Prostate Cancer Skeletal Metastasis: A Spontaneous Evolution from Osteolytic to Osteoblastic Morphology without Treatment.

Skeletal metastases due to prostate cancer (PCa) are more commonly osteoblastic than osteolytic. In the rarer cases of osteolytic skeletal metastasis of PCa, transition to osteoblastic phenotype occurs following treatment, which indicates successful healing. In this report, we present a case of spontaneous osteolytic to osteoblastic evolution of PCa skeletal metastasis without treatment in a patient with recurrence of PCa. Our patient is a 59-year-old male who had a robotic radical prostatectomy in July 2014 for a T2c adenocarcinoma of the prostate gland (Gleason score = 4 + 3). He had adjuvant pelvic radiotherapy in January 2015 due to prostate-specific antigen (PSA) persistence. PSA began to rise in October 2015. An 18 F-fluciclovine positron emission tomography/computed tomography (PET/CT) scan obtained in June 2017 at a PSA of 0.5 ng/mL was negative. Repeat 18 F-fluciclovine PET/CT of February 2020 at PSA of 3.72 ng/mL showed prostate bed recurrence and a nonavid osteolytic left inferior pubic ramus lesion. 18F radiohybrid prostate-specific membrane antigen ( 18 F-rhPSMA) PET/CT scan of August 2020 performed as part of an ongoing clinical trial confirmed local prostate bed recurrence with a low-grade radiotracer uptake in the osteolytic left inferior pubic ramus bone lesion. Without salvage therapy, 18 F-fluciclovine PET/CT of October 2020 and March 2022 shows progressive sclerosis in the left pubic ramus lesion. An osteolytic to osteoblastic transition of a bone lesion as shown in this patient calls for a rethink in our understanding of untreated PCa skeletal metastasis progression. This case provides novel insight into the understanding of the temporal evolution of skeletal metastasis and calls for further research.

Aberrant Vascular Anatomy Associated With Artifactual Focal Avidity in the Liver on PSMA PET.

ABSTRACT: 68 Ga-prostate-specific membrane antigen (PSMA) PET/CT is a valuable tool for staging and restaging of prostate cancer. Prostate-specific membrane antigen expression is not specific to prostate cancer, as it is expressed in normal tissues as well as in neoplastic and nonneoplastic processes. Awareness of the broad possibility of lesions with PSMA avidity is necessary to recognize normal variants and avoid potential pitfalls in image interpretation. We present a series of cases showing physiologic focal PSMA avidity in hepatic segment IVb. We correlate this uptake with aberrant hepatic vasculature. The awareness of this variant is important for accurate image interpretation to prevent additional invasive procedures, undue treatment escalation, and denial of curative treatment to patients.

Computer assisted interpretation of Tc-99m mercaptoacetyltriglycine diuretic scintigraphy enhances resident performance.

OBJECTIVE: iRENEX is a software module that incorporates scintigraphic and clinical data to interpret 99m Tc- mercaptoacetyltriglycine (MAG3) diuretic studies and provide reasons for their conclusions. Our objectives were to compare iRENEX interpretations with those of expert physicians, use iRENEX to evaluate resident performance and determine if iRENEX could improve the diagnostic accuracy of experienced residents. METHODS: Baseline and furosemide 99m Tc-MAG3 acquisitions of 50 patients with suspected obstruction (mean age ± SD, 58.7 ±â€…15.8 years, 60% female) were randomly selected from an archived database and independently interpreted by iRENEX, three expert readers and four nuclear medicine residents with one full year of residency. All raters had access to scintigraphic data and a text file containing clinical information and scored each kidney on a scale from +1.0 to -1.0. Scores ≥0.20 represented obstruction with higher scores indicating greater confidence. Scores +0.19 to -0.19 were indeterminate; scores ≤-0.20 indicated no obstruction. Several months later, residents reinterpreted the studies with access to iRENEX. Receiver operating characteristic (ROC) analysis and concordance correlation coefficient (CCC) quantified agreement. RESULTS: The CCC among experts was higher than that among residents, 0.84, versus 0.39, respectively, P  < 0.001. When residents reinterpreted the studies with iRENEX, their CCC improved from 0.39 to 0.73, P  < 0.001. ROC analysis showed significant improvement in the ability of residents to distinguish between obstructed and non-obstructed kidneys using iRENEX ( P  = 0.036). CONCLUSION: iRENEX interpretations were comparable to those of experts. iRENEX reduced interobserver variability among experienced residents and led to better agreement between resident and expert interpretations.

Impact of 18 F-Fluciclovine PET/CT Findings on Failure-Free Survival in Biochemical Recurrence of Prostate Cancer Following Salvage Radiation Therapy.

PURPOSE: We aimed to evaluate the impact of 18 F-fluciclovine PET/CT imaging on failure-free survival (FFS) post-salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence. METHODS: Seventy-nine patients were recruited in a phase 2/3 clinical trial to undergo 18 F-fluciclovine PET/CT before SRT for PCa. Four patients with extrapelvic disease were excluded. All patients were followed up at regular intervals up to 48 months. Treatment failure was defined as a serum prostate-specific antigen level of ≥0.2 ng/mL above the nadir after SRT, confirmed with an additional measurement, requiring systemic treatment or clinical progression. Failure-free survival was computed and compared between patients grouped according to 18 F-fluciclovine PET/CT imaging findings. RESULTS: Eighty percent (60/75) of patients had a positive finding on 18 F-fluciclovine PET/CT, of which 56.7% (34/60) had prostate bed-only uptake, whereas 43.3% (26/60) had pelvic nodal ± bed uptake. Following SRT, disease failure was detected in 36% (27/75) of patients. There was a significant difference in FFS between patients who had a positive versus negative scan (62.3% vs 92.9% [ P < 0.001] at 36 months and 59.4% vs 92.9% [ P < 0.001] at 48 months). Similarly, there was a significant difference in FFS between patients with uptake in pelvic nodes ± bed versus prostate bed only at 36 months (49.8% vs 70.7%; P = 0.003) and at 48 months (49.8% vs 65.6%; P = 0.040). Failure-free survival was also significantly higher in patients with either negative PET/CT or prostate bed-only disease versus those with pelvic nodal ± prostate bed disease at 36 (78% vs 49.8%, P < 0.001) and 48 months (74.4% vs 49.8%, P < 0.001). CONCLUSIONS: Findings on pre-SRT 18 F-fluciclovine PET/CT imaging, even when acted upon to optimize the treatment decisions and treatment planning, are predictive of post-SRT FFS in men who experience PCa recurrence after radical prostatectomy. A negative 18 F-fluciclovine PET/CT is most predictive of a lower risk of failure, whereas the presence of pelvic nodal recurrence portends a higher risk of SRT failure.

Differences in Failure-Free Survival After Salvage Radiotherapy Guided by Conventional Imaging Versus 18F-Fluciclovine PET/CT in Postprostatectomy Patients: A Post Hoc Substratification Analysis of the EMPIRE-1 Trial.

The EMPIRE-1 (Emory Molecular Prostate Imaging for Radiotherapy Enhancement 1) trial reported a survival advantage in recurrent prostate cancer salvage radiotherapy (SRT) guided by 18F-fluciclovine PET/CT versus conventional imaging. We performed a post hoc analysis of the EMPIRE-1 cohort stratified by protocol-specified criteria, comparing failure-free survival (FFS) between study arms. Methods: EMPIRE-1 randomized patients to SRT planning via either conventional imaging only (bone scanning plus abdominopelvic CT or MRI) (arm A) or conventional imaging plus 18F-fluciclovine PET/CT (arm B). Randomization was stratified by prostate-specific antigen (PSA) level (<2.0 vs. ≥ 2.0 ng/mL), adverse pathology, and androgen-deprivation therapy (ADT) intent. We subdivided patients in each arm using the randomization stratification criteria and compared FFS between patient subgroups across study arms. Results: Eighty-one and 76 patients received per-protocol SRT in study arms A and B, respectively. The median follow-up was 3.5 y (95% CI, 3.0-4.0). FFS was 63.0% and 51.2% at 36 and 48 mo, respectively, in arm A and 75.5% at both 36 and 48 mo in arm B. Among patients with a PSA of less than 2 ng/mL (mean, 0.42 ± 0.42 ng/mL), significantly higher FFS was seen in arm B than arm A at 36 mo (83.2% [95% CI, 70.0-91.0] vs. 66.5% [95% CI, 51.6-77.8], P < 0.001) and 48 mo (83.2% [95% CI, 70.0-91.0] vs. 56.2% [95% CI, 40.5-69.2], P < 0.001). No significant difference in FFS between study arms in patients with a PSA of at least 2 ng/mL was observed. Among patients with adverse pathology, significantly higher FFS was seen in arm B than arm A at 48 mo (68.9% [95% CI, 52.1-80.8] vs. 42.8% [95% CI, 26.2-58.3], P < 0.001) though not at the 36-mo follow-up. FFS was higher in patients without adverse pathology in arm B versus arm A (90.2% [95% CI, 65.9-97.5] vs. 73.1% [95% CI, 42.9-89.0], P = 0.006) at both 36 and 48 mo. Patients in whom ADT was intended in arm B had higher FFS than those in arm A, with the difference reaching statistical significance at 48 mo (65.2% [95% CI, 40.3-81.7] vs. 29.1 [95% CI, 6.5-57.2], P < 0.001). Patients without ADT intent in arm B had significantly higher FFS than patients in arm A at 36 mo (80.7% [95% CI, 64.9-90.0] vs. 68.0% [95% CI, 51.1-80.2]) and 48 mo (80.7% [95% CI, 64.9-90.0] vs. 58.6% [95% CI, 41.0-72.6]). Conclusion: The survival advantage due to the addition of 18F-fluciclovine PET/CT to SRT planning is maintained regardless of the presence of adverse pathology or ADT intent. Including 18F-fluciclovine PET/CT to SRT leads to survival benefits in patients with a PSA of less than 2 ng/mL but not in patients with a PSA of 2 ng/mL or higher.

Root Cause Analysis in Nuclear Medicine for Sentinel Events.

A sentinel event is any unexpected event that results in death or serious physical or psychological injury to a patient unrelated to a patient's illness. Establishing and determining cause-and-effect relationships is key to preventing future sentinel/near-miss events. However, it can be challenging to establish a cause-and-effect relationship when a process involves multiple steps or people. Root cause analysis (RCA) is a technique that can pinpoint the causes of sentinel events for medical procedures involving numerous steps and people. This article provides a rationale for RCA and the basic steps in a nonmedical RCA investigation. The article then describes a more detailed, nine-step RCA approach for investigating sentinel events and illustrates the technique with a nuclear medicine example.

PD-1 derived CA-170 is an oral immune checkpoint inhibitor that exhibits preclinical anti-tumor efficacy.

Small molecule immune checkpoint inhibitors targeting PD-1 and other pathways may offer advantages including ease of dosing, ability to manage immune-related adverse events (irAEs) due to their shorter pharmacokinetic exposure and opportunity to target more than one pathway for improving efficacy. Here we describe the identification and characterization of CA-170, an amino acid inspired small molecule inhibitor of PD-L1 and VISTA derived from the interface of PD-1 and PD-L1. CA-170 exhibited potent rescue of proliferation and effector functions of T cells inhibited by PD-L1/L2 and VISTA with selectivity over other immune checkpoint proteins as well as a broad panel of receptors and enzymes. Observed blocking of PD-L1 signaling and binding to PD-L1 in the cellular context without preventing the assembly of PD-1:PD-L1 complex support the formation of a defective ternary complex as the mechanism of action of CA-170. Oral administration of CA-170 resulted in increased proliferation and activation of T cells in the tumor, and significant anti-tumor efficacy in a number of immunocompetent mouse tumor models either as a single agent or in combination with approved therapeutics. These results prompted the advancement of CA-170 to human clinical trials.

Head to head comparison of [99mTc]Tc(CO)3(NTA) and [99mTc]Tc-MAG3 in patients with suspected obstruction.

PURPOSE: 99mTc-tricarbonyl-nitrilotriacetic acid, [99mTc]Tc(CO)3(NTA), is a new 99mTc-renal radiopharmaceutical with a clearance equal to that of 131I-ortho-iodohippuran, [131I]I-OIH. Our purpose was to compare the performance of [99mTc]Tc(CO)3(NTA) and [99mTc]Tc-MAG3 in patients with suspected obstruction. METHODS: [99mTc]Tc(CO)3(NTA) was prepared with commercially available NTA ligand and CRS Isolink kit, and isolated by HPLC. Eighteen adult patients referred for diuretic renography received an intravenous injection of approximately 40 mg of furosemide 15 min prior to either [99mTc]Tc(CO)3(NTA) or [99mTc]Tc-MAG3 (mean activity of 47 ± 4.4 MBq). Data were acquired for 24 min followed by an anterior image of the liver and gall bladder and a measure of voided volume. Patients received a second furosemide injection equal to one third of the original dose followed fifteen minutes later by administration of the alternate tracer, mean activity of 320 ± 34 MBq. Clearances were measured using a camera-based technique. RESULTS: The clearance of NTA was greater than that of MAG3, 331 ± 146 versus 271 ± 105 mL/min/1.73 m2, respectively, p < 0.0001. The kidney to background ratio for NTA was greater than that of MAG3 for both left and right kidneys, p < 0.001; the 20 min/maximum count ratio was significantly less, p < 0.0001. There was no significant difference in the voiding volumes following NTA and MAG3 administration, 598 ± 237 mL versus 498 ± 170 mL, respectively, p = 0.07. Gall bladder activity was not observed with NTA but was present in 6/17 MAG3 studies. Images and renogram curves were comparable except for two patients where the NTA study excluded obstruction but the MAG3 study suggested an indeterminate or obstructed kidney. CONCLUSIONS: Unlike MAG3, NTA is not eliminated via the hepatobiliary track. Moreover, NTA has a higher kidney to background ratio and more rapid clearance than MAG3. These advantages should allow more robust camera-based clearance measurements and may lead to better discrimination between obstructed and non-obstructed kidneys.

Salvage Radiotherapy Management Decisions in Postprostatectomy Patients with Recurrent Prostate Cancer Based on 18F-Fluciclovine PET/CT Guidance.

Imaging with novel PET radiotracers has significantly influenced radiotherapy decision making and radiation planning in patients with recurrent prostate cancer (PCa). The purpose of this analysis was to report the final results for management decision changes based on 18F-fluciclovine PET/CT findings and determine whether the decision change trend remained after completion of accrual. Methods: Patients with detectable prostate-specific antigen (PSA) after prostatectomy were randomized to undergo either conventional imaging (CI) only (arm A) or CI plus 18F-fluciclovine PET/CT (arm B) before radiotherapy. In arm B, positivity rates on CI and 18F-fluciclovine PET/CT for detection of recurrent PCa were determined. Final decisions on whether to offer radiotherapy and whether to include only the prostate bed or also the pelvis in the radiotherapy field were based on 18F-fluciclovine PET/CT findings. Radiotherapy decisions before and after 18F-fluciclovine PET/CT were compared. The statistical significance of decision changes was determined using the Clopper-Pearson (exact) binomial method. Prognostic factors were compared between patients with and without decision changes. Results: All 165 patients enrolled in the study had standard-of-care CI and were initially planned to receive radiotherapy. Sixty-three of 79 (79.7%) patients (median PSA, 0.33 ng/mL) who underwent 18F-fluciclovine PET/CT (arm B) had positive findings. 18F-Fluciclovine PET/CT had a significantly higher positivity rate than CI did for the whole body (79.7% vs. 13.9%; P < 0.001), prostate bed (69.6% vs. 5.1%; P < 0.001), and pelvic lymph nodes (38.0% vs. 10.1%; P < 0.001). Twenty-eight of 79 (35.4%) patients had the overall radiotherapy decision changed after 18F-fluciclovine PET/CT; in 4 of 79 (5.1%), the decision to use radiotherapy was withdrawn because of extrapelvic disease detected on 18F-fluciclovine PET/CT. In 24 of 75 (32.0%) patients with a final decision to undergo radiotherapy, the radiotherapy field was changed. Changes in overall radiotherapy decisions and radiotherapy fields were statistically significant (P < 0.001). Overall, the mean PSA at PET was significantly different between patients with and without radiotherapy decision changes (P = 0.033). Conclusion:18F-Fluciclovine PET/CT significantly altered salvage radiotherapy decisions in patients with recurrent PCa after prostatectomy. Further analysis to determine the impact of 18F-fluciclovine PET/CT guidance on clinical outcomes after radiotherapy is in progress.

Poorly Differentiated Neuroendocrine Tumor With 18F-Fluciclovine Uptake in a Patient With Metastatic Castrate-Resistant Prostate Cancer.

ABSTRACT: 18F-Fluciclovine is an amino acid-based radiopharmaceutical used primarily for PET imaging of patients with biochemical recurrence of prostate cancer. We report a case of a 66-year-old man with recently diagnosed metastatic castrate-resistant prostate cancer and a left supraclavicular lymph node with incidental radiotracer uptake on 18F-fluciclovine PET/CT. Left neck core needle biopsy confirmed high-grade, poorly differentiated carcinoma with neuroendocrine features positive for synaptophysin and chromogranin, and negative for prostate markers.

A Rationally Designed Peptide Antagonist of the PD-1 Signaling Pathway as an Immunomodulatory Agent for Cancer Therapy.

Pioneering success of antibodies targeting immune checkpoints such as PD-1 and CTLA4 has opened novel avenues for cancer immunotherapy. Along with impressive clinical activity, severe immune-related adverse events (irAE) due to the breaking of immune self-tolerance are becoming increasingly evident in antibody-based approaches. As a strategy to better manage severe adverse effects, we set out to discover an antagonist targeting PD-1 signaling pathway with a shorter pharmacokinetic profile. Herein, we describe a peptide antagonist NP-12 that displays equipotent antagonism toward PD-L1 and PD-L2 in rescue of lymphocyte proliferation and effector functions. In preclinical models of melanoma, colon cancer, and kidney cancers, NP-12 showed significant efficacy comparable with commercially available PD-1-targeting antibodies in inhibiting primary tumor growth and metastasis. Interestingly, antitumor activity of NP-12 in a preestablished CT26 model correlated well with pharmacodynamic effects as indicated by intratumoral recruitment of CD4 and CD8 T cells, and a reduction in PD-1+ T cells (both CD4 and CD8) in tumor and blood. In addition, NP-12 also showed additive antitumor activity in preestablished tumor models when combined with tumor vaccination or a chemotherapeutic agent such as cyclophosphamide known to induce "immunologic cell death." In summary, NP-12 is the first rationally designed peptide therapeutic targeting PD-1 signaling pathways exhibiting immune activation, excellent antitumor activity, and potential for better management of irAEs.

ODM-203, a Selective Inhibitor of FGFR and VEGFR, Shows Strong Antitumor Activity, and Induces Antitumor Immunity.

Alterations in the gene encoding for the FGFR and upregulation of the VEGFR are found often in cancer, which correlate with disease progression and unfavorable survival. In addition, FGFR and VEGFR signaling synergistically promote tumor angiogenesis, and activation of FGFR signaling has been described as functional compensatory angiogenic signal following development of resistance to VEGFR inhibition. Several selective small-molecule FGFR kinase inhibitors are currently in clinical development. ODM-203 is a novel, selective, and equipotent inhibitor of the FGFR and VEGFR families. In this report we show that ODM-203 inhibits FGFR and VEGFR family kinases selectively and with equal potency in the low nanomolar range (IC50 6-35 nmol/L) in biochemical assays. In cellular assays, ODM-203 inhibits VEGFR-induced tube formation (IC50 33 nmol/L) with similar potency as it inhibits proliferation in FGFR-dependent cell lines (IC50 50-150 nmol/L). In vivo, ODM-203 shows strong antitumor activity in both FGFR-dependent xenograft models and in an angiogenic xenograft model at similar well-tolerated doses. In addition, ODM-203 inhibits metastatic tumor growth in a highly angiogenesis-dependent kidney capsule syngenic model. Interestingly, potent antitumor activity in the subcutaneous syngenic model correlated well with immune modulation in the tumor microenvironment as indicated by marked decrease in the expression of immune check points PD-1 and PD-L1 on CD8 T cells and NK cells, and increased activation of CD8 T cells. In summary, ODM-203 shows equipotent activity for both FGFR and VEGFR kinase families and antitumor activity in both FGFR and angigogenesis models.

Multimodality Radionuclide Imaging in a Patient With Hereditary Paraganglioma-Pheochromocytoma Syndrome.

Hereditary paraganglioma (PGL)-pheochromocytoma (PCC) syndrome is a genetic disorder caused by a mutation of the tumor suppressor gene SDHD that results in a predisposition for head and neck PGLs and PCCs. We present a case of a 33-year-old woman where F-FDG PET/CT showed areas of increased uptake in both the adrenal and cervical regions, consistent with PCCs and PGLs, respectively. Further imaging revealed that PCCs were I-MIBG avid, whereas the PGLs were In-octreotide avid. This demonstrates the varying sensitivities of different imaging modalities in regard to neuroendocrine tumors and the potential for treatment using multiple targeted therapies.

A Novel Timesaving Method for Hepatobiliary Imaging for Suspected Acute Cholecystitis.

OBJECTIVE: To optimize resource utilization of cholescintigraphy for suspected acute cholecystitis with a time-saving method without a loss in diagnostic accuracy. MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study. Hepatobiliary imaging data for 81 patients with suspected acute cholecystitis were recalled for modification into 2 summed static images, using only the first and last 5 minutes of the dynamic images, thereby eliminating the middle 50 minutes of imaging data. Two nuclear medicine physicians interpreted the summed images to assess visualization, and those interpretations were compared to the original reports based on using all 60 minutes of dynamic imaging. A third nuclear medicine physician mediated rare inter-reader interpretive disagreements. Comparison of interpretations of time-saving and conventional methods and also inter-observer variability was achieved using the Cohen κ coefficient analysis. RESULTS: Interpretations rendered using the time-saving method showed near-perfect agreement with those based on the full dynamic imaging protocol (Cohen κ coefficient = 0.92 for both readers). Furthermore, nuclear medicine physician readers agreed with each other (Cohen κ coefficient = 0.95 between the 2 readers), indicating minimal inter-observer variability using this novel optimized technique. CONCLUSION: In the setting of suspected acute cholecystitis, imaging resource utilization may be improved, via reduced gamma camera and technologist time, using a novel time-saving method without sacrificing diagnostic accuracy. Multicenter larger trials, however, will be necessary to establish reproducibility.

Change in Salvage Radiotherapy Management Based on Guidance With FACBC (Fluciclovine) PET/CT in Postprostatectomy Recurrent Prostate Cancer.

PURPOSE: We explored the influence of FACBC (fluciclovine) PET/CT on the decision to offer radiotherapy and radiotherapy treatment field recommendations in postprostatectomy patients with recurrent prostate cancer. PATIENTS AND METHODS: After obtaining institutional review board approval and informed consent, 87 patients with detectable prostate-specific antigen (PSA) levels were recruited into a prospective clinical trial. After an initial provider-determined radiotherapy plan based on conventional imaging, 44 of 87 patients were randomized to additionally undergo fluciclovine PET/CT. Pre- and post-fluciclovine radiotherapy decisions were compared and changes were noted. Statistical significance of these decision changes was determined. RESULTS: Two of 44 patients in the experimental arm dropped out before fluciclovine scanning. Thirty-four (81.0%) of 42 had positive results on fluciclovine. Overall radiotherapy decision was changed in 17 (40.5%) of 42. Mean PSA, original Gleason score, and prostatectomy-PET interval did not differ significantly between patients with and without radiotherapy decision changes. Two (4.8%) of 42 had the decision for radiotherapy withdrawn due to positive extrapelvic findings. Radiotherapy field decision was changed in 15 (35.7%) of 42. Eleven (73.3%) of 15 had fields changed from prostate bed only to both prostate bed and pelvis, while 4 (26.7%) of 15 had fields changed from both prostate bed and pelvis to prostate bed only. Changes in overall radiotherapy decision and field were statistically significant (P < 0.0001). However, the change in the decision to offer radiotherapy or not was not statistically significant (P = 0.15). CONCLUSIONS: Fluciclovine PET/CT significantly changed radiotherapy management decisions in postprostatectomy patients with recurrent prostate cancer. Further work in determining differences in PSA-free survival is ongoing.

Recurrent prostate cancer detection with anti-3-[(18)F]FACBC PET/CT: comparison with CT.

PURPOSE: To compare the diagnostic performance of the synthetic amino acid analogue PET radiotracer anti-3-[(18)F]FACBC (fluciclovine) with that of CT in the detection of recurrent prostate carcinoma. METHODS: This was a retrospective analysis of 53 bone scan-negative patients with suspected recurrent prostate carcinoma who underwent fluciclovine PET/CT and routine clinical CT within 90 days of each other. The correlation between imaging findings and histology and clinical follow-up was evaluated. Positivity rates and diagnostic performance were calculated for fluciclovine PET/CT and CT. RESULTS: Of 53 fluciclovine PET/CT and 53 CT examinations, 41 (77.4 %) and 10 (18.9 %), respectively, had positive findings for recurrent disease. Positivity rates were higher with fluciclovine PET/CT than with CT at all prostate-specific antigen (PSA) levels, PSA doubling times and original Gleason scores. In the prostate/bed, fluciclovine PET/CT was true-positive in 31 and CT was true-positive in 4 of 51 patients who met the reference standard. In extraprostatic regions, fluciclovine PET/CT was true-positive in 12 and CT was true-positive in 3 of 41 patients who met the reference standard. Of the 43 index lesions used to prove positivity, 42 (97.7 %) had histological proof. In 51 patients with sufficient follow-up to calculate diagnostic performance in the prostate/bed, fluciclovine PET/CT demonstrated a sensitivity of 88.6 %, a specificity of 56.3 %, an accuracy of 78.4 %, a positive predictive value (PPV) of 81.6 %, and a negative predictive value (NPV) of 69.2 %; the respective values for CT were 11.4 %, 87.5 %, 35.3 %, 66.7 % and 31.1 %. In 41 patients with sufficient follow-up to calculate diagnostic performance in extraprostatic regions, fluciclovine PET/CT demonstrated a sensitivity of 46.2 %, a specificity of 100 %, an accuracy of 65.9 %, a PPV of 100 %, and an NPV of 51.7 %; the respective values for CT were 11.5 %, 100 %, 43.9 %, 100 % and 39.5 %. CONCLUSION: The diagnostic performance of fluciclovine PET/CT in recurrent prostate cancer is superior to that of CT and fluciclovine PET/CT provides better delineation of prostatic from extraprostatic recurrence.

Characteristics and Limitations of FDG PET/CT for Imaging of Squamous Cell Carcinoma of the Head and Neck: A Comprehensive Review of Anatomy, Metastatic Pathways, and Image Findings.

OBJECTIVE: This image-based article illustrates the anatomic regions of squamous cell carcinomas of the head and neck and describes the metastatic pathways in and TNM staging for each region. Both the role and limitations of FDG PET/CT in imaging such cancers are discussed, and cases exemplifying these issues are reported. Also included is a discussion of the use of FDG PET/CT to monitor the response of squamous cell carcinomas of the head and neck to therapy, in addition to a brief comparison of PET/CT with such traditional imaging modalities as CT, MRI, and ultrasound. CONCLUSION: Understanding the characteristics of squamous cell carcinoma of the head and neck, as imaged by FDG PET/CT, is crucial for determining treatment strategy, because it helps to avoid incorrect staging and also provides an accurate assessment of treatment response.

The nuclear medicine therapy care coordination service: a model for radiologist-driven patient-centered care.

We developed a longitudinal care coordination service to proactively deliver high-quality and family-centered care in patients receiving radioiodine therapy for thyroid cancer. In an iterative, multidisciplinary team manner, a pretherapy consultation service, which included scripted interactions, documentation, and checklists for quality control, evolved over time into a robust patient-centered longitudinal care coordination nuclear medicine service. Radiation safety precautions, the rationale for therapy, and management of patient expectations were addressed through the initial consultation, and discharge and posttreatment care were managed during subsequent follow-up. The patient-physician relationship created during longitudinal nuclear medicine therapy care is one tool to help counteract the growing commoditization of radiology. This article describes the process that the nuclear medicine specialists in our department established to enhance radiologist value by providing both exceptional thyroid cancer treatment and continuity of care.

Reproducibility and reliability of anti-3-[¹8F]FACBC uptake measurements in background structures and malignant lesions on follow-up PET-CT in prostate carcinoma: an exploratory analysis.

PURPOSE: The aim of this study is to examine the reproducibility of anti-1-amino-3-[(18)F]fluorocyclobutane-1-carboxylic acid (anti-3-[(18)F]FACBC) quantitative measurements in key background structures and untreated malignant lesions. PROCEDURES: Retrospective review of 14 patients who underwent follow-up anti-3-[(18)F]FACBC positron emission tomography-X-ray computed tomography (PET-CT) for prostate carcinoma recurrence. Standard uptake values (SUV) were measured in both original and follow-up scans in key background structures and untreated malignant lesions. Absolute and percent mean difference in SUV between scans and interclass correlation coefficients (ICC) were also computed. RESULTS: Mean (±SD, range) scan interval was 17.4 months (±7.1, 4-29). %Mean difference in SUVmean was <20 % in background structures with low absolute differences. ICCs were >0.6 except for early-phase blood pool (ICC = 0.4). SUVmax in malignant lesions without interim therapy increased or remained stable over time. CONCLUSIONS: Despite variable time interval between scans, FACBC PET-CT demonstrates acceptable reproducibility in key background structures. Untreated malignant lesions showed stable or increased uptake over time. A formal test-retest study is planned.