Systemic and tumor-directed therapy for oligometastatic prostate cancer: study protocol for a phase II trial for veterans with de novo oligometastatic disease.

BACKGROUND: The treatment paradigm for metastatic hormone-sensitive prostate cancer (mHSPC) patients is evolving. PET/CT now offers improved sensitivity and accuracy in staging. Recent randomized trial data supports escalated hormone therapy, local primary tumor therapy, and metastasis-directed therapy. The impact of combining such therapies into a multimodal approach is unknown. This Phase II single-arm clinical trial sponsored and funded by Veterans Affairs combines local, metastasis-directed, and systemic therapies to durably render patients free of detectable disease off active therapy. METHODS: Patients with newly-diagnosed M1a/b prostate cancer (PSMA PET/CT staging is permitted) and 1-5 radiographically visible metastases (excluding pelvic lymph nodes) are undergoing local treatment with radical prostatectomy, limited duration systemic therapy for a total of six months (leuprolide, abiraterone acetate with prednisone, and apalutamide), metastasis-directed stereotactic body radiotherapy (SBRT), and post-operative fractionated radiotherapy if pT ≥ 3a, N1, or positive margins are present. The primary endpoint is the percent of patients achieving a serum PSA of < 0.05 ng/mL six months after recovery of serum testosterone ≥150 ng/dL. Secondary endpoints include time to biochemical progression, time to radiographic progression, time to initiation of alternative antineoplastic therapy, prostate cancer specific survival, health related quality-of-life, safety and tolerability. DISCUSSION: To our knowledge, this is the first trial that tests a comprehensive systemic and tumor directed therapeutic strategy for patients with newly diagnosed oligometastatic prostate cancer. This trial, and others like it, represent the critical first step towards curative intent therapy for a patient population where palliation has been the norm. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03298087 (registration date: September 29, 2017).

Assessing utilities for muscle-invasive bladder cancer-related health states.

OBJECTIVES: How patients value functional outcomes against oncologic outcomes during decision-making for muscular-invasive bladder cancer (MIBC) remains unclear. We sought to quantify individuals' preferences on a scale of 0 to 1, where 1 represents perfect health and 0 represents death. METHODS: Descriptions of 6 hypothetical health states were developed. These included: Neoadjuvant chemotherapy followed by radical cystectomy with ileal conduit (IC) or with neobladder reconstruction (NB), Transurethral resection and chemotherapy/radiation (CRT), CRT requiring salvage cystectomy (SC), Recurrent/metastatic bladder cancer after local therapy (RMBC), and Metastatic bladder cancer (MBC). Descriptions consisted of diagnosis, treatments, adverse effects, follow-up protocol, and prognosis and were reviewed for accuracy by expert panel. Included individuals were asked to evaluate states using the visual analog scale (VAS) and standard gamble (SG) methods. RESULTS: Fifty-four individuals were included for analysis. No score differences were observed between IC, NB, and CRT on VAS or SG. On VAS, SC (value = 0.429) was rated as significantly worse (P < 0.001) than NB (value = 0.582) and CRT (value = 0.565). However, this was not the case using the SG method. Both RMBC (VAS value = 0.178, SG value = 0.631) and MBC (VAS value = 0.169, SG value = 0.327) rated as significantly worse (P < 0.001) than the other states using both VAS and SG. CONCLUSIONS: Within this sample of the general population, preferences for local treatments including IC, NB, and CRT were not found to be significantly different. These values can be used to calculate quality-adjusted life expectancy in future cost-effectiveness analyses.

Experience of Telemedicine Visits in Radiation Oncology During the COVID-19 Pandemic: A US National Survey and Lessons Learned for Incorporating Telemedicine Post-COVID-19.

Purpose: We sought to survey the attitudes and perceptions of US radiation oncologists toward the adoption of telemedicine during the COVID-19 pandemic and offer suggestions for its integration in the postpandemic era. Methods and Materials: A 25-question, anonymous online survey was distributed nationwide to radiation oncologists. Results: One hundred and twenty-one respondents completed the survey, with 92% from academia. Overall, 79% worked at institutions that had implemented a work-from-home policy, with which 74% were satisfied. Despite nearly all visit types being conducted in-person before COVID-19, 25%, 41%, and 5% of the respondents used telemedicine for more than half of their new consultations, follow-up, and on-treatment visits, respectively, during the COVID-19 pandemic. Most (83%) reported being comfortable integrating telemedicine. Although telemedicine was appreciated as being more convenient for patients (97%) and reducing transmission of infectious agents (83%), the most commonly perceived disadvantages were difficulty in performing physical examinations (90%), patients' inability to use technology adequately (74%), and technical malfunctions (72%). Compared with in-person visits, telemedicine was felt to be inferior in establishing a personal connection during consultation (90%) and assessing for toxicity while on-treatment (88%) and during follow-up (70%). For follow-up visits, genitourinary and thoracic were perceived as most appropriate for telemedicine while gynecologic and head and neck were considered the least appropriate. Overall, 70% were in favor of more telemedicine, even after pandemic is over. Conclusions: Telemedicine will likely remain part of the radiation oncology workflow in most clinics after the pandemic. It should be used in conjunction with in-person visits, and may be best used for conducting follow-up visits in certain disease sites such as genitourinary and thoracic malignancies.

Rectal Radiation Dose and Clinical Outcomes in Prostate Cancer Patients Treated With Stereotactic Body Radiation Therapy With and Without Hydrogel.

Background: Patients with prostate cancer treated with stereotactic body radiation therapy (SBRT) may experience gastrointestinal (GI) toxicity. The hydrogel may mitigate this toxicity by reducing the rectal radiation dose. The purpose of this study is to compare rectal radiation dose and GI toxicity in patients receiving prostate SBRT with and without hydrogel. Methods: Consecutive patients treated with SBRT between February 2017 and January 2020 with and without hydrogel were retrospectively identified. Baseline characteristics including prostate volume, rectal diameter, body mass index (BMI), age, pretreatment prostate-specific antigen (PSA), Gleason score, T-stage, and androgen deprivation therapy (ADT) usage were compared. Dosimetric outcomes (V40Gy, V36Gy, V32Gy, V38Gy, and V20Gy), rates of acute (≤90 days) and late (>90 days) GI toxicity, and PSA outcomes were evaluated for patients with and without hydrogel. Results: A total of 92 patients were identified (51 hydrogel and 41 non-hydrogel). There were no significant differences in baseline characteristics. Rectal V38(cc) was significantly less in the hydrogel group (mean 0.44 vs. mean 1.41 cc, p = 0.0002), and the proportion of patients with V38(cc) < 2 cc was greater in the hydrogel group (92% vs. 72%, p = 0.01). Rectal dose was significantly lower for all institutional dose constraints in the hydrogel group (p < 0.001). The hydrogel group experienced significantly less acute overall GI toxicity (16% hydrogel vs. 28% non-hydrogel, p = 0.006), while the difference in late GI toxicity trended lower with hydrogel but was not statistically significant (4% hydrogel vs. 10% non-hydrogel, p = 0.219). At a median follow-up of 14.8 months, there were no biochemical recurrences in either group. Conclusion: Hydrogel reduces rectal radiation dose in patients receiving prostate SBRT and is associated with a decreased rate of acute GI toxicity.

Identifying the Best Candidates for Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography as the Primary Staging Approach Among Men with High-risk Prostate Cancer and Negative Conventional Imaging.

Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) is an emerging imaging modality with greater sensitivity and specificity over conventional imaging for prostate cancer (PCa) staging. Using data from two prospective trials (NCT03368547 and NCT04050215), we explored predictors of overall upstaging (nodal and metastatic) by PSMA PET/CT among patients with cN0M0 National Comprehensive Cancer Network high-risk PCa on conventional imaging (n = 213). Overall, 21.1%, 8.9%, and 23.9% of patients experienced nodal, metastatic, and overall upstaging, respectively, without histologic confirmation. On multivariable analysis, Gleason grade group (GG) and percent positive core (PPC) on systematic biopsy significantly predict overall upstaging (odds ratio [OR] 2.15, 95% confidence interval [CI] 1.33-3.45; p = 0.002; and OR 1.03, 95% CI 1.01-1.04; p < 0.001). Overall upstaging was significantly more frequent among men with GG 5 disease (33.0% vs. 17.6%; p = 0.0097) and PPC ≥50% (33.0% vs 15.0%; p = 0.0020). We constructed a nomogram that predicts overall upstaging using initial prostate-specific antigen, PPC, GG, and cT stage, with coefficients estimated from a standard logistic regression model (using maximum likelihood estimation). It is internally validated with a tenfold cross-validated area under the receiver operating characteristic curve estimated at 0.74 (95% CI 0.67-0.82). In our cohort, 90% of patients who had a nomogram-estimated risk below the cutoff of 22% for overall upstaging could have been spared PSMA PET/CT as our model correctly predicted no upstaging. In other words, the predictive model only missed 10% of patients who would otherwise have benefitted from PSMA PET/CT. PATIENT SUMMARY: We analyzed predictors of overall upstaging (lymph node or/and metastasis) by prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) from conventional imaging in men with high-risk prostate cancer undergoing initial staging deemed free of disease in the lymph nodes and distant metastasis by conventional imaging techniques. We found that the pathologic grade and disease burden in a prostate biopsy are associated with upstaging. We also developed a tool that predicts the probability of upstaging according to an individual patient's characteristics. Our study may help in defining patient groups who are most likely to benefit from the addition of a PSMA PET/CT scan.

Time-Driven Activity-Based Costing of CT-Guided vs MR-Guided Prostate SBRT.

BACKGROUND AND PURPOSE: Stereotactic body radiation therapy (SBRT) has become a standard-of-care option for localized prostate cancer. While prostate SBRT has traditionally been delivered using computed-tomography-guided radiation therapy (CTgRT), MR-imaging-guided radiation therapy (MRgRT) is now available. MRgRT offers real-time soft-tissue visualization and ease of adaptive planning, obviating the need for fiducial markers, and potentially allowing for smaller planning target volume (PTV) margins. Although prior studies have focused on evaluating the cost-effectiveness of MRgRT vs CTgRT from a payor perspective, the difference in provider costs to deliver such treatments remains unknown. This study thus used time-driven activity-based costing (TDABC) to determine the difference in provider resources consumed by delivering prostate SBRT via MRgRT vs CTgRT. METHODS: Data was collected from a single academic institution where prostate SBRT is routinely performed using both CTgRT and MRgRT. Five-fraction SBRT (40 Gy total dose) was assumed to be delivered through volumetric-modulated arc therapy for CTgRT patients, and through step-and-shoot, fixed-gantry intensity-modulated radiation therapy for MRgRT patients. Process maps were constructed for each portion of the radiation delivery process via interviews/surveys with departmental personnel and by measuring CTgRT and MRgRT treatment times. Prior to simulation, only CTgRT patients underwent placement of three gold fiducial markers. Personnel capacity cost rates were calculated by dividing total personnel costs by the annual minutes worked by a given personnel. Equipment costs included both an annualized purchase price and annual maintenance costs. Ultimately, the total costs of care encompassing personnel, space/equipment, and materials were aggregated across the entire chain of care for both CTgRT and MRgRT patients in a base case. RESULTS: Direct costs associated with delivering a 5-fraction course of prostate SBRT were $1,497 higher with MRgRT than with CTgRT - comprised of personnel costs ($210 higher with MRgRT), space/equipment ($1,542 higher with MRgRT), and materials ($255 higher with CTgRT). Only CTgRT patients underwent fiducial placement, which accounted for $591. MRgRT patients were assumed to undergo both CT simulation (for electron density calculation) and MRI simulation, with the former accounting for $168. Mean time spent by patients in the treatment vault per fraction was 20 minutes (range 15-26 minutes) for CTgRT, and 31 minutes (range 30-34 minutes) for MRgRT. Patient time spent during fiducial placement (CTgRT only) was 60 minutes. Modifying the number of fractions treated would result in the cost difference of $1,497 (5 fractions) changing to $441 (1 fraction) or to $2,025 (7 fractions). CONCLUSION: This study provides an approximate comparison of the direct resources required for a radiation oncology provider to deliver prostate SBRT with CTgRT vs MRgRT. We await findings from the currently accruing phase III MIRAGE trial, which is comparing these modalities, and will subsequently measure acute and late genitourinary/gastrointestinal (GU/GI) toxicities, temporal change in quality-of-life outcomes, and 5-year biochemical, recurrence-free survival. Results from studies comparing the efficacy and safety of MRgRT vs CTgRT will ultimately allow us to put this cost difference into context.

The Mutational Landscape of Metastatic Castration-sensitive Prostate Cancer: The Spectrum Theory Revisited.

BACKGROUND: Emerging data suggest that metastasis is a spectrum of disease burden rather than a binary state, and local therapies, such as radiation, might improve outcomes in oligometastasis. However, current definitions of oligometastasis are solely numerical. OBJECTIVE: To characterize the somatic mutational landscape across the disease spectrum of metastatic castration-sensitive prostate cancer (mCSPC) to elucidate a biological definition of oligometastatic CSPC. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective study of men with mCSPC who underwent clinical-grade sequencing of their tumors (269 primary tumor, 25 metastatic sites). Patients were classified as having biochemically recurrent (ie, micrometastatic), metachronous oligometastatic (≤5 lesions), metachronous polymetastatic (>5 lesions), or de novo metastatic (metastasis at diagnosis) disease. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We measured the frequency of driver mutations across metastatic classifications and the genomic associations with radiographic progression-free survival (rPFS) and time to castrate-resistant prostate cancer (CRPC). RESULTS AND LIMITATIONS: The frequency of driver mutations in TP53 (p = 0.01), WNT (p = 0.08), and cell cycle (p = 0.04) genes increased across the mCSPC spectrum. TP53 mutation was associated with shorter rPFS (26.7 vs 48.6 mo; p = 0.002), and time to CRPC (95.6 vs 155.8 mo; p = 0.02) in men with oligometastasis, and identified men with polymetastasis with better rPFS (TP53 wild-type, 42.7 mo; TP53 mutated, 18.5 mo; p = 0.01). Mutations in TP53 (incidence rate ratio [IRR] 1.45; p = 0.004) and DNA double-strand break repair (IRR 1.61; p < 0.001) were associated with a higher number of metastases. Mutations in TP53 were also independently associated with shorter rPFS (hazard ratio [HR] 1.59; p = 0.03) and the development of CRPC (HR 1.71; p = 0.01) on multivariable analysis. This study was limited by its retrospective nature, sample size, and the use of commercially available sequencing platforms, resulting in a limited predefined set of genes examined. CONCLUSIONS: Somatic mutational profiles reveal a spectrum of metastatic biology that helps in redefining oligometastasis beyond a simple binary state of lesion enumeration. PATIENT SUMMARY: Oligometastatic prostate cancer is typically defined as less than three to five metastatic lesions and evidence suggests that using radiation or surgery to treat these sites improves clinical outcomes. As of now, treatment decisions for oligometastasis are solely defined according to the number of lesions. However, this study suggests that tumor mutational profiles can provide a biological definition of oligometastasis and complement currently used numerical definitions.

Stereotactic Body Radiotherapy for Prostate Cancer.

Prostate cancer remains the most common and second most deadly cancer diagnosed amongst U.S. men. External beam radiotherapy is a standard-of-care definitive treatment option for localized prostate cancer and historically constituted an 8-9-week treatment course comprised of 39-45 doses of 1.8-2.0 Gy each (conventional fractionation, CF). Based on the notion that prostate cancer may respond favorably to a higher dose per day, considerable research efforts have been focused on characterizing the safety and efficacy profile of shorter and shorter radiation courses. Ultrahypofractionation (UHF) involves condensing the radiation course into just 5-7 treatments of 6-8 Gy each. When utilizing modern techniques that allow the precise sculpting of a dose distribution that delivers high doses to the prostate and lower doses to surrounding normal tissues over five or fewer treatments, this treatment is called stereotactic body radiotherapy (SBRT). Two randomized trials (HYPO-RT-PC and PACE-B) have compared UHF to longer radiation courses. The former demonstrated that UHF and CF have similar long-term toxicity and efficacy, while the latter demonstrated that modern SBRT has equivalent short-term toxicity as well. A separate report from a consortium of studies data provides prospective, albeit nonrandomized, data supporting the longer-term safety and efficacy of SBRT specifically. Thus, mounting high-level evidence suggests that SBRT is an acceptable standard care of option for men with localized prostate cancer.

A generative adversarial network-based (GAN-based) architecture for automatic fiducial marker detection in prostate MRI-only radiotherapy simulation images.

PURPOSE: Clinical sites utilizing magnetic resonance imaging (MRI)-only simulation for prostate radiotherapy planning typically use fiducial markers for pretreatment patient positioning and alignment. Fiducial markers appear as small signal voids in MRI images and are often difficult to discern. Existing clinical methods for fiducial marker localization require multiple MRI sequences and/or manual interaction and specialized expertise. In this study, we develop a robust method for automatic fiducial marker detection in prostate MRI simulation images and quantify the pretreatment alignment accuracy using automatically detected fiducial markers in MRI. METHODS AND MATERIALS: In this study, a deep learning-based algorithm was used to convert MRI images into labeled fiducial marker volumes. Seventy-seven prostate cancer patients who received marker implantation prior to MRI and CT simulation imaging were selected for this study. Multiple-Echo T1 -VIBE MRI images were acquired, and images were stratified (at the patient level) based on the presence of intraprostatic calcifications. Ground truth (GT) contours were defined by an expert on MRI using CT images. Training was done using the pix2pix generative adversarial network (GAN) image-to-image translation package and model testing was done using fivefold cross validation. For performance comparison, an experienced medical dosimetrist and a medical physicist each manually contoured fiducial markers in MRI images. The percent of correct detections and F1 classification scores are reported for markers detected using the automatic detection algorithm and human observers. The patient positioning errors were quantified by calculating the target registration errors (TREs) from fiducial marker driven rigid registration between MRI and CBCT images. Target registration errors were quantified for fiducial marker contours defined on MRI by the automatic detection algorithm and the two expert human observers. RESULTS: Ninety-six percent of implanted fiducial markers were correctly identified using the automatic detection algorithm. Two expert raters correctly identified 97% and 96% of fiducial markers, respectively. The F1 classification score was 0.68, 0.75, and 0.72 for the automatic detection algorithm and two human raters, respectively. The main source of false discoveries was intraprostatic calcifications. The mean TRE differences between alignments from automatic detection algorithm and human detected markers and GT were <1 mm. CONCLUSIONS: We have developed a deep learning-based approach to automatically detect fiducial markers in MRI-only simulation images in a clinically representative patient cohort. The automatic detection algorithm-predicted markers can allow for patient setup with similar accuracy to independent human observers.

Time-Driven Activity-Based Costing Analysis of Telemedicine Services in Radiation Oncology.

PURPOSE: Health systems have increased telemedicine use during the SARS-CoV-2 outbreak to limit in-person contact. We used time-driven activity-based costing to evaluate the change in resource use associated with transitioning to telemedicine in a radiation oncology department. METHODS AND MATERIALS: Using a patient undergoing 28-fraction treatment as an example, process maps for traditional in-person and telemedicine-based workflows consisting of discrete steps were created. Physicians/physicists/dosimetrists and nurses were assumed to work remotely 3 days and 1 day per week, respectively. Mapping was informed by interviews and surveys of personnel, with cost estimates obtained from the department's financial officer. RESULTS: Transitioning to telemedicine reduced provider costs by $586 compared with traditional workflow: $47 at consultation, $280 during treatment planning, $237 during on-treatment visits, and $22 during the follow-up visit. Overall, cost savings were $347 for space/equipment and $239 for personnel. From an employee perspective, the total amount saved each year by not commuting was $36,718 for physicians (7243 minutes), $19,380 for physicists (7243 minutes), $17,286 for dosimetrists (7210 minutes), and $5599 for nurses (2249 minutes). Patients saved $170 per treatment course. CONCLUSIONS: A modified workflow incorporating telemedicine visits and work-from-home capability conferred savings to a department as well as significant time and costs to health care workers and patients alike.

Time-Driven Activity-Based Costing Comparison of CT-Guided Versus MR-Guided SBRT.

PURPOSE: Magnetic resonance-guided radiation therapy (MRgRT) has recently become commercially available, offering the opportunity to accurately image and target moving tumors as compared with computed tomography-guided radiation therapy (CTgRT) systems. However, the costs of delivering care with these 2 modalities remain poorly described. With localized unresectable hepatocellular carcinoma as an example, we were able to use time-driven activity-based costing to determine the cost of treatment on linear accelerators with CTgRT compared with MRgRT. MATERIALS AND METHODS: Process maps, informed via interviews with departmental personnel, were created for each phase of the care cycle. Stereotactic body radiation therapy was delivered at 50 Gy in 5 fractions, either with CTgRT using fiducial placement, deep inspiration breath-hold (DIBH) with real-time position management, and volumetric-modulated arc therapy, or with MRgRT using real-time tumor gating, DIBH, and static-gantry intensity-modulated radiation therapy. RESULTS: Direct clinical costs were $7,306 for CTgRT and $8,622 for MRgRT comprising personnel costs ($3,752 v $3,603), space and equipment costs ($2,912 v $4,769), and materials costs ($642 v $250). Increased MRgRT costs may be mitigated by forgoing CT simulation ($322 saved) or shortening treatment to 3 fractions ($1,815 saved). Conversely, adaptive treatment with MRgRT would result in an increase in cost of $529 per adaptive treatment. CONCLUSION: MRgRT offers real-time image guidance, avoidance of fiducial placement, and ability to use adaptive treatments; however, it is 18% more expensive than CTgRT under baseline assumptions. Future studies that elucidate the magnitude of potential clinical benefits of MRgRT are warranted to clarify the value of using this technology.

Time-Driven Activity-Based Costing Comparison of Stereotactic Radiosurgery to Multiple Brain Lesions Using Single-Isocenter Versus Multiple-Isocenter Technique.

PURPOSE: Stereotactic radiosurgery (SRS) historically has been used to treat multiple brain lesions using a multiple-isocenter technique-frequently associated with significant complexity in treatment planning and long treatment times. Recently, given innovations in planning algorithms, patients with multiple brain lesions may now be treated with a single-isocenter technique using fewer total arcs and less time spent during image guidance (though with stricter image guided radiation therapy tolerances). This study used time-driven activity-based costing to determine the difference in cost to a provider for delivering SRS to multiple brain lesions using single-isocenter versus multiple-isocenter techniques. METHODS AND MATERIALS: Process maps, consisting of discrete steps, were created for each phase of the SRS care cycle and were based on interviews with department personnel. Actual treatment times (including image guidance) were extracted from treatment record and verify software. Additional sources of data to determine costs included salary/benefit data of personnel and average list price/maintenance costs for equipment. RESULTS: Data were collected for 22 patients who underwent single-isocenter SRS (mean lesions treated, 5.2; mean treatment time, 30.2 minutes) and 51 patients who underwent multiple-isocenter SRS (mean lesions treated, 4.4; mean treatment time, 75.2 minutes). Treatment time for multiple-isocenter SRS varied substantially with increasing number of lesions (11.8 minutes/lesion; P < .001), but to a much lesser degree in single-isocenter SRS (1.8 minutes/lesion; P = .029). The resulting cost savings from single-isocenter SRS based on number of lesions treated ranged from $296 to $3878 for 2 to 10 lesions treated. The 2-mm planning treatment volume margin used with single-isocenter SRS resulted in a mean 43% increase of total volume treated compared with a 1-mm planning treatment volume expansion. CONCLUSIONS: In a comparison of time-driven activity-based costing assessment of single-isocenter versus multiple-isocenter SRS for multiple brain lesions, single-isocenter SRS appears to save time and resources for as few as 2 lesions, with incremental benefits for additional lesions treated.

The Impact of 18F-DCFPyL PET-CT Imaging on Initial Staging, Radiation, and Systemic Therapy Treatment Recommendations for Veterans With Aggressive Prostate Cancer.

PURPOSE: Our purpose was to study the effect of 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (18F-DCFPyL) positron emission tomography (PET)-computed tomography (CT) on staging/treatment recommendations of previously untreated prostate cancer. We report here results of a prospective single center single arm imaging trial within Veterans Affairs (Greater Los Angeles): the frequency of patients upstaged to M1 disease (primary endpoint) and the frequency of patients with change in treatment recommendations (secondary endpoint). This is the first report of prostate-specific membrane antigen PET-CT exclusive to U.S. veterans. METHODS AND MATERIALS: Veterans with Gleason ≥4 + 3, clinical stage ≥T2c, or prostate-specific antigen >10 ng/mL were eligible. Patients underwent conventional imaging (99mTc-methyl diphosphonate bone scan or 18F-NaF PET-CT; and pelvic CT or pelvic magnetic resonance imaging) in addition to 18F-DCFPyL PET-CT. The effect of 18F-DCFPyL PET-CT on treatment change was determined by applying prespecified treatment recommendations based on National Comprehensive Cancer Network guidelines and modern clinical practice. RESULTS: One hundred patients underwent 18F-DCFPyL PET-CT. Nineteen out of 84 (23%) patients initially thought to be nonmetastatic were upstaged to M1; 8/16 (50%) patients initially thought to have M1 disease were downstaged to M0. In total, 39/100 (39%) had a change in prespecified treatment recommendations, including change of radiation therapy volume/dose in 39/100 (39%) and starting abiraterone in 22/100 (22%). CONCLUSIONS: Incorporation of 18F-DCFPyL PET-CT into the initial conventional imaging workup for prostate cancer can substantially affect staging/treatment recommendations.

Cost-Effectiveness of Metastasis-Directed Therapy in Oligorecurrent Hormone-Sensitive Prostate Cancer.

PURPOSE: Oligorecurrent prostate cancer has historically been treated with indefinite androgen deprivation therapy (ADT), although many patients and providers opt to defer this treatment at the time of recurrence given quality-of-life and/or comorbidity considerations. Recently, metastasis-directed therapy (MDT) has emerged as a potential intermediary between surveillance and immediate continuous ADT. Simultaneously, advanced systemic therapy in addition to ADT has also been shown to improve survival in metastatic hormone-sensitive disease. This study aimed to compare the cost-effectiveness of treating oligorecurrent patients with upfront MDT before standard-of-care systemic therapy. METHODS AND MATERIALS: A Markov-based cost-effectiveness analysis was constructed comparing 3 strategies: (1) upfront MDT → salvage abiraterone acetate plus prednisone (AAP) + ADT → salvage docetaxel + ADT; (2) upfront AAP + ADT → salvage docetaxel + ADT; and (3) upfront docetaxel + ADT → salvage AAP + ADT. Transition probabilities and utilities were derived from the literature. Using a 10-year time horizon and willingness-to-pay threshold of $100,000/quality-adjusted life year (QALY), net monetary benefit values were subsequently calculated for each treatment strategy. RESULTS: At 10 years, the base case revealed a total cost of $141,148, $166,807, and $136,154 with QALYs of 4.63, 4.89, and 4.00, respectively, reflecting a net monetary benefit of $322,240, $322,018, and $263,407 for upfront MDT, upfront AAP + ADT, and upfront docetaxel + ADT, respectively. In the probabilistic sensitivity analysis using a Monte Carlo simulation (1,000,000 simulations), upfront MDT was the cost-effective strategy in 53.6% of simulations. The probabilistic sensitivity analysis revealed 95% confidence intervals for cost ($75,914-$179,862, $124,431-$223,892, and $103,298-$180,617) and utility in QALYs (3.85-6.12, 3.91-5.86, and 3.02-5.22) for upfront MDT, upfront AAP + ADT, and upfront docetaxel + ADT, respectively. CONCLUSIONS: At 10 years, upfront MDT followed by salvage AAP + ADT, is comparably cost-effective compared with upfront standard-of-care systemic therapy and may be considered a viable treatment strategy, especially in patients wishing to defer systemic therapy for quality-of-life or comorbidity concerns. Additional studies are needed to determine whether MDT causes a sustained meaningful delay in disease natural history and whether any benefit exists in combining MDT with upfront advanced systemic therapy.

Phase 1 Trial of Stereotactic Body Radiation Therapy Neoadjuvant to Radical Prostatectomy for Patients With High-Risk Prostate Cancer.

PURPOSE: This study aimed to evaluate the feasibility and safety of prostate stereotactic body radiation therapy (SBRT) neoadjuvant to radical prostatectomy (RP) in a phase 1 trial. The primary endpoint was treatment completion rate without severe acute surgical complications. Secondary endpoints included patient-reported quality of life and physician-reported toxicities. METHODS AND MATERIALS: Patients with nonmetastatic high-risk or locally advanced prostate cancer received 24 Gy in 3 fractions to the prostate and seminal vesicles over 5 days, completed 2 weeks before RP. Patients with pN1 disease were treated after multidisciplinary discussion and shared decision making. Patient-reported quality of life (International Prostate Symptom Score and Expanded Prostate Cancer Index Composite 26-item version questionnaires) and physician-reported toxicity (Common Terminology Criteria for Adverse Events, version 4.03) were assessed before SBRT, immediately before surgery, and at 3-month intervals for 1 year. RESULTS: Twelve patients were enrolled, and 11 completed treatment (1 patient had advanced disease on prostate-specific membrane antigen positron emission tomography after enrollment but before treatment). There were no significant surgical complications. After RP, 2 patients underwent additional radiation therapy to nodes with androgen suppression for pN1 disease. Median follow-up after completion of treatment was 20.1 months, with 9 of 11 patients having a follow-up period of >12 months. Two patients had biochemical recurrence (prostate-specific antigen ≥0.05) within the first 12 months, with an additional 2 patients found to have biochemical recurrence after the 12-month period. The highest Common Terminology Criteria for Adverse Events genitourinary grades were 0, 1, 2, and 3 (n = 1, 4, 4, and 2, respectively), and the highest gastrointestinal grades were 0, 1, and 2 (n = 9, 1, and 1, respectively). At 12 months, incontinence was the only grade ≥2 toxicity. One and 2 of 9 patients had grade 2 and 3 incontinence, respectively. On the Expanded Prostate Cancer Index Composite (26-item version), the mean/median changes in scores from baseline to 12 months were -32.8/-31.1 for urinary incontinence, -1.6/-6.2 for urinary irritative/obstructive, -2.1/0 for bowel, -34.4/-37.5 for sexual function, and -10.6/-2.5 for hormonal. The mean/median change in International Prostate Symptom Score from baseline to 12 months was 0.5/0.5. CONCLUSIONS: RP after neoadjuvant SBRT appears to be feasible and safe at the dose tested. The severity of urinary incontinence may be higher than RP alone.

Prognostic significance of EGFR and KRAS mutations in NSCLC patients with brain metastases treated with radiosurgery†.

PURPOSE: Determine whether EGFR and KRAS mutations carry prognostic significance in non-small cell lung cancer (NSCLC) patients with brain metastases treated with stereotactic radiosurgery. METHODS AND MATERIALS: Ninety-four NSCLC patients with brain metastases initially treated with stereotactic radiosurgery were retrospectively reviewed. Both EGFR and KRAS mutation status were recorded in 67 patients: EGFR+/KRAS- status in 9 patients, EGFR-/KRAS+ in 15 patients, and EGFR-/KRAS- in 43 patients. Survival was determined using the Kaplan-Meier method. Cox regression was used to assess the effects of patient factors on overall survival, local control, and distant brain control - all from time of brain metastasis diagnosis. RESULTS: Median overall survival from time of brain metastasis diagnosis was 30.6 months for EGFR+/KRAS- patients, 9.8 months for EGFR-/KRAS+ patients, and 19.1 months for EGFR-/KRAS- patients (p=0.094). Local control at 2 years was 100% for EGFR+/KRAS- patients, 66.7% for EGFR-/KRAS+ patients, and 97.2% for EGFR-/KRAS- patients (p=0.399). Distant brain control at 12 months was achieved in 66.7% of EGFR+/KRAS- patients, 30.0% of EGFR-/KRAS+ patients, and 73.7% of EGFR-/KRAS- patients (p=0.039). On multivariate analysis, the most important predictors of mortality were baseline DS-GPA>2 (HR=0.27; p=0.001), EGFR mutation positivity (HR=0.30; p=0.054), and KRAS mutation positivity (HR=2.12; p=0.056); the most important predictors of distant brain failure were KRAS status (HR=4.44; p=0.004) and extracranial disease (HR=3.28; p=0.058); there was no statistically significant multivariate model identified for local control. CONCLUSIONS: In NSCLC patients with brain metastases, KRAS mutations portend higher rates of distant brain failure. Our data also suggests that EGFR portends better overall survival and KRAS portends worse overall survival, though this still needs to be verified by a larger study.

Predictors of survival in contemporary practice after initial radiosurgery for brain metastases.

PURPOSE: The number of brain metastases (BM) is a major consideration in determining patient eligibility for stereotactic radiosurgery (SRS), but the evidence for this popular practice is equivocal. The purpose of this study was to determine whether, following multivariate adjustment, the number and volume of BM held prognostic significance in a cohort of patients initially treated with SRS alone. METHODS AND MATERIALS: A total of 251 patients with primary malignancies, including non-small cell lung cancer (34%), melanoma (30%), and breast carcinoma (16%), underwent SRS for initial treatment of BM. SRS was used as the sole management (62% of patients) or was combined with salvage treatment with SRS (22%), whole-brain radiation therapy (WBRT; 13%), or resection (3%). Median follow-up time was 9.4 months. Survival was determined using the Kaplan-Meier method. Cox regression was used to assess the effects of patient factors on distant brain failure (DBF), local control (LC), and overall survival (OS). RESULTS: LC at 1 year was 94.6%, and median time to DBF was 10 months. Median OS was 11.1 months. On multivariate analysis, statistically significant predictors of OS were presence of extracranial disease (hazard ratio [HR], 4.2, P<.001), total tumor volume greater than 2 cm(3) (HR, 1.98; P<.001), age ≥60 years (HR, 1.67; P=.002), and diagnosis-specific graded prognostic assessment (HR, 0.71; P<.001). The presence of extracranial disease was a statistically significant predictor of DBF (HR, 2.15), and tumor volume was predictive of LC (HR, 4.56 for total volume >2 cm(3)). The number of BM was not predictive of DBF, LC, or OS. CONCLUSIONS: The number of BM is not a strong predictor for clinical outcomes following initial SRS for newly diagnosed BM. Other factors including total treatment volume and systemic disease status are better determinants of outcome and may facilitate appropriate use of SRS or WBRT.