Papers by Timothy Masterson
The Journal of Urology, Feb 1, 2019
Purpose: The development of Clostridium difficile infection after cystectomy is associated with s... more Purpose: The development of Clostridium difficile infection after cystectomy is associated with significant morbidity and mortality. We implemented a prospective screening program to identify asymptomatic carriers of Clostridium difficile and assessed its impact on clinical Clostridium difficile infection rates compared to historical matched controls. Materials and Methods: Prospective Clostridium Difficile screening prior to cystectomy began in March 2015. The 380 consecutive patients undergoing cystectomy prior to initiation of screening (control cohort) were matched based on 5 clinical factors with the 386 patients who underwent cystectomy from March 2015 to December 2017 (trial cohort). Screened positive patients were placed in contact isolation and treated prophylactically with Metronidazole. Multivariable models were built on an intention-to-screen and an effectiveness of screening basis to determine if screening reduced the rates of symptomatic Clostridium Difficile infections postoperatively. Results: With the implementation of the screening protocol, Clostridium difficile infections rates declined from 9.4 to 5.5% (OR 0.52, p=0.0268) on an intention-to-screen protocol and from 9.2 to 4.9% on an effectiveness of screening protocol (OR 0.46, p=0.0174). Conclusions: Clostridium difficile screening prior to cystectomy is associated with a significant decrease in rates of clinically symptomatic infections postoperatively. These results should be confirmed in a randomized controlled trial.
The Journal of Urology, Jul 1, 2020
The Journal of Urology, Apr 1, 2018
prior to RC. The primary outcome was downstaging to non-muscle invasive status (ypT<2) at RC. Var... more prior to RC. The primary outcome was downstaging to non-muscle invasive status (ypT<2) at RC. Variables examined included: age, gender, BMI, Charlson Comorbidity Index (CCI), ECOG status, cT stage, squamous vs urothelial histology, other histologic variants (small cell or micropapillary), lymphovascular invasion, hydronephrosis, concurrent carcinoma in situ, tobacco use, prior non-muscle invasive bladder cancer, tumor multifocality, days from NAC, and days from transurethral resection. Univariable and multivariable logistic regression models were used to identify associations of variables with primary outcomes. RESULTS: A total of 300 patients were identified who underwent NAC prior to RC. Of these, 46% (n¼138) were downstaged to nonmuscle invasive disease at RC. The rate of downstaging decreased significantly (p¼0.02) with increasing cT stage: 51% for cT2, 43% for cT3, and 29% for cT4. Similarly patients with a CCI of 3 or more were less likely to be downstaged compared to patients with CCI 0-2: 36% vs 71%; p<0.01. Moreover, on multivariable logistic regression analysis, clinical stage (cT4 vs cT2 (odds ratio (OR) 0.41, 95% CI 0.19-0.88, p¼0.02) and CCI 3 vs 0-2 (OR 0.26, 95% CI 0.15-0.45, p<0.01) remained the only significant variables significantly associated with downstaging. The area under the curve (AUC) for the model with cT stage and CCI was 0.69. CONCLUSIONS: There are a paucity of clinical parameters associated with pathologic downstaging. Given the modest AUC of our model, these data highlight the need for continued research in order to integrate genomic predictors of downstaging into clinical decisionmaking for receipt of NAC.
Urology, Sep 1, 2005
Objectives. To analyze the feasibility of neurovascular bundle (NVB) preservation and peripheral ... more Objectives. To analyze the feasibility of neurovascular bundle (NVB) preservation and peripheral nerve grafting during salvage radical prostatectomy (RP) for radiorecurrent prostate cancer and analyze their effect on the recovery of potency. Methods. Of 100 patients who underwent salvage RP with curative intent from 1984 to 2003, 7 patients had bilateral NVBs preserved, 22 had a unilateral NVB preserved with (n ϭ 11) and without (n ϭ 11) a unilateral nerve graft, and 9 had bilateral NVBs resected with bilateral nerve grafts. Preoperative erections were graded as normal (grade 1) in 12 patients and full but recently diminished (grade 2) in 16. Recovery of potency after salvage RP was defined as erections satisfactory for intercourse, with or without the use of sildenafil. Results. Overall, 6 patients recovered potency after salvage RP, and the 5-year actuarial recovery rate was 16% (95% confidence interval 4% to 28%). The 6 patients who recovered erections all had preoperative grade 1 to 2 erections, and 5 had bilateral NVBs preserved. Only 1 of 11 patients who had a unilateral nerve graft recovered potency. No patient with bilateral nerve grafts recovered potency. The 5-year actuarial recovery rate among patients with preoperative grade 1 to 2 erections was 45% (95% confidence interval 16% to 75%). Conclusions. Compared with standard RP, the overall potency results after salvage RP are poor. However, select patients with good preoperative erectile function who have bilateral NVB preservation may recover erections sufficient for intercourse aided by sildenafil. Peripheral nerve grafts did not appear to influence the recovery of erections in this patient population.
Author eBooks, 2017
Aims: Sacrococcygeal teratomas are rare tumors that occur most frequently in neonates, although a... more Aims: Sacrococcygeal teratomas are rare tumors that occur most frequently in neonates, although adult cases also occur. Molecular pathogenesis of these tumors and long term outcome is uncertain. Methods and results: Fifty four sacrococcygeal teratoma specimens from 52 patients were identified and available follow up information was obtained. Fluorescent in situ hybridization analysis was performed to identify i(12p) abnormalities on paraffin blocks of the tumor. Among the 48 pediatric patients, there were 44 teratomas and 4 tumors with teratoma and yolk sac tumor (1 of which also had primitive neuroectodermal tumor). The teratomas included 37 mature teratomas and 11 immature teratomas (4 grade 1, 2 grade 2, and 5 grade 3). The 44 teratomas lacking a yolk sac tumor component were all negative for i(12p). The 4 tumors with a yolk sac tumor component were all positive for i(12p). The 4 adult cases all lacked nonteratomatous germ cell tumor components, immature elements, and i(12p). Follow up information was available for 32 patients. Two patients with teratoma had recurrence, but were alive with no evidence of disease after long-term follow up. One patient with teratoma and yolk sac tumor had recurrence 7 months after resection. The other patients were alive with no evidence of disease at last follow up. Conclusions: Our data suggest that pediatric sacrococcygeal teratomas should be considered as two distinct groups with a divergent histogenetic pathway. Prognosis of these tumors are excellent, despite rare recurrence.
The Journal of Urology, Apr 1, 2008
Purpose AS is a treatment regimen used in patients with low-risk prostate cancer. Decision making... more Purpose AS is a treatment regimen used in patients with low-risk prostate cancer. Decision making is based on pre-treatment PSA, clinical stage, and prostate biopsy results. We review our experience with immediate repeat biopsy in patients eligible for AS.
Clinical Genitourinary Cancer, Apr 1, 2018
MicroAbstract The purpose of the study was determine is survival differences exist between BEP x3... more MicroAbstract The purpose of the study was determine is survival differences exist between BEP x3 vs. EP x4 for good risk testicular cancer patients. In 223 patients, we found a nonsignificant trend toward improved survival when men where treated with BEPx3 compared to EP x4.
Prostate Cancer, 2013
Since the introduction of robot-assisted radical prostatectomy (RALP), robotics has become increa... more Since the introduction of robot-assisted radical prostatectomy (RALP), robotics has become increasingly more commonplace in the armamentarium of the urologic surgeon. Robotic utilization has exploded across surgical disciplines well beyond the fields of urology and prostate surgery. The literature detailing technical steps, comparison of large surgical series, and even robotically focused randomized control trials are available for review. RALP, the first robot-assisted surgical procedure to achieve widespread use, has recently become the primary approach for the surgical management of localized prostate cancer. As a result, surgeons are constantly trying to refine and improve upon current technical aspects of the operation. Recent areas of published modifications include bladder neck anastomosis and reconstruction, bladder drainage, nerve sparing approaches and techniques, and perioperative and postoperative management including penile rehabilitation. In this review, we summarize recent advances in perioperative management and surgical technique for RALP. Prostate Cancer Table 1: Modifications to RALP. Modifications Year introduced References Urinary continence Sling construction 1997 Jorion [18] Bladder neck preservation 2002 Deliveliotis et al. [16], Selli et al. [15], and von Bodman et al. [85] Intraoperative cooling 2009 Finley et al. [29] Pubovesical complex sparing 2011 Asimakopoulos et al. [28] UVA Posterior reconstruction 2008 Rocco et al. [19, 86], Coelho et al. [87] Anterior reconstruction 2009 Campenni et al. [20], Patel et al. [21] Double layer anastomosis 2009 Menon et al. [22], Sammon et al. [23], and Joshi et al. [25], Sutherland et al. [24], Sammon et al. [23], and Hurtes et al. [88] Barbed suture 2011 Sammon et al. [26], and Kaushik et al. [27] NVB sparing NVB sparing 1991 Quinlan et al. [36], Catalona et al. [39], Dubbelman et al. [38], Rabbani et al. [37], and Walsh et al. [40] Veil of Aphrodite 2002 Menon et al. [41, 45] Athermal dissection 2007 Tewari et al. [52], Mandhani et al. [56], and Khan et al. [57], Ahlering et al. [58], Chien et al. [59], and Gill et al. [60] Tension-free 2007 Kowalczyk et al. [53], Mattei et al. [55] Bladder drainage SP drainage 2009 Krane et al. [31], Sammon et al. [32], and Tewari et al. [33]
Analytical and Bioanalytical Chemistry, May 20, 2016
Touch spray-mass spectrometry (TS-MS) is an ambient ionization technique (ionization of unprocess... more Touch spray-mass spectrometry (TS-MS) is an ambient ionization technique (ionization of unprocessed samples in the open air) that may find intraoperative applications in quickly identifying the disease state of cancerous tissues and in defining surgical margins. In this study, TS-MS was performed on fresh kidney tissue (~1-5 cm 3), within one hour of resection, from 21 human subjects afflicted by renal cell carcinoma (RCC). The preliminary diagnostic value of TS-MS data taken from freshly resected tissue was evaluated. Principal component analysis (PCA) of the negative ion mode (m/z 700-1000) data provided separation between RCC (16 samples) and healthy renal tissue (13 samples). Linear discriminant analysis (LDA) on the PCA compressed data estimated sensitivity (true positive rate) and specificity (true negative rate) of 98% and 95%, respectively, based on histopathological evaluation. The results indicate that TS-MS might provide rapid diagnostic information in spite of the complexity of unprocessed kidney tissue and the presence of interferences such as urine and blood. Desorption electrospray ionization imaging (DESI-MSI) in the negative ionization mode was performed on the tissue specimens after TS-MS analysis as a reference method. The DESI imaging experiments provided phospholipid profiles (m/z 700-1000) that also separated RCC and healthy tissue in the PCA space, with PCA-LDA sensitivity and specificity of 100% and 89%, respectively. The TS and DESI loading plots indicated that different ions contributed most to the separation of RCC from healthy renal tissue (m/z 794
BJUI, May 1, 2008
Purpose-We recently modified our radical prostatectomy (RP) technique such that the neurovascular... more Purpose-We recently modified our radical prostatectomy (RP) technique such that the neurovascular bundle (NVB) is completely mobilized off the prostate from the apex to above the seminal vesicles, including incision of Denonvilliers' fascia, prior to urethral division and mobilization of the prostate off the rectum. We prospectively evaluated whether this modification in surgical technique was associated with an improvement in postoperative erectile function (EF) recovery. Materials and Methods-Data from patients treated prior to technique modification was used to create a predictive model for EF at 6 months after RP using age, date of surgery, and nerve sparing (none vs unilateral vs bilateral) as predictors for patients who received the modified technique (MT) to estimate the expected outcomes had they received the standard technique (ST), and compared these with actual outcomes.
The Journal of Urology, Apr 1, 2006
Purpose-We examined the association between the number of LNs removed, the number of positive LNs... more Purpose-We examined the association between the number of LNs removed, the number of positive LNs and disease progression in patients undergoing pelvic lymph node dissection and radical retropubic prostatectomy for clinically localized prostate cancer. Materials and Methods-We analyzed 5,038 consecutive patients who underwent radical retropubic prostatectomy between 1983 and 2003. Clinicopathological parameters, including the administration of neoadjuvant hormonal therapy, preoperative prostate specific antigen, specimen Gleason score, surgeon and pathological stage, were collected prospectively in our prostate cancer database. We excluded men treated with radiation or chemotherapy before surgery. BCR was defined as 2 postoperative prostate specific antigen increases greater than 0.2 ng/ml. Cox models were used to determine whether the number of nodes removed or the number of positive nodes predicted freedom from BCR after adjustment for prognostic covariates. Results-The 4,611 eligible patients had a median of 9 LNs (IQR 5 to 13) removed. Positive nodes were found in 175 patients (3.8%). Overall the number of LNs removed did not predict freedom from BCR (HR per additional 10 nodes removed 1.02, 95% CI 0.92 to 1.13, p = 0.7). Results were similar in patients receiving and not receiving neoadjuvant hormonal therapy. Finding any LN involvement was associated with a BCR HR of 5.2 (95% CI 4.2 to 6.4, p <0.0005). However, in men without nodal involvement an increased number of nodes removed correlated significantly with freedom from BCR (p = 0.01). Conclusions-Nodal disease increased the risk of progression. Extensive lymphadenectomy enhances the accuracy of surgical staging. However, we were unable to determine that removing more nodes improves freedom from BCR uniformly. Since the proportion of patients with prostate cancer with positive nodes is low, the value of extensive lymphadenectomy requires a multiinstitutional, randomized clinical trial.
The Journal of Urology, Nov 1, 2008
Purpose-AS is a treatment regimen used in patients with low-risk prostate cancer. Decision making... more Purpose-AS is a treatment regimen used in patients with low-risk prostate cancer. Decision making is based on pre-treatment PSA, clinical stage, and prostate biopsy results. We review our experience with immediate repeat biopsy in patients eligible for AS. Materials and Methods-A retrospective review of consecutive patients undergoing repeat biopsy within 3 months of a first positive biopsy from March 2002 until June 2007 was analyzed. Patients were considered eligible if they had a PSA < 10 ng/ml, clinical stage ≤ T2a, Gleason pattern ≤ 3, 3 or less cores positive, and no single core with ≥ 50% cancer involvement. Results-A total of 104 patients met the eligibility criteria. Of the repeat biopsies performed, 27/104 (26%) were negative, 59/104 (57%) had Gleason score ≤ 6, 17/104 (16%) had Gleason score 7, one patient had Gleason score 9, 10/104 (10%) of patients had > 3 cores involved on repeat biopsy, and 12/104 (12%) had ≥ 50% involvement of at least one core. A total of 28/104 (27%) patients were upgraded and/or upstaged. Treated patients who were upgraded and/or upstaged were more likely to have higher pathologic stage (p = 0.003) and grade (p = 0.001) at RP than those who were not. Conclusions-Immediate repeat biopsy for patients on AS resulted in 27% being upgraded or upstaged, and those were more likely to have higher grade and stage disease at RP. We recommend repeat biopsy as it improved our discrimination as to whom are the best candidates for AS.
Advances in Urology, 2018
e surgical management of both early and advanced stage germ cell tumors of the testis remains a c... more e surgical management of both early and advanced stage germ cell tumors of the testis remains a complex process of surgical decision making to maximize oncologic control while minimizing morbidity. Over the past 5 decades, the evolution of the surgical template for retroperitoneal lymphadenectomy (RPLND) has resulted in important modifications to achieve these goals. In this review, we will characterize the historical motivating factors that led to the modified template, outline patient and clinical factors in selecting these approaches in both early and advanced stage disease, and briefly discuss future horizons for their implementation.
The Journal of Urology, Nov 1, 2020
Purpose: Coronavirus Disease 2019 (COVID-19) is a global pandemic affecting hospital systems and ... more Purpose: Coronavirus Disease 2019 (COVID-19) is a global pandemic affecting hospital systems and the availability of resources for surgical procedures. Our aim is to provide guidance for urologists to help prioritize urologic cancer surgeries. Material and Methods: We reviewed published literature on bladder cancer, upper tract urothelial carcinoma (UTUC), penile cancer, testis cancer, prostate cancer, renal cancer, and adrenal cancer. Results: For muscle invasive bladder cancer (MIBC), delays should be less than roughly 10 weeks and neoadjuvant chemotherapy should be considered. For non-MIBC, patients should be counseled appropriately based on risk and intravesical therapies can continue. UTUC should also be treated with minimal delays for high risk patients, especially with ureteral tumors. Surgery for T1 renal cancers when indicated can be delayed until adequate resources are available. Patients with T2 renal cancer should be considered for early surgery if there are unfavorable preoperative characteristics. Higher stage renal tumors should be considered for early surgery. Early multidisciplinary approach is recommended for metastatic renal cancers. High risk prostate cancer may need preferential treatment and consideration of neoadjuvant hormonal therapy. Penile cancer can have worse sexual or oncologic outcome with prolonged surgical delay. Likewise, adrenal cancer is aggressive and needs early surgical treatment. Testicular cancer should be treated in a timely manner with surgery or chemotherapy, as indicated.
The Journal of Urology, Sep 1, 2009
Purpose-We sought to assess the impact of prostate size on operative difficulty as measured by es... more Purpose-We sought to assess the impact of prostate size on operative difficulty as measured by estimated blood loss (EBL), operating room (OR) time and positive surgical margins (SM) and secondarily to assess the impact on biochemical recurrence (BCR) and the functional outcomes of potency and continence at one year following radical prostatectomy (RP) as well as postoperative bladder neck contracture (BNC). Materials and Methods-During 1998-2007, 3067 men underwent RP by one of 5 dedicated prostate surgeons with no neoadjuvant or adjuvant therapy. Pathologic specimen weight was used as a measure of prostate size. Cox proportional hazards and logistic regression analysis was used to study the association between specimen weight and biochemical recurrence (BCR) and SM status, respectively, controlling for adverse pathologic features. Continence and potency were analyzed controlling for age, nerve-sparing status, and surgical approach. Results-With increasing prostate size, there was increased EBL (p=0.013) and OR time (p=0.004) and a decrease in positive SM (84/632 (14%) for ≤40g, 99/862 (12%) for 41-50g, 78/842 (10%) for 51-65g, 68/731 (10%) for >65g (p<0.001)). BCR was observed in 186 of 2882 patients followed postoperatively and was not significantly associated with specimen weight (p=0.3). Complete continence was observed in 1165/1422 (82%) and potency in 425/827 (51%) at one year. Specimen weight was not significantly associated with potency (p=0.8), continence (p=0.08) or BNC (p=0.22). Conclusions-Prostate size does not appear to affect biochemical recurrence or one-year functional results. However, EBL and OR time increased with larger prostate size and positive SM are more often observed in smaller glands.
Chemistry: A European Journal, Jan 31, 2011
Diagnosis of human bladder cancer in untreated tissue sections is achieved by using imaging data ... more Diagnosis of human bladder cancer in untreated tissue sections is achieved by using imaging data from desorption electrospray ionization mass spectrometry (DESI-MS) combined with multivariate statistical analysis. We use the distinctive DESI-MS glycerophospholipid (GP) mass spectral profiles to visually characterize and formally classify twenty pairs (40 tissue samples) of human cancerous and adjacent normal bladder tissue samples. The individual ion images derived from the acquired profiles correlate with standard histological hematoxylin and eosin (H&E)stained serial sections. The profiles allow us to classify the disease status of the tissue samples with high accuracy as judged by reference histological data. To achieve this, the data from the twenty pairs were divided into a training set and a validation set. Spectra from the tumor and normal regions of each of the tissue sections in the training set were used for orthogonal projection to latent structures (O-PLS) treated partial least-square discriminate analysis (PLS-DA). This predictive model was then validated by using the validation set and showed a 5% error rate for classification and a misclassification rate of 12%. It was also used to create synthetic images of the tissue sections showing pixel-by-pixel disease classification of the tissue and these data agreed well with the independent classification that uses histological data by a certified pathologist. This represents the first application of multivariate statistical methods for classification by ambient ionization although these methods have been applied previously to other MS imaging methods. The results are encouraging in terms of the development of a method that could be utilized in a clinical setting through visualization and diagnosis of intact tissue.
Urology, Feb 1, 2009
Purpose-We evaluated clinical parameters associated with recovery of ejaculation following nerve-... more Purpose-We evaluated clinical parameters associated with recovery of ejaculation following nerve-sparing post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) for nonseminomatous germ cell tumor. Methods-We queried our institutional database for all patients who underwent nerve-sparing PC-RPLND between 1995 and 2005 using a bilateral template. Nerve-sparing was carried out whenever technically feasible and oncologically prudent. Antegrade ejaculation was defined as any seminal fluid expulsion and was determined by patient report. We evaluated recovery of antegrade ejaculation based on clinical and pathologic parameters and fit a logistic regression model to determine which pre-operative variables are associated with antegrade ejaculation. Results-A total of 341 patients had PC-RPLND during the study period, 136 (40%) with nerve sparing techniques. Post-operative antegrade ejaculation was reported by 107/136 (79%) of patients with information available. On the multivariable analysis, a right-sided primary testicular tumor (OR 0.4, 95% CI: 0.1, 1.0, p=0.044) and residual masses ≥5 cm (OR 0.1, 95% CI: 0.0, 0.7, p=0.020) were associated with retrograde ejaculation. However, 40/54 (74%) with right-sided primary tumors and 4/9 (44%) with mass ≥5 cm reported antegrade ejaculation. The 5-year relapse free survival was 98% with a median follow up of 39 months (IQR 19, 66). Conclusions-Nerve-sparing PC-RPLND is associated with excellent functional return of antegrade ejaculation, is feasible in select patients with bulky disease, and has excellent oncologic outcomes.
Urologic Oncology-seminars and Original Investigations, Nov 1, 2021
INTRODUCTION AND OBJECTIVE The management of severe symptoms secondary to radiation changes to th... more INTRODUCTION AND OBJECTIVE The management of severe symptoms secondary to radiation changes to the bladder can be difficult. Many patients often endure costly procedures, hospitalizations, transfusions, and physician visits for intractable symptoms. Our aim was to evaluate the short-term efficacy and feasibility of urinary diversion in patients with severe, debilitating symptoms related to radiation cystitis by focusing on perioperative data examining surgical feasibility and assess for any improvement in the number of procedures, transfusions, hospitalizations, and office visits required. METHODS With IRB approval, we queried our institutional database for patients with a diagnosis code of radiation cystitis who underwent urinary diversion with or without bladder removal from 2011 to 2018. We reviewed institutional and regional record to assess pre, peri and postoperative outcomes, including rates of surgical procedures, hospitalizations, transfusions and clinic visits, in the year before and after treatment. Non-parametric statistics and linear regression were used. RESULTS Of the 286 patients with radiation cystitis, 45 patients underwent definitive urinary diversion - 31 with concomitant cystectomy and 14 with diversion alone. Analysis of perioperative variables such as estimated blood loss, surgical time, post-operative hospital stay or complication rates were similar to our experience with cystectomy in non-radiated patients. With a mean follow up of 14.6 months, we found that the number of procedures, hospitalizations and transfusions objectively improved following radical surgery. Office visits, however, did not seem to be impacted by performing urinary diversion. There were no significant differences in post-operative benefits between patients that received a concomitant cystectomy and those that only underwent diversion. CONCLUSION Patients suffering from severe refractory symptomatic radiation cystitis may be best treated with a radical surgical approach. Definitive urinary diversion with or without cystectomy can lower burden of disease by reducing the need for additional procedures, hospitalizations, and blood transfusions on short term follow-up.
European Urology, Jun 1, 2023
The Journal of Urology, Apr 1, 2019
nonparametric curve fitting method graphically explored the relationship between the risk of prog... more nonparametric curve fitting method graphically explored the relationship between the risk of progression and actual progression rate RESULTS: We enrolled 235 patients. Overall, MRI was performed in 139 (60%) patients. Within a median follow-up of 25.2 months, 92 (39%) patients had progression. The C-index of our model was 84%. The interaction between the use of MRI and the risk of progression was statistically significant (p[0.04). The nonparametric curve fitting method showed that the use of MRI was associated with reduced risk of progression only for those patients with predicted probabilities >30% (Fig) CONCLUSIONS: Our results suggest that the utility of mp-MRI before confirmatory biopsy in men on AS vary significantly according to patient profile. In patients with very low risk PCa, according to our model, the added value of mp-MRI in reducing the risk of progression or misclassification is minimal. Thus, mp-MRI can be safely spared in these men. Only patients with a baseline probability of progression >30% might benefit from mp-MRI in order to exclude clinically significant PCa
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Papers by Timothy Masterson