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Cancer 12/2012; · 4.77 Impact Factor
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ABSTRACT: PURPOSE: Treatment with intensity-modulated radiation therapy (IMRT) is increasingly standard for prostate cancer. Volume-modulated arc therapy (VMAT) to deliver IMRT potentially enables shorter treatment time. The aim of this study was to test this hypothesis by measuring the average patient in-room time with VMAT versus dynamic multileaf collimator (DMLC) IMRT. METHODS: Custom institutional software (RTMetrix) was used to mine the treatment times from the record-and-verify database. The in-room time (the time between patient entry and exit) was computed for each patient using RTMetrix. Average room time was compared between VMAT patients (n = 44) and IMRT patients (n = 99). Subgroup comparisons (1-arc or 2-arc VMAT, 5-field or 7-field IMRT, and electromagnetic transponder [Calypso] or gold-marker tracking) were performed. For all comparisons, 2-tailed, 2-sample, equal variance Student's t-tests were used. RESULTS: Average room time was significantly shorter for all VMAT versus DMLC IMRT (P = .0014) procedures, along with VMAT versus 7-field DMLC IMRT (P < .001), but not VMAT versus 5-field DMLC IMRT (P = .81). Room time was longer for Calypso versus gold seed patients (P < .001), but VMAT reduced treatment time in Calypso patients (P = .01). This resulted in Calypso VMAT patients' having similar treatment times to non-Calypso DMLC IMRT patients (P = .220). CONCLUSIONS: These data show that VMAT can shorten room times and improve patient throughput over 7-field DMLC IMRT. Additionally, the data demonstrate that treatment with VMAT permits the use of advanced prostate tracking (Calypso), resulting in similar room times as with standard 7-field DMLC IMRT with conventional tracking.
Journal of the American College of Radiology: JACR 12/2012;
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ABSTRACT: External beam radiotherapy (EBRT) is widely utilized as primary therapy for clinically localized prostate cancer. For patients who develop locally recurrent disease after EBRT, local salvage therapy may be indicated. The primary modalities for local salvage treatment in this setting include radical prostatectomy, cryotherapy, and brachytherapy. To date, there is little data describing outcomes and toxicity associated with each of these salvage modalities.
A review of the literature was performed to identify studies of local salvage therapy for patients who had failed primary EBRT for localized prostate cancer. We focused on prospective trials and multi-institutional retrospective series in order to identify the highest level of evidence describing these therapies.
The majority of reports describing the use of local salvage treatment for recurrent prostate cancer after EBRT are single-institution, retrospective reports, although small prospective studies are available for salvage cryotherapy and salvage brachytherapy. Clinical outcomes and toxicity for each modality vary widely across studies, which is likely due to the heterogeneity of patient populations, treatment techniques, and definitions of failure. In general, most studies demonstrate that local salvage therapy after EBRT may provide long-term local control in appropriately selected patients, although toxicity is often significant.
As there are no randomized trials comparing salvage treatment modalities for localized prostate cancer recurrence after EBRT, the selection of a local treatment modality should be made on a patient-by-patient basis, with careful consideration of each patient's disease characteristics and tolerance for the risks of treatment. Additional data, ideally from prospective randomized trials, is needed to guide decision making for patients with local recurrence after EBRT failure.
The Canadian Journal of Urology 12/2012; 19(6):6534-41. · 0.64 Impact Factor
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ABSTRACT: To evaluate the impact of short-course androgen deprivation therapy (ADT) on cancer control outcomes and toxicity in intermediate-risk prostate cancer treated with dose-escalated external beam radiotherapy (high-dose radiotherapy [HDRT]).
Demographic, disease, and treatment characteristics of prostate cancer patients at 2 institution consortiums were charted. Of 296 men with intermediate-risk prostate cancer (defined as ≥T2b, prostate-specific antigen level >10 ng/mL, or Gleason score [GS] of 7, with none of the following: ≥T3, prostate-specific antigen level >20 ng/mL, GS ≥8, or positive nodes) treated with HDRT to a dose of 72 Gy or greater, 123 received short-course ADT and 173 did not. Univariate and multivariate analyses on biochemical failure-free survival (BFFS) (including subset analysis by disease factors) and on overall survival (OS) were performed, as were comparisons of gastrointestinal (GI) and genitourinary (GU) toxicity rates.
For the whole group, the median dose was 75.6 Gy; the minimum follow-up was 2 years, and the median follow-up was 47.4 months. For ADT vs. no ADT, the 5-year BFFS rate was 86% vs. 79% (p = 0.138) and the 5-year OS rate was 87% vs. 80% (p = 0.159). On multivariate analysis, percent positive cores (PPC) (p = 0.002) and GS (p = 0.008) were significantly associated with BFFS, with ADT showing a trend (p = 0.055). The impact of ADT was highest in the subsets with PPC greater than 50% (p = 0.019), GS 4+3 (p = 0.078), and number of risk factors greater than 1 (p = 0.022). Only intensity-modulated radiotherapy use (p = 0.012) and GS (p = 0.023) reached significance for OS, and there were no significant differences in GU or GI toxicity.
Although the use of ADT with HDRT did not influence BFFS, our study suggests a benefit in patients with PPC greater than 50%, GS 4+3, or multiple risk factors. No OS benefit was shown, and ADT was not associated with additional radiotherapy-related GI or GU toxicity.
International journal of radiation oncology, biology, physics 01/2012; 83(5):1473-9. · 4.59 Impact Factor
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David M Schuster,
Bital Savir-Baruch,
Peter T Nieh,
Viraj A Master,
Raghuveer K Halkar, Peter J Rossi,
Melinda M Lewis,
Jonathon A Nye,
Weiping Yu,
F DuBois Bowman,
Mark M Goodman
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ABSTRACT: To compare the diagnostic performance of the synthetic amino acid analog radiotracer anti-1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid (anti-3-(18)F-FACBC) with that of indium 111 ((111)In)-capromab pendetide in the detection of recurrent prostate carcinoma.
This prospective study was approved by the institutional review board and complied with HIPAA guidelines. Written informed consent was obtained. Fifty patients (mean age, 68.3 years ± 8.1 [standard deviation]; age range, 50-90 years) were included in the study on the basis of the following criteria: (a) Recurrence of prostate carcinoma was suspected after definitive therapy for localized disease, (b) bone scans were negative, and (c) anti-3-(18)F-FACBC positron emission tomography (PET)/computed tomography (CT) and (111)In-capromab pendetide single photon emission computed tomography (SPECT)/CT were performed within 6 weeks of each other. Studies were evaluated by two experienced interpreters for abnormal uptake suspicious for recurrent disease in the prostate bed and extraprostatic locations. The reference standard was a combination of tissue correlation, imaging, laboratory, and clinical data. Diagnostic performance measures were calculated and tests of the statistical significance of differences determined by using the McNemar χ(2) test as well as approximate tests based on the difference between two proportions.
For disease detection in the prostate bed, anti-3-(18)F-FACBC had a sensitivity of 89% (32 of 36 patients; 95% confidence interval [CI]: 74%, 97%), specificity of 67% (eight of 12 patients; 95% CI: 35%, 90%), and accuracy of 83% (40 of 48 patients; 95% CI: 70%, 93%). (111)In-capromab pendetide had a sensitivity of 69% (25 of 36 patients; 95% CI: 52%, 84%), specificity of 58% (seven of 12 patients; 95% CI: 28%, 85%), and accuracy of 67% (32 of 48 patients; 95% CI: 52%, 80%). In the detection of extraprostatic recurrence, anti-3-(18)F-FACBC had a sensitivity of 100% (10 of 10 patients; 95% CI: 69%, 100%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 100% (17 of 17 patients; 95% CI: 80%, 100%). (111)In-capromab pendetide had a sensitivity of 10% (one of 10 patients; 95% CI: 0%, 45%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 47% (eight of 17 patients; 95% CI: 23%, 72%).
anti-3-(18)F-FACBC PET/CT was more sensitive than (111)In-capromab pendetide SPECT/CT in the detection of recurrent prostate carcinoma and is highly accurate in the differentiation of prostatic from extraprostatic disease.
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102023/-/DC1.
Radiology 06/2011; 259(3):852-61. · 5.73 Impact Factor
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ABSTRACT: Several randomized trials have demonstrated a biochemical control advantage to an increase from the "conventional" 66 to 70 Gy range to the "high-dose" 75 to 81 Gy range; these trials have also, however, demonstrated a toxicity disadvantage. Our objective was to perform a toxicity analysis of a minor dose escalation (from 75.6 to 81.0 Gy) within this "high-dose" range.
A total of 189 patients comprised the study population-119 received 75.6 Gy and 70 received 81.0 Gy. Acute, late, and final (at most recent follow-up) gastrointestinal (GI) and genitourinary (GU) toxicity were charted for each group and compared using the χ test. Ordered logit regression analyses were performed on each toxicity end point, using all major demographic, disease, and treatment factors as covariates.
The 81.0 Gy group had higher rates of grade 2 acute GU (P < 0.001), late GU (P = 0.001), and late GI (P = 0.082) toxicity, a lower rate of acute GI toxicity (P = 0.002) and no notable differences in final GU (P = 0.551) or final GI (P = 0.194) toxicity compared with the 75.6 Gy group. The ordered logit regression analyses showed that only age (P = 0.019) and radiotherapy dose (P = 0.016) correlated with acute GU toxicity and only radiotherapy dose (P = 0.018) correlated with late GU toxicity. Only intensity modulated radiotherapy use (P = 0.001) correlated with acute GI toxicity; no factors correlated with late GI toxicity or final GU or GI toxicity.
Although some increases in acute and late toxicity rates were observed with even a minor dose escalation from 75.6 to 81.0 Gy, notably no increases in final late GI or GU toxicity rates were observed.
American journal of clinical oncology 02/2011; 34(1):11-5. · 2.21 Impact Factor
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ABSTRACT: To use the Surveillance, Epidemiology, and End Results (SEER) registry to analyze age-specific time trends in the use of radiotherapy (RT) (external beam radiotherapy [EBRT], brachytherapy [brachy], and combination therapy [combo]) as first-line treatment for prostate cancer.
A total of 820,649 prostate cancer patients in the SEER public-use registry (1973-2004) with diagnosis year, treatment, and age information available were identified. Modality use time-trend curves were plotted for patients 45 to 85+ years of age, grouped in 5-year intervals. A nonparametric (Spearman) test was used to assess the correlation between diagnosis year and (a) percentage use of RT and (b) relative percentage use of EBRT, brachy, and combo therapy.
Over the study period from 1973 to 2004, RT use increased in patients ≥65 years of age, but has remained stable in patients <65 years of age. All age groups experienced a similar relative rise in the use of brachy and combo therapy, with brachy use surpassing combo use in approximately year 2000.
Trends in treatment choice for early prostate cancer generally reflect treatment advances, but do not appear to be uniform among all age groups. The SEER database is a valuable asset for analyzing these trends and can be used to investigate age-specific treatment patterns.
American journal of clinical oncology 12/2010; 33(6):619-23. · 2.21 Impact Factor
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ABSTRACT: In the prostate specific antigen era most prostate cancer presents at an early stage. However, a significant number of patients have advanced disease, including those with stage IV disease. Assignment to stage IV prostate cancer may occur by different modes, namely as T4N0M0 vs N1 vs M1 disease. We hypothesize that patients with clinical T4 disease have better outcomes than those with N1 or M1 disease.
A total of 17 SEER registries were queried from 1995 through 2003. Multivariate and univariate analyses examined overall survival and prostate cancer specific survival across subcategories of stage IV disease while controlling for various patient and disease related characteristics.
There were 615 patients with cT4N0M0 disease, 3,189 with TxN1M0 and 10,893 with TxNxM1 who met the study inclusion criteria. Survival differences were observed between cT4N0M0 and M1 cancer, between N1 and M1 disease, and were most pronounced in younger patients (age 50 years or younger), gradually narrowing with increasing patient age. Factors that demonstrated significant association with poor survival included higher tumor grade, unknown tumor grade and absence of a spouse.
Staging systems based on American Joint Committee on Cancer/TNM staging enables the grouping of patients into homogenous categories for treatment selection and prognostication. However, our data suggest that not all stage IV prostate cancers behave similarly. The difference in survival among locally advanced (T4), node positive and distantly metastatic stage IV prostate cancer appears to be dependent on patient age.
The Journal of urology 08/2010; 184(2):512-8. · 4.02 Impact Factor
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ABSTRACT: Prostate cancer is the most common male cancer in the United States and the second leading cause of male cancer death. The main therapeutic modalities for the treatment of prostate cancer are surgery, external beam radiation therapy, hormonal therapy, and brachytherapy. In recent years, brachytherapy has been increasingly utilized for the treatment of early-stage prostate cancer. Technological advances, including improvements in imaging, planning, and postimplant quality assessment by dosimetry have led to widespread use of brachytherapy. Outcomes for prostate brachytherapy have been shown to be equivalent, in selected patients, to those of other treatment modalities for prostate cancer, including radical prostatectomy and external beam radiation therapy. Further, prostate brachytherapy has quality-of-life benefits in comparison to these other treatment modalities, particularly in the domain of sexual function. This paper describes the history of low-dose rate brachytherapy; current techniques for brachytherapy implantation and postoperative dosimetric evaluation; recent outcomes studies; recent quality-of-life analyses; and current and future prostate brachytherapy developments, including open clinical trials. As research in prostate brachytherapy continues, it is likely that this modality will play an increasingly important role in the treatment of early-stage prostate cancer patients in the future.
Journal of the National Medical Association 06/2010; 102(6):500-10. · 1.16 Impact Factor
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ABSTRACT: Discovery of positive lymph nodes (LNs) in patients with cervix cancer is important prognostically, may direct adjuvant therapy, and may have therapeutic benefit. The purpose of this Surveillance Epidemiology and End Results (SEER) analysis was to assess the value of lymphadenectomy (LND) in patients with cervical cancer.
The 17-registry SEER database was searched for patients treated for cervical cancer between 1988 and 1998. Observed survival (OS) and expected survival (ES) were reported with a minimum of 5-year follow-up. Chi-square analysis and log-rank test were used to compare OS and ES.
Between 1988 and 1998, 4,059 of 12,882 patients underwent LND for cervical cancer and were registered. By stage, 2,653 of 7,621 stage I, 341 of 2,042 stage II, 814 of 1,986 stage III, 251 of 1,233 stage IV, and 28 of 226 stage IVA patients underwent LND. Of these, 778 stage III and 210 stage IV patients had a +LN. Patients who underwent LND had improved OS (P = 0.001). OS was significantly increased for each stage after LND. OS increased based on number of nodes resected. OS increased up to 15 nodes resected (P = 0.01).
This SEER analysis of 12,882 patients suggests that LND benefited patients with cervical cancer and OS was improved.
Journal of Surgical Oncology 10/2009; 100(5):404-6. · 2.10 Impact Factor
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The Journal of urology 02/2009; 181(3):947-8. · 4.02 Impact Factor
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ABSTRACT: Prostate cancer represents a model site for advances in understanding inter- and intrafraction motion for radiotherapy. In this study, we examined the correlation of the electromagnetic transponder system/Calypso 4D Localization System with conventional on-board imaging (OBI) using kilovoltage imaging. Initially using a quality assurance (QA) phantom and subsequently using data of seven patients, the vector distances between Calypso- and OBI-recorded shifts were compared using the t-test. For the 30 phantom measurements, the average differences between the measured Calypso offset and the calculated OBI shift were 0.4 +/- 0.4, 0.2 +/- 0.3, and 0.4 +/- 0.3 mm in the lateral, longitudinal, and vertical directions, respectively (p = 0.73, p = 0.91, and p = 0.99, respectively), and the average difference vector for all sessions was 0.8 +/- 0.4 mm. For the 259 patient measurements, the average differences between the measured Calypso offset and the calculated OBI shift were 0.7 +/- 0.5, 1.1 +/- 0.9, and 1.2 +/- 0.9 mm in the lateral, longitudinal, and vertical directions, respectively (p = 0.45, p = 0.28, and p = 0.56, respectively), and the average difference vector for all sessions was 2.1 +/- 1.0 mm. Our results demonstrated good correlation between Calypso and OBI. While other studies have explored the issue of Calypso/OBI correlation, our analysis is unique in our use of phantom validation and in our performing the patient analysis on an initial population prior to routine setup using Calypso without OBI. Implications for Calypso's role as a QA tool are discussed.
TheScientificWorldJOURNAL 02/2009; 9:449-58. · 1.66 Impact Factor
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ABSTRACT: The purpose of this report is to evaluate the movement of the planning target volume (PTV) in relation to the pelvic lymph nodes (PLNs) during treatment of high-risk prostate cancer.
We reviewed the daily treatment course of ten consecutively treated patients with high-risk prostate cancer. PLNs were included in the initial PTV for each patient. Daily on-board imaging of gold fiducial markers implanted in the prostate was used; daily couch shifts were made as needed and recorded. We analyzed how the daily couch shifts impacted the dose delivered to the PLN.
A PLN clinical target volume was identified in each man using CT-based treatment planning. At treatment planning, median minimum planned dose to the PLN was 95%, maximum 101%, and mean 97%. Daily couch shifting to prostate markers degraded the dose slightly; median minimum dose to the PLN was 92%, maximum, 101%, and mean delivered, 96%. We found two cases, where daily systematic shifts resulted in an underdosing of the PLN by 9% and 29%, respectively. In other cases, daily shifts were random and led to a mean 2.2% degradation of planned to delivered PLN dose.
We demonstrated degradation of the delivered dose to PLN PTV, which may occur if daily alignment only to the prostate is considered. To improve PLN PTV, it maybe preferable to deliver the prostate/boost treatment first, and adapt the PTV of the pelvic/nodal treatment to uncertainties documented during prostate/boost treatment.
Radiotherapy and Oncology 11/2008; 90(3):353-8. · 5.58 Impact Factor
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ABSTRACT: To assess the role of radiotherapy (RT) in women with Stage IIIC endometrial cancer.
The 17-registry Survival, Epidemiology, and End Results (SEER) database was searched for patients with lymph node-positive non-Stage IV epithelial endometrial cancer diagnosed and treated between 1988 and 1998. Two subgroups were identified: those with organ-confined Stage IIIC endometrial cancer and those with Stage IIIC endometrial cancer with direct extension of the primary tumor. RT was coded as external beam RT (EBRT) or brachytherapy (BT). Observed survival (OS) was reported with a minimum of 5 years of follow-up; the survival curves were compared using the log-rank test.
The therapy data revealed 611 women with Stage IIIC endometrial cancer during this period. Of these women, 51% were treated with adjuvant EBRT, 21% with EBRT and BT, and 28% with no additional RT (NAT). Of the 611 patients, 293 had organ-confined Stage IIIC endometrial cancer and 318 patients had Stage IIIC endometrial cancer with direct extension of the primary tumor. The 5-year OS rate for all patients was 40% with NAT, 56% after EBRT, and 64% after EBRT/BT. Adjuvant RT improved survival compared with NAT (p <0.001). In patients with organ-confined Stage IIIC endometrial cancer, the 5-year OS rate was 50% for NAT, 64% for EBRT, and 67% for EBRT/BT. Again, adjuvant RT contributed to improved survival compared with NAT (p = 0.02). In patients with Stage IIIC endometrial cancer and direct tumor extension, the 5-year OS rate was 34% for NAT, 47% for EBRT, and 63% for EBRT/BT. RT improved OS compared with NAT (p <0.001). Also, in this high-risk subgroup, adding BT to EBRT was superior to EBRT alone (p = 0.002).
Women with Stage IIIC endometrial cancer receiving adjuvant EBRT and EBRT/BT had improved OS compared with patients receiving NAT. When direct extension of the primary tumor was present, the addition of BT to EBRT was even more beneficial.
International Journal of Radiation OncologyBiologyPhysics 02/2008; 70(1):134-8. · 4.11 Impact Factor
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ABSTRACT: We previously reported the applications of population dynamics modeling on cancer populations. Cancer death populations show a reproducible progression from an essentially linear phase, in which cure is likely, through a Gompertzian phase of advancing disease to an exponential phase of incurable disease. The latter 2 phases meet at an inflection, at which the disease process becomes incurable. Patients with prostate cancer and positive lymph nodes are often considered to be doomed to distant failure. We applied these models to that population to examine whether those data support this presumption.
The public use Surveillance, Epidemiology and End Results Registry was queried for observed survival data on the population of men with nonmetastatic prostate cancer and positive lymph nodes presenting between 1988 and 1993. Lymph node data were first collated in 1988. The closing date was selected to allow a minimum 10-year followup since Surveillance, Epidemiology and End Results data are complete through 2003. These data were modeled using Gompertzian and exponential models to determine whether an inflection point exists.
Gompertzian modeling best described the observed survival of the 2,265 patients retrieved from the Surveillance, Epidemiology and End Results Registry. Analysis of the data revealed an inflection 4 years after diagnosis. We interpreted this to indicate that there is a 4-year window during which curative therapy may be initiated in this population of patients.
Patients with lymph node positive prostate cancer need not be considered to represent a doomed population, although new therapies are crucial in that case. We theorize that a 4-year window exists during which potentially curable therapies may be performed.
The Journal of Urology 12/2007; 178(5):1952-5; discussion 1955-6. · 3.75 Impact Factor
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ABSTRACT: The objective of this study was to describe a simple model that predicts freedom from biochemical recurrence (FFBR) in men with prostate cancer after treatment with low-dose rate prostate brachytherapy (LDRPB) alone.
One hundred thirty-two men were treated with LDRPB alone between September 1997 and April 2001. Sixty-four percent of men had low-risk disease (prostate-specific antigen [PSA] <10, Gleason <7, and T stage <T2b) and 36% had intermediate-risk disease (PSA > or =10, Gleason > or =7, or T stage T2b). The dosimetric quantifier D90 was calculated from a computed tomography scan performed 1 month after LDRPB. The percent positive biopsies (PPB) were determined for all patients. FFBR was estimated using the product limit method. All P values are 2-sided.
The median follow-up is 65 months. The median D90 is 138 Gy (range, 47-221 Gy). Fourteen men have developed evidence of biochemical relapse at a median of 27 months (range, 6-42 months). The 5-year FFBR rate for the entire cohort is 88%. On univariate analysis, variables found to be associated with FFBR included: PSA, Gleason score, T stage, risk group, PPB, and D90. Multivariate analysis indicated that D90, PPB, and risk group were independently associated with FFBR. Patients were categorized based on the following 3 adverse prognostic factors: D90 <140 Gy, PPB > or =50%, and intermediate-risk group. Group 1 (0 factors, n = 30), group 2 (1 factor, n = 72), and group 3 (> or =2 factors, n = 30) patients had 5-year FFBR rates of 100% (+/-0%), 92% (+/-6%), and 67% (+/-18%) (P < 0.0001).
We have developed a simple, robust model based on implant quality and disease factors that predicts FFBR in men with prostate cancer treated with LDRPB alone.
American journal of clinical oncology 04/2007; 30(2):199-204. · 2.21 Impact Factor
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ABSTRACT: To examine the relationship between the percentage of positive biopsies (PPBs) and freedom from biochemical recurrence (FFBR) in men treated with low-dose-rate prostate brachytherapy (LDRPB) alone. The PPBs has been associated with FFBR in men treated with radical prostatectomy and external beam radiotherapy for prostate cancer.
This report concerns 108 men treated with LDRPB alone between November 1997 and December 1999. All patients had clinically localized prostate cancer confirmed by biopsy. All men were treated with iodine-125 to 144 Gy. FFBR was estimated using the product-limit method. Putative covariates for FFBR, including T stage, Gleason score, pretreatment prostate-specific antigen level, minimal dose received by 90% of the target volume, and PPBs, were examined using the proportional hazards regression model.
The median follow-up was 61 months. Of the 108 men, 13 developed evidence of biochemical relapse at a median of 25 months. The 5-year estimate of FFBR was 87% (95% confidence interval 81% to 93%) for the entire cohort. On univariate analysis, prostate-specific antigen, T stage, minimal dose received by 90% of the target volume, and PPBs were associated with FFBR. In the multivariate model, the PPBs was the only variable that predicted for FFBR (P = 0.002). The 5-year estimate of FFBR was 95% for patients with less than 50% PPB disease versus 63% in patients with more than 50% PPB disease (P < 0.0001).
The PPBs is an important independent predictor of FFBR after LDRPB alone. The FFBR after LDRPB in the group of patients with more than 50% PPBs was poor.
Urology 02/2006; 67(2):349-53. · 2.43 Impact Factor
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ABSTRACT: One of the explicit goals of the American Society of Therapeutic Radiology and Oncology (ASTRO) is to promote research and disseminate research results. In the past few years, ASTRO has required that manuscripts be submitted for publication for all papers accepted for oral presentation at its annual meeting. The purpose of this study was to determine the publication rate of abstracts accepted for oral presentation at ASTRO's 1999, 2000, and 2001 annual meetings.
The authors reviewed the proceedings of ASTRO's annual meetings in 1999, 2000, and 2001 to identify all abstracts accepted for oral presentation. The following information was collected: year of presentation, study design (phase I or II, phase III, or retrospective), country of origin (domestic or foreign), abstract category (clinical or nonclinical), disease site (if applicable), publication (yes or no), publication date, and publishing journal. A computer-based search using Medline was used to determine whether the full publication of each abstract had occurred. The computer search included publication up to November 1, 2003.
The publication rate was 56% (452 of 802). There was no difference in publication rate according to country of origin (domestic 56%, foreign 57%; p = NS), abstract category (clinical 59%, nonclinical 48%; p = NS), or study design. Half of the published abstracts were published within 1 year of the meeting, and 90% were published within 2 years. The 452 publications were distributed among 54 different journals. The majority of papers were published in the International Journal of Radiation Oncology, Biology and Physics (62%), followed by the Journal of Clinical Oncology (8%) and Radiotherapy and Oncology (3%).
Slightly more than one-half of the abstracts accepted for oral presentation at the annual ASTRO meeting are published within 2 years. This rate is similar to those of other specialties and suggests that ASTRO is succeeding in its mission to promote and disseminate research.
Journal of the American College of Radiology: JACR 02/2005; 2(1):72-5.
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ABSTRACT: The purpose of the present report is to describe the relationship between two dosimetric quantifiers (V(100) and D(90)) and freedom from biochemical recurrence (FFBR) in a cohort of men treated with low-dose-rate prostate brachytherapy (LDRPB) alone.
One hundred three men were treated with LDRPB alone between September 1997 and December 1999. All men had histologically confirmed clinically localized prostate cancer. Fifty-nine percent of the cohort had low-risk disease (defined as PSA<10, Gleason <7, and T stage <T2b), and 41% had intermediate-risk disease (defined as PSA>/=10, Gleason>/=7, or T stage T2b). The prescription dose was 144Gy according to the Task Group 43 formalism. LDRPB was performed jointly by a radiation oncologist and a urologist. Dosimetric quantifiers (D(90), V(100)) were calculated from a CT scan performed 1 month after LDRPB. Biochemical recurrence was defined according to the ASTRO Consensus Definition. FFBR was estimated using the product-limit method. Disease-specific and treatment variables were examined as putative covariates for FFBR using the proportional hazards regression method. Univariate and multivariate methods were used. All p values are two sided.
The median followup for the entire cohort is 61 months. The median followup of patients at risk for biochemical failure is 66 months. The median D(90) is 129Gy (range 47-221Gy), and the median V(100) is 86% (range 51-99%). Thirteen men have developed evidence of biochemical relapse at a median of 25 months (range 6-42 months). The 5-year estimate of FFBR for the entire cohort is 87% (95% CI 80-94%). On univariate analysis, disease-specific variables found to be significantly associated with FFBR included pretreatment PSA and percent positive biopsies. When considered as a continuous variable, each of the dosimetric quantifiers was associated with FFBR (V(100): p=0.007; D(90): p=0.05). D'Amico risk group classification is highly predictive of FFBR after LDRPB (HR 5.68, p=0.003). Multivariate analysis indicated that each dosimetric quantifier was independently associated with FFBR, but due to the high degree of correlation (Pearson correlation coefficient 0.94, p<0.0001) between the dosimetric quantifiers both could not be included simultaneously in the model. In the two models explored, V(100) was at least as good as D(90) in predicting FFBR.
Dosimetric quantifiers (V(100) and D(90)) are independent predictors of FFBR after treatment with LDRPB alone. In our experience, V(100) seems to be at least equivalent (and perhaps superior) to D(90) for predicting FFBR.
Brachytherapy 01/2005; 4(4):252-8. · 1.47 Impact Factor
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ABSTRACT: This report examines the relationship between pretreatment prostate-specific antigen (PSA) velocity (PSAV) and freedom from biochemical recurrence (FFBR) in men with prostate cancer treated with low-dose-rate prostate brachytherapy (LDRPB).
This is a report of 51 men treated with LDRPB between 1997 and 1999. Inclusion criteria: two or more evaluable PSA values >3 months apart and <18 months before treatment. PSAV is calculated using a linear regression equation. All patients had biopsy confirmed, clinically localized prostate cancer. All men were treated with (125)I LDRPB. The prescription dose was 144Gy. Biochemical failure is determined from PSA values over time using the ASTRO Consensus Definition. FFBR is estimated using Kaplan-Meier method. Pretreatment variables analyzed include percentage positive biopsy cores, D(90), risk group, and PSAV. All p values are two-sided.
The median followup is 60 months. The median pretreatment PSA is 6.5, 75% of men were Stage T1c, and 88% had Gleason score > or =6; 10% developed evidence of biochemical recurrence at a median of 13 months (range, 6-36). The 6-year estimate of FFBR is 90% for the entire cohort. On univariate analysis, pretreatment PSAV and risk group are associated with FFBR. The 6-year estimate of FFBR in patients with a PSAV <2 ng/mL/yr is 100% vs. 80% (95% confidence interval: 64-96%) when the pretreatment PSAV is > or =2 ng/mL/yr before LDRPB (p = 0.017).
Pretreatment PSAV is a predictor of FFBR after LDRPB in this population of men with prostate cancer. Men with a pretreatment PSAV > or =2 ng/mL/yr may warrant more aggressive treatment.
Brachytherapy 7(4):286-9. · 1.47 Impact Factor
