Noncontrast MR imaging followed by cognitively guided MR biopsy (no standard biopsy if MR imaging findings were negative) was the most cost-effective approach, yielding an additional NHB of 0.198 QALY compared with the standard biopsy approach. Noncontrast MR imaging followed by in-gantry MR imaging–guided biopsy (no standard biopsy if MR imaging findings were negative) led to the highest NHB gain of 0.251 additional QALY compared with the standard biopsy strategy. All MR imaging strategies were cost-effective in 94.05% of Monte Carlo simulations. Analysis by age groups yielded similar results.

A decision-analysis model was created for biopsy-naive men who had been recommended for prostate biopsy on the basis of abnormal digital rectal examination results or elevated prostate-specific antigen levels (age groups: 41–50 years, 51–60 years, and 61–70 years). The following three major strategies were evaluated: (a) standard transrectal ultrasonography (US)-guided biopsy; (b) diagnostic MR imaging followed by MR imaging–targeted biopsy, with no biopsy performed if MR imaging findings were negative; and (c) diagnostic MR imaging followed by MR imaging–targeted biopsy, with a standard biopsy performed when MR imaging findings were negative. The following three MR imaging–guided biopsy strategies were further evaluated in each MR imaging category: (a) biopsy with cognitive guidance, (b) biopsy with MR imaging/US fusion guidance, and (c) in-gantry MR imaging–guided biopsy. Model parameters were derived from the literature. The primary outcome measure was net health benefit (NHB), which was measured as quality-adjusted life-years (QALYs) gained or lost by investing resources in a new strategy compared with a standard strategy at a willingness-to-pay (WTP) threshold of $50 000 per QALY gained. Probabilistic sensitivity analysis was performed by using Monte Carlo simulations.

To evaluate the cost-effectiveness of multiparametric diagnostic magnetic resonance (MR) imaging examination followed by MR imaging–guided biopsy strategies in the detection of prostate cancer in biopsy-naive men presenting with clinical suspicion of cancer for the first time.

Introduction

The current standard for detecting prostate cancer is a systematic transrectal ultrasonography (US)-guided biopsy with the acquisition of 12–16 cores (referred to as a “standard biopsy” hereafter) performed in predefined locations in patients with elevated serum prostate-specific antigen (PSA) levels or abnormal digital rectal examination results (1). Most tumors are not visible at US; approximately 25%–40% of clinically significant cancers are missed (2), and up to 42% of indolent cancers that would not have caused symptoms in the patient’s lifetime are detected with these biopsies (3,4). Tumors that are less than 0.5 cm3 in volume, are confined to the prostate, and have a Gleason score 6 or lower without Gleason pattern 4 or 5 are categorized as clinically insignificant (5). Approximately 60% of patients given a diagnosis of indolent tumor choose aggressive treatment options such as radical surgery (6), leading to complications such as erectile dysfunction and urinary incontinence in up to 75% and 48% of patients, respectively, 5–10 years after surgery (7). The biopsies can also lead to complications such as infections and bleeding that might result in prolonged health care system contact (8,9). The health care costs of prostate cancer care were $11.85 billion in the year 2012 and are expected to increase by 42% by the year 2020 (10). The high false-positive rate of the current paradigms for detecting clinically significant prostate cancer has been repeatedly criticized (11,12). At the same time, the need to identify clinically significant disease that causes death and morbidity is well recognized.

Magnetic resonance (MR) imaging and MR imaging–guided biopsy techniques are highly sensitive and specific in the detection of clinically significant prostate cancer (13–16). The following three MR imaging–guided biopsy techniques are most commonly used: (a) cognitively guided biopsy, in which the operator performs a US-guided biopsy on the basis of his or her knowledge of the location of the lesion at MR imaging; (b) MR imaging/US fusion biopsy, in which MR images are fused with real-time US images to target the lesion detected at MR imaging; and (c) in-gantry MR imaging–guided biopsy, in which the biopsy is performed in the MR imaging suite by using MR imaging–compatible hardware.

Despite the apparent advantages of MR imaging, there is a reluctance to incorporate MR imaging into practice guidelines for prostate cancer detection because it is perceived to be an expensive technology. Cost-effectiveness analysis is a modeling tool that objectively analyzes the costs and health benefits of a health care intervention compared with those of an existing standard. To our knowledge, only a handful of studies have addressed the question of cost-effectiveness of MR imaging in the detection of prostate cancer (17–21). These studies addressed the cost-effectiveness of a single MR imaging–guided biopsy technique, studied only contrast material–enhanced MR imaging for the detection of prostate cancer, or examined cost-effectiveness in patients with previously negative standard biopsies (17,19).

The aim of our study was to evaluate the cost-effectiveness of multiparametric diagnostic MR imaging examination followed by MR imaging–guided biopsy strategies in the detection of prostate cancer in biopsy-naive men presenting with clinical suspicion of cancer for the first time.

Materials and Methods

Model Development

A decision-tree model was created by using the base case of a biopsy-naive man in whom a prostate biopsy was indicated on the basis of elevated PSA levels or clinically significant digital rectal examination findings. The abridged model is depicted in the Figure, and the detailed model is depicted in Figure E1 (online). The setting for the study is in the United States. The time horizon for the study is until death, to capture the full expected lifetime costs and benefits that may be a consequence of over- or underdiagnosis and over- or undertreatment. The base case was a 65-year-old man, but the model was tested in three age group scenarios (41–50 years, 51–60 years, and 61–70 years) to examine cost-effectiveness given varying levels of cancer prevalence and life expectancy. Seven strategies were evaluated.

Simplified decision-tree model. The model compared MR imaging–guided strategies with standard transrectal US–guided biopsy for the detection of prostate cancer. Each box = a point along the decision model. Blue boxes = decisions (strategies being compared). Red boxes = end states (ie, terminal nodes) of our model. Yellow boxes = clone nodes. A clone node means that the rest of the tree from that point onward is the same as in the labeled node. To see the full decision-tree model, see Figure E1 (online). Download as PowerPointOpen in Image Viewer

Strategy 1.—Detecting prostate cancer with standard biopsy.

Strategies 2–4.—Noncontrast diagnostic MR imaging examination is performed and the lesions so detected are targeted by using 2, cognitively guided biopsy; 3, MR imaging/US fusion biopsy; or 4, in-gantry MR imaging–guided biopsy. No further biopsy was performed if diagnostic MR imaging did not reveal any suspicious lesions.

Strategies 5–7.—Noncontrast diagnostic MR imaging examination is performed and lesions so detected are targeted by using 5, cognitively guided biopsy; 6, MR imaging/US fusion biopsy; or 7, in-gantry MR imaging–guided biopsy. For strategies 5–7, a standard biopsy is performed when MR imaging does not depict suspicious lesions. This paradigm was evaluated because there are no available guidelines for the next step in the event of a negative MR imaging examination, and many urologists would still perform a standard biopsy in this scenario.

We evaluated the cost-effectiveness of both contrast-enhanced and noncontrast diagnostic MR imaging examinations for detection of clinically significant cancer. According to the Prostate Imaging Reporting and Data System (PI-RADS) version 2 recommendations, a contrast-enhanced prostate MR imaging examination would include T2-weighted and diffusion-weighted pulse sequences and a dynamic contrast-enhanced examination. Some authors have explored the value of a noncontrast examination for detection of prostate cancer that consists of only T2-weighted and diffusion-weighted pulse sequences in small prospective studies (22,23). A single sensitivity value of diagnostic MR imaging examination was used with the baseline assumption of no additional benefit with contrast material, and a sensitivity analysis was performed on this assumption (please refer to the section on sensitivity analysis).

Model Probabilities and Assumptions

A tumor confined to the prostate with a volume of less than 0.5 cm3 and a Gleason score of 6 or lower was considered to be clinically insignificant cancer (5). The prevalence of prostate cancer (24), the probability of detecting clinically significant cancer at MR imaging and standard biopsy, the sensitivity and specificity of each technique (15,25–31), and complication rates of biopsy procedures (7–11) were derived from the literature (Table 1). The sensitivity of each of the MR imaging–guided biopsy techniques for detection of clinically significant and insignificant cancers was derived from the literature (Table 1) (29). Once the diagnosis of prostate cancer had been established, the probability of a patient choosing a given treatment pathway (radical prostatectomy, external beam radiation therapy, brachytherapy, androgen deprivation therapy, active surveillance, or watchful waiting) was also derived from the literature (6,33) (Table 2). On the basis of costs described by Hayes et al (33), our model included the costs of intensity-modulated radiation therapy and brachytherapy (with associated complications), which are the most commonly used methods of radiation treatment for prostate cancer. We did not factor in the costs of other forms of radiation therapy used for treating prostate cancer.

Table 1 Parameters Used in the Decision-Tree Model: Disease Prevalence and the Sensitivity of Various Detection Methods

Table 2 Parameters Used in the Decision-Tree Model: Probability of Correct Classification of Disease for a Diagnostic Method and Probability of Patient Choosing a Treatment Option when Given a Diagnosis of Prostate Cancer

Cost Parameters and Assumptions

The cost of procedures used in this study—that is, a diagnostic MR imaging examination, a standard biopsy, an MR imaging–guided biopsy (cognitive, MR imaging/US fusion, or in-gantry biopsy), and pathologic evaluation—are applicable in the United States and were derived from the physician fee schedule at www.CMS.gov (34) (Table E1 [online]). The cost of losing a day of work when a patient undergoes a biopsy or an MR imaging examination was derived from the Bureau of Labor Statistics (35) (Table E1 [online]); the estimated cost of biopsy complications averaged over the population was included in the cost of the procedure (8,19) (Table E1 [online]). The total lifetime costs of treatment procedures were estimated by using average values of ranges of costs found in the literature (33) (Table E1 [online]). Patients with organ-confined tumors with a Gleason grade of 6 or lower have a low risk of prostate cancer–specific mortality at 15 years (ie, < 1%) (36). The costs associated with these missed cancers could not be found in the literature. Therefore, we assumed that the costs associated with these cancers would be similar to costs associated with watchful waiting.

Effectiveness Parameters and Assumptions

The effectiveness measure in this study was quality-adjusted life-years (QALYs), which takes into account both the quantity (life years) and quality (utility score of a health state) of life (37). The estimated lifetime QALY s for each procedure and treatment pathways were derived from a comprehensive simulation study of men with prostate cancer (33) (Table E2 [online]).

We could not find data that measured lifetime QALY s for patients who knew they had clinically significant cancer but who chose to forego treatment. Therefore, we made an estimate for this value on the basis of a study by Bhatnagar et al (38) that showed that patients with clinically significant cancer gained about 2 QALY s over their lifetimes by choosing radical prostatectomy over conservative treatment (Table E2 [online]) (38). All cost estimates from published literature were adjusted for inflation and were put in terms of 2016 U.S. dollars.

Cost-effectiveness Analysis

The primary outcome in this analysis was net health benefit (NHB), and the secondary outcome was incremental cost-effectiveness ratio (ICER), using a willingness-to-pay (WTP) threshold of $50 000 (39). NHB is measured in terms of QALY and is defined as the health effect obtained from a new health strategy minus the health effect obtained by investing the same resources in a marginally effective or standard strategy (40). If the difference between the NHB of two strategies is positive, the new strategy is more cost-effective than the standard strategy. NHB for each strategy is calculated as NHB = E − (C/ WTP ), where E is the lifetime QALY s and C is the lifetime cost (40). The ICER for each strategy is obtained by dividing the difference in the cost of new and standard strategies by the difference in the outcomes (lifetime QALY ) of new and standard strategies (39,41). The strategies that yield lower lifetime QALY s below the WTP threshold are said to be “dominated” and are eliminated, and the next least expensive strategy is used as a comparator to arrive at the most cost-effective strategy. Nonparametric bootstrapping with Monte Carlo simulation was used to create 95% confidence intervals for measures of NHB s.

Discounting is the process of converting future costs to their present value, to reflect the fact that, in general, society prefers to receive benefits sooner rather than later, and pay costs later rather than sooner (42). The estimates of lifetime QALY s and lifetime treatment costs were already discounted at a 3% rate in the study from which they were derived (33).

Sensitivity Analysis

One-way sensitivity analysis was performed on all study variables over a range of values shown in Table 1 (Table E3 [online]). Wide ranges for each variable were chosen to account for uncertainty in parameter estimates and to test our model at extreme values. Additional sensitivity analysis was performed for the cost-effectiveness of each strategy for different levels of Gleason cutoff scores for thresholds of clinically significant cancer: Gleason 3 + 4 or higher, Gleason 4 + 3 or higher, and Gleason 8 or higher (Tables E4–E6 [online]). Sensitivity analysis was also performed on the utilization of gadolinium contrast material, to explore how much improvement in the sensitivity of disease detection would be needed for contrast-enhanced MR imaging to be cost-effective (Table E7 [online]).

A probabilistic sensitivity analysis was performed, and a Monte Carlo simulation was used to create 100 000 samples, for which expected values were calculated. The proportion of samples for each strategy that were cost-effective was then calculated. All analysis and Monte Carlo simulations were performed by using TreeAge Pro 2015 (TreeAge Software, Watertown, Mass).

Results

Cost-effectiveness Analysis in Baseline Case

The lifetime cost, lifetime QALY s, ICER , and NHB s of all investigated strategies are shown in Table 3. All MR imaging–guided strategies led to a gain of NHB (0.123–0.251 additional QALY ) for the patient compared with the standard biopsy strategy (strategy 1) at a cost below the WTP threshold, and they therefore completely dominated the standard biopsy strategy. Strategy 2 (nonenhanced diagnostic MR imaging examination followed by cognitive-guided biopsy of the detected lesions and not performing a standard biopsy if MR imaging did not reveal suspicious findings) cost the least and yielded an NHB that was 0.198 QALY more than strategy 1, at an ICER of −$8946 per QALY . The ICER was negative because the new strategy (ie, strategy 2) cost less than the standard strategy (ie, strategy 1) but yielded higher benefits. Strategy 4, with in-gantry MR imaging–guided biopsy, yielded a maximum NHB of 0.251 additional QALY compared with strategy 1, at an ICER of −$1263 per QALY (again, the new strategy cost less and yielded more benefits than the standard strategy, and therefore the ICER is negative). Compared with strategy 2, it yielded an additional NHB of 0.053 QALY at an ICER of $4147, implying that strategy 4 was more expensive than strategy 2 but was still cost-effective because the additional cost was below the WTP threshold. Strategy 6 (MR imaging examination followed by MR imaging/US fusion biopsy and performing a standard biopsy in the event of negative MR imaging findings) was dominated by other MR imaging–guided strategies, as they yielded a higher NHB for the patient at a lower cost, but this strategy still outperformed strategy 1.

Table 3 Cost-effectiveness Analysis

Similar results were obtained in the analysis by age group (Table E8 [online]). MR imaging–guided strategies cost even less in the 41–50-year age group while yielding a higher NHB (0.107–0.225 QALY higher than strategy 1) (Tables E4–E6 [online]). Using contrast material did not change the incremental effectiveness and only added to the cost for all strategies.

Sensitivity Analysis

One-way sensitivity analysis showed that cancer prevalence, percentage of clinically significant cancers, and the sensitivity of pelvic MR imaging had the maximum influence on cost-effectiveness. Comparing standard biopsy (strategy 1) with the most cost-effective MR imaging strategy of cognitively guided MR biopsy (strategy 2) showed that the model was sensitive to only one parameter: the sensitivity of MR imaging to reveal a tumor. If this value were below 18.6%, then the standard biopsy strategy would have become more cost-effective than strategy 2. Additional sensitivity analysis performed by using different Gleason grade cutoff points for clinically significant cancer again revealed that MR imaging–guided strategies consistently outperformed the standard biopsy strategy in terms of ICER and NHB (Tables E4–E6 [online]). Moreover, a higher Gleason score cutoff, implying a higher threshold for a cancer to be deemed clinically significant, yielded a higher NHB across all strategies, while a lower Gleason cutoff yielded lower NHB s. The benefits were nonetheless persuasive in favor of MR imaging–guided strategies.

In addition, this analysis revealed that even small improvements in the sensitivity and specificity of MR imaging in the detection of clinically significant cancer made the use of gadolinium contrast material cost-effective. The results of this analysis for each MR imaging–guided strategy are detailed in Table E7 (online).

Probabilistic sensitivity analysis comparing all seven strategies showed that MR strategies were superior to standard biopsy in 94.05% of simulations at a WTP threshold of $50 000 and in 93.9% of simulations at a WTP threshold of $100 000 (Table 4). Among the MR imaging strategies, the in-gantry approach (strategy 4) was the most cost-effective in a majority of simulations. There was little difference between gadolinium contrast-enhanced and nonenhanced strategies.

Table 4 Probabilistic Sensitivity Analysis

Discussion

We attempted to determine if solution-based use of imaging in the diagnosis of clinically significant prostate cancer is cost-effective rather than looking at imaging costs in isolation. Our study shows that performing MR imaging before biopsy in a patient with clinical suspicion of prostate cancer using MR imaging–guided biopsy techniques is cost-effective. Our results are consistent with previous cost-effectiveness studies on the detection of prostate cancer using MR imaging–guided methods by Mowatt et al (17), Lotan et al (19), and de Rooij et al (18).

One likely reason for the observed cost-effectiveness of MR imaging–guided strategies is the propensity of MR imaging to not “see” low-risk tumors. The size of the tumor correlates with aggressiveness, and therefore, by avoiding the detection of microscopic clinically insignificant cancers, MR imaging helps avoid unnecessary biopsies, associated complications, and other downstream events that may occur after a diagnosis of cancer. Recent studies have shown that MR imaging–guided pathways reduced the detection of low-risk cancers by 89.4% and reduced the overall need for biopsy by 51% (15). A meta-analysis by Schoots et al (29) revealed that the sensitivity of transrectal US biopsy in the detection of clinically insignificant cancers was approximately 83%, whereas that for MR imaging–guided methods was approximately 44%. A negative MR imaging examination also tends to exclude clinically significant cancers. A prospective study by Pokorny et al (15) revealed that the negative predictive value of a negative MR imaging examination was 96.9%, whereas that of a standard biopsy was 71.9%, for intermediate/high-risk cancers. Thus, taken together, the stratification of the types of cancer typically detected and missed at MR imaging, along with the excellent negative predictive value, likely account for the improved cost-effectiveness seen in the present study.

We explored the cost-effectiveness of MR imaging examinations both with and without contrast material for a number of reasons. Diffusion-weighted and T2-weighted pulse sequences superseded contrast-enhanced pulse sequences for the detection of cancer in recently released PI-RADS version 2.0 guidelines and make up the core prostate MR imaging examination in this version, with dynamic contrast-enhanced pulse sequences playing only an adjunct role (43). Similarly, two meta-analyses showed similar sensitivity values for MR imaging examinations composed of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced examinations (de Rooij et al [25]) and for a combination of T2-weighted and diffusion-weighted examinations (Wu et al [44]). The value of short noncontrast MR imaging examinations for diagnosing prostate cancer has been explored in two small prospective studies (22,23). Furthermore, we tried to explore how much improvement in sensitivity is required for a contrast-enhanced examination to be more cost-effective than a noncontrast MR examination by performing a sensitivity analysis. It revealed that even minor improvements in the accuracy of detection with gadolinium contrast material can further increase cost-effectiveness. The main reason that only a marginal improvement in sensitivity is cost-effective is that the cost of contrast material ($36) is small compared with loss of QALY s from missing a clinically significant cancer.

Strategy 2, using noncontrast diagnostic MR imaging as a “triaging” tool followed by cognitive MR imaging guidance to target biopsy of suspicious lesions, was the most cost-effective strategy. Cognitive guidance involves a simple discussion of MR imaging findings between the radiologist and the urologist, and this strategy can be easily applied in community practice even when advanced MR imaging–guided biopsy techniques are not available. Similar results were reported by Cerantola et al (20). However, their study was performed in the Canadian setting using traditional contrast-enhanced diagnostic MR imaging examination as the triaging tool. Strategy 4, which uses in-gantry MR imaging guidance for biopsy of suspicious lesions, had the highest sensitivity among all strategies for the detection of aggressive disease. Although it was the most expensive MR imaging strategy, it led to maximum NHB gain but was still within the WTP threshold. These results are in line with the results obtained by de Rooij et al (18) and imply that a strategy that improves disease stratification and facilitates placement of patients in appropriate treatment pathways remains cost-effective.

Interestingly, MR imaging–guided strategies cost even less in the 41–50-year age group while yielding higher NHB . The incidence of prostate cancer is lower in this age group (45), and a modality with a negative predictive value greater than 90% (37,42) is expected to give better outcomes in groups with lower disease prevalence (45).

The National Institute for Health and Care Excellence (NICE) of the United Kingdom found that use of contrast-enhanced MR imaging and MR imaging–guided biopsy in detecting prostate cancer was not cost-effective (21). The NICE study differed from our study in many substantial ways. A key difference was an assumption in the NICE study that patients given a diagnosis of low-risk disease choose active surveillance every time. A study of treatment options chosen by patients in the United States revealed that most patients with low-risk disease often choose more costly, aggressive therapies (6). However, we could not find any comparable data from the United Kingdom or Europe that reported patterns of treatment selection in patients with a diagnosis of low-risk prostate cancer. The NICE group assumed that the patients diagnosed with anterior tumors would undergo a transperineal biopsy. A review of the literature did not reveal any significant differences in cancer detection rate and complication rate between transrectal and transperineal approaches (46,47). Transperineal biopsies are performed with general anesthesia and hence are more expensive. The European Society for Medical Oncology guidelines also recommend transrectal biopsy for the detection of prostate cancer (48). Moreover, transperineal biopsies are not routinely performed in the United States. Therefore, we did not factor in the transperineal approach in our decision model. The NICE group factored the cost of two radiologic technologists for a single MR imaging examination in their model, which again diverges from routine practice in the United States. Our study is designed to better model the practice and patient preference patterns encountered in the United States.

The WTP threshold was first established in 1982 (39) and amounted to $125 000 in the year 2016 when adjusted for inflation (49). It is the hypothetical maximum amount society is willing to pay for interventions that increase health per 1 additional QALY gained, given that resources are finite. Because it is from the societal perspective and not from an individual perspective, the WTP value is the same for all people regardless of age, wealth, or disability. A WTP limit of $50 000 has been used as the consensus threshold value in many cost-effectiveness studies, but this is probably a conservative limit, and some suggest it should be $100 000 or higher (50). In our study, NHB was used as the primary outcome, rather than ICER , which has been used in earlier cost-effectiveness studies on prostate cancer. This is because ICER is subject to sampling uncertainties when the costs and effectiveness differences are not normally distributed. Moreover, representing cost-effectiveness in a ratio, as ICER does, does not accurately represent cost and benefit tradeoffs (39).

We did not include PSA ranges and PI-RADS scores in our model. The use of PSA level is controversial, and the U.S. Preventive Services Task Force recently gave it a grade D recommendation, implying that the harms of this service outweigh the benefits (51). Similarly, PI-RADS guidelines are evolving and mainly pertain to performing and reporting a multiparametric prostate MR imaging examination. Recent studies have reported the correlation between PI-RADS ratings and tumor aggressiveness, and these relationships can be explored in future cost-effectiveness studies as more evidence accumulates. For the present study, we relied on Gleason scores, which are the cornerstone of management at present.

There were a number of limitations to our study. Medicare-based data were used for analysis but may not be applicable to other forms of reimbursement practices. Second, the values for the diagnostic performance of various modalities tested in the model were derived from single-institution studies because randomized clinical trials comparing MR imaging–guided pathways with the standard biopsy pathway are not available. Assumptions were also made for values of certain parameters that were not available in the literature according to statistical best practices (Tables E9, E10 [online]). The pattern of treatment options chosen by patients on being given a diagnosis of prostate cancer was based on a single study in the United States (6). Interoperator variability has been reported in the histopathologic evaluation of prostate biopsy specimens and in the accuracy of hitting the targeted lesion in imaging-guided biopsies. For the sake of simplicity, these issues are not addressed our study. We did not evaluate the probability of low-risk cancers transitioning to aggressive disease over time. However, there is strong evidence that unless they are associated with higher rade cancers, Gleason 6 tumors practically never metastasize (52). Many authorities even question the use of the term “cancer” for Gleason 6 disease, as it is virtually never fatal, whereas “cancer” usually implies a disease that is fatal without treatment (52,53). Our work is intended to serve as a starting point in analyzing the effectiveness of various diagnostic strategies in the detection of clinically significant cancers, once a clinical suspicion of prostate cancer exists.

In conclusion, our study evaluated MR imaging–guided strategies for the initial detection of prostate cancer. It shows that improvement in the detection of clinically significant prostate cancer by using MR imaging provides substantial benefit to the patient as measured by NHB , and the cost is well within the WTP threshold accepted in the United States.

Advances in Knowledge ■ Strategies that use diagnostic MR imaging followed by MR-guided biopsy of suspicious lesions were cost-effective compared with a standard transrectal US–guided biopsy strategy for detecting clinically significant prostate cancer, yielding additional net health benefits (NHBs) ranging from 0.123 to 0.251 quality-adjusted life-year (QALY) higher than the standard biopsy strategy at a willingness-to-pay (WTP) threshold of $50 000 per QALY .

■ The strategy of noncontrast diagnostic MR examination followed by cognitively guided biopsy and foregoing standard biopsy in the case of a negative MR examination was the most cost-effective strategy, with an incremental NHB of 0.198 QALY compared with the standard biopsy strategy.

■ Noncontrast MR imaging followed by in-gantry MR-guided biopsy strategy and foregoing standard biopsy if MR findings were negative maximized health benefits, with an additional NHB of 0.251 QALY compared with the standard biopsy strategy and 0.053 QALY compared with the cognitive biopsy strategy.

■ MR-guided strategies remained cost-effective when sensitivity analysis was performed using different Gleason scores as cutoff points for clinically significant versus insignificant cancers, yielding an additional NHB ranging from 0.008 to 0.25 QALY compared with the standard biopsy strategy.

■ Even small increments of improvement in sensitivity or specificity of diagnostic MR imaging for detecting clinically significant prostate cancer by adding gadolinium contrast material are cost-effective.

Implications for Patient Care ■ Diagnostic MR imaging examinations followed by targeted MR-guided biopsy methods are cost-effective compared with the standard transrectal US–guided biopsy strategy for the detection of clinically significant prostate cancer, providing impetus for the use of MR imaging in the triage of patients for biopsy in prostate cancer.

■ In-gantry MR-guided biopsy adds further benefit to the patient in terms of QALY s while still remaining below the WTP threshold.

Author Contributions

disclosed no relevant relationships.disclosed no relevant relationships.disclosed no relevant relationships.disclosed no relevant relationships.Activities related to the present article: has received a grant from Siemens. Activities not related to the present article: has received a grant from Siemens. Other relationships: is a party to a patent for magnetic resonance fingerprinting licensed to Siemens Healthineers.Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: institution receives research support from Siemens Healthineers. Other relationships: is a party to a patent for magnetic resonance fingerprinting licensed to Siemens Healthineers.

Author contributions: Guarantors of integrity of entire study, N.K.S., V.G.; study concepts/study design or data acquisition or data analysis/interpretation, all authors; manuscript drafting or manuscript revision for important intellectual content, all authors; manuscript final version approval, all authors; agrees to ensure any questions related to the work are appropriately resolved, all authors; literature research, S.P., L.E.P., Z.L., V.G.; clinical studies, L.E.P., M.A.G., V.G.; experimental studies, L.E.P., M.A.G., V.G.; statistical analysis, S.P., N.K.S., Z.L., M.A.G., V.G.; and manuscript editing, all authors