Selecting Patients for Exclusive Permanent Implant Prostate Brachytherapy: The Experience of the Paris Institut Curie/Cochin Hospital/Necker Hospital Group on 809 Patients

ACR-ABS-ASTRO Practice Parameter for Transperineal Permanent Brachytherapy of Prostate Cancer

AIM/OBJECTIVES/BACKGROUND

The American College of Radiology (ACR), American Brachytherapy Society (ABS), and American Society for Radiation Oncology (ASTRO) have jointly developed the following practice parameter for transperineal permanent brachytherapy of prostate cancer. Transperineal permanent brachytherapy of prostate cancer is the interstitial implantation of low-dose rate radioactive seeds into the prostate gland for the purpose of treating localized prostate cancer.

METHODS

This practice parameter was developed according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Radiation Oncology of the Commission on Radiation Oncology, in collaboration with ABS and ASTRO.

RESULTS

This practice parameter provides a framework for the appropriate use of low-dose rate brachytherapy in the treatment of prostate cancer either as monotherapy or as part of a treatment regimen combined with external-beam radiation therapy. The practice parameter defines the qualifications and responsibilities of all involved radiation oncology personnel, including the radiation oncologist, medical physicist, dosimetrist, radiation therapist, and nursing staff. Patient selection criteria and the utilization of supplemental therapies such as external-beam radiation therapy and androgen deprivation therapy are discussed. The logistics of the implant procedure, postimplant dosimetry assessment, and best practices with regard to safety and quality control are presented.

CONCLUSIONS

Adherence to established standards can help to ensure that permanent prostate brachytherapy is delivered in a safe and efficacious manner.

Comparison of EBRT and I-125 seed brachytherapy concerning outcome in intermediate-risk prostate cancer

PURPOSE

This study's objective was the comparison of external beam radiotherapy (EBRT) and I‑125 seed brachytherapy regarding clinical outcome and development of side effects.

PATIENTS AND METHODS

In all, 462 localized intermediate-risk prostate cancer patients treated between 2000 and 2019 at our department using either I‑125 seed brachytherapy or EBRT with a dose of 74 or 78 Gy were included: 297 patients were treated with EBRT and 165 with seeds. Biochemical no evidence of disease (bNED) rates according to Phoenix definition as well as late gastrointestinal and urogenital side effects (EORTC/RTOG) were assessed.

RESULTS

Patients were followed up yearly with a median follow-up of 54 (3-192) months. Observed bNED rates for 74 Gy, 78 Gy and seeds were 87, 92, and 88% after 5 years and 71, 85, and 76% after 9 years, respectively. No significant differences were found comparing seeds with 74 Gy (p = 0.81) and 78 Gy (p = 0.19), as well as between 74 and 78 Gy (p = 0.32). Concerning gastrointestinal side effects, EBRT showed significantly higher rates of RTOG grade ≥ 2 toxicity compared to seeds, but at no point of the follow-up more than 10% of all patients. However, genitourinary side effects were significantly more prevalent in patients treated with seeds, with 33% RTOG grade ≥ 2 toxicity 12 months after treatment. Nevertheless, both types of side effects decreased over time.

CONCLUSION

Favorable intermediate-risk prostate cancer patients can be treated either by external beam radiotherapy (74/78 Gy) or permanent interstitial seed brachytherapy.

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.

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.

Five-year effectiveness of low-dose-rate brachytherapy: comparisons with nomogram predictions in patients with non-metastatic prostate cancer presenting significant control of intra- and periprostatic disease

PURPOSE

To assess the effectiveness of low-dose-rate (LDR) brachytherapy in patients with localized prostate cancer and to compare the outcome with predictions from Kattan and Partin nomograms at 60 months after seed implantation.

MATERIAL AND METHODS

One thousand, one hundred and eighty-seven patients with localized prostate cancer at low-, intermediate-, or high-risk of progression received LDR brachytherapy using iodine-125 seeds with curative intent, applied as monotherapy or in combination with external beam radiation therapy (EBRT), and/or androgen deprivation therapy (ADT). At 60 months after seed implantation, data of 1,064 patients (1,058 alive + 6 who died of prostate cancer) were analyzed for biochemical progression-free survival (bPFS) based on prostate-specific antigen (PSA) levels using the Phoenix definition. Five-year bPFS probabilities were determined for various risk group classifications (d'Amico, Mt. Sinai, MSKCC/Seattle, NCCN). Outcomes were also compared to patient-individualized nomogram predictions of 5-year bPFS (Kattan 2002) and probability of organ-confined disease (Kattan 2002, Partin 2007).

RESULTS

Overall, 93.3% (993/1,064) of the patients were free of biochemical progression within 5 years, while the average 5-year bPFS probability according to the Kattan nomogram was significantly lower (85%, p < 0.001). Outcomes were significantly better than Kattan nomogram predictions in the subgroup of patients with monotherapy as well as in patients additionally treated with EBRT. Comparison of the overall outcome with nomogram predictions for organ-confined disease (Kattan nomogram: 50%; Partin nomogram: 65%) revealed a significant probability of LDR brachytherapy to destroy periprostatic tumor spread (p < 0.001) in all risk group constellations, even in high-risk patients.

CONCLUSIONS

The results indicate high effectiveness of LDR brachytherapy in all risk groups, significantly better than predicted with the Kattan nomogram in most subgroups. The significant superiority of LDR brachytherapy compared to nomogram predictions of organ-confined disease suggests that LDR brachytherapy effectively controls both intra- and periprostatic disease.

[Prostate brachytherapy: New techniques, new indications]

Prostate brachytherapy has been for a long time one of the standard treatments for low risk prostate cancer, with high rates of biochemical control and low levels of urinary and sexual late toxicity compared to other available techniques, namely external beam radiotherapy and radical prostatectomy. The aim of this article is to review the recent innovations of prostate brachytherapy, which suggest a bright future for the technique. We will discuss the extension of indications of permanent implant brachytherapy to favorable intermediate-risk patients, the use of novel isotopes such as Palladium 103 and Cesium 131, and the benefit of brachytherapy as a boost following external beam radiotherapy for intermediate and high-risk patients. We will also discuss the rise of high dose rate brachytherapy, as a boost or monotherapy, the increasing use of MRI for patient selection and treatment planning, as well as the development of brachytherapy as a means of focal therapy.

Brachytherapy for prostate cancer: Present and future

Based on recent, important publications on the impact of brachytherapy in the management of prostate cancer, we analysed already validated indications and the "under investigations" use of brachytherapy. Published studies (MEDLINE), randomized trials and recommendations were reviewed, as well as Delphi consensus when available. While low-dose rate brachytherapy remains a standard of care for low-risk eligible patients, three randomized trials are now available to consider that combination of external beam radiation therapy with brachytherapy boost (low- or high-dose rate) appears as a recommended treatment for intermediate and high-risk patients. Other indications of prostate brachytherapy (monotherapy and salvage) remain under evaluation. For low-risk patients with good urinary status, low-dose rate brachytherapy alone should be offered. For low-intermediate risk prostate cancer, low-dose rate brachytherapy alone may be offered as monotherapy, while for high-intermediate risk prostate cancer, a combination of external beam radiation therapy (with or without androgen deprivation therapy) plus brachytherapy boost (low- or high-dose rate) should be offered to eligible patients. For patients with high-risk prostate cancer receiving external beam radiation therapy and androgen deprivation therapy, brachytherapy boost (low- or high-dose rate) should be offered to eligible patients. High-dose rate brachytherapy as monotherapy (single dose for low-risk/multifractionated for intermediate and high-risk) must be explored under clinical investigations, as well as salvage brachytherapy for local recurrence.

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.

125I brachytherapy in younger prostate cancer patients : Outcomes in low- and intermediate-risk disease

PURPOSE

To evaluate local recurrence in younger men treated with low-dose-rate (LDR) ¹²⁵I brachytherapy (BT) for localized prostate cancer.

PATIENTS AND METHODS

A total of 192 patients (≤65-years-old) were treated with LDR ¹²⁵I-BT ± hormone therapy. Local failure was defined as any prostate-specific antigen (PSA) rise leading to salvage treatment or biochemical failure according to the Phoenix definition. A bounce was defined as a rise in the nadir of ≥0.2 ng/mL followed by spontaneous return. Proportions were compared using Fisher's exact tests; continuous variables using the unpaired t-test or its non-parametric equivalent. Cox proportional hazards models were applied for multivariable survival analysis.

RESULTS

Median follow-up was 66 months. The 5‑year local recurrence-free survival was 96.1%. Biopsy-proven local recurrence developed in 13 patients, 4 had a Phoenix-defined recurrence at the last follow-up. Androgen deprivation therapy was started in 1 patient without proven recurrence. Univariable risk factors for local recurrence were: at least 50% positive biopsies, intermediate risk, treatment with neoadjuvant hormone therapy, low preimplantation volume receiving 100% of the prescribed dose, and no bounce development. Hormone-naïve patients not attaining a PSA value <0.5 ng/mL during follow-up also had a higher risk of local recurrences. Cox regression demonstrated that the variables "at least 50% positive biopsies" and "bounce" significantly impacted local failure (hazard ratio, HR 1.02 and 11.59, respectively). A bounce developed in 70 patients (36%). Younger patients and those treated with a lower activity per volume had a higher chance of developing a bounce in the Cox model (HR 0.99 and 0.04, respectively).

CONCLUSION

For younger men, LDR BT is a valid primary curative treatment option in low-risk and is to consider in intermediate-risk localized prostate cancer.

Second malignancies after permanent implant prostate cancer brachytherapy: A single-institution study of 675 patients treated between 1999 and 2003

PURPOSE

To analyse the rate of secondary malignancies observed in a series of 675 prostate cancer patients who underwent a permanent implant brachytherapy between 1999 and 2003, and to compare the incidence with the expected rate in a matched general French population.

MATERIAL AND METHODS

The cohort included low-risk patients and a selection of "favourable-intermediate" risk patients. All patients were homogeneously treated using an intraoperative dynamic planning prostate brachytherapy technique, with loose 125-iodine seeds and a prescription dose of 145Gy. The mean follow-up was 132 months.

RESULTS

The 10-year overall survival for the entire cohort was 92% (95% confidence interval [CI]: 90-94). The 10-year relapse-free survival rate was 82% (95% CI: 79-85). Overall, 61 second cancers were registered. When comparing with a matched general French population, the standard incidence ratio (SIR) for bladder cancer was 1.02 (95% CI: 0.46-1.93). For colorectal cancer, the SIR was 0.45 (95% CI: 0.19-0.89). For lung cancer, the SIR was 0.38 (95% CI: 0.17-0.76). The SIR for all cancers was 0.61 (95% CI: 0.47-0.79). When excluding secondary colorectal and lung cancers (both with low SIRs in this series), the SIR for all cancers was 1.06 (95% CI: 0.77-1.29).

CONCLUSION

With a mean follow-up of more than 11 years, this series does not detect any excess risk of second cancers associated with permanent implant prostate brachytherapy. However, due to power limitation, a small increase in the risk of secondary malignancies cannot be totally ruled out.

Curative brachytherapy for prostate cancer in African-Caribbean patients: A retrospective analysis of 370 consecutive cases

PURPOSE

Prostate cancer is the most frequent malignancy in African-Caribbean men, a population sharing common genetic traits with African-American (AA) but presenting also genomic and epidemiologic specificities. Despite socioeconomic disparities with French mainland, all patients were treated within the French state-financed equal-access health care system. In this study, we report biochemical outcomes of patients treated by brachytherapy in our department from 2005 to 2014 in an African-Caribbean population.

METHODS AND MATERIALS

Three hundred seventy consecutive patients receiving 125I brachytherapy as a curative treatment for early-stage (localized) disease between 2005 and 2014 were recorded. Selected patients presented with low-risk disease: initial prostate-specific antigen (PSA) <10 ng/mL, clinical stage ≤ T2c, and Gleason score <7. Patients with intermediate risk of recurrence were also included on a case-to-case basis with prostate-specific antigen <15 or Gleason score 7 (3 + 4). Biochemical failure free-survival was defined according to the American Society for Radiation Oncology nadir+2 definition.

RESULTS

The 3-year and 5-year biochemical failure free-survival for the entire cohort were 98.3% and 91.6%, respectively. For patients with low- and intermediate-risk disease, the 5-year BBFS rates were 92.1% and 90.8%, respectively. In univariate and multivariate analyses, only Gleason score (<7 vs. 7; p =  0.030 vs. p < 0.05) was a significant predictor of biochemical failure. The overall rate of late and acute Grade 2 or higher genitourinary toxicity was 12.6% and 10.3%.

CONCLUSIONS

In this large single-center series, brachytherapy achieved excellent rates of medium-term biochemical control in both low and selected intermediate-risk localized prostate cancer in African-Caribbean patients. Brachytherapy seems to be an excellent choice of treatment, with excellent outcomes and limited morbidity for African-Caribbean populations.

Treatment results of brachytherapy vs. external beam radiation therapy for intermediate-risk prostate cancer with 10-year followup

PURPOSE

To compare 10-year treatment outcomes of brachytherapy vs. external beam radiation therapy for patients with intermediate-risk prostate cancer (IRPC).

METHODS AND MATERIALS

Between 2004 and 2007, 93 IRPC patients underwent brachytherapy using iodine-125 to a dose of 145 Gy without supplemental external radiation. A retrospective comparison was performed to a contemporary cohort of 597 patients treated with external beam radiation therapy to a median dose of 75.3 Gy using a propensity score-matched analysis.

RESULTS

Median followup was 7.8 years. With brachytherapy, 51.6% had Gleason score 7 vs. 72.0% for external radiation (p < 0.001). Median initial prostate-specific antigen was 8.3 for brachytherapy vs. 9.4 for external radiation (p = 0.01). Neoadjuvant androgen deprivation therapy was given in 59.5% of external radiation vs. 10.8% of brachytherapy patients (p < 0.001). The 10-year freedom from biochemical failure (FFBF) for brachytherapy was 81.7% vs. 54.5% for external radiation (p = 0.002). Unfavorable intermediate-risk patients experienced borderline significant improved FFBF with brachytherapy (p = 0.08). The 10-year freedom from salvage therapy for brachytherapy was 93.2% vs. 72.2% for external radiation (p = 0.006). There were no significant differences in distant metastases-free survival, prostate cancer-specific survival, or overall survival after adjusting for age. Multivariate analysis with propensity score matching showed that brachytherapy remained an independent predictor for improved FFBF (p = 0.007). Grade 1 and 2 late rectal complication rate was 6.5% for brachytherapy vs. 15.2% for external radiation (p = 0.02).

CONCLUSIONS

Brachytherapy using iodine-125 without supplemental external radiation is a reasonable treatment option for selected IRPC patients.

Patterns of failure after iodine-125 seed implantation for prostate cancer

PURPOSE

To determine the site of relapse when biochemical failure (BF) occurs after iodine-125 seed implantation for prostate cancer.

MATERIALS AND METHODS

From 2001-2009, 500 men underwent implantation in Wellington, New Zealand. Men who sustained BF were placed on relapse guidelines that delayed restaging and intervention until the prostate-specific antigen (PSA) was ⩾20 ng/mL.

RESULTS

Most implants (86%) had a prostate D90 of ⩾90%, and multivariate analysis showed that this parameter was not a variable that affected the risk of BF. Of 21 BFs that occurred, the site of failure was discovered to be local in one case and distant in nine cases. Restaging failed to identify the site of relapse in two cases. In nine cases the trigger for restaging had not been reached.

CONCLUSIONS

If post-implant dosimetry is generally within the optimal range, distant rather than local failure appears to be the main cause of BF. Hormone treatment is therefore the most commonly indicated secondary treatment intervention (STI). Delaying the start of STI prevents the unnecessary treatment of men who undergo PSA 'bounce' and have PSA dynamics initially mimicking those of BF.

Impact of national guidelines on brachytherapy monotherapy practice patterns for prostate cancer

BACKGROUND

In 1999 and 2000, 2 national guidelines recommended brachytherapy monotherapy (BT) primarily for treatment of low-risk prostate cancer but not high-risk prostate cancer. This study examined rates of BT use before and after publication of these guidelines, as compared with 4 other treatment options.

METHODS

From 1990 to 2011, 8128 men with localized prostate cancer (≤ T3cN0M0) were treated definitively within the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry with 1 of 5 primary treatments: BT, external beam radiotherapy (EBRT), EBRT with androgen deprivation therapy, EBRT+BT, or radical prostatectomy. Men were categorized into low-, intermediate-, and high-risk groups based on the guidelines' risk-group definitions. Within each risk group, logistic regression was used to estimate odds ratios (OR) comparing BT with other treatment options between the 1990-1998 and 1999-2011 periods, adjusting for age, disease characteristics, and clinic type.

RESULTS

In total, 1117 men received BT alone for low- (n = 658), intermediate- (n = 244), or high-risk disease (n = 215). BT comprised 6.1% of all treatments in 1990-1998 versus 16.6% in 1999-2011 (P < .01). The odds of BT use remained increased after adjusting for potential confounders (OR = 3.06; P < .001) and was seen among low- (OR = 4.52; P < .001), intermediate- (OR = 2.67; P < .001), and even high-risk groups (OR = 2.11; P < .001).

CONCLUSIONS

National guidelines did not appear to influence practice patterns, as BT monotherapy use increased relative to other treatments from the 1990-1998 to 1999-2011 periods in unfavorable risk groups including men with high-risk prostate cancer.

Biochemical outcomes for patients with intermediate risk prostate cancer treated with I-125 interstitial brachytherapy monotherapy

BACKGROUND AND PURPOSE

Routine use of I-125 interstitial brachytherapy (BT) alone in intermediate risk (IR) prostate cancer is controversial. It is often combined with external beam radiotherapy (EBRT). The biochemical outcome of a large cohort of only IR disease treated with BT monotherapy is reported.

MATERIALS AND METHODS

Between 2003 and 2007, 615 patients with Memorial Sloan-Kettering Cancer Centre (MSKCC) defined IR disease (one risk factor only-T2b, or Gleason score (GS) 7, or raised initial PSA (iPSA) 10.1-20ng/ml) were treated with BT monotherapy. ASTRO (3 consecutive rises) and Phoenix (nadir plus 2) criteria defined biochemical failure. Potential prognostic factors (pre- and post-implant dosimetric indices, GS 3+4 versus 4+3, androgen deprivation therapy (ADT)) were analysed.

RESULTS

Median follow-up was 5.0years. Forty-three patients had stage T2b, 180 had raised iPSA, 392 had GS 7 disease. ADT was received by 108 patients. The 5-year biochemical no evidence of disease (bNED) rates are 87.3% (by ASTRO), 88.6% (by Phoenix). Stratification by risk factor (T2b, GS7, raised iPSA) demonstrated raised iPSA to have poorer outcome only by Phoenix criteria (p=0.0002). Other potential prognostic variables were non-significant.

CONCLUSION

Good rates of biochemical control can be achieved in the medium term with BT monotherapy in IR disease. Raised iPSA correlated with a poorer outcome.

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.

Updated results of magnetic resonance imaging guided partial prostate brachytherapy for favorable risk prostate cancer: implications for focal therapy

PURPOSE

We report updated results of magnetic resonance imaging guided partial prostate brachytherapy and propose a definition of biochemical failure following focal therapy.

MATERIALS AND METHODS

From 1997 to 2007, 318 men with cT1c, prostate specific antigen less than 15 ng/ml, Gleason 3 + 4 or less prostate cancer received magnetic resonance imaging guided brachytherapy in which only the peripheral zone was targeted. To exclude benign prostate specific antigen increases due to prostatic hyperplasia, we investigated the usefulness of defining prostate specific antigen failure as nadir +2 with prostate specific antigen velocity greater than 0.75 ng/ml per year. Cox regression was used to determine the factors associated with prostate specific antigen failure.

RESULTS

Median followup was 5.1 years (maximum 12.1). While 36 patients met the nadir +2 criteria, 16 of 17 biopsy proven local recurrences were among the 26 men who also had a prostate specific antigen velocity greater than 0.75 ng/ml per year (16 of 26 vs 1 of 10, p = 0.008). Using the nadir +2 definition, prostate specific antigen failure-free survival for low risk cases at 5 and 8 years was 95.1% (91.0-97.3) and 80.4% (70.7-87.1), respectively. This rate improved to 95.6% (91.6-97.7) and 90.0% (82.6-94.3) using nadir +2 with prostate specific antigen velocity greater than 0.75 ng/ml per year. For intermediate risk cases survival was 73.0% (55.0-84.8) at 5 years and 66.4% (44.8-81.1) at 8 years (the same values as using nadir +2 with prostate specific antigen velocity greater than 0.75 ng/ml per year).

CONCLUSIONS

Requiring a prostate specific antigen velocity greater than 0.75 ng/ml per year in addition to nadir +2 appears to better predict clinical failure after therapies that target less than the whole gland. Further followup will determine whether magnetic resonance imaging guided brachytherapy targeting the peripheral zone produces comparable cancer control to whole gland treatment in men with low risk disease. However, at this time it does not appear adequate for men with even favorable intermediate risk disease.

Comparison between external beam radiotherapy (70 Gy/74 Gy) and permanent interstitial brachytherapy in 890 intermediate risk prostate cancer patients

PURPOSE

Aim of this analysis was to compare biochemical no evidence of disease (bNED) rates in intermediate-risk prostate-cancer patients treated at two centres of excellence using different approaches: permanent interstitial brachytherapy (BT) and external beam radiotherapy (EBRT).

MATERIALS AND METHODS

A total of 890 intermediate-risk prostate-cancer patients, who were treated from 1998 to 2008, were identified in the two local databases. In Utrecht 601 patients received I-125 BT applying a dose of 144 Gy. In Vienna 289 patients were treated by EBRT, applying a local dose of 70 Gy in 105 patients and 74 Gy in 184 patients. bNED-rates (Phoenix-definition) were assessed.

RESULTS

Median follow-up was 48 months (1-150). 5-Year actuarial bNED-rates were 81% for BT-patients and 75% for EBRT-patients (67% for 70 Gy and 82% for 74 Gy), respectively. In univariate analysis no difference between BT and EBRT could be detected. In multivariate analysis including tumour-stage, GleasonScore, initial PSA, hormonal therapy and treatment-centre (BT vs. EBRT) only T-stage, GleasonScore and PSA were found to be significant. Additional analysis including radiation dose showed the same outcome.

CONCLUSIONS

Intermediate-risk prostate cancer patients treated by permanent interstitial brachytherapy show biochemical tumour-control-rates which are comparable to EBRT of 74 Gy.

Image guided, adaptive, accelerated, high dose brachytherapy as model for advanced small volume radiotherapy

Brachytherapy has consistently provided a very conformal radiation therapy modality. Over the last two decades this has been associated with significant improvements in imaging for brachytherapy applications (prostate, gynecology), resulting in many positive advances in treatment planning, application techniques and clinical outcome. This is emphasized by the increased use of brachytherapy in Europe with gynecology as continuous basis and prostate and breast as more recently growing fields. Image guidance enables exact knowledge of the applicator together with improved visualization of tumor and target volumes as well as of organs at risk providing the basis for very individualized 3D and 4D treatment planning. In this commentary the most important recent developments in prostate, gynecological and breast brachytherapy are reviewed, with a focus on European recent and current research aiming at the definition of areas for important future research. Moreover the positive impact of GEC-ESTRO recommendations and the highlights of brachytherapy physics are discussed what altogether presents a full overview of modern image guided brachytherapy. An overview is finally provided on past and current international brachytherapy publications focusing on "Radiotherapy and Oncology". These data show tremendous increase in almost all research areas over the last three decades strongly influenced recently by translational research in regard to imaging and technology. In order to provide high level clinical evidence for future brachytherapy practice the strong need for comprehensive prospective clinical research addressing brachytherapy issues is high-lighted.

Does the outcome of prostate cancer patients with large prostates differ from small prostate size in permanent seed, low dose-rate brachytherapy?

OBJECTIVE

Brachytherapy has good results in the treatment of early prostate cancer (PC). The procedure is challenging in large prostates, and the optimal prostate volume for brachytherapy was previously defined as ≤40 ml. This study analysed the outcome of PC patients with small (group A) and large (group B) prostate volume in prospective data.

MATERIAL AND METHODS

The material consisted of 535 consecutive patients treated with brachytherapy in Kuopio University Hospital. The mean follow-up time was nearly 6 years. Prostate-specific antigen (PSA) failure was defined as PSA rising ≥2.0 μg/l above nadir. A PSA bounce was defined as a rise in PSA of ≥0.2 μg/l. The causes of death were recorded.

RESULTS

A bounce was recorded more frequently in group A (30%) than in group B (18%) (p = 0.006). A bounce correlated with young age predicted a favourable outcome in both groups. PSA failure rate was similar in both groups: 13% and 12% in groups A and B, respectively. Post-treatment PSA ≤0.5 μg/l was the only independent prognostic factor associated with PSA failure in both groups (p < 0.0001, both groups). PC survival was 98.4% in both groups. Overall survival was 91% and 94% in groups A and B, respectively (p = not significant).

CONCLUSIONS

There were no differences between the PC patients with small and large prostate volumes treated with brachytherapy with respect to PSA failure rate, PC survival or overall survival. All patients, independent of prostate size, are potential candidates for brachytherapy.

Impact of primary Gleason grade on risk stratification for Gleason score 7 prostate cancers

PURPOSE

To evaluate the primary Gleason grade (GG) in Gleason score (GS) 7 prostate cancers for risk of non-organ-confined disease with the goal of optimizing radiotherapy treatment option counseling.

METHODS

One thousand three hundred thirty-three patients with pathologic GS7 were identified in the Duke Prostate Center research database. Clinical factors including age, race, clinical stage, prostate-specific antigen at diagnosis, and pathologic stage were obtained. Data were stratified by prostate-specific antigen and clinical stage at diagnosis into adapted D'Amico risk groups. Univariate and multivariate analyses were performed evaluating for association of primary GG with pathologic outcome.

RESULTS

Nine hundred seventy-nine patients had primary GG3 and 354 had GG4. On univariate analyses, GG4 was associated with an increased risk of non-organ-confined disease. On multivariate analysis, GG4 was independently associated with seminal vesicle invasion (SVI) but not extracapsular extension. Patients with otherwise low-risk disease and primary GG3 had a very low risk of SVI (4%).

CONCLUSIONS

Primary GG4 in GS7 cancers is associated with increased risk of SVI compared with primary GG3. Otherwise low-risk patients with GS 3+4 have a very low risk of SVI and may be candidates for prostate-only radiotherapy modalities.