Biomedical subjects

Jose Gonzalez

Publications and source records attributed to Jose Gonzalez.

13 recordsLinked to original sources

PubMed2006

Hypofractionated conformal HDR brachytherapy in hormone naïve men with localized prostate cancer. Is escalation to very high biologically equivalent dose beneficial in all prognostic risk groups?

PURPOSE: To analyze the long-term effect of local dose escalation using conformal hypofractionated high-dose-rate brachytherapy (HDR-BT) boost and pelvic external-beam radiation therapy (EBRT) in hormone-naïve men with localized prostate cancer. PATIENTS AND METHODS: A total of 579 men were consecutively treated with pelvic EBRT and dose escalating HDR-BT since 1986 in two prospective trials: 378 patients at William Beaumont Hospital (1991-2002), and 201 patients at Kiel University (1986-1999). BT optimization was done modulating both, the dwell times and spatial source positions. A short course of neoadjuvant/concurrent androgen deprivation therapy was given to 222 patients. Hormone-naïve patients only (n = 324) with a follow-up > or = 18 months were analyzed. All patients had at least one poor prognostic factor (stage > or = T2b, Gleason Score > or = 7, pretreatment prostate-specific antigen [PSA] > or = 10 ng/ml): any one factor 122 patients, any two factors 122 patients, and three factors 80 patients. This cohort was stratified by equivalent dose (ED): dose level 1, < or = 94 Gy, n = 58, and dose level 2, > 94 Gy, n = 266, assuming an alpha/beta ratio of 1.2. The ASTRO definition for biochemical failure was used. RESULTS: Mean follow-up was 5.3 years (1.5-13.9 years). For all 324 patients, the 5-year biochemical control (BC) rate was 79%. Cancer-specific survival was 98%, and overall survival 90%. Similar analysis by institution demonstrated no difference in outcomes. For the entire cohort of hormone-naïve men, dose escalation to > 94 Gy resulted in a better 5-year BC of 59% versus 85% (p < 0.001). Discriminating by risk group a striking dose escalation effect was seen in the groups with two or three poor prognostic factors (p = 0.022 and < 0.001, respectively). In the group with only one poor prognostic factor, no statistical difference could be detected questioning the need for ED > 94 Gy. CONCLUSION: The results demonstrate that conformal HDR-BT is a successful method for delivering very high radiation dose to the prostate. The ability to escalate dose to ED > 94 Gy was reflected in improved long-term outcomes in terms of BC, significantly for those patients with two or three poor prognostic factors reaching BC rates of 85%.

Actuarial Analysis↗

PubMed2006

Matched-pair analysis of prostate cancer patients with a high risk of positive pelvic lymph nodes treated with and without pelvic RT and high-dose radiation using high dose rate brachytherapy.

OBJECTIVE: Adding pelvic radiation to high-dose prostate radiation for prostate cancer patients with a >15% risk of positive lymph nodes (LN) is controversial. We performed a matched-pair analysis of patients treated at 2 institutions to assess the impact of pelvic radiotherapy (P-RT). METHODS: From January 1993 to March 2003, 2 institutions treated 1432 prostate cancer patients with combined external beam radiotherapy (EBRT) and high-dose rate (HDR) brachytherapy. Those receiving EBRT were treated either to the prostate and seminal vesicles alone or to the entire pelvis (46 Gy). In all cases, prostate dose (EBRT and HDR) resulted in an average BED >100 Gy (alpha/beta = 1.2). There were 755 cases identified as having a pelvic LN risk >15% using the Roach formula. Of these, 255 cases were treated without pelvic RT and randomly matched by Gleason score, T stage, and pretreatment PSA to 500 cases treated with pelvic RT, resulting in 250 pairs (1:1). RESULTS: Median follow-up was 4.0 years (P = 0.7). The 4-year prostate biochemical failure (22% versus 14%, P = 0.12), distant metastasis (9% versus 4%, P = 0.6), event-free survival (72% versus 78%, P = 0.3), prostate cancer death rate (4% versus 2%, P = 0.9), and overall survival (89% versus 88%, P = 0.7) were not significantly different for patients treated with and without P-RT. Analysis with and without androgen deprivation therapy showed similar results. CONCLUSION: Improved biochemical, clinical, or survival outcomes were not observed for prostate cancer patients at risk for positive pelvic LN >15% when treated with high-dose EBRT and HDR brachytherapy to the prostate with or without pelvic radiation.

Aged↗

PubMed2005

Evaluation of factors affecting awareness of and willingness to participate in cancer clinical trials.

PURPOSE: Annually, only 3% of patients participate in cancer clinical trials (CCTs). Barriers to accrual include lack of CCT awareness and uncertain third-party payer coverage. In January 2002, a California law (Senate Bill 37 [SB37]) required all third-party payers to reimburse patient care costs related to CCTs. We evaluated the level of awareness of patients and/or their family members/friends regarding CCTs and SB37. METHODS: We used both a written survey for patients and/or their family members and friends seen in oncology clinics, and a verbal telephone version for Cancer Information Service callers. We tested for correlations between CCT awareness and SB37 knowledge, and willingness to participate in CCTs. RESULTS: Of 1,188 respondents, 59% were aware of CCTs, 19% knew of SB37, and 36% were very likely to consider a CCT. There were significant positive correlations between CCT awareness and willingness to participate (P < .001, Spearman), and between SB37 knowledge and willingness to participate (P = .001, Pearson chi2). Reduced awareness was seen in respondents who were either black or African American (odds ratio [OR], 0.44; P = .004), Hispanic (OR, 0.56; P = .03), had an annual income less than 25,000 dollars (OR, 0.38; P < .001), or had less than a college degree (OR, 0.12 to 0.53; P < .001 to .013). Reduced willingness to participate in CCTs was seen in black or African American participants (OR, 0.38; P < .001), Asians (OR, 0.44; P < .006), or respondents aged 18 to 24 years (OR, 0.35; P = .002). CONCLUSION: These results support the hypothesis that improving CCT awareness and SB37 knowledge especially among lower income, less educated, and minority patients, may potentially overcome barriers to participation and subsequently increase accrual in California.

Adolescent↗

PubMed2005

Lack of benefit from a short course of androgen deprivation for unfavorable prostate cancer patients treated with an accelerated hypofractionated regime.

PURPOSE: High-dose radiotherapy, delivered in an accelerated hypofractionated course, was utilized to treat prostate cancer. Therapy consisted of external beam radiotherapy (EBRT) and transrectal ultrasound (TRUS)-guided conformally modulated high-dose rate (HDR) brachytherapy. The purpose of this report is (1) to assess long-term comparative outcomes from three trials using similar accelerated hypofractionated regimes; and (2) to examine the long-term survival impact of a short course of < or =6 months adjuvant/concurrent androgen deprivation when a very high radiation dose was delivered. METHODS AND MATERIALS: Between 1986 and 2000, 1,260 patients were treated at three institutions with pelvic EBRT (36-50 Gy) integrated with HDR prostate brachytherapy. The total dose including brachytherapy was given over 5 weeks. The biologic equivalent EBRT dose ranged between 90 and 123 Gy (median, 102 Gy) using an alpha /beta of 1.2. Patient eligibility criteria included a pretreatment prostate-specific antigen > or =10, Gleason score > or =7, or clinical stage > or =T2b. A total of 1,260 patients were treated, and 934 meet the criteria. Kiel University Hospital treated 198 patients; William Beaumont Hospital, 315; and California Endocurietherapy Cancer Center, 459 patients. Brachytherapy dose regimes were somewhat different between centers and the dose was escalated from 5.5 x 3 to 15 Gy x 2 Gy. Patients were divided for analysis between the 406 who received up to 6 months of androgen deprivation therapy and the 528 patients who did not. All patients had a minimum follow-up of 18 months (3 times the exposure to androgen deprivation therapy). The American Society for Therapeutic Radiology and Oncology biochemical failure definition was used. RESULTS: Mean age was 69 years. Median follow-up time was 4.4 years (range, 1.5-14.5); 4 years for androgen deprivation therapy patients and 4.9 for radiation alone. There was no difference at 5 and 8 years in overall survival, cause-specific survival, or biochemical control among the three institutions. The corresponding 8-year rates with and without androgen deprivation therapy were biochemical control 85% and 81%; overall survival 83% and 78%; cause-specific survival 89% and 94%; and metastatic rates of 16.6% and 7.3%. A multivariate analysis revealed androgen deprivation therapy did not predict for biochemical failure for either the entire group or the subset of 177 patients harboring all three poor prognostic factors. Moreover, adding androgen deprivation therapy strongly correlated with higher rates of both metastasis (p = 0.09; hazard ratio, 2.08) and cancer-related deaths (p = 0.02, hazard ratio 3.25). These negative results for the most unfavorable group led us to question if androgen deprivation therapy might have a deleterious impact through delay in delivery of the potentially curative radiation or whether there may be a biologic basis by fixing the cycling cells in G0. CONCLUSIONS: Accelerated hypofractionated pelvic EBRT integrated with TRUS-guided conformally modulated HDR administered to 1,260 patients in three institutions was an excellent method of delivering very high radiation dose to the prostate in 5 weeks. Similar high overall, cause-specific, and biochemical no evidence of disease survival rates achieved show that prostate HDR can be successfully delivered in academic and community settings. At 8 years, the addition of a course of < or =6 months of neoadjuvant/concurrent androgen deprivation therapy to a very high radiation dose did not confer a therapeutic advantage but added side effects and cost. Furthermore, for the most unfavorable group, there was a higher rate of distant metastasis and more prostate cancer-related deaths. We question the value of a short course of androgen deprivation therapy when used with high-dose radiation.

Aged↗

PubMed2005

A new model using number of needles and androgen deprivation to predict chronic urinary toxicity for high or low dose rate prostate brachytherapy.

PURPOSE: Prostate brachytherapy is an established treatment modality in early stage prostate cancer. We retrospectively reviewed our experience with low dose rate (LDR) and high dose rate (HDR) brachytherapy as a single treatment modality for early prostate cancer with emphasis on chronic toxicity. MATERIALS AND METHODS: From June 1996 to August 2003, 253 patients with stage II prostate cancer, prostate specific antigen less than 12 and Gleason score less than 7 were treated with brachytherapy alone at our institution. A total of 92 patients underwent HDR brachytherapy with 192Ir, while 161 underwent LDR brachytherapy with 103Pd. HDR minimum prostate dose was 38 Gy, delivered in 4 fractions with a single implant during 36 hours. For HDR we used real-time dynamic 3-dimensional ultrasound base dosimetry. For 103Pd seed implants the dose was 120 Gy using selective peripheral weighted dose distribution. Treatment was given based on patient preference after pretreatment transrectal ultrasound. Toxicity was scored using the National Cancer Institute Common Toxicity Criteria 2.0. Median followup in all 253 cases was 2.9 years. RESULTS: In all patients the rate of 3-year urinary toxicity grade 2 or greater and grade 3 or greater was 26% and 6.9%, which was not significantly different between HDR and LDR (p = 0.3 and 0.4, respectively). However, grade 1 urogenital toxicity was lower for HDR (p = 0.002). The 3-year grade 2 rectal toxicity rate was 0.8% with no grade 3 or greater events, which was and similar in the HDR and LDR groups (1% and 0.6%, respectively). No cancer related deaths occurred and 4-year overall survival was 99% for HDR and 96.4% for LDR (p = 0.4). The 3-year American Society for Therapeutic Radiology and Oncology biochemical control rate was 90% for LDR and 93% for HDR. Cox multivariate analysis for grade 2 or greater urinary toxicity was significant for the use of 14 or greater needles (HR 6.1, p = 0.02) and hormonal therapy (HR 2.2, p = 0.02). In the absence of risk factors the 4-year grade 2 or greater urinary toxicity rate was 7% vs 65% if the 2 risk factors were present (p <0.001). Impotence crude rates were 18.3% for HDR and 41.3% for LDR (p = 0.002). CONCLUSIONS: HDR and LDR chronic urinary toxicity grade 2 or greater rates were equivalent. However, grade 1 was lower for HDR. The impotence rate was decrease by half with HDR. Neoadjuvant hormonal therapy and 14 or greater needles were significantly associated with increased chronic urinary toxicity on multivariate analysis.

Aged↗

PubMed2004

Risk of aspiration pneumonia after an epileptic seizure: a retrospective analysis of 1634 adult patients.

We reviewed the incidence of aspiration pneumonia secondary to seizures in three populations of patients with chronic epilepsy: 733 outpatients seen in an Epilepsy Foundation clinic; 806 adult patients admitted to two university video telemetry units; and 95 institutionalized, profoundly retarded adult patients with chronic epilepsy. Two of the 733 adults who had seizures in the outpatient setting and 2 of the 806 patients who had one or more epileptic seizures in the telemetry units developed aspiration pneumonia. In the 95 institutionalized patients, there were 17 instances of aspiration pneumonia after a generalized seizure and 32 instances of aspiration unrelated to seizures over a 12-month period. Our findings suggest that aspiration pneumonia is not a common complication of seizures in otherwise healthy adults. The increased incidence of aspiration in developmentally delayed individuals seems to derive from a combination of factors. Increased oral secretions, impaired swallowing mechanisms, and difficulty in attaining adequate patient positioning significantly increased the risk of aspiration.

Adult↗

PubMed2004

A novel DNA-based microfluorimetric method to evaluate antimalarial drug activity.

This paper describes the development of a novel microfluorimetric assay to measure the inhibition of Plasmodium falciparum based on the detection of parasitic DNA by intercalation with PicoGreen. The method was used to determine parasite inhibition profiles and 50% inhibitory concentration values of known or potential antimalarial drugs. Values for parasite inhibition with known anti-malarial drugs using the PicoGreen assay were comparable with those determined by the standard method based upon the uptake of 3H-hypoxanthine and the Giemsa stain microscopic technique. The PicoGreen assay is rapid, sensitive, reproducible, easily interpreted, and ideally suited for screening of large numbers of samples for anti-malarial drug development.

Animals↗

PubMed2003

Conformal high dose rate brachytherapy improves biochemical control and cause specific survival in patients with prostate cancer and poor prognostic factors.

PURPOSE: To improve outcome for patients with prostate cancer with poor prognostic factors higher than conventional radiation doses are required. To achieve this outcome a brachytherapy boost was given. We report the results of the first high dose rate dose-escalation brachytherapy trial. MATERIALS AND METHODS: Between 1991 and 2000, 207 patients were prospectively enrolled in a dose escalation trial including pelvic radiotherapy and conformal high dose rate prostate brachytherapy boost. The dose was increased from 5.5 to 11.5 Gy. per implant. Patient eligibility for the study included pretreatment prostate specific antigen 10 or greater, Gleason 7 or greater or clinical stage T2b or higher. No patient received hormonal therapy. The American Society for Therapeutic Radiology and Oncology consensus panel definition of biochemical failure was applied. RESULTS: Median patient age was 69 years. Mean followup was 4.7 years (range 0.6 to 10.4). The 5-year actuarial biochemical control rate was 74%. The 5-year biochemical control was 85% for 1 poor prognostic factor, 75% for 2 and 50% for all 3 (p = 0.001). On Cox regression multivariate analysis lower brachytherapy dose, and higher Gleason and nadir value were associated with biochemical failure. The 5-year actuarial overall survival was 92%, cause specific survival 98% and disease-free survival 68%. The 5-year actuarial rates of complications were 8% and 0% for grades 3 and 4 genitourinary, and 0.5% and 0.5% for grades 3 and 4 gastrointestinal, respectively. The 5-year actuarial impotence rate was 51%. CONCLUSIONS: For patients with poor prognostic factors external beam radiation therapy with conformal high dose rate brachytherapy boost improved biochemical control, resulting in a high cause specific survival rate with low toxicity. Another important advantage is that the patient is not radioactive after the high dose rate implant.

Actuarial Analysis↗

PubMed2003

No apparent benefit at 5 years from a course of neoadjuvant/concurrent androgen deprivation for patients with prostate cancer treated with a high total radiation dose.

PURPOSE: We examined the survival impact of a course of 6 months or less of adjuvant/concurrent androgen deprivation in patients with unfavorable prostate cancer treated to high radiation doses with external beam (EBRT) and a high dose rate (HDR) brachytherapy boost. MATERIALS AND METHODS: Between 1986 and 2000, 507 patients were treated with pelvic EBRT (46 Gy) with HDR prostate brachytherapy as a boost. The biological equivalent EBRT dose was between 90 and 130 Gy. At Kiel University and at William Beaumont Hospital 198 and 309 patients were treated. Patient eligibility was pretreatment prostate specific antigen 10 ng/ml or greater, Gleason score 7 or greater, or clinical stage T2b or greater. The brachytherapy dose was escalated from 5.5 x 3 to 15 x 2 Gy. Patients were divided between 177 receiving and 330 not receiving androgen suppression therapy (AST). AST was given for a mean of 6 months. The American Society for Therapeutic Radiology and Oncology biochemical failure definition was used. RESULTS: Mean patient age was 68 years. Mean followup was 4.8 years (range 0.7 to 15.3), that is 4.5 years for AST and 4.9 for radiation alone. Five-year actuarial rates for biochemical control were 74% and 76%, for overall survival they were 81% and 87%, and for disease-free survival they were 67% and 66%, while cause specific survival with and without AST was 90% and 98%, and the 5-year metastatic rates were 10.7% and 6.9%, respectively. On multivariate analysis AST did not improve biochemical control. CONCLUSIONS: Pelvic EBRT interdigitated with a transrectal ultrasound guided HDR boost is an excellent method of delivering a high radiation dose to the prostate without rendering the patient radioactive. This trial showed high overall, cause specific and no biochemical evidence of disease survival. For this unfavorable group of patients the addition of a course of 6 months or less of neoadjuvant/concurrent AST to a high radiation dose did not appear to confer a 5-year therapeutic advantage. However, it added side effects and the significant cost of hormones.

Actuarial Analysis↗

PubMed2002

Prostate volume reduction with androgen deprivation therapy before interstitial brachytherapy.

PURPOSE: We assessed the degree of prostate downsizing using androgen deprivation, and determined its relation to clinical and pathological variables. MATERIALS AND METHODS: From June 1994 to January 2000, 107 patients with prostate cancer received androgen deprivation before interstitial brachytherapy at our hospital. All charts were reviewed for clinical, pathological and treatment related variables. Prostate volume was measured using transrectal ultrasound. All variables were analyzed with regard to the degree of prostate downsizing. RESULTS: Mean percent volume reduction of the prostate was 33% after a 3.7-month average duration of androgen deprivation. Larger prostate volume before androgen deprivation and longer deprivation duration statistically correlated with mean percent volume reduction. Simple linear and multiple regression analyses revealed that these 2 variables remained significant predictors of percent volume reduction. Subgroup analysis indicated that a significant difference was seen in patients who received androgen deprivation with luteinizing hormone releasing hormone agonists alone versus those who received treatment with total androgen blockade (luteinizing hormone releasing hormone agonists plus antiandrogens 30% versus 35%, p = 0.04), and when prostate volume before androgen deprivation was less than 50 cc versus larger volumes (30% versus 35%, p = 0.01). Of patients with an initial prostate volume of greater than 50 cc 82% achieved a volume of less than 50 cc after androgen deprivation therapy. CONCLUSIONS: Androgen deprivation therapy before brachytherapy is a method of downsizing the prostate to overcome anatomical limitations, including larger gland volume and pubic arch interference.

Adenocarcinoma↗

PubMed1998

Multiple Local Recurrent Myxoma.

Cardiac myxomas, usually considered benign tumors, occasionally pursue an aggressive clinical course. The recurrence of sporadic myxomas is much less frequent than that of complex or familial myxomas (1-3% vs. 22% vs. 12%, respectively). We report a case of sporadic myxoma with multiple local recurrence in the left atrium diagnosed by transesophageal two-dimensional echocardiography 4 years after the first excision.

Journal Article↗

PubMedDate not supplied

Familial interstitial deletion of chromosome 4 (p15.2p16.1).

Interstitial deletion of the proximal short arm of chromosome 4, extending from p14 to p16.1 region, results in a distinct clinical syndrome. This proximal 4p deletion syndrome is characterized by variable degrees of mental retardation, unusual facies and minor dysmorphic features. Majority of the patients also show a tall, ectomorphic habitus and normal to excessive linear growth with age. While there have been several cases of such interstitial del(4p) cases reported, familial transmission of this condition has not been documented in the literature. This is the first report of a familial transmission of proximal del(4p) from a mother to her daughter, with both patients showing similar features. This report of the familial transmission of del(4p) has wider implications in genetic counseling.

Abnormalities, Multiple↗

PubMedDate not supplied

Extrapulmonary oat-cell carcinoma presenting as a primary left ventricular tumor: a case report.

An asymptomatic 57-year-old man had an abnormal resting electrocardiogram and a positive treadmill stress test. Cardiac catheterization with left ventriculography revealed a large left ventricular mass in the apex, but otherwise normal coronary arteries. Excisional biopsy of the mass was consistent with oat-cell carcinoma. Additional evaluation was negative for metastasis. The patient was treated with combined chemoradiotherapy and was doing well at 16 months follow-up.

Carcinoma, Small Cell↗