Assessing Hospital Resource Utilization with Application to Imaging for Patients Diagnosed with Prostate Cancer

Resource utilization measures are typically modeled by relying on clinical characteristics. However, in some settings, those clinical markers are not available, and hospitals are unable to explore potential inefficiencies or resource misutilization. We propose a novel approach to exploring misutilization that solely relies on administrative data in the form of patient characteristics and competing resource utilization, with the latter being a novel addition. We demonstrate this approach in a 2019 patient cohort diagnosed with prostate cancer (n = 51,111) across 1056 U.S. healthcare facilities using Premier, Inc.’s (Charlotte, NC, USA) all payor databases. A multivariate logistic regression model was fitted using administrative information and competing resources utilization. A decision curve analysis informed by industry average standards of utilization allows for a definition of misutilization with regards to these industry standards. Odds ratios were extracted at the patient level to demonstrate differences in misutilization by patient characteristics, such as race; Black individuals experienced higher under-utilization compared to White individuals (p < 0.0001). Volume-adjusted Poisson rate regression models allow for the identification and ranking of facilities with large departures in utilization. The proposed approach is scalable and easily generalizable to other diseases and resources and can be complemented with clinical information from electronic health record information, when available.

Locally advanced prostate cancer imaging findings and implications for treatment from the surgical perspective

The anatomy of the prostate is reviewed in the context of discussing the staging of prostate cancer and patterns of tumor spread. The utility of prostate magnetic resonance imaging along with new advancements in tumor staging are discussed specifically in locally advanced disease. What should be included in the radiology report carries a substantial weight to formulate the urologist's decision in regards to the selection of surgical candidates, preoperative planning and avoiding postoperative complications.

Symmetry based prostate cancer detection

OBJECTIVE

To retrospectively assess the value of left and right half symmetry analysis in prostate T2 weighted images (T2WI) for improving prostate cancer (PCa) screening.

METHODS

T2WI and other data of a total of 66 males were collected; the control group and cancer group had 33 patients each. Thresholding geometric active contours algorithm was used for prostate region segmentation, and the measure of local reflectional symmetry algorithm was applied to extract the longitudinal symmetry axes. After that, cross-correlation coefficients (CCs) of the left and right halves of each prostate were obtained.

RESULTS

Data analysis showed that the mean and variance of the value of the left and right half CCs of prostate T2WI in the cancer group and control group were 0.73 ± 0.05 and 0.82 ± 0.06, respectively. The area under the receiver operating characteristic curve was 0.87, and the specificity and the sensitivity were 91% and 70%, respectively. The p < 0.001 indicated that the value of CCs of the prostates between the two groups was significantly different.

CONCLUSION

The symmetry in T2WI is a potential useful index for PCa screening and has a potential value for PCa detection and localizations of tumours for biopsy.

ADVANCES IN KNOWLEDGE

Texture bilateral symmetry of prostate T2WI is employed to screen the suspected prostate tumour.

Prostate cancer imaging: what the urologist wants to know

No consensus exists at present regarding the use of imaging for the evaluation of prostate cancer. Ultrasonography is mainly used for biopsy guidance and magnetic resonance imaging is the mainstay in evaluating the extent of local tumor. Computed tomography and radionuclide bone scanning are mainly reserved for assessment of advanced disease. Positron emission tomography is gaining acceptance in the evaluation of treatment response and recurrence. The combination of anatomic, functional, and metabolic imaging modalities has promise to improve treatment. This article reviews current imaging techniques and touches on the evolving technologies being used for detection and follow-up of prostate cancer.

Magnetic resonance imaging-based treatment planning for prostate brachytherapy

PURPOSE

Transrectal ultrasound (TRUS) is the standard imaging modality for planning prostate brachytherapy. However, magnetic resonance imaging (MRI) provides greater anatomic detail than TRUS. We compared treatment plans generated using TRUS, endorectal coil MRI (erMRI), and standard body array coil MRI (sMRI).

METHODS AND MATERIALS

Treatment plans were used from patients treated with permanent, stranded-seed (125)I brachytherapy in a prospective trial. All men underwent pretreatment planning based on TRUS, and all underwent erMRI before treatment and sMRI 30 days after the implant. Treatments for 20 consecutive patients were replanned on sMRI and erMRI images by investigators blinded to TRUS-based plans. Prostate volume/dimensions, radioactivity-to-prostate-volume ratio, and dosimetric parameters were compared.

RESULTS

Compared with TRUS, mean prostate volume measured by erMRI was smaller, medial-lateral diameter was larger, and anterior-posterior diameter was smaller, suggesting that the endorectal coil produced anatomic distortions. Craniocaudal prostate length was smaller on both types of MRI than on TRUS, suggesting that TRUS overestimates prostate length. Activity per volume was 7.5% lower for plans based on sMRI than on TRUS (0.901 vs. 0.974mCi/cm(3), p<0.001). sMRI plans had similar coverage of the planning target volume (PTV) (dose to 90% of the prostate [D(90)] 116.6% sMRI vs. 117.5% TRUS, p=0.526) and improved dose homogeneity (percentage of PTV receiving 150% of the prescription dose [V(150)] 47.4% sMRI vs. 53.8% TRUS, p=0.001 and percentage of PTV receiving 200% of the prescription dose [V(200)] 16.6% sMRI vs. 19.2% TRUS, p<0.001).

CONCLUSIONS

Staging erMRI should not be routinely used for treatment planning because it produces anatomic distortion. sMRI may have treatment planning advantages over TRUS because of superior soft-tissue delineation of the prostate and adjacent normal tissue structures.

Development and Evaluation of an Actuated MRI-Compatible Robotic System for MRI-Guided Prostate Intervention

This paper reports the design, development, and magnetic resonance imaging (MRI) compatibility evaluation of an actuated transrectal prostate robot for MRI-guided needle intervention in the prostate. The robot performs actuated needle MRI-guidance with the goals of providing (i) MRI compatibility, (ii) MRI-guided needle placement with accuracy sufficient for targeting clinically significant prostate cancer foci, (iii) reducing interventional procedure times (thus increasing patient comfort and reducing opportunity for needle targeting error due to patient motion), (iv) enabling real-time MRI monitoring of interventional procedures, and (v) reducing the opportunities for error that arise in manually actuated needle placement. The design of the robot, employing piezo-ceramic-motor actuated needle guide positioning and manual needle insertion, is reported. Results of a MRI compatibility study show no reduction of MRI signal-to-noise-ratio (SNR) with the motors disabled. Enabling the motors reduces the SNR by 80% without RF shielding, but SNR is only reduced by 40% to 60% with RF shielding. The addition of radio-frequency shielding is shown to significantly reduce image SNR degradation caused by the presence of the robotic device. An accuracy study of MRI-guided biopsy needle placements in a prostate phantom is reported. The study shows an average in-plane targeting error of 2.4 mm with a maximum error of 3.7 mm. These data indicate the system's needle targeting accuracy is similar to that obtained with a previously reported manually actuated system, and is sufficient to reliably sample clinically significant prostate cancer foci under MRI-guidance.

Active surveillance for favorable-risk prostate cancer: background, patient selection, triggers for intervention, and outcomes

With the advent of increasingly sensitive and widely used diagnostic testing, cancer overdiagnosis in particular has emerged as a problem in multiple organ sites. This has the greatest ramifications in the case of prostate cancer because of the very high incidence of latent prostate cancer in aging men, the availability of the prostate-specific antigen (PSA) test, and the long-term effects of definitive therapy. The condition of most men with favorable-risk prostate cancer is far removed from the consequences of a rampaging, aggressive disease. Most of these men are not destined to die of their disease, even in the absence of treatment. Unfortunately, most of these patients are treated radically and are exposed to the risk of significant side effects. Therefore, a selective approach to treatment is appealing. The concept is to identify the subset that harbor more aggressive disease early enough that curative therapy is still a possibility, thereby allowing the others to enjoy improved quality of life, free from the side effects of treatment. This review article summarizes the evidence supporting active surveillance, and the current approach to this management strategy, including the roles of serial biopsy, PSA kinetics, and MR imaging.

Prostate cancer localization using multiparametric MRI based on semi-supervised techniques with automated seed initialization

In this paper, we propose a novel and efficient semisupervised technique for automated prostate cancer localization using multiparametric magnetic resonance imaging (MRI). This method can be used in guiding biopsy, surgery, and therapy. We systematically present a new segmentation technique by developing a multiparametric graph based random walker (RW) algorithm with automated seed initialization to perform prostate cancer segmentation using multiparametric MRI. RW algorithm has proved to be accurate and fast in segmentation applications; however it requires a set of (user provided) seed points in order to perform segmentation. In this study, we first developed a novel RW method, which can be used with multiparametric MR images and then devised alternative methods that can determine seed points in an automated manner using discriminative classifiers such as support vector machines (SVM). Proposed RW method with automated seed initialization is able to produce improved segmentation results by assigning more weights to the images with more discriminative power.We applied the proposed method to a multiparametric dataset obtained from biopsy confirmed prostate cancer patients. Proposed method produces a sensitivity/ specificity rate of 0.76 and 0.86, respectively. Both visual, quantitative as well as statistical results are presented to show the significant performance improvements. Fisher sign test is used to demonstrate the statistical significance of our results by achieving p-values less than 0.05. This method outperforms available RW and SVM based methods by achieving a high specificity rate while not reducing sensitivity.

Diffusion-weighted MRI for locally recurrent prostate cancer after external beam radiotherapy

OBJECTIVE

The objectives of our study were to establish the apparent diffusion coefficients (ADCs) of tumor and nontumor irradiated tissues in patients with suspected postradiation recurrence of prostate cancer and to determine the sensitivity and specificity of a combination of T2-weighted and diffusion-weighted imaging (DWI) for detecting local recurrence.

MATERIALS AND METHODS

Twenty-four patients with rising prostate-specific antigen levels after having completed radiation therapy 30-130 months earlier (median, 62 months) underwent endorectal T2-weighted imaging and DWI (b = 0, 100, 300, 500, and 800 s/mm(2)) followed by transrectal ultrasound (TRUS)-guided biopsy. Images were scored prospectively as positive for tumor if a region of low signal intensity on T2-weighted imaging within the prostate corresponded with a focally restricted area on the ADC map. A region of interest (ROI) was drawn around the suspicious lesion on a single slice of the ADC map and a corresponding ROI was drawn around presumed nontumor irradiated peripheral zone and central gland tissues on the opposite side of the prostate. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined against TRUS-guided biopsy reference standard (octant, n = 17; sextant, n = 5; two samples, n = 1; 12 samples, n = 1).

RESULTS

Sixteen of 24 patients (66.7%) had positive histology findings. The median tumor ROI area was 0.37 cm(2) (quartiles, 0.30 and 0.82 cm(2)). The sensitivity, specificity, PPV, and NPV for detecting tumor were 93.8%, 75%, 88.2%, and 85.7%, respectively. A cutoff ADC of 1216 × 10(-6) mm(2)/s could predict tumor with 100% sensitivity and 96% specificity (area under the receiver operating characteristic curve = 0.992).

CONCLUSION

An ADC derived from DWI is a useful adjunct to T2-weighted MRI for detecting local tumor recurrence larger than 0.4 cm(2) within the prostate.

A workspace-orientated needle-guiding robot for 3T MRI-guided transperineal prostate intervention: evaluation of in-bore workspace and MRI compatibility

BACKGROUND

Magnetic resonance imaging (MRI)-guided prostate interventions have been introduced to enhance the cancer detection. For accurate needle positioning, in-bore-operated robotic systems have been developed and optimal use of the confined in-bore space become a critical engineering challenge.

METHODS

As preliminary evaluation of our prostate intervention robot, we conducted a workspace design analysis, using a new evaluation method that we developed for in-bore-operated robots for transperineal prostate interventions, and an MRI compatibility study.

RESULTS

The workspace analysis resulted in the effective workspace (VW ) of 0.32, which is greater than that of our early prototype, despite the current robot being ca. 50% larger than the early prototype in sectional space. The MRI compatibility study resulted in < 15% signal:noise ratio (SNR) reduction.

CONCLUSIONS

The new workspace evaluation method quantifies the workspace utilization of the in-bore-operated robots for MRI-guided transperineal prostate interventions, providing a useful tool for evaluation and new robot design. The robot creates insignificant electromagnetic noise during typical prostate imaging sequences.

An MRI-compatible robotic system with hybrid tracking for MRI-guided prostate intervention

This paper reports the development, evaluation, and first clinical trials of the access to the prostate tissue (APT) II system-a scanner independent system for magnetic resonance imaging (MRI)-guided transrectal prostate interventions. The system utilizes novel manipulator mechanics employing a steerable needle channel and a novel six degree-of-freedom hybrid tracking method, comprising passive fiducial tracking for initial registration and subsequent incremental motion measurements. Targeting accuracy of the system in prostate phantom experiments and two clinical human-subject procedures is shown to compare favorably with existing systems using passive and active tracking methods. The portable design of the APT II system, using only standard MRI image sequences and minimal custom scanner interfacing, allows the system to be easily used on different MRI scanners.

Imaging in prostate cancer staging: present role and future perspectives

Despite recent improvements in detection and treatment, prostate cancer continues to be the most common malignancy and the second leading cause of cancer-related mortality. Thus, although survival rate continues to improve, prostate cancer remains a compelling medical health problem. The major goal of prostate cancer imaging in the next decade will be more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information in order to plan the most appropriate therapeutic strategy. No consensus exists regarding the use of imaging for evaluating primary prostate cancer. However, conventional and functional imaging are expanding their role in detection and local staging and, moreover, functional imaging is becoming of great importance in oncologic management and monitoring of therapy response. This review presents a multidisciplinary perspective on the role of conventional and functional imaging methods in prostate cancer staging.

Predictors in the outcome of 125I brachytherapy as monotherapy for prostate cancer

A number of different prostate cancer treatment modalities exist. Nomograms are used to assist clinicians and patients in choosing the most appropriate treatment. However, the predicted outcome for (125)I brachytherapy is much worse than what would be expected considering the actual survival rates. This underestimation may result in suboptimal treatment decisions. Therefore, better predictors for outcome after (125)I brachytherapy are necessary. The following factors, which may either influence outcome or predict outcome after brachytherapy, are discussed: tumor characteristics and risk stratification, patient age at treatment, obesity, adjuvant androgen-deprivation therapy, prostate-specific antigen bounce, implantation technique and dosimetry. For the prediction of outcome after (125)I brachytherapy, as long as the quality of the implant is optimal, only high-risk prostate cancer was found to have a negative impact on outcome.

[Imaging diagnostics of the prostate]

Prostate cancer is the most common malignancy of men with approximately 32,000 new cases of prostate cancer in Germany and approximately 11,000 men who would die of the disease each year. For early diagnosis of prostate cancer PSA testing is used, whereas at present screening cannot be recommended due to the lack of confirmed medical and economic benefits. Regarding the imaging modalities, ultrasound of the prostate, currently performed in combination with elastography and histoscanning, magnetic resonance imaging of the prostate in combination with endorectal coils and positron emission tomography combined with computed tomography (PET-CT) are the methods of choice. Using these methods benign prostatitis can be differentiated from prostate cancer and staging of the tumor can be accomplished. On the other hand using these imaging methods it is possible to define the dominant intraprostatic lesion with different sensitivities and specificities, which is important for minimally invasive therapeutic strategies.