Introduction: Prostate-specific antigen (PSA) bounce after brachytherapy has been well-documented. This phenomenon has also been identified in patients undergoing stereotactic body radiation therapy (SBRT). While the parameters that predict PSA bounce have been extensively studied in prostate brachytherapy patients, this study is the first to analyze the clinical and pathologic predictors of PSA bounce in prostate SBRT patients.
Materials and Methods: Our institution has maintained a prospective database of patients undergoing SBRT for prostate cancer since 2006. Our study population includes patients between May 2006 and November 2011 who have at least 18 months of follow-up. All patients were treated using the CyberKnife treatment system. The prescription dose was 35–36.25 Gy in five fractions.
Results: One hundred twenty patients were included in our study. Median PSA follow-up was 24 months (range 18–78 months). Thirty-four (28%) patients had a PSA bounce. The median time to PSA bounce was 9 months, and the median bounce size was 0.50 ng/mL. On univariate analysis, only younger age (p = 0.011) was shown to be associated with an increased incidence of PSA bounce. Other patient factors, including race, prostate size, prior treatment by hormones, and family history of prostate cancer, did not predict PSA bounces. None of the tumor characteristics studied, including Gleason score, pre-treatment PSA, T-stage, or risk classification by NCCN guidelines, were associated with increased incidence of PSA bounces. Younger age was the only statistically significant predictor of PSA bounce on multivariate analysis (OR = 0.937, p = 0.009).
Conclusion: PSA bounce, which has been reported after prostate brachytherapy, is also seen in a significant percentage of patients after CyberKnife SBRT. Close observation rather than biopsy can be considered for these patients. Younger age was the only factor that predicted PSA bounce.
PSA; SBRT; SAbR; prostate cancer; CyberKnife
To report early observation of transient PSA elevations on this pilot study of external beam radiation therapy and magnetic resonance imaging (MRI) guided high dose rate (HDR) brachytherapy boost.
Materials and methods
Eleven patients with intermediate-risk and high-risk localized prostate cancer received MRI guided HDR brachytherapy (10.5 Gy each fraction) before and after a course of external beam radiotherapy (46 Gy). Two patients continued on hormones during follow-up and were censored for this analysis. Four patients discontinued hormone therapy after RT. Five patients did not receive hormones. PSA bounce is defined as a rise in PSA values with a subsequent fall below the nadir value or to below 20% of the maximum PSA level. Six previously published definitions of biochemical failure to distinguish true failure from were tested: definition 1, rise >0.2 ng/mL; definition 2, rise >0.4 ng/mL; definition 3, rise >35% of previous value; definition 4, ASTRO defined guidelines, definition 5 nadir + 2 ng/ml, and definition 6, nadir + 3 ng/ml.
Median follow-up was 24 months (range 18–36 mo). During follow-up, the incidence of transient PSA elevation was: 55% for definition 1, 44% for definition 2, 55% for definition 3, 33% for definition 4, 11% for definition 5, and 11% for definition 6.
We observed a substantial incidence of transient elevations in PSA following combined external beam radiation and HDR brachytherapy for prostate cancer. Such elevations seem to be self-limited and should not trigger initiation of salvage therapies. No definition of failure was completely predictive.
To determine the incidence and magnitude of the rapid increase in the serum PSA (riPSA) level after high-intensity focused ultrasound (HIFU) therapy for prostate cancer, and its correlation with clinical factors.
A total of 176 patients with localized prostate cancer underwent HIFU therapy. Serum riPSA was determined on the basis of the same criteria as those for “PSA bounce”, ie, an increase of ≥0.2 ng/ml with a spontaneous return to the prebounce level or lower. Patients were stratified according to neoadjuvant PSA level, T stage, risk group, age, Gleason score, pretreatment PSA level, post-treatment PSA nadir, and number of HIFU sessions.
riPSA was seen in 53% of patients during a median follow-up period of 43 months. A PSA nadir was achieved within 3 months for 85.1% of the treatments. In all cases, onset of riPSA was seen two days after HIFU therapy, and the median magnitude was 23.69 ng/ml. A magnitude of >2 ng/ml was seen in 89.4% of cases. Univariate analysis revealed that patients with riPSA were associated with usage of hormonal therapy and the post-treatment PSA nadir level. Multivariate Cox regression analysis revealed that riPSA and the number of HIFU sessions were predictors of biochemical recurrence. A significant statistical association was found between the presence of riPSA and the risk of biochemical failure only in the low- and intermediate-risk group.
Patients treated with HIFU who experience post-treatment riPSA may have an increased risk of biochemical recurrence, especially in non-high-risk patients.
HIFU; prostate cancer; PSA
To explore patterns of time to failure in men receiving high doses of permanent seed brachytherapy with or without external beam radiation therapy as a function of risk status.
Material and methods
Two thousand two hundred and thirty four patients were treated with prostate brachytherapy with median follow up of 8.0 years. The population was 35% low risk, 49% intermediate risk, and 16% high risk (NCCN). Median day 0 implant D90 was 119% and V100 was 98%. Treatment failure was defined as PSA > 0.40 ng/mL after nadir. Rates of biochemical failure, distant metastases, and prostate cancer death were determined with non-prostate death as a competing risk.
For all patients, the 10-year biochemical failure, distant metastases, and cause-specific mortality were 4.4%, 1.4%, and 1.3%, respectively. The biochemical failure rates were 1.3%, 4.8%, and 10.0% for men with low, intermediate, and high risk disease, respectively. Median time to failure was 2.8 years. In men who died from prostate cancer, the median time from treatment failure to death was 4.2 years. Overall, 83% of biochemical failures and 97% of metastases occurred within the first 4 years after treatment.
With the dose escalation achieved by high quality brachytherapy dosimetry, even high-risk prostate cancer patients have excellent long term biochemical outcomes. Treatment failures occur early, and one third become metastatic and progress rapidly to prostate cancer death. The low frequency and pattern of failures suggest the presence of micrometastatic disease prior to treatment is rare, even in high risk patients.
biochemical survival; brachytherapy dose escalation; cause specific survival; metastases free survival; prostate cancer
Controversy exists whether the prostate-specific antigen (PSA) bounce phenomenon following definitive radiation for prostate cancer has prognostic significance. Here, we perform a meta-analysis to determine the association between PSA bounce and biochemical control after brachytherapy alone.
Material and methods
We reviewed Medline, EMBASE, and CENTRAL citations through February 2012. Studies that recorded biochemical failure rates in bouncers and non-bouncers were included. Hazard ratios describing the impact of bounce on biochemical failure were extracted directly from the studies or calculated from survival curves. Pooled estimates were obtained using the inverse variance method. A random effects model was used in cases of significant effect heterogeneity (p < 0.10 using Q test).
The final analysis included 3011 patients over 6 studies treated with brachytherapy. Meta-analysis revealed that patients experiencing PSA bounce after brachytherapy, conferred a decreased risk of biochemical failure (random effects model HR = 0.42, 95% CI: 0.30-0.59; p < 0.001).
Our meta-analysis determined that PSA bounce predicts for improved biochemical control following brachytherapy. To our knowledge, this is the first study describing this effect.
brachytherapy; prostate cancer; PSA bounce
To clarify the significant clinicopathological and postdosimetric parameters to predict PSA bounce in patients who underwent low-dose-rate brachytherapy (LDR-brachytherapy) for prostate cancer.
We studied 200 consecutive patients who received LDR-brachytherapy between July 2004 and November 2008. Of them, 137 patients did not receive neoadjuvant or adjuvant androgen deprivation therapy. One hundred and forty-two patients were treated with LDR-brachytherapy alone, and 58 were treated with LDR-brachytherapy in combination with external beam radiation therapy. The cut-off value of PSA bounce was 0.1 ng/mL. The incidence, time, height, and duration of PSA bounce were investigated. Clinicopathological and postdosimetric parameters were evaluated to elucidate independent factors to predict PSA bounce in hormone-naïve patients who underwent LDR-brachytherapy alone.
Fifty patients (25%) showed PSA bounce and 10 patients (5%) showed PSA failure. The median time, height, and duration of PSA bounce were 17 months, 0.29 ng/mL, and 7.0 months, respectively. In 103 hormone-naïve patients treated with LDR-brachytherapy alone, and univariate Cox proportional regression hazard model indicated that age and minimal percentage of the dose received by 30% and 90% of the urethra were independent predictors of PSA bounce. With a multivariate Cox proportional regression hazard model, minimal percentage of the dose received by 90% of the urethra was the most significant parameter of PSA bounce.
Minimal percentage of the dose received by 90% of the urethra was the most significant predictor of PSA bounce in hormone-naïve patients treated with LDR-brachytherapy alone.
Prostate cancer; Brachytherapy; PSA bounce; Post-dosimetry; UD90 (%)
To evaluate the outcomes of patients presenting with cancer at the base of the prostate after brachytherapy as monotherapy.
Material and methods
We retrospectively reviewed the medical records of all patients who had undergone transperineal ultrasound-guided implantation with 125I or 103Pd seeds as monotherapy between March 1998 and December 2006, at our institution. A minimum follow-up interval of 2 years was required for inclusion in our analysis. Dosimetry was assessed using computed tomography 30 days after the implant. Treatment failure was defined as the appearance of biopsy-proved tumor after seed implantation, radiographic evidence of metastases, receipt of salvage therapy, or elevation of the prostate-specific antigen level beyond the nadir value plus 2 ng/mL.
With a median follow-up interval of 89 months (range 25–128 months), all 52 of the identified patients had no evidence of disease progression or biochemical failure. The mean number of cores sampled at the prostate base was 2.84 (median 2); Gleason scores assigned at central review were 6-8 in all patients. Of the 30 patients (58%) for whom dosimetric data were available at day 30, the median V100 values of the right and left base were 92.0% and 93.5%, respectively, and the median D90 values of the right and left base were 148 Gy and 151 Gy, respectively.
Permanent prostate brachytherapy as monotherapy results in a high probability of disease-free survival for men with cancer at the base of the prostate.
prostate cancer; monotherapy; sector analysis
The nadir prostate-specific antigen (PSA) at 1 year (nPSA12) was investigated as an early estimate of biochemical and clinical outcome after radiotherapy (RT) alone for localized prostate cancer.
From May 1989 to November 1999, 1000 men received 3D conformal RT alone (median, 76 Gy) with minimum and median follow-up periods of 26 and 58 months, respectively, from the end of treatment. The calculation of PSA doubling time (PSADT) was possible in 657 patients. Multivariate analyses (MVAs) via Cox proportional hazards regression were used to determine the association of nPSA12 to biochemical failure (BF; ASTRO definition), distant metastasis (DM), cause-specific mortality (CSM), and overall mortality (OM). Dichotomization of nPSA12 was optimized by evaluating the sequential model likelihood ratio and P-values.
In MVA, nPSA12 as a continuous variable was independent of RT dose, T-stage, Gleason score, pretreatment initial PSA, age, and PSADT in predicting for BF, DM, CSM, and OM. Dichotomized nPSA12 (≤2 versus >2 ng/mL) was independently related to DM and CSM. Kaplan-Meier 10-year DM rates for nPSA12 ≤2 versus >2 ng/mL were 4% versus 19% (P < .0001).
nPSA12 is a strong independent predictor of outcome after RTalone for prostate cancer and should be useful in identifying patients at high risk for progression to metastasis and death.
prostate cancer; prostate-specific antigen nadir; 3D conformal radiotherapy; distant metastasis; cause-specific mortality
The purpose of this study was to evaluate the relationship between the kinetics of PSA decline after androgen deprivation therapy (ADT) initiation and overall survival (OS) in men with metastatic hormone-sensitive prostate cancer (HSPC).
We identified a cohort of metastatic HSPC patients treated with androgen deprivation therapy (ADT) using our institutional database. Patients were included if they had at least 2 serum PSA determinations before nadir PSA and at least one serum PSA value available within 1 month of ADT initiation. Patient characteristics, PSA at ADT initiation, nadir PSA, time to PSA nadir (TTN) and PSA decline (PSAD) in relation to OS were analyzed.
179 patients were identified, with a median follow-up after ADT initiation of 4.0 years. Median OS after ADT initiation was 7.0 years. Median PSA at ADT initiation and PSA nadir were 47 and 0.28 ng/mL, respectively. On univariate analysis: TTN <6 months, a PSAD >52 ng/mL/year, PSA nadir ≥ 0.2 ng/mL, a PSA≥47.2 ng/mL at ADT initiation and Gleason score >7, were associated with a shorter OS. On multivariate analysis, TTN<6 months, Gleason score >7 and a PSA nadir ≥ 0.2 ng/mL independently predicted a shorter OS.
To our knowledge, this is the first report to show that a faster time to reach a PSA nadir post-ADT initiation is associated with shorter survival duration in men with metastatic HSPC. These results need confirmation, but may indicate that a rapid initial response to ADT indicates more aggressive disease.
Prostate cancer; androgen deprivation therapy; hormone-sensitive metastatic prostate cancer; PSA kinetics; Time to PSA nadir
To examine the rates of long-term biochemical recurrence-free survival (BRFS) with respect to isotope in intermediate-risk prostate cancer treated with external beam radiotherapy (EBRT) and brachytherapy.
A total of 242 consecutive patients with intermediate-risk prostate cancer were treated with iodine-125 (125I) or palladium-103 (103Pd) implants after EBRT (range 45.0–50.4 Gy) from 1996 to 2002. Of the 242 patients, 119 (49.2%) were treated with 125I and 123 (50.8%) with 103Pd. Multivariate Cox regression analysis was used to analyze BRFS, defined according to the Phoenix definition (prostate-specific antigen nadir plus 2 ng/mL) with respect to Gleason score, stage, pretreatment prostate-specific antigen level, and source selection. Late genitourinary/gastrointestinal toxicities were assessed using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale.
At a median follow-up of 10 years, the BRFS rate was 77.3%. A statistically significant difference was found in the 10-year BRFS rate between the 125I- and 103Pd-treated groups (82.7% and 70.6%, respectively; P = .001). The addition of hormonal therapy did not improve the 10-year BRFS rate (77.6%) compared with RT alone (77.1%; P = .22). However, a statistically significant difference in the BRFS rate was found with the addition of hormonal therapy to 103Pd, improving the 10-year BRFS rate for (73.8%) compared with 103Pd alone (69.1%; P = .008). On multivariate analysis, isotope type (103Pd vs 125I), pretreatment prostate-specific antigen level > 10 ng/mL, and greater tumor stage increased the risk of recurrence by 2.6-fold (P = .007), 5.9-fold (P < .0001), and 1.7-fold (P = .14), respectively.
125I renders a superior rate of BRFS compared with 103Pd when used with EBRT. Hormonal therapy does not provide additional benefit in patients with intermediate-risk prostate cancer treated with a combination of EBRT and brachytherapy, except for the addition of hormonal therapy to 103Pd.
To report the toxicity and long-term outcomes of dose-escalated intensity-modulated radiation therapy (IMRT) for patients with localised prostate cancer.
Methods and Materials
From 2001 to 2005, a total of 125 patients with histologically confirmed T1-3N0M0 prostate cancer were treated with IMRT to 74Gy at the Austin Health Radiation Oncology Centre. The median follow-up was 5.5 years (range 0.5–8.9 years). Biochemical prostate specific antigen (bPSA) failure was defined according to the Phoenix consensus definition (absolute nadir + 2ng/mL). Toxicity was scored according to the RTOG/EORTC criteria. Kaplan-Meier analysis was used to calculate toxicity rates, as well as the risks of bPSA failure, distant metastases, disease-specific and overall survival, at 5 and 8-years post treatment.
All patients completed radiotherapy without any treatment breaks. The 8-year risks of ≥ Grade 2 genitourinary (GU) and gastrointestinal (GI) toxicity were 6.4% and 5.8% respectively, and the 8-year risks of ≥ Grade 3 GU and GI toxicity were both < 0.05%. The 5 and 8-year freedom from bPSA failure were 76% and 58% respectively. Disease-specific survival at 5 and 8 years were 95% and 91%, respectively, and overall survival at 5 and 8 years were 90% and 71%, respectively.
These results confirm existing international data regarding the safety and efficacy of dose-escalated intensity-modulated radiation therapy for localised prostate cancer within an Australian setting.
dose escalation; IMRT; late effects; prostate cancer; toxicity; radiation
The purpose of the study is to evaluate the long-term clinical outcome through biochemical no evidence of disease (bNED) rates among men with low to intermediate risk prostate cancer treated with two different brachytherapy implant techniques: preoperative planning (PP) and real-time planning (IoP).
From June 1998 to July 2011, 1176 men with median age of 67 years and median follow-up of 47 months underwent transperineal ultrasound-guided prostate 125I-brachytherapy using either PP (132) or IoP (1044) for clinical T1c-T2b prostate adenocarcinoma Gleason <8 and prostate-specific antigen (PSA) <20 ng/ml. Men with Gleason 7 received combination of brachytherapy, external beam radiation and 6-month androgen deprivation therapy (ADT). Biological effective dose (BED) was calculated using computerized tomography (CT)-based dosimetry 1-month postimplant. Failure was determined according to the Phoenix definition.
The 5- and 7-year actuarial bNED rate was 95% and 90% respectively. The 7-year actuarial bNED was 67% for the PP group and 95% for the IoP group (P < 0.001). Multivariate Cox regression analyses identified implant technique or BED, ADT and PSA as independent prognostic factors for biochemical failure.
Following our previous published results addressing the limited and disappointing outcomes of PP method when compared to IoP based on CT dosimetry and PSA kinetics, we now confirm the long-term clinical, bNED rates clear cut superiority of IoP implant methodology.
Prostate cancer; Brachytherapy; Implant technique; Biochemical failure
To quantify the impact of radiotherapy (RT) dose escalation on the timing of biochemical failure (BF) and distant metastasis (DM) for prostate cancer treated with RT alone.
Methods and Materials
A total of 667 men with clinically localized intermediate and high risk prostate cancer treated with 3D-conformal RT alone were retrospectively analyzed. The interval hazard rates of DM and biochemical failure (BF), using ASTRO and Phoenix (Nadir+2) definitions, were determined. Median follow-up was 77 months.
Multivariate analysis showed that increasing RT dose was independently associated with decreased ASTRO BF (P<.0001), Nadir+2 BF (P=.001), and DM (P=.006). The preponderance (85%) of ASTRO BF occurred at ≤4 years after RT, while Nadir+2 BF was more evenly spread over years 1-10, with 55% BF in ≤4 years. RT dose escalation caused a shift in the BF from earlier to later years. The interval hazard function for DM appeared to be biphasic (early and late peaks) overall and for the <74 Gy group. In patients receiving ≥74 Gy, there was a reduction in the risk of DM in both the early and late waves, although the late wave appears reduced to a greater degree.
The ASTRO definition of BF systematically underestimates late BF due to backdating. RT dose escalation diminished and delayed BF; the delay suggests that there may still be local persistence in some patients. For DM, higher RT dose reduced both the early and late waves, suggesting that persistence of local disease contributes to both.
Prostate cancer; Radiotherapy dose; Hazard function; Biochemical failure; Distant metastasis
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.
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).
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.
prostatic neoplasms; brachytherapy; magnetic resonance imaging
To assess the biochemical recurrence (BCR)-free rate in patients who underwent prostate low-dose-rate brachytherapy (LDR-brachytherapy), using two different definitions (Phoenix definition and PSA ≥ 0.2 ng/mL).
Two hundreds and three patients who were clinically diagnosed with localized prostate cancer (cT1c-2cN0M0) and underwent LDR-brachytherapy between July 2004 and September 2008 were enrolled. The median follow-up period was 72 months. We evaluated the BCR-free rate using the Phoenix definition and the PSA cut-off value of 0.2 ng/mL, as in the definition for radical prostatectomy. To evaluate an independent variable that can predict BCR, Cox’s proportional hazard regression analysis was carried out.
The BCR-free rate in patients using the Phoenix definition was acceptable (5-year: 92.8%). The 5- year BCR-free rate using the strict definition (PSA ≥ 0.2 ng/mL) was 74.1%. Cox’s proportional hazard regression analysis showed that a higher biological effective dose (BED) of ≥180 Gy2 was the only independent variable that could predict BCR (HR: 0.570, 95% C.I.: 0.327-0.994, p = 0.048). Patients with a higher BED (≥180 Gy2) had a significantly higher BCR-free rate than those with a lower BED (<180 Gy2) (5-year BCR-free rate: 80.5% vs. 67.4%).
A higher BED ≥180 Gy2 promises a favorable BCR-free rate, even if the strict definition is adopted.
Prostate cancer; LDR-brachytherapy; Biochemical recurrence-free rate; BED
This retrospective review compares prostate-specific antigen (PSA) doubling time (DT) prior to the initiation of a 5-alpha-reductase inhibitor (pre-5-ARI) to after the PSA nadir (post-nadir) has been reached for patients on active surveillance for favourable-risk prostate cancer.
Between 1996 and 2010, a total of 100 men with a history of 5-ARI use were captured from our active surveillance database. Twenty-nine patients had a sufficient number of PSA values to determine both pre-5-ARI and post-nadir DTs. PSADT was calculated using the general linear mixed-model method.
The median follow-up was 69.5 months. The median pre-5-ARI PSADT was 55.8 (range: 6–556.8) months, while the post-nadir value was 25.2 (range: 6–231) months (p = 0.0081). Six patients were reclassified after an average of 67.7 (range: 59–95) months, due to progression in PSADT (n = 2) or Gleason score (n = 4). The median pre-5-ARI and post-nadir DTs for this group were 42.3 (range: 32.4–91.1) and 21.1 (range: 6–44.3) months, respectively.
5-ARIs significantly decreased PSADT compared to prior to their initiation. This effect may be due to preferential suppression of benign tissue following PSA nadir. The resulting PSADT would then represent a more accurate depiction of the true cancer-related DT. If validated with a larger cohort, 5-ARIs may enhance the utility of PSADT as a biomarker of disease progression in active surveillance.
We describe five patients receiving a re-implantation (RI) after post-operative dosimetry of the primary 125-I permanent prostate brachytherapy (BT) for prostate cancer revealed an insufficient dose coverage.
Materials and methods
Five out of 222 consecutive patients treated (from March, 2001 to August, 2012) with 125-I BT, received a RI after dosimetric verification by CT and MRI fusion four to eight weeks after implantation displayed an insufficient dose coverage. RIs were performed with 10 to 19 seeds, three to four months after primary intervention. Dosimetry after RI showed an improved and sufficient total dose coverage in all patients.
At last follow-up (18 to 99 months, median 57 months), none of the patients had relevant implant associated side-effects. Functional outcome was comparable to patients after one-time implantation. PSA levels post intervention showed a decreasing tendency in 4 patients. One patient had a local recurrence after 12 months.
In our series, approximately 2% of the patients treated with permanent prostate BT required a RI due to insufficient dose coverage. None of the patients who underwent RI experienced complications. Our series, although only with 5 cases and limited follow-up, along with other published reports, demonstrates good tolerability.
Prostate cancer; Brachytherapy; Re-implantation; Salvage; LDR; Seeds
To evaluate prognostic factors in salvage radiotherapy (RT) for patients with pre-RT prostate-specific antigen (PSA) < 1.0 ng/ml.
Between January 2000 and December 2009, 102 patients underwent salvage RT for biochemical failure after radical prostatectomy (RP). Re-failure of PSA after salvage RT was defined as a serum PSA value of 0.2 ng/ml or more above the postradiotherapy nadir followed by another higher value, a continued rise in serum PSA despite salvage RT, or initiation of systemic therapy after completion of salvage RT. Biochemical relapse-free survival (bRFS) was estimated using the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression model.
The median follow-up period was 44 months (range, 11-103 months). Forty-three patients experienced PSA re-failure after salvage RT. The 4-year bRFS was 50.9% (95% confidence interval [95% CI]: 39.4-62.5%). In the log-rank test, pT3-4 (p < 0.001) and preoperative PSA (p = 0.037) were selected as significant factors. In multivariate analysis, only pT3-4 was a prognostic factor (hazard ratio: 3.512 [95% CI: 1.535-8.037], p = 0.001). The 4-year bRFS rates for pT1-2 and pT3-4 were 79.2% (95% CI: 66.0-92.3%) and 31.7% (95% CI: 17.0-46.4%), respectively.
In patients who have received salvage RT after RP with PSA < 1.0 ng/ml, pT stage and preoperative PSA were prognostic factors of bRFS. In particular, pT3-4 had a high risk for biochemical recurrence after salvage RT.
Prostate cancer; Radiotherapy; Radical Prostatectomy; PSA; Pathological tumor stage
To report the clinical outcome of high dose rate brachytherapy as sole treatment for clinically localised prostate cancer.
Between March 2004 and January 2008, a total of 351 consecutive patients with clinically localised prostate cancer were treated with transrectal ultrasound guided high dose rate brachytherapy. The prescribed dose was 38.0 Gy in four fractions (two implants of two fractions each of 9.5 Gy with an interval of 14 days between the implants) delivered to an intraoperative transrectal ultrasound real-time defined planning treatment volume. Biochemical failure was defined according to the Phoenix Consensus and toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3.
The median follow-up time was 59.3 months. The 36 and 60 month biochemical control and metastasis-free survival rates were respectively 98%, 94% and 99%, 98%. Toxicity was scored per event with 4.8% acute Grade 3 genitourinary and no acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were respectively 3.4% and 1.4%. No instances of Grade 4 or greater acute or late adverse events were reported.
Our results confirm high dose rate brachytherapy as safe and effective monotherapy for clinically organ-confined prostate cancer.
Prostate cancer; Brachytherapy; High dose rate; Iridium; Monotherapy
To evaluate the efficacy of hypofractionated radiotherapy (HyRT) with or without image guided radiotherapy (IGRT) in intermediate risk prostate cancer.
105 patients were treated with HyRT, 43,8 Gy and 54,75 Gy were delivered to the seminal vescicles and to the prostate, respectively; 3,65 Gy/fraction three times weekly. All patients underwent 9 months hormonal therapy. Patient position was verified with daily kV cone beam CT in 69 patients (IGRT group). Acute and late toxicities were evaluated according to RTOG scale. Biochemical relapse was defined using PSA nadir + 2 ng/mL. The data were prospectively collected and retrospectively analyzed to evaluate the efficacy of IGRT.
After a median follow-up of 31 months the actuarial 3-year bNED was 93,7%. During RT, 10.5% and 7.6% of patients developed ≥Grade 2 rectal and urinary toxicities, respectively. The cumulative incidence of ≥Grade 2 late rectal and urinary toxicities at 3 years were 6,9%, and 10,8%, respectively. The incidence of ≥Grade 2 late rectal toxicities was significant reduced in the IGRT group (1,6% vs. 14,5%, p=0,021). Two patients developed Grade 3 urethral obstruction and one patient developed grade 3 rectal bleeding.
HyRT represents a well-tolerated treatment able to achieve a high bNED. The use of daily IGRT is beneficial for reducing the incidence of late toxicities.
Intermediate-risk prostate cancer; Hypofractionated radiotherapy; IGRT; 3D-CRT
Prostate cancer is the most common tumor in men. The most commonly used diagnostic and tumor recurrence marker is Prostate Specific Antigen (PSA). After surgical removal or radiation treatment, PSA levels drop (PSA nadir) and subsequent elevated or increased PSA levels are indicative of recurrent disease (PSA recurrence). For clinical follow-up and local care PSA nadir and recurrence is often hand calculated for patients, which can result in the application of heterogeneous criteria. For large datasets of prostate cancer patients used in clinical studies PSA measurements are used as surrogate measures of disease progression. In these datasets a method to measure PSA recurrence is needed for the subsequent analysis of outcomes data and as such need to be applied in a uniform and reproducible manner. This method needs to be simple and reproducible, and based on known aspects of PSA biology.
We have created a simple Perl-based algorithm for the calculation of post-treatment PSA outcomes results based on the initial PSA and multiple PSA values obtained after treatment. The algorithm tracks the post-surgical PSA nadir and if present, subsequent PSA recurrence. Times to PSA recurrence or recurrence free intervals are supplied in months.
Use of the algorithm is demonstrated with a sample dataset from prostate cancer patients. The results are compared with hand-annotated PSA recurrence analysis. The strengths and limitations are discussed.
The use of this simple PSA algorithm allows for the standardized analysis of PSA recurrence in large datasets of patients who have undergone treatment for prostate cancer. The script is freely available, and easily modifiable for desired user parameters and improvements.
Obesity is associated with an increased risk of biochemical recurrence (BCR) after radical prostatectomy (RP). It is unclear whether this is due to technical challenges related to operating on obese men or other biologic factors.
To examine whether obesity predicts higher prostate-specific antigen (PSA) nadir (as a measure of residual PSA-producing tissue) after RP and if this accounts for the greater BCR risk in obese men.
Design, setting, and participants
A retrospective analysis of 1038 RP patients from 2001 to 2010 in the multicenter US Veterans Administration–based Shared Equal Access Regional Cancer Hospital database with median follow-up of 41 mo.
All patients underwent RP.
Outcome measurements and statistical analysis
We evaluated the relationship between body mass index (BMI) and ultrasensitive PSA nadir within 6 mo after RP. Adjusted proportional hazards models were used to examine the association between BMI and BCR with and without PSA nadir.
Results and limitations
Mean BMI was 28.5 kg/m2. Higher BMI was associated with higher PSA nadir on both univariable (p = 0.001) and multivariable analyses (p < 0.001). Increased BMI was associated with increased BCR risk (hazard ratio [HR]: 1.06; p = 0.007). Adjusting for PSA nadir slightly attenuated, but did not eliminate, this association (HR: 1.04, p = 0.043). When stratified by PSA nadir, obesity only significantly predicted BCR in men with an undetectable nadir (p = 0.006). Unfortunately, other clinically relevant end points such as metastasis or mortality were not available.
Obese men are more likely to have a higher PSA nadir, suggesting that either more advanced disease or technical issues confound an ideal operation. However, even after adjusting for the increased PSA nadir, obesity remained predictive of BCR, suggesting that tumors in obese men are growing faster. This provides further support for the idea that obesity is biologically associated with prostate cancer progression.
Prostate cancer; PSA nadir; obesity; radical prostatectomy; biochemical recurrence
To report the outcomes of patients treated with combined iodine-125 (I-125) brachytherapy and external beam radiotherapy (EBRT) for high-risk prostate cancer.
Between 2003 and 2009, I-125 permanent prostate brachytherapy plus EBRT was performed for 206 patients with high-risk prostate cancer. High-risk patients had prostate-specific antigen ≥ 20 ng/mL, and/or Gleason score ≥ 8, and/or Stage ≥ T3. One hundred and one patients (49.0%) received neoadjuvant androgen deprivation therapy (ADT) but none were given adjuvant ADT. Biochemical failure-free survival (BFFS) was determined using the Phoenix definition.
The 5-year actuarial BFFS rate was 84.8%. The 5-year cause-specific survival and overall survival rates were 98.7% and 97.6%, respectively. There were 8 deaths (3.9%), of which 2 were due to prostate cancer. On multivariate analysis, positive biopsy core rates and the number of high-risk factors were independent predictors of BFFS. The 5-year BFFS rates for patients in the positive biopsy core rate <50% and ≥50% groups were 89.3% and 78.2%, respectively (p = 0.03). The 5-year BFFS rate for patients with the any single high-risk factor was 86.1%, compared with 73.6% for those with any 2 or all 3 high-risk factors (p = 0.03). Neoadjuvant ADT did not impact the 5-year BFFS.
At a median follow-up of 60 months, high-risk prostate cancer patients undergoing combined I-125 brachytherapy and EBRT without adjuvant ADT have a high probability of achieving 5-year BFFS.
Prostate cancer; Brachytherapy; High risk; Androgen deprivation therapy
To evaluate the influence of prostate-specific antigen (PSA) kinetics following maximal androgen blockade (MAB) on disease progression and cancer-specific survival in patients with metastatic, hormone-sensitive prostate cancer.
Materials and Methods
One hundred thirty-one patients with metastatic, hormone-sensitive prostate cancer treated with MAB at our institution were included in this study. Patients' characteristics, PSA at MAB initiation, PSA nadir, time to PSA nadir (TTN), and PSA decline were analyzed by using univariate and multivariate analysis.
At a median follow-up of 30 months, 97 patients (74.0%) showed disease progression and 65 patients (49.6%) died. Fifty-nine patients (45.0%) died from prostate cancer. In the univariate analysis, PSA at MAB initiation, PSA nadir, TTN, and PSA decline were significant predictors of progression-free survival. Also, PSA nadir, TTN, and PSA decline were significant predictors of cancer-specific survival. In the multivariate analysis, higher PSA nadir (≥0.2 ng/ml) and shorter TTN (<8 months) were independent predictors of shorter progression-free and cancer-specific survival. In the combined analysis of PSA nadir and TTN, patients with higher PSA nadir and shorter TTN had the worst progression-free survival (hazard ratio [HR], 14.098; p<0.001) and cancer-specific survival (HR, 14.050; p<0.001) compared with those with lower PSA nadir and longer TTN.
Our results suggest that higher PSA nadir level and shorter TTN following MAB are associated with higher risk of disease progression and poorer survival in patients with metastatic, hormone-sensitive prostate cancer. Furthermore, these two variables have a synergistic effect on the outcome.
Prognosis; Prostate-specific antigen; Prostatic neoplasms
To investigate the role of low dose rate (LDR) brachytherapy-based multimodal therapy in high-risk prostate cancer (PCa) and analyze its optimal indications.
Materials and Methods
We reviewed the records of 50 high-risk PCa patients [clinical stage ≥T2c, prostate-specific antigen (PSA) >20 ng/mL, or biopsy Gleason score ≥8] who had undergone 125I LDR brachytherapy since April 2007. We excluded those with a follow-up period <3 years. Biochemical recurrence (BCR) followed the Phoenix definition. BCR-free survival rates were compared between the patients with Gleason score ≥9 and Gleason score ≤8.
The mean initial PSA was 22.1 ng/mL, and mean D90 was 244.3 Gy. During a median follow-up of 39.2 months, biochemical control was obtained in 72% (36/50) of the total patients; The estimated 3-year BCR-free survival was 92% for the patients with biopsy Gleason scores ≤8, and 40% for those with Gleason scores ≥9 (p<0.001). In Cox multivariate analysis, only Gleason score ≥9 was observed to be significantly associated with BCR (p=0.021). Acute and late grade ≥3 toxicities were observed in 20% (10/50) and 36% (18/50) patients, respectively.
Our results showed that 125I LDR brachytherapy-based multimodal therapy in high-risk PCa produced encouraging relatively long-term results among the Asian population, especially in patients with Gleason score ≤8. Despite small number of subjects, biopsy Gleason score ≥9 was a significant predictor of BCR among high risk PCa patients after brachytherapy.
Prostate cancer; brachytherapy; high risk group; biochemical recurrence