SIMULTANEOUS IRRADIATION FOR PROSTATE CANCER: INTERMEDIATE RESULTS WITH MODERN TECHNIQUES

Three-Dimensional Conformal External Beam Radiotherapy versus the Combination of External Radiotherapy with High-Dose Rate Brachytherapy in Localized Carcinoma of the Prostate: Comparison of Acute Toxicity

Aims and background

Radiotherapy represents one of the basic therapeutic methods in treatment of localized carcinoma of the prostate. Optimal irradiation dose is the cornerstone of a successful treatment. Along with local control of the disease and overall survival of the patient, possible acute and long-term side effects need to be monitored very closely.

Methods

A non-randomized prospective study comparing the acute genitourinary and gastrointestinal toxicity in patients irradiated for localized carcinoma of the prostate. Fifty-seven patients were treated with three-dimensional conformal external beam radiotherapy alone, and in the second treatment arm a combination of external beam radiotherapy and high-dose rate brachytherapy was employed in 40 patients.

Results

Three-dimensional conformai external beam radiotherapy. Acute G1 genitourinary toxicity was recorded in 35.1% of patients, G2 in 22.8%, and G2-3 in one patient (1.7%). Acute gastrointestinal toxicity was experienced by 54.4% of patients, G1 in 28.1%, G2 in 17.5%, and G3 in 8.8%. Three-dimensional conformal external beam radiotherapy + brachytherapy. Acute G1 genitourinary toxicity was recorded in 37.5% and grade 2 in 15% of the patients. Only G1 acute gastrointestinal toxicity was recorded in 40% of the patients.

Conclusions

Acute G1 genitourinary toxicity was experienced by a similar percentage of patients in both treatment arms. Acute G2 genitourinary toxicity was more frequent in the three-dimensional conformal radiotherapy arm. Higher acute genitourinary toxicity, G3 or G4, was recorded only in one patient per treatment arm. Acute gastrointestinal toxicity was more frequent in the three-dimensional conformal radiotherapy arm. Higher acute gastrointestinal toxicity, G2 and G3, was only observed in the three-dimensional conformal radiotherapy arm. The acute toxicity observed was of a low grade. The combination of external beam radiotherapy with brachytherapy resulted in a lower incidence of gastrointestinal toxicity than external beam radiotherapy alone.

Combination external beam radiation and brachytherapy boost with androgen deprivation for treatment of intermediate-risk prostate cancer: long-term results of CALGB 99809

BACKGROUND

Combined transperineal prostate brachytherapy and external beam radiation therapy (EBRT) is widely used for treatment of prostate cancer. Long-term efficacy and toxicity results of a multicenter phase 2 trial assessing combination of EBRT and transperineal prostate brachytherapy boost with androgen deprivation therapy (ADT) for intermediate-risk prostate cancer are presented.

METHODS

Intermediate-risk patients per Memorial Sloan-Kettering Cancer Center/National Comprehensive Cancer Network criteria received 6 months of ADT, and 45 grays (Gy) EBRT to the prostate and seminal vesicles, followed by transperineal prostate brachytherapy with I125 (100 Gy) or Pd103 (90 Gy). Toxicity was graded using the National Cancer Institute Common Toxicity Criteria version 2 and Radiation Therapy Oncology Group late radiation morbidity scoring systems. Disease-free survival (DFS) was defined as time from enrollment to progression (biochemical, local, distant, or prostate cancer death). In addition to the protocol definition of biochemical failure (3 consecutive prostate-specific antigen rises>1.0 ng/mL after 18 months from treatment start), the 1997 American Society for Therapeutic Radiology and Oncology (ASTRO) consensus and Phoenix definitions were also assessed in defining DFS. The Kaplan-Meier method was used to estimate DFS and overall survival.

RESULTS

Sixty-one of 63 enrolled patients were eligible. Median follow-up was 73 months. Late grade 2 and 3 toxicity, excluding sexual dysfunction, occurred in 20% and 3% of patients. Six-year DFS applying the protocol definition, 1997 ASTRO consensus, and Phoenix definitions was 87.1%, 75.1%, and 84.9%. Six deaths occurred; only 1 was attributed to prostate cancer. Six-year overall survival was 96.1%.

CONCLUSIONS

In a cooperative setting, combination of EBRT and transperineal prostate brachytherapy boost plus ADT resulted in excellent DFS with acceptable late toxicity for patients with intermediate-risk prostate cancer.

Technology Insight: Combined external-beam radiation therapy and brachytherapy in the management of prostate cancer

External-beam radiation therapy (EBRT) combined with brachytherapy is an attractive treatment option for selected patients with clinically localized prostate cancer. This therapeutic strategy offers dosimetric coverage if local-regional microscopic disease is present and provides a highly conformal boost of radiation to the prostate and immediate surrounding tissues. Either low-dose-rate (LDR) permanent brachytherapy or high-dose-rate (HDR) temporary brachytherapy can be combined with EBRT; such combined-modality therapy (CMT) is typically used to treat patients with intermediate-risk to high-risk, clinically localized disease. Controversy persists with regard to indications for CMT, choice of LDR or HDR boost, isotope selection for LDR, and integration of EBRT and brachytherapy. Initial findings from prospective, multicenter trials of CMT support the feasibility of this strategy. Updated results from these trials as well as those of ongoing and new phase III trials should help to define the role of CMT in the management of prostate cancer. In the meantime, long-term expectations for outcomes of CMT are based largely on the experience of single institutions, which demonstrate that CMT with EBRT and either LDR or HDR brachytherapy can provide freedom from disease recurrence with acceptable toxicity.

Comparison of two treatment approaches for prostate cancer: intensity-modulated radiation therapy combined with 125I seed-implant brachytherapy or 125I seed-implant brachytherapy alone

The purpose of the present study was to assess the results of two different treatment approaches for clinically localized prostate cancer: intensity‐modulated radiation therapy (IMRT) followed by I125 seed‐implant brachytherapy and I125 seed‐implant brachytherapy alone. We studied our 30 most recent consecutive patients. The sample population consisted of 15 cases treated with IMRT (50.4 Gy) followed by I125 seed‐implant boost (95 Gy), and 15 cases treated with I125 seed implant only (144 Gy). We analyzed established dosimetric indices and various clinical parameters. In addition, we also evaluated and compared the acute urinary morbidities of the two treatment approaches, as assessed by the international prostate symptom score (IPSS). In our series, acute urinary morbidity was slightly increased with IMRT followed by I125 seed‐implant brachytherapy as compared with I125 seed‐implant brachytherapy alone. In addition, we observed no statistically significant correlation between the IPSS and the maximum or mean urethral dose. The combination of IMRT and seed‐implant brachytherapy presents an alternative opportunity to treat clinically localized prostate cancer. The full potential of the procedure needs to be further investigated.

PACS number: 87.53.Tf

Multi-institutional analysis of long-term outcome for stages T1–T2 prostate cancer treated with permanent seed implantation

PURPOSE

To assess long-term prostate-specific antigen (PSA) outcome after permanent prostate brachytherapy (BT) and identify predictors of improved disease-free survival.

METHODS AND MATERIALS

Eleven institutions combined data on 2,693 patients treated with permanent interstitial BT monotherapy for T1-T2 prostate cancer. Of these patients, 1,831 (68%) were treated with I-125 (median dose, 144 Gy) and 862 (32%) were treated with Pd-103 (median dose, 130 Gy). Criteria for inclusion were: available pre-BT PSA, BT > or =5 years before data submission, BT between 1988-1998, and no androgen deprivation before failure. The median follow-up was 63 months.

RESULTS

Among patients where the I-125 dose to 90% of the prostate (D90) was > or =130 Gy, the 8-year PSA relapse-free survival (PRFS) was 93% compared with 76% for those with lower D90 dose levels (p < 0.001). A multivariable analysis identified tumor stage (p = 0.002), Gleason score (p < 0.001), pretreatment PSA level (p < 0.001), treatment year (p = 0.001), and the isotope used (p = 0.004) as pretreatment and treatment variables associated with PRFS. When restricted to patients with available postimplantation dosimetric information, D90 emerged as a significant predictor of biochemical outcome (p = 0.01), and isotope was not significant. The 8-year PRFS was 92%, 86%, 79%, and 67%, respectively, for patients with PSA nadir values of 0-0.49, 0.5-0.99, 1.0-1.99, and >2.0 ng/mL (p < 0.001). Among patients free of biochemical relapse at 8 years, the median nadir level was 0.1 ng/mL, and 90% of these patients achieved a nadir PSA level <0.6 ng/mL.

CONCLUSIONS

Outcome after permanent BT for prostatic cancer relates to tumor stage, Gleason score, pretreatment PSA, BT year, and post-BT dosimetric quality. PSA nadir < or =0.5 ng/mL was particularly associated with durable long-term PSA disease-free survival. The only controllable factor to impact on long-term outcome was the D90 which is a reflection of implant quality.

Is seminal vesicle implantation with permanent sources possible? A dose–volume histogram analysis in patients undergoing combined 103Pd implantation and external beam radiation for T3c prostate cancer

PURPOSE

Combined brachytherapy and external beam radiation therapy (EBRT) of the prostate and seminal vesicles (SVs) is evolving as a successful treatment option for high-risk prostate cancer. Dose-volume histogram (DVH) analysis of the SV was performed in patients with biopsy-positive SV who received implantation of the SV and prostate.

METHODS AND MATERIALS

Fifteen consecutive patients with high-risk features (prostate-specific antigen [PSA] > or =10 ng/mL, Gleason score > or = 7, or clinical stage > or = T2b) and a positive SV biopsy were treated with a 103Pd implant of the prostate and SV followed by 45Gy of EBRT. DVHs were generated for the prostate and total SV volume (SVT). In addition, the SV was divided into 3-mm-thick volumes identified as SV1, SV2, SV3, SV4, SV5, and SV6 starting from the junction of the prostate and SV and extending distally. Delivered dose was defined as the D90 (dose delivered to 90% of the organ on DVH).

RESULTS

The median number of seeds implanted into the prostate and the SVT was 59 (41-94) and 9 (4-21), respectively. The median D90 values for the prostate, SVT, SV1, SV2, SV3, SV4, SV5, and SV6 were 103.2 (87.4-137.1), 46.2 (4.0-69.4), 76.0 (31.2-147), 63.4 (25.1-145.9), 49.7 (15.3-118), 27.4 (9.3-135.1), 14.2 (2.3-100.3), and 3.9 (0-61.5) Gy, respectively.

CONCLUSIONS

Implantation of the SV using a real-time intraoperative approach is technically feasible and results in higher doses to the SV than has been reported with implantation of the prostate alone. Although dose distribution in the SV can be variable and unpredictable, these doses, in combination with 45 Gy of EBRT, may be adequate to control disease spread in these organs.

Treatment of intermediate-risk prostate cancer with brachytherapy without supplemental pelvic radiotherapy: A review of the H. Lee Moffitt Cancer Center experience

PURPOSE

To determine the biochemical outcomes of patients with intermediate-risk prostate cancer treated at the H. Lee Moffitt Cancer Center with an I-125 permanent seed implant without supplemental pelvic radiotherapy.

METHODS AND MATERIALS

Under an institutional review board approved protocol, the charts of 88 patients with intermediate-risk prostate cancer and a minimum follow-up of 36 months treated with brachytherapy without supplemental pelvic radiotherapy were reviewed. Median follow-up for the whole cohort was 57 months (range 37-121). Biochemical failure was defined using the American Society for Therapeutic Radiology and Oncology definition.

RESULTS

The 5-year biochemical failure-free survival for the cohort was 83%. Patients with perineural invasion had a worse biochemical outcome, which was statistically significant (perineural invasion vs. no perineural invasion, 5-year biochemical failure-free survival 64% vs. 89%, P = 0.004). None of the following factors were found significant in this subset of patients: Gleason scores 6 versus 7, primary Gleason grades 3 versus 4, percentage of core positive <20% versus >20%, number of cores positive <2 versus 2 versus >2, hormonal therapy versus no hormonal therapy, T1 versus T2, prostate-specific antigen <10 versus >10, or > or =2 intermediate risk factors versus 1 intermediate risk factor.

CONCLUSIONS

Our data suggest that patients with intermediate-risk prostate cancer may be treated effectively with brachytherapy without supplemental pelvic radiotherapy. However, because of the limited nature of our study, we cannot exclude that patients with intermediate-risk prostate cancer may benefit from supplemental external beam radiotherapy.

Early observed transient prostate-specific antigen elevations on a pilot study of external beam radiation therapy and fractionated MRI guided high dose rate brachytherapy boost

Purpose

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.

Results

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.

Conclusion

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.

The Effect of Age on Prostate Implantation Results

PURPOSE

The current study was undertaken to determine the effect of young age (60 years or younger) on the 5-year biochemical disease-free survival rate following ultrasound-guided transperineal prostate implantation.

PATIENTS AND METHODS

The radiation therapy charts of 330 patients who underwent ultrasound-guided transperineal prostate implantation who were treated from 1992 through 2004 were retrospectively reviewed. Follow-up ranged from 12 to 120 months, with a mean of 48 months. A total of 63 patients were 60 years of age or younger, and 267 patients were over 60 years of age. Prostate-specific antigen (PSA) recurrence was defined as three successive increases following ultrasound-guided transperineal prostate implantation. Biochemical disease-free survival was determined using the life-table method.

RESULTS

There were no statistically significant differences in the 5-year biochemical disease-free survival rates for the younger versus the older group. On univariate analysis, age was not a statistically significant factor in predicting PSA failure. Univariate analysis revealed that Gleason score, PSA at diagnosis, and clinical T stage were significant in predicting for PSA failure. Patients with Gleason score<7, PSA<10, and clinical stage T1c disease had statistically significant lower PSA failure rates than patients with Gleason score>or=7, PSA>or=10, and clinical stage T2 disease, respectively.

CONCLUSIONS

Patients who are 60 years of age or younger who are treated with ultrasound-guided transperineal prostate implantation can expect 5-year biochemical disease-free survival rates similar to those of older patients treated with ultrasound-guided transperineal prostate implantation therapy.

Combination therapy-permanent interstitial brachytherapy and external beam radiotherapy for patients with localized prostate cancer

BACKGROUND

Combination of permanent interstitial brachytherapy based on radioactive iodine with external beam radiotherapy is an alternative to other treatment modalities, such as radical prostatectomy or external beam radiotherapy alone in patients with intermediate-risk localized prostate cancer. In this article we report our experience with this combination modality.

METHODS

Among patients who were treated in our institute with brachytherapy, there were 64 patients who received combination therapy for the above indication. Combination therapy enables administration of 110 Gy as brachytherapy and thereafter 45 Gy as external beam radiation. All patients received adjuvant androgen deprivation therapy for 6 months. The prospective follow-up was done with the aid of validated evaluation instruments (questionnaires).

RESULTS

Combination therapy was administered without additional urinary (IPSS-based) or sexual (IIEF-based) side effects above those with brachytherapy alone. No severe perianal and lower intestinal tract side effects were observed. Short-to-moderate-term results based on serum PSA levels are encouraging, and are not inferior to what is accepted by the literature for other radical therapies.

CONCLUSION

Combination of permanent interstitial brachytherapy and external beam radiotherapy in the appropriate patients does not cause any additional morbidity, and its biochemical results justify its application. This modality should be offered as an accepted and good alternative to other radical treatment options, to men with prostate cancer with moderate risk factors.

Role of external beam radiotherapy with low-dose-rate brachytherapy in treatment of prostate cancer

OBJECTIVES

To report a single-institution experience and analysis of the role of supplemental external beam radiotherapy (EBRT) with brachytherapy. EBRT is often used in addition to low-dose-rate brachytherapy in the treatment of prostate cancer, particularly for disease with adverse features.

METHODS

A cohort of 189 consecutive patients, who had undergone low-dose-rate brachytherapy at our institution and who had demographic, disease, and treatment information and a minimum of 2 years of follow-up available, constituted the study group. This cohort was divided into two major groups according to the use of supplemental EBRT. Using two successive prostate-specific antigen rises greater than 1 ng/mL as the definition of failure, biochemical failure-free survival curves were constructed for the EBRT and no-EBRT groups and compared using the log-rank test. Additionally, a multivariate analysis of all major disease and treatment factors was performed using the Cox proportional hazards model.

RESULTS

Despite the greater proportion of adverse disease factors in the EBRT group, the 5-year biochemical failure-free survival rate in the EBRT versus no-EBRT groups was 80% versus 59%, respectively (P < 0.01). On multivariate analysis, the only factor reaching significance in predicting biochemical control was the use of EBRT (P = 0.043).

CONCLUSIONS

In our study, the addition of EBRT conferred a significant biochemical control advantage when added to low-dose-rate brachytherapy. Because our study was not designed to permit detailed subset analyses, more work is needed to determine the precise brachytherapy population that will benefit from this use of supplemental EBRT.

A phase II study of external beam radiotherapy combined with permanent source brachytherapy for intermediate-risk, clinically localized adenocarcinoma of the prostate: Preliminary results of RTOG P-0019

PURPOSE

To estimate the rate of acute and late Grade 3-5 genitourinary and gastrointestinal toxicity after treatment with external beam radiotherapy and permanent source brachytherapy in a multi-institutional, cooperative group setting.

METHODS AND MATERIALS

All patients were treated with external beam radiotherapy (45 Gy in 25 fractions), followed 2-6 weeks later by an interstitial implant using 125I to deliver an additional 108 Gy. Late genitourinary toxicity was graded according to the Common Toxicity Criteria Version 2.0, and the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring system was used for all other toxicity.

RESULTS

A total of 138 patients from 28 institutions were entered on this study. Acute toxicity information was available in 131 patients, and 127 patients were analyzable for late toxicity. Acute Grade 3 toxicity was documented in 10 of 131 patients (7.6%). No Grade 4 or 5 acute toxicity has been observed. The 18-month month estimate of late Grade 3 genitourinary and gastrointestinal toxicity was 3.3% (95% confidence interval, 0.1-6.5). No late Grade 4 or 5 toxicity has been observed.

CONCLUSIONS

The acute and late morbidity observed in this multi-institutional, cooperative group study is consistent with previous reports from single institutions with significant prostate brachytherapy experience.

Tumor control outcomes of patients treated with trimodality therapy for locally advanced prostate cancer

OBJECTIVES

To evaluate, in a pilot study, the tumor control outcomes of our approach and define the pretreatment characteristics that predict a response to therapy. Patients with advanced clinically localized prostate cancer have a high likelihood of prostate-specific antigen (PSA) failure 3 to 5 years after initial treatment. We adopted trimodality therapy (neoadjuvant and adjuvant androgen ablation, external beam radiotherapy [RT], and a brachytherapy boost) to augment biochemical disease-free survival in this patient population.

METHODS

From 1997 to 2000, 93 patients with clinical Stage T2b or greater, or PSA level greater than 10 ng/mL, or Gleason score 7 or greater were treated with external beam RT followed by palladium-103 brachytherapy. Two to three months before external beam RT, an 8 to 9-month regimen of leuprolide and an oral antiandrogen was initiated. Patients were followed up at 3 to 4-month intervals with PSA determination and digital rectal examination. Perineural invasion, the percentage of cancer in biopsy cores, pretreatment PSA level, clinical T stage, and Gleason score were analyzed as prognostic factors for biochemical failure defined by both the American Society for Therapeutic Radiology and Oncology (ASTRO) criteria and PSA level greater than 0.2 ng/mL.

RESULTS

The median length of follow-up was 45 months. The overall probability of biochemical failure using a PSA level greater than 0.2 ng/mL at 4 years was 79% (95% confidence interval 69% to 89%). With the ASTRO criteria, the overall failure rate at the same point was 77% (95% confidence interval 68% to 87%). Gleason score (P = 0.07) showed a trend toward predicting biochemical failure using the PSA level greater than 0.2 ng/mL criterion.

CONCLUSIONS

Trimodality RT offers excellent tumor control in patients with poor prognosis who often relapse early. Longer follow-up will be important to determine whether these results are durable over time.

The efficacy of conventional external beam, three-dimensional conformal, intensity-modulated, particle beam radiation, and brachytherapy for localized prostate cancer

Technologic advances in radiation treatment planning and delivery have generated popular interest in the different radiation therapy techniques used in treating patients with localized prostate cancer. Throughout the past decade, high-energy (> 4 MV) linear accelerators have largely replaced Cobalt machines in external beam radiation therapy (EBRT) delivery. Conventional EBRT has been used to treat prostate cancer successfully since the 1950s. By switching to computed tomography-based planning, three-dimensional conformal radiation therapy provides better relative conformality of dose than does conventional EBRT. Intensity-modulated radiation therapy (IMRT) has further refined dose conformality by spreading the low-dose region to a larger volume. However, the potential long-term risks of larger volumes of normal tissues receiving low doses of radiation in IMRT are unknown. Particle-beam radiation therapy offers unique dose distributions and characteristics with higher relative biologic effect and linear energy transfer. Transperineal prostate brachytherapy offers the shortest treatment time with equivalent efficacy without significant risk of radiation exposure. The addition of hormonal therapy to radiation therapy has been shown to improve the outcome of radiation therapy.

Methodology for biologically-based treatment planning for combined low-dose-rate (permanent implant) and high-dose-rate (fractionated) treatment of prostate cancer

PURPOSE

The combination of permanent low-dose-rate interstitial implantation (LDR-BRT) and external beam radiotherapy (EBRT) has been used in the treatment of clinically localized prostate cancer. While a high radiation dose is delivered to the prostate in this setting, the actual biologic dose equivalence compared to monotherapy is not commonly invoked. We describe methodology for obtaining the fused dosimetry of this combined treatment and assigning a dose equivalence which in turn can be used to develop desired normal tissue and target constraints for biologic-based treatment planning.

METHODS AND MATERIALS

Patients treated with this regimen initially receive an I-125 implant prescribed to 110 Gy followed, 2 months later, by 50.4 Gy in 28 fractions using intensity-modulated external beam radiotherapy. Ab initio methodology is described, using clinically derived biologic parameters (alpha, beta, potential doubling time for prostate cancer cells [T(pot)], cell loss factor), for calculating tumor control probability isoeffective doses for the combined LDR and conventional fraction EBRT treatment regimen. As no such formalism exists for assessing rectal or urethral toxicity, we make use of semi-empirical expressions proposed for describing urethral and rectal complication probabilities for specific treatment situations (LDR and fractionation, respectively) and utilize the notion of isoeffective dose to extend these results to combined LDR-EBRT regimens.

RESULTS

The application to treatment planning of the methodology described in this study is illustrated with real-patient data. We evaluate the effect of changing LDR and EBRT prescription doses (in a manner that remains isoeffective with 81 Gy EBRT alone or with 144 Gy LDR monotherapy) on rectal and urethral complication probabilities, and suggest that it should be possible to improve the therapeutic ratio by exploiting joint LDR-EBRT planning.

CONCLUSIONS

We describe new methodology for biologically based treatment planning for patients who receive combined low-dose-rate brachytherapy and external beam radiotherapy for prostate cancer. Using relevant mathematical tools, we demonstrate the feasibility of fusing dose distributions from each treatment for this combined regimen, which can then be expressed as isoeffective dose distributions. Based on this information, dose constraints for the rectum and urethra are described which could be used for planning such combination regimens.

10-YEAR DISEASE-FREE SURVIVAL RATES AFTER SIMULTANEOUS IRRADIATION FOR PROSTATE CANCER WITH A FOCUS ON CALCULATION METHODOLOGY

PURPOSE

We documented the 10-year disease-free survival rate after simultaneous irradiation for prostate cancer and suggested standards for outcome calculation methodology.

MATERIALS AND METHODS

From 1992 to 1998, 1,469 consecutive men with clinical stage T1T2NxM0 prostate cancer who did not receive neoadjuvant hormones were treated with simultaneous irradiation, an ultrasound guided transperineal prostate I seed implant followed by external irradiation. Median pretreatment prostate specific antigen (PSA) was 7.1 ng/ml (range 0.3 to 88). All men were treated 5 or more years ago. Median followup was 6 years (range 3 months to 11 years). Disease freedom was defined as the achievement and maintenance of PSA 0.2 ng/ml or less, and treatment failure was defined as a PSA nadir greater than 0.2 ng/ml or a subsequent PSA increase above this level.

RESULTS

The overall 10-year disease-free survival rate was 83%. Median time to recurrence was 30 months (range 3 months to 8 years) and 24% of recurrences were after 5-year followup. The 10-year outcome according to low, intermediate and high risk group was 93%, 80% and 61%, respectively (p <0.0001). Multivariate analysis of factors related to disease freedom documents that pretreatment PSA, Gleason score and percent positive biopsies were significant but stage and age were not.

CONCLUSIONS

By calculating outcome with PSA cut point 0.2 ng/ml and evaluation only of men treated 5 or more years ago, the 10-year disease-free survival rates from this study can be reasonably compared with the outcome of radical prostatectomy performed in the PSA era.

Analysis of serial CT scans to assess template and catheter movement in prostate HDR brachytherapy

PURPOSE

As prostate high-dose-rate (HDR) brachytherapy becomes more prevalent, varying amounts of catheter displacement have been noted. To investigate the constancy of catheter position and its impact on dose distribution, we analyzed serial dosimetric CT scans.

METHODS AND MATERIALS

The data from 50 patients were analyzed. During initial CT treatment planning, transverse images of the implant volume were collected, and all structures were digitized into the Nucletron Brachytherapy Planning System. Digitally reconstructed radiographs were generated with rendering of the catheter tips, ischial tuberosity, and perineal template. The distance from each catheter tip to the template and to the ischial tuberosity was measured. The distance between the ischial tuberosity and the template was similarly measured. A second CT set was obtained at different intervals and compared with the first measurement to assess catheter and/or template movement. In 10 patients, the second CT set was obtained before the third fraction in both 2-mm and 5-mm slice sequences, and the latter was used to re-create the HDR plan.

RESULTS

Although no interfraction catheter movement relative to the template was found, the template-catheter unit moved in a caudal direction between HDR fractions. The amount of displacement was time dependent: 2 mm before the second fraction, 8 mm before the third, and 10 mm before the fourth. When comparing the first HDR treatment with the third, median decreases in the following dosimetric parameters were noted: dose to 90% of the prostate volume, 35% (r = 0-60); minimal dose to the base, 35% (r = 17-65); and maximal dose to 1 cm(3), 13% (r = 3-19%).

CONCLUSION

The interstitial catheters did not slip within the template and were not caudally displaced independently but rather in conjunction with the template. The displacement occurred in a time-dependent fashion, and, without redress, significant dosimetric changes are encountered by the third fraction.

The 1999 patterns of care study of radiotherapy in localized prostate carcinoma

BACKGROUND

The objective of the current study was to provide descriptive information on a representative national sample of patients with prostate carcinoma who were treated with prostate brachytherapy (PB) in calendar year 1999.

METHODS

A random survey was conducted by the Patterns of Care Study in radiation oncology of 59 facilities (1 facility had no eligible patients) that treated patients with prostate carcinoma in 1999 in the United States. A weighted sample size of 36,496 patients with prostate cancer was included in the 1999 survey (unweighted sample size, 554 patients). The main measures were the clinical characteristics of men prior to treatment and the technical characteristics of PB. Patients were classified into three prognostic groups according to T stage, pretreatment prostate specific antigen (PSA) level, and Gleason score.

RESULTS

A weighted sample size of 13,293 patients (36%; unweighted sample size, 162 patients) was treated with PB. Compared with a weighted sample size of 23,203 patients (64%; unweighted sample size, 392 patients) was treated with external beam radiotherapy (EB), patients who received PB were significantly younger (mean age: PB group, 67.7 years; EB group, 70.8 years; P = 0.0006). The mean pretreatment PSA level for the PB group was lower compared with the EB group (9.9 ng/mL vs. 13.33 ng/mL; P = 0.0015). The prognostic groupings were more favorable for patients in the PB group compared with patients in EB group (P = 0.0365). The utilization of androgen deprivation therapy (ADT) in the PB group was similar to the utilization of ADT in the EB group (40.4% vs. 51.3%; P = 0.2282). The vast majority of men who were treated with PB received low-dose-rate, permanent sources (89%). Fifty-four percent of men received PB monotherapy (PBM), and the remaining 46% were treated with EB in addition to PB (EBPB). The prognostic groupings were more favorable for patients in the PBM group compared with patients in the EBPB group (P = 0.0037). Of the men who were treated with low-dose-rate PB, 59% were treated with iodine-125 (I-125), and 41% were treated with palladium-103 (Pd-103). I-125 was used more frequently in men who were treated with PBM, and Pd-103 was used more frequently in men who were treated with EBPB. Postimplantation dosimetry was documented in 61.0% of men who were treated with low-dose-rate PB. Computed tomography imaging was used for 46.5% of men.

CONCLUSIONS

PB was used in 36% of men who were treated with radiotherapy nationally. The mean age of men who were treated with PB was younger than the population of men who were treated with EB alone. Nearly 50% of men who received PB also received EB. EB was used more frequently in men with higher-risk disease. ADT was used in 40% of patients in the PB group. Techniques and prescription doses were consistent with published guidelines.

Extracapsular Radiation Dose Distribution After Permanent Prostate Brachytherapy

The physical extent of the radiation therapy dose delivered to the periprostatic region was evaluated in 26 consecutive patients with low-risk prostate cancer (prostate-specific antigen <or=10, Gleason score <or=6, and clinical T1c/T2a) who underwent prostate brachytherapy using either 103Pd or 125I without supplemental external beam radiation therapy between October and December 1999. All patients underwent a transrectal ultrasound volumetric study of the prostate gland followed by the generation of a preplan based on a consistent, modified uniform seed-loading philosophy. The planning treatment volume (PTV) consisted of the prostate gland with approximately 5-mm anterior and lateral margins. The radiation dose was prescribed to the PTV with margin. Day 0 computed tomography-based dosimetric evaluation revealed an overall mean 100% isodose margin of 6.5 mm +/- 1.8 mm. For 125I and 103Pd, the 100% isodose margins were 6.8 mm +/- 1.6 mm and 6.3 mm +/- 1.9 mm, respectively. At the 90% and 75% isodose lines, the isodose margins differed by no more than 1 mm for the 2 isotopes. With the exception of the area near the bladder neck and the posterior border of the prostate, the 100% isodose margin was >or=5.0 mm for all slices evaluated. The utilization of preplanning periprostatic margins is strongly correlated with the administration of prescription radiation doses to the periprostatic region. The extent of the postimplant periprostatic margin (6.5 +/- 1.8 mm) satisfies the preplanning margin criterion of >5 mm.

Permanent Prostate Brachytherapy in Men with Clinically Localised Prostate Cancer

Permanent prostate brachytherapy techniques are associated with excellent biochemical control for patients with localised prostate cancer. Ten-year data show that permanent prostate brachytherapy is compatible with external beam irradiation or radical prostatectomy. However, treatment protocols and techniques for prostate brachytherapy vary between centres and there is little conformity of treatment protocols. The selection of patients for monotherapy or combined external beam irradiation and brachytherapy is controversial. The role of neoadjuvant androgen deprivation also remains unanswered in patients with localised prostate cancer. In addition, post-implant dosimetry may in fact be more significant for predicting outcome than the addition of adjuvant therapies, and should be a requirement when performing prostate brachytherapy. Data now seem to support specific computed tomography (CT)-based criteria to evaluate implant quality and delivered dose to the prostate. Unfortunately, prostate oedema and poor imaging techniques are limiting factors for evaluating implant dosimetry. Treatment planning techniques that use new treatment planning computers may assist in improving the implant procedure and dosimetry and are now available.

Permanent interstitial brachytherapy for the management of carcinoma of the prostate gland

PURPOSE

We summarize the permanent prostate brachytherapy literature, including biochemical outcomes, quality of life parameters and areas of controversy.

MATERIALS AND METHODS

The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness.

RESULTS

Using various planning and intraoperative techniques the majority of the brachytherapy literature demonstrates durable biochemical outcomes for patients with low, intermediate and high risk features. For low risk patients there is no advantage to combining supplemental external beam radiation therapy with brachytherapy. In addition, supplemental external beam radiation therapy may not improve biochemical outcomes for patients at intermediate and high risk if the target volume consists of the prostate with a generous periprostatic margin. There is no defined role for adjuvant hormonal manipulation. Although a reliable set of pretreatment criteria to predict implant related morbidity is not available, severe urinary and rectal morbidity is rare. The incidence of brachytherapy induced erectile dysfunction is significantly greater than initially reported but the majority of patients respond favorably to sildenafil.

CONCLUSIONS

Continued refinements in brachytherapy planning and implementation techniques, postimplantation evaluation and continued elucidation of the etiology of urinary, bowel and sexual dysfunction should result in further improvements in biochemical and quality of life outcomes.

Surgery, brachytherapy, and external-beam radiotherapy for early prostate cancer

Patients diagnosed with early prostate cancer after 2000 can expect better outcomes from treatment than patients who were diagnosed in the 1980s and early 1990s. These improved outcomes are the result of stage migration, new technologies such as three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated external-beam radiotherapy (IMRT), better implant techniques, and optimum use of hormone therapy. We review the outcomes for radical prostatectomy, permanent seed implant, 3DCRT, and IMRT. For patients with clinical stage T1c or T2 disease and a Gleason score of less than 8, 5-year biochemical disease-free survival is remarkably similar for all the above treatments. Furthermore, complication rates are acceptable for all these modalities. For patients with bulky T2-3 disease or a Gleason score of 8-10, hormone therapy plus 3DCRT or IMRT is an excellent treatment choice. Studies of radical prostatectomy show the most reliable long-term results, and the studies of external-beam radiotherapy have used the best scientific methods to assess efficacy. On the basis of current data, we recommend specific treatment options.

Multimodality radiotherapy and androgen ablation in the treatment of clinically localized prostate cancer: early results in high risk patients

In patients presenting with clinically localized prostate cancer, the risk of biochemical failure increases significantly with higher Gleason scores, prostate specific antigen (PSA) levels, and clinical stages. Current surgical and radiotherapeutic approaches appear to offer limited success in patients with highly adverse prognostic factors. In an attempt to improve on these outcomes, we have combined external beam radiotherapy (EBRT) with a brachytherapy (BT) boost and neo adjuvant and adjuvant androgen ablation in a population at significant risk of biochemical failure. Here we present early biochemical progression data for this approach. From October 1997 to July 1999, 72 men with a serum PSA >or=10 ng/ml or Gleason score >or=7 or clinical stage >or=T2c (AJC/UICC 1992) underwent EBRT followed by palladium-103 BT. All patients underwent 8 months of combined androgen ablation with leuprolide and an oral antiandrogen beginning 3 months prior to initiation of EBRT. Patients were followed by PSA and digital rectal examination (DRE) at 3-month intervals and a chart review on all patients was carried out during July 2001. To allow comparisons to contemporary literature, Kaplan-Meier survival curves were generated utilizing three alternate definitions of biochemical recurrence: PSA >0.2 ng/ml, PSA >1.0 ng/ml, and the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition of three consecutive rising PSAs. Our results indicate that when PSA >0.2 ng/ml was used to define biochemical progression, 88% (95% CI 80-97) of patients remained free of disease at 24 months. When PSA >1.0 ng/ml was used, 97% (CI 92-100) of patients remained disease free at 24 months. ASTRO criteria yielded 90% (CI 82-98) recurrence-free survival at 24 months. In conclusion, this very early report indicates that in patients who are at increased risk of biochemical failure, EBRT with a BT boost in conjunction with short-term androgen ablation offers potentially superior biochemical disease-free survival to contemporary alternative approaches in the literature. Clearly, longer follow-up is required to confirm the durability of this approach.

The effects of edema on urethral dose following palladium-103 prostate brachytherapy

The effects of edema on urethral dose after interstitial prostate brachytherapy with palladium-103 (103Pd) were studied. Fifty patients underwent a 90-Gy 103Pd implant followed by dosimetric computed tomography (CT). Twenty-one days later, a Foley catheter was reinserted and a dosimetric CT was repeated. The mean reduction in prostate volume between day 0 and day 21 was 16%. Median prostate D90 on day 0 was 89.7 Gy (range 59.5 to 127) and 99.5 Gy (range 62.5 to 130) on day 21. Median prostate V100 was 90% (range 63 to 98%) on day 0 and 96% (range 66 to 99%) on day 21. Median V150 was 61% (range 31 to 85%) on day 0 and 75% (range 39 to 93%) on day 21. Median urethral D50 was 107 Gy (range 57 to 201) on day 0 and 126 Gy (range 64 to 193) on day 21. Regression analysis demonstrated a significant correlation between the decrease in the prostate volume and the increased urethral D50 (r 0.58, p < 0.05). Acute urinary toxicity was 32% grade 0, 38% grade 1, and 30% grade 2. The median urethral D50 increased by a mean of 18% with a correlation coefficient of 0.58 (p < 0.05). Catheterization of the urethra was well tolerated and was of value in better characterizing urethral dose after 103Pd brachytherapy.

A structured literature review to determine the use of the American Society for Therapeutic Radiology and Oncology consensus definition of biochemical failure

OBJECTIVES

The American Society for Therapeutic Radiology and Oncology consensus definition (ACD) of biochemical failure after radiotherapy for prostate cancer requires three consecutive prostate-specific antigen increases from a nadir value. The members of the Consensus Panel recognized that the timing and frequency of prostate-specific antigen determinations could affect the comparability among different reports if this definition was used. For this reason, the Consensus Panel members recommended three guidelines for studies presented for publication (publication guidelines [PGs]). The present analysis examined the extent to which the ACD has been used in the peer-reviewed published literature and how frequently the PGs have been followed.

METHODS

A structured literature review of 10 relevant journals was done. The inclusion criteria for the literature review required publication in calendar year 1999 or 2000; treatment with external beam radiotherapy and/or brachytherapy for previously untreated, nonmetastatic prostate cancer; and the use of a prostate-specific antigen-defined disease-free endpoint. A standardized checklist was created and completed by both of the authors. We independently reviewed each publication to determine whether the ACD of biochemical failure was used and whether the PGs were followed. Discrepancies between us were resolved by joint review of each publication in question to achieve a consensus.

RESULTS

Fifty-seven articles met the inclusion criteria. The median number of patients in the articles reviewed was 302 (range 22 to 2222). The ACD was followed in 37 (64.9%) of 57 articles. None of the reviewed articles followed all three PGs. In five articles (8.7%), two of the three PGs were followed. The vast majority of the articles reviewed (52 of 57, 91.3%) followed one or none of the PGs recommended by the Consensus Panel.

CONCLUSIONS

The ACD was used in two thirds of peer-reviewed published articles. The PGs were followed much less frequently. Consistent standards of reporting have not been uniformly applied to peer-reviewed manuscripts.

Does hormonal manipulation in conjunction with permanent interstitial brachytherapy, with or without supplemental external beam irradiation, improve the biochemical outcome for men with intermediate or high-risk prostate cancer?

OBJECTIVE

To determine whether hormonal manipulation improves the biochemical outcome for men with intermediate or high-risk prostate cancer and undergoing permanent brachytherapy with or without supplemental external beam radiation therapy.

PATIENTS AND METHODS

From April 1995 to August 2000, 350 patients with intermediate-risk (225 men; a Gleason score of >or= 7 or a prostate specific antigen, PSA, level of >or= 10 ng/mL or clinical stage >or= T2b) or high-risk features (125 men; two or three of a Gleason score of >or= 7 or PSA >or= 10 ng/mL or clinical stage >or= T2b) underwent transperineal ultrasonography-guided permanent brachytherapy. No patient underwent pathological lymph node staging. Of these patients, 293 received supplemental external beam radiation therapy (EBRT), 141 received hormonal manipulation, with 82 having hormonal therapy for <or= 4 months (median 4) for cytoreduction, while 59 had neoadjuvant and adjuvant hormonal manipulation (median 8 and 12 months for intermediate- and high-risk, respectively). The median patient age was 68.5 years. No patient was lost to follow-up. The mean (sd) and median follow-up was 50 (18) and 49 months (calculated from the day of implantation). Biochemical disease-free (BDF) survival was defined using a consensus definition. The clinical variables evaluated for BDF survival included risk group, Gleason score, patient age, clinical T-stage and pretreatment PSA. Treatment variables included use of hormonal manipulation stratified into cytoreductive (<or= 4 months) vs adjuvant (> 4 months) regimens, supplemental EBRT, isotope and dosimetric variables.

RESULTS

For intermediate-risk patients, the 6-year actuarial BDF survival rates were 98%, 96% and 100% for hormone naïve, cytoreductive and adjuvant treatment, respectively (P = 0.693); for high-risk patients the respective values were 79%, 94% and 92% (P = 0.046). When stratified by pretreatment PSA, hormonal manipulation improved the outcome for patients with a PSA of >or= 10 ng/mL (P = 0.019), but not for those with < 10 ng/mL (P = 0.661). Hormonal status was not statistically significant in predicting biochemical outcome when stratified by Gleason score. The follow-up in hormone-naïve patients was significantly longer than that in hormonally manipulated patients, at 55 (20) vs 43 (15) months (P < 0.001). In a multivariate analysis only the Gleason score predicted failure in intermediate-risk patients, while pretreatment PSA, the use of hormonal manipulation and Gleason score predicted the outcome in high-risk patients (P = 0.035). For both hormone-naïve and hormonally manipulated BDF patients, the median PSA level after implantation was < 0.1 ng/mL.

CONCLUSION

In patients treated by permanent prostate brachytherapy, hormonal manipulation improved the biochemical outcome for those at high-risk and those with an initial PSA of >or= 10 ng/mL, but not for those with intermediate-risk features. The use of hormonal therapy for> 4 months conferred no additional biochemical advantage over short-course regimens. Because the follow-up in hormone-naïve patients was longer than that for those receiving hormonal manipulation, additional follow-up will be mandatory to confirm the durability of these findings.

Treatment outcomes and quality-of-life issues for patients treated with prostate brachytherapy

The increasing popularity of brachytherapy for treatment of early-stage prostate cancer requires oncology nurses to have a comprehensive knowledge of the disease, its treatment, and management of side effects. Because quality-of-life (QOL) issues have become an important consideration in treatment selection for many patients, oncology nurses must have a thorough understanding of these QOL issues and their management. Armed with knowledge about prostate brachytherapy and its effect on QOL, oncology nurses can offer accurate information and evidence-based symptom management techniques to patients undergoing brachytherapy for prostate cancer.

Primary radiation therapy for localized prostate cancer

Prostate cancer in men is similar to breast cancer in women; both cancers rank first, respectively, in incidence and are normally responsive to radiation therapy. In addition, advances in mammography help detect earlier breast cancers, and the development and refinement of prostatic specific antigen (PSA) has resulted in early detection of low-stage localized prostate cancers. This has generated debate over the proper management of localized prostate cancer. While there have not been any controlled, prospective, randomized trials of sufficient power to compare the various local therapies, based on the current available data, the three commonly used local modalities, surgery, and external beam radiation therapy and brachytherapy (radioactive seed implant), have similar efficacy controlling the disease up to 10 years in many patients. Technological advances in treatment delivery and planning have improved the treatment of prostate cancer with external-beam radiotherapy using three-dimensional conformal radiotherapy (3DCRT), ultrasound-guided transperineal implant, or intensity-modulated radiotherapy (IMRT), as well as proton or neutron beam based therapies.

Localized prostate cancer: brachytherapy

Brachytherapy is a treatment for localized prostate cancer that has become popular with physicians and patients. The use and convenience of transrectal ultrasound and transperineal placement of the sources make contemporary forms of this procedure more accurate and more patient-friendly than their predecessors. In addition, the early detection of cancer by the use of prostate-specific antigen (PSA) makes contemporary tumors more amenable to successful treatment by such a localized technique. Brachytherapy offers cancer control rates at 5 years, as measured by PSA, that seem to be as effective as surgery and external beam therapy. Less information is available for 10 years, and none afterward. The acute urinary morbidity rate of brachytherapy is higher than for external beam therapy, but the late urinary morbidity rate is probably equal. The rectal morbidity rate is less. The risk of erectile impotence is uncertain but not as low as originally hoped. The use of external radiation in combination with brachytherapy may increase 5-year tumor control rates but is substantially more expensive and likely carries an increased risk of morbidity. Newer forms of brachytherapy such as magnetic resonance-guided and high-dose-rate temporary implants have vocal advocates but a shorter track record and fewer published prospective studies. Their use remains investigational. Therefore, prostate brachytherapy remains a reasonable option for men with early stage disease, but there remain unanswered questions regarding long-term efficacy and morbidity.

Biochemical outcome for hormone-naive patients with Gleason score 3+4 versus 4+3 prostate cancer undergoing permanent prostate brachytherapy

OBJECTIVES

To determine the effect of the dominant pattern in Gleason score 7 histologic findings on biochemical no evidence of disease survival for hormone-naive patients undergoing permanent prostate brachytherapy.

METHODS

A total of 114 hormone-naive patients with Gleason score 7 histologic findings underwent transperineal ultrasound-guided permanent prostate brachytherapy for clinical T1c-T3a NxM0 adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. Sixty-four patients were diagnosed with Gleason score 3+4 and 50 with Gleason score 4+3 prostate cancer. Twenty-one patients were implanted with either palladium 103 or iodine 125 monotherapy, and 93 patients received supplemental external beam radiotherapy with a brachytherapy boost. The median patient age was 69 years (range 49 to 79). The median follow-up was 46.4 months (range 20 to 80). The American Society for Therapeutic Radiology and Oncology consensus definition was used to determine the biochemical disease-free survival.

RESULTS

The actuarial 5-year biochemical disease-free survival rate was 90.3%. No statistically significant difference in outcome was found when stratified by the dominant pattern in Gleason score 7 histologic features (89.4% versus 91.5% for 3+4 and 4+3, respectively, P = 0.700). The biochemical no evidence of disease survival analysis in terms of the Gleason cohorts revealed no difference in terms of the choice of isotope, use of supplemental external beam radiotherapy, or preimplant prostate-specific antigen level. The median and mean postimplant prostate-specific antigen level was less than 0.1 ng/mL and 0.12 +/- 0.20 ng/mL, respectively, without a significant difference between Gleason score 3+4 and 4+3.

CONCLUSIONS

Our results indicate that the 5-year biochemical outcome with a hormone-naive prostate brachytherapy approach that uses multiple periprostatic seeds is not dependent on Gleason score 3+4 versus 4+3 histologic features.

Biochemical outcome for hormone-naïve patients with high-risk prostate cancer managed with permanent interstitial brachytherapy and supplemental external-beam radiation

PURPOSE

The purpose of this article is to report the 5-year biochemical disease-free outcome for hormone-naive patients with high-risk disease who underwent permanent prostate brachytherapy. Multiple clinical and treatment parameters were also evaluated to determine whether any of these influence biochemical outcome.

MATERIALS AND METHODS

Sixty-six hormone-naïve patients underwent transperineal ultrasound-guided permanent prostate brachytherapy with generous periprostatic margins by use of either 103Pd or 125I for high-risk prostate cancer from April 1995 to October 1999. High-risk patients presented with two or three of the following risk factors: Gleason score > or = 7, prostate-specific antigen > or = 10 ng/mL, and clinical stage > or = T2b, 1997 AJCC. No patient underwent pathological lymph node staging. Only one patient was implanted with monotherapy, whereas 65 patients received supplemental external-beam radiation therapy before a prostate brachytherapy boost. The median patient age was 69 years (range, 50-81 years). No patient was lost to follow-up. The mean follow-up and median follow-up were 53.2 +/- 14.9 months and 53.7 months, respectively (range, 19.8-79.7 months). Follow-up was calculated from the day of implantation. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition. Clinical parameters evaluated for biochemical disease-free survival included patient age, clinical stage, Gleason score, and pretreatment prostate-specific antigen. Treatment parameters included use of supplemental external-beam radiation therapy and choice of isotope.

RESULTS

The 5-year actuarial biochemical disease-free survival rate was 79.9%. In multivariate analysis, preimplantation prostate-specific antigen (P = 0.008) was the only clinical or treatment parameter that predicted for biochemical failure. The mean and median posttreatment prostate-specific antigen levels were 0.13 +/- 0.22 ng/mL and < 0.1 ng/mL, respectively.

DISCUSSION

At a median follow-up of 53.7 months, hormone-naive patients with high-risk disease who undergo permanent prostate brachytherapy have a high probability of 5-year biochemical disease-free survival and an apparent plateau on the biochemical disease-free survival curve.

Relationship between prostate volume, prostate-specific antigen nadir, and biochemical control

PURPOSE

In patients treated with definitive three-dimensional conformal radiotherapy (3D-CRT) for localized prostatic adenocarcinoma, we sought to evaluate the relationship between pretreatment prostate gland volume and posttreatment prostate-specific antigen (PSA) nadir, as well as the relationship of prostate volume and PSA nadir with biochemical control (bNED). Two subgroups were studied: favorable (PSA <10 ng/mL, Gleason score 2-6, and T1-T2A) and unfavorable (one or more: PSA >/=10 ng/mL, Gleason score 7-10, T2B-T3).

MATERIALS AND METHODS

A total of 655 men (n = 271 favorable and 384 unfavorable) were treated with 3D-CRT alone between May 1989 and November 1997. All patients had information on prostate volume and a minimum follow-up of 24 months (median 56, range 24-126). Of the 655 men, 481 (n = 230 favorable and 251 unfavorable) remained bNED at time of analysis, with biochemical failure defined in accordance with the American Society for Therapeutic Radiology and Oncology consensus definition. Factors analyzed for predictors of bNED included pretreatment prostate volume, posttreatment PSA nadir, pretreatment PSA, palpation T stage, Gleason score, center of the prostate dose, and perineural invasion (PNI). We also analyzed pretreatment prostate volume and its correlation to prognostic factors. For bNED patients, the relationship between PSA nadir and prostate volume was evaluated.

RESULTS

On multivariate analysis, prostate volume (p = 0.04) and palpation T stage (p = 0.02) were the only predictors of biochemical failure in the favorable group. On multivariate analysis of the unfavorable group, pretreatment PSA (p <0.0001), Gleason score (p = 0.02), palpation T stage (p = 0.009), and radiation dose (p <0.0001) correlated with biochemical failure, and prostate volume and PNI did not. For all 481 bNED patients, a positive correlation between pretreatment volume and PSA nadir was demonstrated (p <0.0001). Subgroup analysis of the favorable and unfavorable patients also demonstrated a positive correlation between prostate volume and PSA nadir (p = 0.003 and p = 0.0002, respectively). Using multiple regression analysis, the following were found to be predictive of PSA nadir in all bNED patients: prostate volume (p <0.0001), pretreatment PSA (p <0.0001), palpation T stage (p = 0.0002), and radiation dose (p = 0.0034). Gleason score and PNI were not predictive. For the favorable group, palpation T stage (p = 0.0006), pretreatment PSA (p = 0.0083), prostate volume (p = 0.0186), and Gleason score (p = 0.0592) were predictive of PSA nadir, and PNI and radiation dose were not predictive. In the unfavorable group, prostate volume (p = 0.0024), radiation dose (p = 0.0039), pretreatment PSA (p = 0.0182), and palpation T stage (p = 0.0296) were predictive of PSA nadir, and Gleason score and PNI were not predictive.

CONCLUSION

This report is the first demonstration that prostate volume is predictive of PSA nadir for patients who are bNED in both favorable and unfavorable subgroups. PSA nadir did not correlate with bNED status in the favorable patients, but it was strongly predictive in the unfavorable patients. Prostate gland volume was also predictive of bNED failure in the favorable but not the unfavorable group.

The role of external radiotherapy in patients treated with permanent prostate brachytherapy

To examine the difference in Prostate Specific Antigen (PSA)-Relapse Free Survival (RFS) in patients (pts) with prostate cancer treated with permanent prostate brachytherapy (PPB) alone (monotherapy) or combined modality PPB and external radiotherapy (CMT) by a matched pair analysis. There were 1476 pts who were treated loosely based on the American Brachytherapy Society criteria for monotherapy or CMT. PSA-RFS was based upon the Kattan modification of the ASTRO consensus panel definition. A computer generated matching process was undertaken to produce two equally weighted pairs of patients divided by treatment methodology and Kaplan-Meier PSA-RFS curves were generated and compared by chi(2) testing. All pts were treated between 1992 and 2000 with a 6-y PSA-RFS of 81.9%. The median follow-up was 34.7 months. Patients treated with CMT presented with higher pre-treatment PSA values, Gleason sum score, clinical stage, risk classification, and were more likely to be treated with neoadjuvant hormones. A matched-pair analysis with 314 pts in each group was created stratified by the addition of neoadjuvant hormones, Gleason score sum and the pretreatment PSA value. Actuarial 5-y PSA-RFS was 77.0% for the monotherapy group and 81.1% for the combined therapy group (P=0.54).chi(2) testing by pretreatment PSA value, Gleason score sum, risk stratification, isotope and the addition of neoadjuvant hormones failed to identify any group with a significant difference in 5-y PSA-RFS. In conclusion, this retrospective study presents a large cohort of patients treated with PPB that failed to identify a significant advantage for the addition of combined therapy. A matched pair analysis performed also failed to identify any significant difference based on treatment modality.

Relationship between percent positive biopsies and biochemical outcome after permanent interstitial brachytherapy for clinically organ-confined carcinoma of the prostate gland

PURPOSE

Recently, the percentage of positive prostate biopsies has been reported to be statistically significant in predicting the biochemical outcome after either radical prostatectomy or 3-dimensional conformal external beam radiotherapy. In this study, we evaluated the impact of the percentage of positive prostate biopsies in predicting the 5-year biochemical outcome for patients with clinically organ-confined prostate cancer undergoing permanent interstitial brachytherapy.

METHODS AND MATERIALS

Two hundred sixty-two hormone naive patients underwent transperineal ultrasound-guided permanent prostate brachytherapy with generous periprostatic margins, using either 103Pd or 125I for clinical T1b/T2b NXM0 (1997 AJCC) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. The actual percentage of positive biopsies (number of positive biopsies/total number of biopsies) was determinable for 255 of the 262 patients. Of the evaluated cases, 133 patients were implanted with 103Pd and 122 patients with 125I. The median patient age was 68 years (range 48-81). The median follow-up was 38.6 months (range 6-73). Follow-up was calculated from the day of implantation. Patients were stratified by the percentage of positive biopsies into the following groups: <34%, 34-50%, and >50%. Additional clinical parameters evaluated included patient age, clinical T-stage, Gleason score, pretreatment prostate specific antigen (PSA), risk group, and prostate volume. Low-risk patients were staged as clinical T1c/T2a, Gleason score < or =6, and pretreatment PSA < or =10 ng/mL, intermediate-risk patients presented with one unfavorable prognostic parameter, and high-risk patients presented with two or more unfavorable prognostic parameters (clinical stage T2b, PSA >10 ng/mL, Gleason score > or =7). Treatment parameters included the use of supplemental external beam radiation and choice of isotope. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology consensus definition.

RESULTS

For the 255 evaluated patients, the 5-year actuarial biochemical no evidence of disease survival rate was 92.5%. For patients with low, intermediate, and high-risk disease, 95.8%, 98.1%, and 79.4% of patients were free of biochemical failure, respectively. When each risk group was stratified into the percent positive biopsy categories of <34%, 34-50%, and >50%, no statistical difference was found in biochemical outcome for the biopsy subgroups. In multivariate analysis, none of the clinical or treatment parameters predicted for failure in the low-risk group; only Gleason score was predictive for intermediate-risk patients and only PSA for high-risk patients. In the overall population, PSA and Gleason score were both found to be predictors of biochemical failure, but not risk group, clinical stage, or percentage of positive biopsies. There was no significant dependence between the percent positive biopsy group and the Kaplan-Meier biochemical survival rates for any of the various subgroups of clinical and treatment parameters, except for clinical stage T1c-T2a (p = 0.006). The median postimplant PSA was 0.2 ng/mL for patients with either low-risk disease or <34% positive biopsies and 0.1 ng/mL for all other risk groups or percent positive biopsy subgroups.

CONCLUSION

Although a significant trend was found for biochemical failure with increasing percent positive biopsies in the overall population, our results suggest that the percentage of positive biopsies is not statistically significant in predicting the 5-year biochemical disease-free outcome for patients with low, intermediate, and high-risk disease undergoing permanent prostate brachytherapy. Only the Gleason score in intermediate-risk patients and the pretreatment PSA level in high-risk patients was predictive of biochemical failure. We believe this relative lack of significance for the percentage of positive biopsies is a result of dose escalation far exceeding other radiotherapy modalities and the ability to aggressively treat the periprostatic region compared with radical prostatectomy by way of the accurate placement of periprostatic seeds.

Role of hormonal therapy in the management of intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation

PURPOSE

To study the impact of hormonal therapy (HTx) on intermediate- to high-risk prostate cancer treated with permanent radioactive seed implantation.

METHODS AND MATERIALS

Patients with Stage T1b-T3bN0 prostate cancer, and Gleason score > or = 7 or prostate-specific antigen (PSA) level >10 ng/mL were treated with seed implantation with or without HTx. Their disease was defined as intermediate risk (PSA 10-20, Gleason score 7, or Stage T2b) or high risk (two or more intermediate criteria, or PSA >20 ng/mL, Gleason score 8-10, or Stage T2c-T3). The median follow-up for 201 eligible patients was 42 months (range 18-110). Biochemical failure was defined as a rising PSA >1.0 ng/mL. Pretreatment disease characteristics, implant dose, and HTx were evaluated using univariate and multivariate analyses.

RESULTS

HTx significantly improved 5-year actuarial freedom from biochemical failure rate, 79% vs. 54% without HTx. In addition, high-dose, PSA < or = 15 ng/mL, intermediate risk, and Stage T2a or lower significantly improved outcome in the univariate analyses. HTx was the most significant predictor of 5-year actuarial freedom from biochemical failure (p <0.0001) in a multivariate analysis. The best outcome was in the intermediate-risk patients treated with a high implant dose and HTx, resulting in a 4-year actuarial freedom from biochemical failure rate of 94%.

CONCLUSION

In this retrospective review, HTx improved outcome in intermediate- to high-risk prostate cancer patients treated with brachytherapy. HTx was the most important prognostic factor in the univariate and multivariate analyses.

External radiotherapy and permanent prostate brachytherapy in patients with localized prostate cancer•

We examined the difference in prostate-specific antigen (PSA)-freedom from recurrence (FFR) in patients with localized prostate cancer treated with permanent prostate brachytherapy (PPB) alone or external radiotherapy combined with PPB (RT-PPB). A total of 1476 patients with prostate cancer (T1/T2) were treated with PPB by following the American Brachytherapy Society criteria. Patient self-selection and preference allowed for an overlap of treatment methodologies and risk factors. Monotherapy consisted of 125I or 103Pd. RT-PPB consisted of RT followed by PPB. PSA-FFR was based on a published modification of the American Society for Therapeutic Radiology and Oncology definition. Cox regression analysis was performed to assess the role of Gleason sum, pretreatment PSA value, clinical stage, RT-PPB, the addition of hormones, and the minimum dose covering 90% of the prostate volume (D90 dose). Monotherapy was used for 1016 patients (79%), and RT-PPB was used for 281 patients (21%), with an overall 6-year PSA-FFR of 83.2% (median follow-up of 34.7 months; range, 6-91 months). Multivariate Cox regression analysis to predict PSA-FFR identified the following highly significant variables: pretreatment PSA value, Gleason sum, and the addition of hormones. When the D90% (D90 dose relative to the prescribed dose) was included as a variable, Cox regression identified only the following significant variables: D90%, pretreatment PSA, and Gleason sum. Cox regression failed to identify an improvement in PSA-FFR with RT-PPB or the addition of hormones. Although these conclusions question the role for RT-PPB, only a comparative trial will be able to answer this question definitively.

Biochemical outcome for hormone-naı̈ve intermediate-risk prostate cancer managed with permanent interstitial brachytherapy and supplemental external beam radiation

PURPOSE

To report the 6-year biochemical disease-free outcome for hormone-naïve patients with intermediate-risk disease (Gleason score > or =7, prostate-specific antigen (PSA) > or =10 ng/ml, or clinical stage > or =T2b [1997 American Joint Committee on Cancer]) undergoing brachytherapy with supplemental external beam radiation (XRT).

METHODS AND MATERIALS

Seventy-seven consecutive hormone-naïve intermediate-risk prostate cancer patients received supplemental XRT followed by a brachytherapy boost. No patient underwent pathologic lymph node staging. The median patient age was 69 years and the median follow-up was 52 months. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition. Clinical and treatment parameters evaluated included patient age, clinical stage, Gleason score, pretreatment PSA, and isotope.

RESULTS

The 6-year actuarial biochemical no-evidence-of-disease survival rate was 97.4%. None of the evaluated clinical or treatment parameters, except for a Gleason score > or =8, predicted for failure. The mean and median posttreatment PSA was 0.08 +/- 0.19 ng/ml and <0.1 ng/ml, respectively. When stratified by isotope, the mean posttreatment PSA was not significantly different (0.07 +/- 0.11 ng/ml for 103Pd vs. 0.14 +/- 0.32 ng/ml for 125I; p=0.397).

CONCLUSIONS

Hormone-naïve intermediate-risk prostate cancer patients undergoing brachytherapy with supplemental XRT have a high probability of 6-year biochemical disease-free survival. None of the evaluated clinical or treatment parameters, except Gleason score > or =8, predicted for treatment failure.

Five-year biochemical outcome following permanent interstitial brachytherapy for clinical T1-T3 prostate cancer

PURPOSE

To evaluate 5-year biochemical disease-free outcome for men with clinical T1b-T3a NxM0 1977 American Joint Committee on Cancer (1997 AJCC) adenocarcinoma of the prostate gland who underwent transperineal ultrasound-guided permanent prostate brachytherapy.

METHODS AND MATERIALS

Four hundred twenty-five patients underwent transperineal ultrasound-guided prostate brachytherapy using either 103Pd or 125I, for clinical T1b-T3a NxM0 (1997 AJCC) adenocarcinoma of the prostate gland, from April 1995 to October 1999. No patient underwent pathologic lymph-node staging. One hundred ninety patients were implanted with either 103Pd or 125I monotherapy; 235 patients received moderate-dose external beam radiation therapy (EBRT), followed by a prostate brachytherapy boost; 163 patients received neoadjuvant hormonal manipulation, in conjunction with either 103Pd or 125I monotherapy (77 patients) or in conjunction with moderate-dose EBRT and a prostate brachytherapy boost (86 patients). The median patient age was 68.0 years (range, 48.2-81.3 years). The median follow-up was 31 months (range, 11-69 months). Follow-up was calculated from the day of implantation. No patient was lost to follow-up. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology (ASTRO) consensus definition.

RESULTS

For the entire cohort, the 5-year actuarial biochemical no evidence of disease (bNED) survival rate was 94%. For patients with low-, intermediate-, and high-risk disease, the 5-year biochemical disease-free rates were 97.1%, 97.5%, and 84.4%, respectively. For hormone-naive patients, 95.7%, 96.4%, and 79.9% of patients with low-, intermediate-, and high-risk disease were free of biochemical failure. Clinical and treatment parameters predictive of biochemical outcome included: clinical stage, pretreatment prostate-specific antigen (PSA), Gleason score, risk group, age > 65 years, and neoadjuvant hormonal therapy. Isotope choice was not a statistically significant predictor of disease-free survival for any risk group. The median postimplant PSA was < or = 0.2 for all risk groups, regardless of hormonal status. The mean posttreatment PSA, however, was significantly lower for men implanted with 103Pd (0.14 ng/mL) than for those implanted with 125I (0.25 ng/mL), p < or = 0.001.

CONCLUSION

With a median follow-up of 31 months, permanent prostate brachytherapy results in a high probability of actuarial 5-year biochemical disease-free survival (DFS) for patients with clinical T1b-T3a (1997 AJCC) adenocarcinoma of the prostate gland, with an apparent plateau on the PSA survival curve.

Five-year biochemical outcome after prostate brachytherapy for hormone-naive men < or = 62 years of age

PURPOSE

To evaluate 5-year biochemical disease-free outcome for hormone naïve men 62 years of age or less who underwent transperineal ultrasound-guided permanent prostate brachytherapy.

METHODS AND MATERIALS

76 patients underwent transperineal ultrasound guided prostate brachytherapy using either (103)Pd or (125)I for clinical T1b--T2b NxM0 (1997 AJCC) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up, and no patient underwent pathologic lymph-node staging. 47 patients were implanted with either (103)Pd or (125)I monotherapy, and 29 patients received moderate-dose external-beam radiation therapy followed by a prostate brachytherapy boost. No patient received hormonal manipulation. The median patient age was 58 years (range, 48--62 years). The median follow-up was 37 months (range, 14--70 months). Follow-up was calculated from the day of implantation. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology (ASTRO) consensus definition.

RESULTS

The actuarial 5-year biochemical disease-free survival rate was 98.7%. For patients with low-, intermediate-, and high-risk disease, 97.7%, 100%, and 100%, respectively, were free of biochemical failure. The median posttreatment prostate-specific antigen (PSA) for the entire group was 0.2 ng/mL. When stratified by risk group, the median posttreatment PSA was 0.2, 0.15, and 0.1 for patients with low-, intermediate-, and high-risk disease, respectively.

CONCLUSION

With a median follow-up of 37 months, hormone naïve patients < or = 62 years of age have a high probability of 5-year biochemical disease-free survival following permanent prostate brachytherapy with an apparent plateau on the PSA curve.

Radiation for prostate cancer

The balance between tumour control and normal tissue damage with conventional radiotherapy is critical to outcome and morbidity in the treatment of localised prostate cancer. Recent technological advances have allowed a reduction in the amount of normal tissue included in target treatment volumes. This reduces morbidity and allows dose escalation, theoretically increasing the likelihood of tumour control. The methods used to achieve dose escalation are discussed and the available evidence for their safety and efficacy, relative to conventional treatment, is reviewed. Although there are no randomised studies to provide evidence of increased survival, the available evidence supports the hypothesis that dose escalation produces survival rates equivalent to surgical series and provides a realistic choice for patients.