The impact of [68Ga]PSMA I&T PET/CT on radiotherapy planning in patients with prostate cancer.

PURPOSE: To determine the impact of Gallium-68-labled prostate-specific membrane antigen positron-emission tomography/computed tomography ([68Ga]PSMA PET/CT) on radiotherapy planning for primary disease, biochemical cancer relapse, and advanced disease of prostate cancer. METHODS: A total of 106 patients with prostate cancer scheduled for radiation therapy underwent 120 [68Ga]PSMA PET/CT scans prior to radiotherapy treatment. In 20 cases, patients underwent [68Ga]PSMA PET/CT for primary therapy (PT), 75 cases were referred for biochemical relapse after surgery (RL), and 25 cases were intended for palliative treatment of localized metastases (MD). We retrospectively compared the impact of [68Ga]PSMA PET/CT on lesion detection and treatment decision to CT alone. RESULTS: [68Ga]PSMA PET/CT revealed a total of 271 positive lesions, whereas CT detected 86 lesions (32%). Overall, the radiotherapy regime was changed in 55 of 120 cases (46%) based on the higher detection rate of [68Ga]PSMA PET/CT: in 15% of cases with PT, in 43% of cases with RL, and in 44% of cases with MD. CONCLUSION: [68Ga]PSMA PET/CT is superior to CT alone for lesion detection in prostate cancer, thereby significantly impacting on radiotherapy planning for primary disease, biochemical cancer relapse, and advanced disease of prostate cancer.

Diagnostic Value of Positron Emission Tomography Combined with Computed Tomography for Evaluating Critically Ill Neurological Patients.

PURPOSE: 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is a promising new tool for the identification of inflammatory, infectious, and neoplastic foci. The aim of our work was to evaluate the diagnostic value of FDG-PET/CT in patients treated on a neurological/neurosurgical ICU or stroke unit. METHODS: We performed a single-center, 10-year, retrospective evaluation of the value of FDG-PET/CT in critically ill adult patients with severe neurological disease. RESULTS: 42 patients underwent FDG-PET/CT. Of these, 15 were ventilated and 10 were under vasopressor support. We identified four indications for performing FDG-PET/CT: (1) excluding a paraneoplastic etiology in an otherwise unexplained encephalitis, encephalopathy or neuropathy, (2) detecting a large-vessel vasculitis in patients with ischemic stroke, (3) detecting an infectious focus in sepsis, and less frequently (4) evaluating cerebral metabolism. In 22 patients who were evaluated for an unknown malignancy, 5 scans revealed either a previously unknown tumor or unknown metastases of a previously treated malignancy. Of 11 patients investigated for large-vessel vasculitis, 2 showed an inflammation of arteries supplying the brain. Of six sepsis cases, FDG-PET/CT identified an infectious focus in four. SUMMARY: We found FDG-PET/CT to be a helpful tool in critically ill neurological patients. The results of the FDG-PET/CT had direct therapeutic consequences in the 12 true-positive cases. In 24 of the 29 negative cases, FDG-PET/CT helped exclude alternative diagnoses and/or influenced therapy. Our findings demonstrate the feasibility and diagnostic benefit of FDG-PET/CT in this group of patients.

The value of fluorine-18 deoxyglucose positron emission tomography scans in patients with ventricular assist device specific infections†.

BACKGROUND: Infections are major complications in patients with ventricular assist devices (VAD). Positron emission tomography with deoxyglucose marked by fluorine-18 ( 18 F-FDG PET/CT) is a diagnostic tool to scan for tissue with high metabolism as present in infections. The specificity of 18 F-FDG PET/CT to discriminate between infection and an aseptic reaction of the implanted device is not defined and its evaluation is the aim of this retrospective analysis. METHODS: Until September 2015 a total of 100 patients underwent VAD implantations in our institution. Twenty-one patients (mean age 53.7 ± 14.3 years) had 29 PET-CT examinations for a suspected infection. All radiology reports were compared to clinical and intraoperative parameters. Infections were reported according to the guidelines of the International Society of Heart and Lung Transplantation. Follow-up was 222 days (range 107-484 days) after PET-CT scans and was complete in all patients. RESULTS: In 7 patients PET-CT scan ruled out any VAD associated infection. Sixteen patients had a VAD specific infection. Two patients had false negative PET-CT scan results. The sensitivity of VAD-specific infections was 87.5%, the specificity 100%, the positive predictive value was 100% and the negative predictive value 86.7%. Seven patients had more than one PET-CT scans at different time points. CONCLUSIONS: PET-CT scan findings showed a high specificity and positive predictive value for VAD-specific infections. Therefore, it may have the potential to guide the clinician in handling patients with infectious complications after VAD implantation.

Detection rate of PET/CT in patients with biochemical relapse of prostate cancer using [68Ga]PSMA I&T and comparison with published data of [68Ga]PSMA HBED-CC.

PURPOSE: To determine the detection rate of PET/CT in biochemical relapse of prostate cancer using [68Ga]PSMA I&T and to compare it with published detection rates of [68Ga]PSMA HBED-CC. METHODS: We performed a retrospective analysis in 83 consecutive patients with documented biochemical relapse after prostatectomy. All patients underwent whole body [68Ga]PSMA I&T PET/CT. PET/CT images were evaluated for presence of local recurrence, lymph node metastases, and distant metastases. Proportions of positive PET/CT results were calculated for six subgroups with increasing prostate specific antigen (PSA) levels (<0.5 ng/mL, 0.5 to <1.0 ng/mL, 1.0 to <2.0 ng/mL, 2.0 to <5.0 ng/mL, 5.0 to <10.0, ≥10.0 ng/mL). Detection rates of [68Ga]PSMA I&T were statistically compared with published detection rates of [68Ga]PSMA HBED-CC using exact Fisher's test. RESULTS: Median PSA was 0.81 (range: 0.01 - 128) ng/mL. In 58/83 patients (70 %) at least one [68Ga]PSMA I&T positive lesion was detected. Local recurrent cancer was present in 18 patients (22 %), lymph node metastases in 29 patients (35 %), and distant metastases in 15 patients (18 %). The tumor detection rate was positively correlated with PSA levels, resulting in detection rates of 52 % (<0.5 ng/mL), 55 % (0.5 to <1.0 ng/mL), 70 % (1.0 to <2.0 ng/mL), 93 % (2.0 to <5.0 ng/mL), 100 % (5.0 to <10.0 ng/mL), and 100 % (≥10.0 ng/mL). There was no significant difference between the detection rate of [68Ga]PSMA I&T and published detection rates of [68Ga]PSMA HBED-CC (all p>0.05). CONCLUSIONS: [68Ga]PSMA I&T PET/CT has high detection rates of recurrent prostate cancer that are comparable to [68Ga]PSMA HBED-CC.