Seminars in urologic oncology最新文献

The purpose of this study is to evaluate the use of a relatively simple equation for predicting the risk of extracapsular extension (ECE) based on the pretreatment prostate-specific antigen (PSA) and Gleason score (GS) in patients with clinically localized prostate cancer. Three hundred and seventy-four patients who underwent radical prostatectomy between 1988 and 1994 and 521 men undergoing definitive radiotherapy during a similar time period were eligible for this analysis. Surgically treated patients were considered eligible if the pathological stage, preoperative PSA, and GS were available. Among these patients, the median preoperative PSA was 8.1 ng/mL (range, 0 to 195 ng/mL), and the median preoperative GS was 6 (range, 2 to 10). The empirically derived equation tested was (1.5 x PSA + [GS - 3] x 10). For this equation, the range of calculated risk was limited to 0% to 100%. Using the empirically derived equation, patients with a low calculated risk (CR) of < or = 33% had an average calculated risk (ACR) of 21.9% and an observed incidence (OI) of ECE was 17.8%. Patients with a moderate CR of 34% to 66% had an ACR of 46.3%, and an OI of ECE was 46.7%. Patients with a CR of 67% to 100% had an ACR of 83.7% and an OI of ECE of 66.7%. Of the 21 patients who had a PSA < or = 4 and a GS < or = 4, only 1 patient (4.8%) was found to have ECE. Men with an estimated risk of ECE of <33%, 33% to 67%, and >67% had a 4-year risk of biochemical failure following radiotherapy of 29%, 56%, and 78% (P < .00001). This empirically derived data appears to be reasonably accurate at estimating the incidence of ECE in patients with at low or intermediate risk before surgery. The risk of biochemical failure following radiotherapy also correlated the risk of ECE. Future staging systems for prostate cancer should use similar approach for defining risk groups.

Many studies have reported that African-American men have the highest incidence and mortality rates for prostate cancer in the United States. A retrospective analysis of 607 patients treated with definitive radiation therapy was performed at the University of California San Francisco and its affiliated hospitals between 1987 and 1995. The patient population analyzed included African-American, Caucasian, and Asian men with AJCC T1-T3 disease. Race, Gleason score, pretreatment prostate-specific antigen levels, stage, and treatment delivery were all evaluated. The percent free from PSA failure at 48 months for African-American, Caucasian, and Asian men were 53%, 59%, and 53%, respectively. There was no difference among the three races or for any of the pairwise comparisons. Gleason score and stage of disease were each independent predictors of outcome, but race was not associated with remaining free from PSA failure. These results are similar to those recently reported in the literature from centers of excellence across the United States.

This article summarizes recent American Brachytherapy Society (ABS) recommendations for permanent prostate brachytherapy. The ABS recommends treating patients with high probability of organ-confined disease with brachytherapy alone. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy (EBRT). The recommended prescription doses for monotherapy are 145 Gy for (125)I and 125 Gy for (103)Pd. The corresponding boost doses (after 40 to 50 Gy EBRT) are 110 Gy and 100 Gy, respectively. The ABS recommends that post-implant dosimetry should be performed on all patients undergoing permanent prostate brachytherapy for optimal patient care. A dose-volume histogram (DVH) of the prostate should be performed and the D(90) (dose to 90% of the prostate gland) reported by all centers. Additionally, the D(80) D(100), the fractional V(80), V(90), V(100), V(150), V(200) (ie, the percentage of prostate volume receiving 80%, 90%, 100%, 150%, and 200% of the prescribed dose, respectively), the rectal and urethral doses should be reported and ultimately correlated with clinical outcome in the research environment. On-line, real-time dosimetry, the effects of dose heterogeneity, and the effects of tissue heterogeneity need further investigation.

The purpose of this study was to prospectively assess the patient-reported quality of life (QOL) and changes in QOL during the first 3 months after prostate brachytherapy (PB). Seventy-four men treated with PB between September 1997 and December 1998 completed a QOL questionnaire (Functional Assessment of Cancer Therapy-Prostate [FACT-P]) and a measurement of urinary symptoms (International Prostate Symptom Score [IPSS]) before treatment (T0), 1 month (T1), and 3 months (T3) following PB. All participants were treated with (125)I alone. The mean score (and standard deviation) at T0, T1, and T3 FACT-P questionnaire are as follows: 139.2 (15.7), 125.4 (20.2), and 133.0 (18.2). For the global test across time, statistically significant differences were observed for the cumulative scores of FACT-P (P < .0001). Examination of the subscales within the FACT-P instrument demonstrated statistically significant changes over time for the following: physical well-being, functional well-being and the prostate cancer subscale. The mean score (and standard deviation) at T0, T1, and T3 for the IPSS questionnaire are as follows: 9.1 (5.9), 20.0 (7.8), and 16.6 (7.2). For the global test across time, statistically significant differences were observed for the IPSS scores (P < .0001). Clinically meaningful decreases in QOL are evident within weeks after PB. Moderate to severe urinary symptoms persist for at least 3 months following PB.

Transperineal interstitial permanent prostate brachytherapy (TIPPB) has become an increasingly popular treatment for early-stage/favorable-risk adenocarcinoma of prostate. Within TIPPB, permanent implants often use either (103)Pd (T(1/2) = 17 days) or (125)I (T(1/2) = 60 days). This review compares the radiobiological and treatment planning effectiveness of (103)Pd and (125)I implants by using the linear-quadratic model with recently published data regarding: prostate tumor cell doubling times, T(pot), alpha and alpha/beta, ratio. The tumor potential doubling times (T(pot)) were determined based on recently published proliferation constants (K(p)). The initial slope of the cell radiation dose survival curve, alpha, the terminal slope beta and the alpha/beta ratio were taken from recent published clinical and cellular results. The total dose delivered from each isotope was the dose used clinically, that is, 120 Gy for (103)Pd and 145 Gy for (125)I. Dale's modified linear-quadratic equation was used to estimate the biological effective dose, the cell-surviving fraction, the effective treatment time, and the wasted radiation dose for different values of T(pot). Treatment plans for peripherally loaded implants were compared. The T(pot) reported for organ-confined prostate carcinomas varied from 16 to 67 days. At short T(pot) both isotopes were less effective, but (103)Pd had much less dependence on T(pot) than (125)I. However, at long T(pot) both isotopes produced similar effects. The minimum surviving fraction for exposure to (103)Pd decreased from 1.40 x 10(-4) to 1.31 x 10(-5) as the T(pot) increased from 16 to 67 days. By contrast for exposure to (125)I, the minimum surviving fraction decreased from 3.98 x 10(-3) to 1.98 x 10(-5) over the same range of T(pot). A comparison of treatment plans revealed that (103)Pd plans required more needles and seeds; however, this was a function of seed strength. Both isotopes had similar dose-volume histograms for prostate, urethra, and rectum. The theoretical prediction of effectiveness using the linear quadratic equation for the common clinically prescribed total radiation doses indicated that (103)Pd should be more effective than (125)I because it had less dependence on T(pot). The greatest benefit of (103)Pd was shown to be with tumors with a short T(pot). Although the regrowth delay would be longer with (125)I, the benefit was inconsequential compared with the very slow doubling times of localized prostate cancer. Treatment planning with either isotope revealed no significant differences. These findings may explain why clinically there seemed to be no clear difference in treatment outcome with either isotope. Based on these predictions, we recommend a clinical trial to compare the efficacy of the two isotopes.

Beam radiation with three-dimensional conformal planning appears to decrease morbidity of prostate cancer therapy. The 3-field, arc technique (3-FAT) technique was designed by computer modeling to improve radiation dose to the target and minimize dispersion to nearby organs. Toxicity was studied in patients with prostate cancer. We performed a retrospective study of 168 consecutive men with prostate cancer after 3-FAT radiotherapy with a median follow-up of 24 months. All patients, treated from 1996 through 1999 at the University of Colorado had a pathological diagnosis of cancer before irradiation. Therapy was designed with a urethrogram and planning computed tomography scan. The 3-FAT was employed using noncoplanar, rotational beams, and nonuniform blocking of portals. Patients were treated to a minimal tumor dose of 74 Gy in 37 fractions. Adverse effects were investigated. Definitive radiotherapy was given to 80% of the group, and 58% received total androgen blockade. 3-FAT produced favorable dose distributions for the rectum, bladder, femoral heads, and base of the penis. Patients routinely report minimal dysuria and frequency during treatment. There were minimal urinary complaints after irradiation and no proctitis, diarrhea, incontinence, or change in potency as a result of radiotherapy. The 3-FAT represents a technical improvement in the treatment of prostate cancer by minimizing radiation delivered to adjacent critical structures. There were minimal side effects to the rectum, bladder, and penis base despite high doses to the prostate and seminal vesicles. The large percentage of patients with preliminary prostate-specific antigen values below 1.0 portends efficacy.

Prostate brachytherapy is an increasingly popular treatment for early-stage prostate cancer. Until now, spinal or general anesthesia for the procedure has been the standard of care. For patient safety, patient convenience, and to limit use of operating facilities, the authors started performing implants routinely with local anesthesia. We present here an evaluation of patients' acceptance of prostate brachytherapy under local anesthesia. On arrival at our department on the morning of the procedure, the patient is brought into the simulator suite, an intravenous line is started, and a urinary catheter is inserted. With the patient in the lithotomy position, a 5-by-5-cm patch of perineal skin and subcutaneous tissue is anesthetized by local infiltration of 10 mL of 1% lidocaine, using a 25-gauge 5/8-inch needle. Immediately following injection into the subcutaneous tissues, the deeper tissues, including the pelvic floor and prostate apex, are anesthetized by injecting 15 mL lidocaine solution with approximately 8 passes of a 20-gauge 1-inch needle. Following subcutaneous and periapical lidocaine injections, the transrectal ultrasound (TRUS) probe is positioned to reproduce the planning images and a 3.5- or 6-inch, 22-gauge spinal needle is inserted into the peripheral planned needle tracks, monitored by TRUS. When the tips of the needles reach the prostatic base, about 1 mL of lidocaine solution is injected in the intraprostatic track, as the needle is slowly withdrawn. The lidocaine infiltration procedure takes approximately 10 to 15 minutes. Seed implantation is then performed as previously described. At the time of this report preparation, 58 of the 71 patients (81%) were interviewed, with a median follow-up of 6 months since the implant procedure. On a scale of 1 to 10, the median biopsy pain score was 4.5 compared with a median pain score with the implant procedure of 3.0. There was no clear correlation between the two scores (r = .26). There was no correlation between patients' implant pain score and the number of implant needles used, the pre-implant prostate size, or patient age. The prostate radiation dose coverage, calculated as the percent of the post-implant volume covered by the prescription isodose, averaged 88% (range, 75% to 99%). Five of the 55 patients interviewed (9%) stated that they would have preferred to have the procedure under general anesthesia. Ranked on a 1 to 5 scale, the median patient satisfaction was 5 and the average was 4.4. The substitution of local anesthesia has facilitated rapid introduction of a high-volume brachytherapy program at an institution, without requiring the allocation of significant operating room time. We are pleased with the overall level of patient comfort and satisfaction.

Based on suggestions by anecdotal evidence to date, an attempt is made to estimate the occurrence of non-disease-related prostate-specific antigen (PSA) spiking in the serum PSA profiles of a series of men treated by (125)I/(103)Pd brachytherapy with or without external beam irradiation. Five hundred ninety-one patients treated between January 1988 and December 1993 were eligible for study. Patients whose clinical status was described as equivocal (declining PSA > 1.0 ng/mL or rising PSA without documented disease [9.6% of the cohort]) were not considered. Evidence of PSA increases that were followed by decline were identified. Treatment and disease-specific parameters were examined for influence of the occurrence of spiking. In patients judged biochemical successes at last follow-up (serum PSA < or = 1.0 ng/mL), 35.8% exhibited a temporary increase of 0.2 ng/mL or more. Seventy-five percent of these patients exhibited a temporary increase between 0.3 and 3.4 ng/mL. The average time of the temporary increases was 24.8 months after implant. Spiking was not associated with a higher risk of clinical failure in this data set. Conventional risk factors for recurrent disease were not associated with benign PSA spiking. Low-magnitude serum PSA spiking may occur in up to one third of patients following permanent, low-dose rate brachytherapy of the prostate. Most of these observations occur up to 3 years after implant and do not appear to be related to disease recurrence. Caution should be taken before initiating further therapy pursuant to the observation of PSA spiking of less than 2 to 3 ng/mL shortly following brachytherapy. Frequent serum PSA sampling following prostate brachytherapy with early follow-up may overestimate biochemical failure rates.

The anatomic extent of prostate cancer has long served the role of providing prognostic information to assist in therapeutic decision-making, evaluating treatment outcomes, facilitating information exchange between medical centers, and promoting cancer research. However, nonanatomic factors are also associated with important pathological features of this condition and may be used to estimate therapeutic outcome. At present, tumor grade (eg, Gleason score) ascertained from the diagnostic biopsy specimen and the pretherapy serum prostate-specific antigen level are readily available in clinical practice. This information may be used along with clinical tumor stage to construct predictive models. These models may provide reliable estimates for the likelihood of extraprostatic tumor extension, seminal vesicle invasion, or pelvic lymph-node involvement. Consideration of this information may play a vital role in the selection of radiotherapeutic modality and in the definition of external beam radiotherapy treatment volumes. These same factors are also associated with disease relapse and may be combined in a fashion to estimate the prospects for cancer control in the individual patient and in homogeneous patient groups. Grouping patients according to the risk for and site of disease recurrence may be instrumental in the development of clinical trials that assess therapeutic approaches in appropriate subsets of patients.