment modality for certain intermediate-risk and high-risk prostate cancer patients, though limitations exist in drawing conclusions from the currently published studies.

The effects of metallic implants on electroporation therapies: feasibility of irreversible electroporation for brachytherapy salvage

PURPOSE

Electroporation-based therapies deliver brief electric pulses into a targeted volume to destabilize cellular membranes. Nonthermal irreversible electroporation (IRE) provides focal ablation with effects dependent on the electric field distribution, which changes in heterogeneous environments. It should be determined if highly conductive metallic implants in targeted regions, such as radiotherapy brachytherapy seeds in prostate tissue, will alter treatment outcomes. Theoretical and experimental models determine the impact of prostate brachytherapy seeds on IRE treatments.

MATERIALS AND METHODS

This study delivered IRE pulses in nonanimal, as well as in ex vivo and in vivo tissue, with and in the absence of expired radiotherapy seeds. Electrical current was measured and lesion dimensions were examined macroscopically and with magnetic resonance imaging. Finite-element treatment simulations predicted the effects of brachytherapy seeds in the targeted region on electrical current, electric field, and temperature distributions.

RESULTS

There was no significant difference in electrical behavior in tissue containing a grid of expired radiotherapy seeds relative to those without seeds for nonanimal, ex vivo, and in vivo experiments (all p > 0.1). Numerical simulations predict no significant alteration of electric field or thermal effects (all p > 0.1). Histology showed cellular necrosis in the region near the electrodes and seeds within the ablation region; however, there were no seeds beyond the ablation margins.

CONCLUSION

This study suggests that electroporation therapies can be implemented in regions containing small metallic implants without significant changes to electrical and thermal effects relative to use in tissue without the implants. This supports the ability to use IRE as a salvage therapy option for brachytherapy.

PSA-nadir at 1 year as a sound contemporary prognostic factor for low-dose-rate iodine-125 seeds brachytherapy

OBJECTIVES

To identify predictors of outcomes in patients with localized prostate cancer treated with iodine-125 brachytherapy in a longitudinal uncontrolled study.

METHODS

Between 2000 and 2011, 560 histologically confirmed patients were treated with brachytherapy of whom 305 with ≥24-month follow-up and localized tumor were evaluated after exclusion of those locally advanced and under androgen ablation.

RESULTS

Patients' mean age was 63.93 years (44-88), mean pretreatment prostate-specific antigen (PSA) was 6.34 ng/mL (0.67-33.09), overall median follow-up was 75.35 months (24-158.37), biochemical recurrence occurred in 17 patients (5.57 %), cancer-specific survival was 100 %, and overall survival was 98.03 %. At multivariate analyses, only PSA-nadir at 1 year and age were related to disease-free survival: To each unit of PSA-nadir, the risk increases 87.3 %-OR 1.87 (p < 0.001; 95 % CI 1.31-2.67), and risk was 4.7 times higher for those under 50 years (vs. >70)-OR 4.69 (p = 0.04; 95 % CI 1.39-18.47). Best cutoff for PSA-nadir at one year was 0.285 (AUC = 0.78; p < 0.001; 95 % CI 0.68-0.89). Kaplan-Meier analysis confirmed PSA-nadir (p < 0.001) as prognostic, while D'Amico's classification failed (p = 0.24). No grade 3 or 4 complication was reported, and only 31.4 % of patients had grade 2 urinary or rectal toxicity. PSA bounce ≥0.4 ng/mL occurred in 18.4 % with no impact on biochemical recurrence.

CONCLUSIONS

Half (50.49 %) of patients in the scenario of localized prostate cancer treated with iodine-125 brachytherapy reach PSA-nadir at 1 year <0.285, recognized as a key independent prognostic factor.

Treatment outcomes and morbidity following definitive brachytherapy with or without external beam radiation for the treatment of localized prostate cancer: 20-year experience at Mount Sinai Medical Center

OBJECTIVES

To present our treatment algorithm and 20-year experience in treating prostate cancer with brachytherapy since 1990, with focus on cancer-control outcomes and treatment-related morbidity.

METHODS AND MATERIALS

We selected patients treated for localized prostate cancer with brachytherapy, combination therapy with external beam radiotherapy, and adjuvant androgen deprivation therapy as prescribed by our Mount Sinai risk stratification and treatment algorithm. Outcomes were analyzed with respect to biochemical failure, distant metastases, prostate cancer-specific survival, and overall survival. Morbidity was assessed with respect to urinary, sexual, and rectal outcomes.

RESULTS

In total, 2,495 patients met inclusion criteria. The 12-year actuarial freedom from biochemical failure was 83% (low risk: 90%, intermediate risk: 84%, and high risk: 64%); freedom from distant metastasis was 95%; prostate cancer-specific survival was 95%; and overall survival was 70%. On multivariate analysis, significant associations were found between cancer control and risk group, total biologically effective dose, and androgen deprivation therapy. With regard to morbidity, potency was preserved in 61%, and urinary symptoms improved in 35%. The 12-year actuarial freedom from urinary retention events was 90% and from severe rectal bleed was 93%.

CONCLUSIONS

Brachytherapy, as administered via the Mount Sinai algorithm, remains an efficacious and benign treatment option for patients with localized prostate cancer of all risk groups.

Focal brachytherapy for selected low-risk prostate cancers: a pilot study

PURPOSE

To evaluate the feasibility and the early toxicity of focal brachytherapy in highly selected localized prostate cancer patients.

METHODS AND MATERIALS

Twenty-one patients underwent a focal brachytherapy between February 2010 and March 2012, representing 3.7% of the cases treated by our group during this period. Patient selection was based on (at least) two series of prostate biopsies and a high-resolution MRI. Only patients with very limited and localized tumors, according to strict criteria, were selected for the procedure. The technique used a real-time procedure with the implantation of free (125)I seeds and dynamic dose calculation. The prescribed dose for the focal volume was 145Gy.

RESULTS

The treated volume corresponded to a mean value of 34% of the total prostatic volume (range, 20-48%). For the focal volume, the mean D90 and V100 was 183.2Gy (range, 176-188Gy) and 99.3% (range, 98.8-100%), respectively. The technique was performed in an hour and a half. When compared with a previous cohort treated by whole-prostate brachytherapy, urinary toxicity (International Prostate Symptom Score) was borderline reduced (p = 0.04) at 6 months only, whereas the recovery of the International Index of Erectile Function 5 was better (p = 0.014). The International Continence Score was nil in almost all cases as well as rectal toxicity.

CONCLUSION

Focal treatment by brachytherapy is easily feasible with little acute toxicity. Further investigation is needed to assess the results in terms of tumor control and long-term toxicity.

Stereotactic body radiation therapy for prostate cancer: is the technology ready to be the standard of care?

Prostate cancer is the second most prevalent solid tumor diagnosed in men in the United States and Western Europe. Stereotactic body radiation therapy (SBRT) is touted as a superior type of external beam radiation therapy (EBRT) for the treatment of various tumors. SBRT developed from the theory that high doses of radiation from brachytherapy implant seeds could be recapitulated from advanced technology of radiation treatment planning and delivery. Moreover, SBRT has been theorized to be advantageous compared to other RT techniques because it has a treatment course shorter than that of conventionally fractionated EBRT (a single session, five days per week, for about two weeks vs. eight weeks), is non-invasive, is more effective at killing tumor cells, and is less likely to cause damage to normal tissue. In areas of the US and Europe where there is limited access to RT centers, SBRT is frequently being used to treat prostate cancer, even though long-term data about its efficacy and safety are not well established. We review the impetus behind SBRT and the current clinical evidence supporting its use for prostate cancer, thus providing oncologists and primary care physicians with an understanding of the continually evolving field of prostate radiation therapy. Studies of SBRT provide encouraging results of biochemical control and late toxicity. However, they are limited by a number of factors, including short follow-up, exclusion of intermediate- and high-risk patients, and relatively small number of patients treated. Currently, SBRT regimens should only be used in the context of clinical trials.

Endorectal magnetic resonance imaging for predicting pathologic T3 disease in Gleason score 7 prostate cancer: implications for prostate brachytherapy

PURPOSE

To determine the ability of endorectal magnetic resonance imaging (erMRI) and other pretreatment factors to predict the presence and extent of extraprostatic extension (EPE) in men with Gleason score (GS) 7 prostate cancer.

METHODS AND MATERIALS

We included patients with clinical stage T1c-T2c, GS=7 (3+4 or 4+3), and prostate-specific antigen (PSA) <10ng/mL who underwent pre-prostatectomy erMRI. We compared pathologic EPE findings with pretreatment factors.

RESULTS

One hundred seventy-one men were eligible for inclusion. Pretreatment characteristics were: median age=60 years (42-76); median PSA 4.9ng/mL (0.4-9.9); GS 3+4=61%; T1c=51%; T2a=25%; T2b=21%; T2c=3%; ≥50% positive cores=46%; EPE-positive (EPE+) erMRI=28%. Thirty-three percent had pathologic EPE. Increasing T-stage (p<0.0001) and EPE+ erMRI (p<0.0001) were significant predictors of pathologic EPE, whereas GS (4+3 vs. 3+4) (p=0.14), percentage of positive core biopsies (p=0.15), and pretreatment PSA (p=0.41) were not. Median EPE distance was 1.75mm (range, <1-15mm). The rates of EPE >5mm and EPE >3mm were 11% and 15%, respectively. The odds ratios for erMRI detection of any EPE and of EPE >5mm were 3.06 and 3.75, respectively.

CONCLUSIONS

T-stage and EPE+ erMRI predict pathologic EPE in men with GS 7 prostate cancer. The ability of erMRI to detect EPE increases with increasing EPE distance. These findings may be useful in patient selection for prostate brachytherapy monotherapy.

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.

Update on prostate brachytherapy: long-term outcomes and treatment-related morbidity

Current research in prostate brachytherapy focuses on five key concepts covered in this review. Transrectal ultrasound-guided prostate brachytherapy assisted by intraoperative treatment planning is the most advanced form of image-guided radiation delivery. Prostate brachytherapy alone for low-risk prostate cancer achieves lower prostate-specific antigen (PSA) nadirs than intensity-modulated radiotherapy (IMRT) or protons while maintaining durable biochemical control in about 90% of patients without late failures seen in surgically treated patients. As an organ-conserving treatment option, seed implant results in a lower rate of erectile dysfunction and urinary incontinence than surgery that has been validated in several recent prospective studies. Combined IMRT and seed implant has emerged as a rational and highly effective approach to radiation-dose escalation for intermediate- and high-risk prostate cancer. Preliminary results suggest that seed implantation may play a role in improving outcomes for historically poor-prognosis locally advanced and recurrent prostate cancers.

A review of low-dose-rate prostate brachytherapy--techniques and outcomes

Prostate cancer is the most common male cancer in the United States and the second leading cause of male cancer death. The main therapeutic modalities for the treatment of prostate cancer are surgery, external beam radiation therapy, hormonal therapy, and brachytherapy. In recent years, brachytherapy has been increasingly utilized for the treatment of early-stage prostate cancer. Technological advances, including improvements in imaging, planning, and postimplant quality assessment by dosimetry have led to widespread use of brachytherapy. Outcomes for prostate brachytherapy have been shown to be equivalent, in selected patients, to those of other treatment modalities for prostate cancer, including radical prostatectomy and external beam radiation therapy. Further, prostate brachytherapy has quality-of-life benefits in comparison to these other treatment modalities, particularly in the domain of sexual function. This paper describes the history of low-dose rate brachytherapy; current techniques for brachytherapy implantation and postoperative dosimetric evaluation; recent outcomes studies; recent quality-of-life analyses; and current and future prostate brachytherapy developments, including open clinical trials. As research in prostate brachytherapy continues, it is likely that this modality will play an increasingly important role in the treatment of early-stage prostate cancer patients in the future.