Improved freedom from PSA failure with whole pelvic irradiation for high-risk prostate cancer

High-dose-rate brachytherapy combined with long-term hormonal therapy for high-risk prostate cancer: Results of a retrospective analysis

PURPOSE

High-dose-rate (HDR) brachytherapy combined with hormonal therapy (HTx), without the addition of external beam radiation therapy (EBRT) for high-risk prostate cancer was evaluated retrospectively.

MATERIALS AND METHODS

Between May 1995 and April 2002, 35 patients with prostate cancer [Stage > or = T2b (UICC 1997) or tumor grading=3 or prostate-specific antigen (PSA) level > or = 20 ng/mL] were treated with HDR brachytherapy combined with HTx. Most patients (74%) had two or more of these factors. All patients received Iridium-192 HDR brachytherapy with a total dose of 54 Gy/9 fractions/5 days (48 Gy/8 fractions/5 days for the first 6 cases) in one implant session. The median neoadjuvant HTx [luteinizing hormone-releasing hormone (LH-RH) agonist and antiandrogen] period was 7 months. The median adjuvant HTx (ATH) (LH-RH agonist) period was 40 months, and median follow-up was 57 months (range, 23-117 months).

RESULTS

The 5-year actuarial biochemical control, local control, and disease-free rates were 62%, 96%, and 76% respectively. No patients experienced local and/or regional relapse without distant progression. The 5-year actuarial cause-specific survival and overall survival rates were 89% and 87%, respectively. The acute and late toxicity were moderate and well tolerated.

CONCLUSION

HDR brachytherapy plus long-term HTx is at least as effective as conventional EBRT plus long-term HTx.

Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

PURPOSE

Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard "four-field box." We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer.

METHODS AND MATERIALS

Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy.

RESULTS

Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort.

CONCLUSIONS

Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities.

Risk-Adapted Androgen Deprivation and Escalated Three-Dimensional Conformal Radiotherapy for Prostate Cancer: Does Radiation Dose Influence Outcome of Patients Treated With Adjuvant Androgen Deprivation? A GICOR Study

Purpose

Multicenter study conducted to determine the impact on biochemical control and survival of risk-adapted androgen deprivation (AD) combined with high-dose three-dimensional conformal radiotherapy (3DCRT) for prostate cancer. Results of biochemical control are reported.

Patients and Methods

Between October 1999 and October 2001, 416 eligible patients with prostate cancer were assigned to one of three treatment groups according to their risk factors: 181 low-risk patients were treated with 3DCRT alone; 75 intermediate-risk patients were allocated to receive neoadjuvant AD (NAD) 4-6 months before and during 3DCRT; and 160 high-risk patients received NAD and adjuvant AD (AAD) 2 years after 3DCRT. Stratification was performed for treatment/risk group and total radiation dose.

Results

After a median follow-up of 36 months (range, 18 to 63 months), the actuarial biochemical disease-free survival (bDFS) at 5 years for all patients was 74%. The corresponding figures for low-risk, intermediate-risk, and high-risk disease were 80%, 73%, and 79%, respectively (P = .847). Univariate analysis showed that higher radiation dose was the only significant factor associated with bDFS for all patients (P = .0004). When stratified for treatment group, this benefit was evident for low-risk patients (P = .009) and, more interestingly, for high-risk patients treated with AAD. The 5-year bDFS for high-risk patients treated with AAD was 63% for radiation doses less than 72 Gy and 84% for those ≥ 72 Gy (P = .003).

Conclusion

The results of combined AAD plus high-dose 3DCRT are encouraging. To our knowledge, this is the first study showing an additional benefit of high-dose 3DCRT when combined with long-term AD for unfavorable disease.

Intensity modulated radiotherapy for high risk prostate cancer based on sentinel node SPECT imaging for target volume definition

Background

The RTOG 94-13 trial has provided evidence that patients with high risk prostate cancer benefit from an additional radiotherapy to the pelvic nodes combined with concomitant hormonal ablation. Since lymphatic drainage of the prostate is highly variable, the optimal target volume definition for the pelvic lymph nodes is problematic. To overcome this limitation, we tested the feasibility of an intensity modulated radiation therapy (IMRT) protocol, taking under consideration the individual pelvic sentinel node drainage pattern by SPECT functional imaging.

Methods

Patients with high risk prostate cancer were included. Sentinel nodes (SN) were localised 1.5–3 hours after injection of 250 MBq ^99mTc-Nanocoll using a double-headed gamma camera with an integrated X-Ray device. All sentinel node localisations were included into the pelvic clinical target volume (CTV). Dose prescriptions were 50.4 Gy (5 × 1.8 Gy / week) to the pelvis and 70.0 Gy (5 × 2.0 Gy / week) to the prostate including the base of seminal vesicles or whole seminal vesicles. Patients were treated with IMRT. Furthermore a theoretical comparison between IMRT and a three-dimensional conformal technique was performed.

Results

Since 08/2003 6 patients were treated with this protocol. All patients had detectable sentinel lymph nodes (total 29). 4 of 6 patients showed sentinel node localisations (total 10), that would not have been treated adequately with CT-based planning ('geographical miss') only. The most common localisation for a probable geographical miss was the perirectal area. The comparison between dose-volume-histograms of IMRT- and conventional CT-planning demonstrated clear superiority of IMRT when all sentinel lymph nodes were included. IMRT allowed a significantly better sparing of normal tissue and reduced volumes of small bowel, large bowel and rectum irradiated with critical doses. No gastrointestinal or genitourinary acute toxicity Grade 3 or 4 (RTOG) occurred.

Conclusion

IMRT based on sentinel lymph node identification is feasible and reduces the probability of a geographical miss. Furthermore, IMRT allows a pronounced sparing of normal tissue irradiation. Thus, the chosen approach will help to increase the curative potential of radiotherapy in high risk prostate cancer patients.

Role of prostate dose escalation in patients with greater than 15% risk of pelvic lymph node involvement

PURPOSE

To determine whether the radiation dose is a determinant of clinical outcome in patients with a lymph node risk of >15% treated using whole pelvic (WP), partial pelvic (PP), or prostate only (PO) fields.

METHODS AND MATERIALS

A total of 420 patients with prostate cancer treated with three-dimensional conformal radiotherapy with or without short-term androgen deprivation (STAD) between June 1989 and July 2000 were included in this study. Patients had an initial pretreatment prostate-specific antigen level of <100 ng/mL and a lymph node index of > or =15% or T2c tumors with a Gleason score of 6-10. No patient had radiologic evidence of lymph node involvement. Of the 460 patients, 48 were treated with PO, 74 with PP, and 298 with WP fields. The median prostate dose was 74 Gy for PO, 82 Gy for PP, and 76 Gy for WP. The median radiation dose to the pelvis was 46 Gy for both PP and WP. Of the 460 patients, 72 underwent STAD for a median of 3 months (range, 3-6 months). Cox regression multivariate analysis was used to identify independent predictors of freedom from biochemical failure (FFBF) defined according to the American Society for Therapeutic Radiology Oncology consensus guidelines. Univariate comparisons were done using the Kaplan-Meier method and the log-rank test.

RESULTS

At a median follow-up of 43 months, 121 patients had treatment failure: 22, 7, and 92 in the PO, PP, and WP arms, respectively. Independent predictors of FFBF in multivariate analysis included radiation dose, T stage, Gleason score, and initial prostate-specific antigen level. The 5-year FFBF rate by dose group was 48% for <73 Gy, 64% for 73-76.9 Gy, and 74% for > or =77 Gy (p = 0.002). The use of STAD and radiation field size were not significantly associated with FFBF.

CONCLUSION

The radiation dose was the most significant determinant of FFBF in patients with a lymph node risk >15% in the patient population studied. These data suggest that the primary tumor takes precedence over lymph node coverage or the use of STAD. Doses >70 Gy are of paramount importance in such intermediate- and high-risk patients.

Clinical results of combined treatment conformal high-dose-rate iridium-192 brachytherapy and external beam radiotherapy using staging lymphadenectomy for localized prostate cancer

PURPOSE

To report the first long-term biochemical control rate of patients treated with two protocols using a combination of external beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy for localized prostate cancer in Japan.

METHODS AND MATERIALS

Between October 1997 and July 2001, 71 patients with localized prostatic adenocarcinoma were treated with a combination of EBRT and HDR brachytherapy. Patient age ranged from 58 to 81 years (mean 70.5). Of the 71 patients, 12, 41, and 18 had Stage T1c, T2, and T3, respectively, according to the International Union Against Cancer classification system (1997). The mean initial prostate-specific antigen (PSA) level was 24.2 ng/mL (median, 11.9 ng/mL); 30% of the patients had an initial PSA level >20 ng/mL. Of the 71 patients, 31 had received neoadjuvant hormonal therapy. Hormonal therapy before treatment was stopped at the beginning of RT in all cases. Patients in this series were treated on two protocols. In the initial protocol, patients were treated with whole pelvis EBRT to 45.0 Gy in 25 fractions and three HDR fractions of 5.5 Gy each (35 patients). In the second protocol, patients were treated with prostatic EBRT to 41.8 Gy in 19 fractions, with an added staging lymphadenectomy to rule out lymph node metastasis for patients with high-risk factors, and four HDR fractions of 5.5 Gy each (36 patients). The American Society for Therapeutic Radiology and Oncology consensus definition for biochemical failure was used. Acute and chronic toxicities were scored using the Radiation Therapy Oncology Group guidelines. Follow-up ranged from 24 to 65 months (median, 44 months).

RESULTS

Of the 71 patients, 69 were alive at the last follow-up. Two patients had died of hepatocellular carcinoma and gastric cancer at 3.5 and 4.0 years after treatment with no biochemical failure. Sixty-six patients (93%), including the two who had died of intercurrent disease, showed a tendency for a PSA decline after treatment and had no biochemical or clinical evidence of disease at the last follow-up visit. Sixty patients (85%) achieved PSA nadir levels of < or =1.0 ng/mL. The biochemical/clinical failure-free control rate at 3 and at 5 years was 93% and 93%, respectively. The bladder and rectal complications were minimal.

CONCLUSION

Despite the high frequency of high-risk patients in the present patient population, the actuarial biochemical control rate was 93% at 5 years. Acute and chronic toxicity with this method was acceptable. Additional long-term follow-up is required to assess this treatment, because the median survival is not likely to be reached for several years.

Time to metabolic atrophy after permanent prostate seed implantation based on magnetic resonance spectroscopic imaging

PURPOSE

To characterize the time to metabolic atrophy (TMA) after permanent prostate implantation (PPI) using combined MRI and magnetic resonance spectroscopic imaging (MRSI) compared with the time to prostate-specific antigen (PSA) nadir.

METHODS AND MATERIALS

This study was based on a posttreatment analysis comparing the MRI/MRSI findings with the PSA levels of 65 patients treated with PPI alone or combined with external beam radiotherapy and/or HT. The fraction of interpretable voxels demonstrating metabolic atrophy was used to compare the TMA with the time to PSA nadir.

RESULTS

The fraction of patients with metabolic atrophy in >95% of usable voxels after PPI increased from approximately 46% to 100% at 6 and 48 months, respectively. The mean time for PSA nadir vs. TMA was 42.5 vs. 28.9 months (PPI), 32.8 vs. 25.6 months (external beam radiotherapy + PPI), and 25.3 vs. 28.0 months (external beam radiotherapy + hormonal therapy + PPI).

CONCLUSION

Magnetic resonance spectroscopic imaging may provide an early tool for evaluating the treatment response for patients treated with PPI. If supported by longer follow-up, TMA may be a useful adjunct to PSA measurement for assessing local control after PPI and could be useful in evaluating the complex relationships between the quality of the implant and the time to indication of successful therapy.

Radiation therapy for increasing prostate-specific antigen levels after radical prostatectomy

Herein we present data on outcomes in patients with increasing prostate-specific antigen (PSA) levels treated with irradiation to the pelvis and/or prostatic bed after radical prostatectomy. Between 1988 and 1998, 92 patients who presented with increasing PSA levels after radical prostatectomy were treated with irradiation, 29 to the pelvis and prostatic bed and 63 to the prostatic bed only. The mean follow-up was 4 years for the 3D-CRT group and 6.5 years for the standard radiation therapy group. Criterion for biochemical failure was an increase in post irradiation PSA level on > or = 1 consecutive measurement. Patients were classified into 3 risk groups based on prognostic factors: pathologic tumor extent and stage, Gleason score, and PSA levels before irradiation. Acute and late morbidity was quantitatively evaluated in all patients. There was a close correlation between the preirradiation PSA level and the probability of 4-year biochemical failure-free survival (75% with PSA levels < or = 1 ng/mL, 30% with PSA levels of 1.1-2 ng/mL, and 20% with PSA levels > 2 ng/mL; P = 0.05). The 4-year chemical failure rate was 20% in the low/intermediate-risk group and 65% in the high-risk group (P = 0.36). In 20 patients in the low-PSA group (< or =1 ng/mL) receiving doses > 62 Gy, no biochemical failures have been detected in comparison to a 70% failure rate at 4 years in patients treated with lower doses (P = 0.15). In the higher-PSA groups, no impact of irradiation dose on outcome was noted (40%-60% incidence of failure at 3 years). Pelvic irradiation was associated with a trend toward decreased biochemical failure rate in the low-PSA group (70% vs. 0% at 4 years; P = 0.35), but not in the high-PSA group. Only 1 patient (1.5%) experienced clinical local recurrence in the prostatic bed and 2 patients (1.8%) had distant metastases. Treatment has been very well tolerated, with only 3 patients in the arc-rotation group experiencing grade 2 treatment toxicity. Prostate bed irradiation is an effective treatment in a significant proportion of patients who present with a biochemical failure after radical prostatectomy.

Phase III trial comparing whole-pelvic versus prostate-only radiotherapy and neoadjuvant versus adjuvant combined androgen suppression: Radiation Therapy Oncology Group 9413

PURPOSE

This trial tested the hypothesis that combined androgen suppression (CAS) and whole-pelvic (WP) radiotherapy (RT) followed by a boost to the prostate improves progression-free survival (PFS) by 10% compared with CAS and prostate-only (PO) RT. This trial also tested the hypothesis that neoadjuvant and concurrent hormonal therapy (NCHT) improves PFS compared with adjuvant hormonal therapy (AHT) by 10%.

MATERIALS AND METHODS

Eligibility included localized prostate cancer with an elevated prostate-specific antigen (PSA) < or = 100 ng/mL and an estimated risk of lymph node (LN) involvement of 15%. Between April 1, 1995, and June 1, 1999, 1,323 patients were accrued. Patients were randomly assigned to WP + NCHT, PO + NCHT, WP + AHT, or PO + AHT. Failure for PFS was defined as the first occurrence of local, regional, or distant disease; PSA failure; or death for any cause.

RESULTS

With a median follow-up of 59.5 months, WP RT was associated with a 4-year PFS of 54% compared with 47% in patients treated with PO RT (P =.022). Patients treated with NCHT experienced a 4-year PFS of 52% versus 49% for AHT (P =.56). When comparing all four arms, there was a progression-free difference among WP RT + NCHT, PO RT + NCHT, WP RT + AHT, and PO RT + AHT (60% v 44% v 49% v 50%, respectively; P =.008). No survival advantage has yet been seen.

CONCLUSION

WP RT + NCHT improves PFS compared with PO RT and NCHT or PO RT and AHT, and compared with WP RT + AHT in patients with a risk of LN involvement of 15%.

Prostate cancer radiation dose response: results of the M. D. Anderson phase III randomized trial

PURPOSE

A randomized radiotherapy dose escalation trial was undertaken between 1993 and 1998 to compare the efficacy of 70 vs. 78 Gy in controlling prostate cancer.

METHODS AND MATERIALS

A total of 305 Stage T1-T3 patients were entered into the trial and, of these, 301 with a median follow-up of 60 months, were assessable. Of the 301 patients, 150 were in the 70 Gy arm and 151 were in the 78 Gy arm. The primary end point was freedom from failure (FFF), including biochemical failure, which was defined as 3 rises in the prostate-specific antigen (PSA) level. Kaplan-Meier survival analyses were calculated from the completion of radiotherapy. The log-rank test was used to compare the groups. Cox proportional hazard regression analysis was used to examine the independence of study randomization in multivariate analysis.

RESULTS

There was an even distribution of patients by randomization arm and stage, Gleason score, and pretreatment PSA level. The FFF rates for the 70- and 78 Gy arms at 6 years were 64% and 70%, respectively (p = 0.03). Dose escalation to 78 Gy preferentially benefited those with a pretreatment PSA >10 ng/mL; the FFF rate was 62% for the 78 Gy arm vs. 43% for those who received 70 Gy (p = 0.01). For patients with a pretreatment PSA <or=10 ng/mL, no significant dose response was found, with an average 6-year FFF rate of about 75%. Although no difference occurred in overall survival, the freedom from distant metastasis rate was higher for those with PSA levels >10 ng/mL who were treated to 78 Gy (98% vs. 88% at 6 years, p = 0.056). Rectal side effects were also significantly greater in the 78 Gy group. Grade 2 or higher toxicity rates at 6 years were 12% and 26% for the 70 Gy and 78 Gy arms, respectively (p = 0.001). Grade 2 or higher bladder complications were similar at 10%. For patients in the 78 Gy arm, Grade 2 or higher rectal toxicity correlated highly with the proportion of the rectum treated to >70 Gy.

CONCLUSION

An increase of 8 Gy resulted in a highly significant improvement in FFF for patients at intermediate-to-high risk, although the rectal reactions were also increased. Dose escalation techniques that limit the rectal volume that receives >or=70 Gy to <25% should be used.

Influence of 3D-CRT pelvic irradiation on outcome in prostate cancer treated with external beam radiotherapy

PURPOSE

The role of pelvic irradiation (PRT) in the treatment of prostate cancer remains unclear. We reviewed our institution's experience with three-dimensional conformal external beam radiotherapy (3D-CRT) during the prostate-specific antigen era to determine the influence of PRT on the risk of biochemical recurrence in patients who have a predicted risk of lymph node involvement.

METHODS AND MATERIALS

Between March 1985 and January 2001, 1832 patients with clinically localized prostate cancer were treated with definitive 3D-CRT. All treatments involved CT planning to ensure coverage of the intended targets. Treatment consisted of prostate-only treatment, prostate and seminal vesicle treatment, or PRT of lymph nodes at risk followed by a boost. To create relatively homogenous analysis groups, each patient's percentage of risk of lymph node (%rLN) involvement was assigned by matching the patient's T stage, Gleason score, and initial prostate-specific antigen level to the appropriate value as described in the updated Partin tables. Three categories of %rLN involvement were defined: low, 0-5%; intermediate, >5-15%; and high, >15%. Biochemical recurrence was defined as the first occurrence of either the American Society for Therapeutic Radiology and Oncology consensus definition of prostate-specific antigen failure or the initiation of salvage hormonal therapy for any reason.

RESULTS

The risk status (%rLN) could be determined for 709 low-risk, 263 intermediate-risk, and 309 high-risk patients. The actuarial freedom from biochemical recurrence (bNED) and the log-rank test for the similarity of the control and treatment survival functions are reported for each risk group. Multivariate analysis demonstrated a statistically significant benefit for the entire population treated with PRT, with a relative risk reduction of 0.72 (95% confidence interval 0.54-0.97). Although the multivariate analysis could not determine the patient population that would most benefit from PRT, the beneficial effect appeared to be most pronounced within the intermediate-risk group. Univariate analysis revealed that the intermediate-risk patients treated with PRT had an improved 2-year bNED rate, 90.1% vs. 80.6% (p = 0.02), and both low-risk and high-risk patients treated with PRT had statistically similar 2-year bNED rates compared with those who did not receive it.

CONCLUSION

Pelvic 3D-CRT appears to improve bNED in prostate cancer patients. Additional studies are needed to elucidate the %rLN population for which this treatment should be recommended.

Radiation therapy for the treatment of locally advanced and metastatic prostate cancer

Radiation therapy for locally advanced PCa continues to evolve. A current treatment recommendation for nonmetastatic, high-risk disease includes AS combined with RT. The precise duration and sequencing of AS has not been established but most frequently includes treatment in the neoadjuvant, concomitant and, occasionally, adjuvant periods. As technology allows higher doses without significant increases in morbidity and as clinical data provide proof of a radiation dose response, RT doses continue to escalate. The goal of therapy for metastatic disease continues to focus on the relief of pain and the improvement in quality of life. Multiple studies document the significant role RT plays in achieving these goals. Focal RT and systemic radioisotopes have become the mainstay of management in this patient group and the development of newer isotopes that cause less marrow toxicity will improve the therapeutic ratio and provide an opportunity for their use with systemic chemotherapy. As molecular and genomic technologies advance, directed targeting of critical cellular radiation-response pathways hold the promise of improved radiation response and individualized, tailored therapy.

Toxicity following high-dose three-dimensional conformal and intensity-modulated radiation therapy for clinically localized prostate cancer

OBJECTIVES

To report the toxicity profile of patients treated with three-dimensional conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) receiving doses of 82 Gy or more to portions of their prostate.

METHODS

Forty-four patients treated with radiation therapy for prostate cancer between June 1992 and August 1998 at the University of California, San Francisco received a maximal dose within the target volume (Dmax) of 82 Gy or more. Eighteen patients were boosted selectively to a limited portion of their prostate using IMRT, whereas 26 patients were treated with 3D-CRT and had unselected "hot spots" within their prostate. The Radiation Therapy Oncology Group (RTOG) acute and late toxicity scales were used to score gastrointestinal (GI) and genitourinary (GU) morbidity.

RESULTS

Median follow-up and Dmax were 23.1 months (range 10.0 to 84.7) and 84.5 Gy (range 82.0 to 96.7), respectively. Of the patients, 59.1% and 34.1% developed some level of acute GU and GI toxicity, respectively. One patient experienced grade 3 acute GI toxicity. No other grade 3 or greater acute toxicity was observed. The 2-year actuarial rates for freedom from late GI and GU morbidity were 77.1% (95% confidence interval [CI] 60.4% to 87.5%) and 79.5% (95% CI 62.7% to 89.3%), respectively. Although no grade 3 or greater late GU morbidity has been observed to date, 3 patients experienced grade 3 late GI morbidity. However, these cases involved rectal bleeding and were effectively managed with laser coagulation/fulguration.

CONCLUSIONS

Doses of 82 Gy or more to a portion of the prostate gland can be tolerated with acceptable morbidity. This observation supports the continued investigation of IMRT as a means for improving disease control in prostate cancer.

Matched-pair analysis of conformal high-dose-rate brachytherapy boost versus external-beam radiation therapy alone for locally advanced prostate cancer

PURPOSE

We performed a matched-pair analysis to compare our institution's experience in treating locally advanced prostate cancer with external-beam radiation therapy (EBRT) alone to EBRT in combination with conformal interstitial high-dose-rate (HDR) brachytherapy boosts (EBRT + HDR).

MATERIALS AND METHODS

From 1991 to 1998, 161 patients with locally advanced prostate cancer were prospectively treated with EBRT + HDR at William Beaumont Hospital, Royal Oak, Michigan. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen (PSA) level of >/= 10.0 ng/mL, Gleason score >/= 7, or clinical stage T2b to T3c. Pelvic EBRT (46.0 Gy) was supplemented with three (1991 through 1995) or two (1995 through 1998) ultrasound-guided transperineal interstitial iridium-192 HDR implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Each of the 161 EBRT + HDR patients was randomly matched with a unique EBRT-alone patient. Patients were matched according to PSA level, Gleason score, T stage, and follow-up duration. The median PSA follow-up was 2.5 years for both EBRT + HDR and EBRT alone.

RESULTS

EBRT + HDR patients demonstrated significantly lower PSA nadir levels (median, 0.4 ng/mL) compared with those receiving EBRT alone (median, 1.1 ng/mL). The 5-year biochemical control rates for EBRT + HDR versus EBRT-alone patients were 67% versus 44%, respectively (P <.001). On multivariate analyses, pretreatment PSA, Gleason score, T stage, and the use of EBRT alone were significantly associated with biochemical failure. Those patients in both treatment groups who experienced biochemical failure had a lower 5-year cause-specific survival rate than patients who were biochemically controlled (84% v 100%; P <.001).

CONCLUSION

Locally advanced prostate cancer patients treated with EBRT + HDR demonstrate improved biochemical control compared with those who are treated with conventional doses of EBRT alone.