MSG Use With 18F-DCFPyL PET/CT Imaging

Study Overview
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Brief Summary
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18F-DCFPyL is an agent that binds to prostate specific membrane antigen (PSMA). Due to high levels of PSMA in prostate cancer, treatments targeting PSMA have been developed to deliver therapy to these specific target cells. Unfortunately when this treatment is delivered there is radiotracer uptake in the salivary glands and kidneys, not related to cancer, which causes dry mouth and causes patients to stop treatment. It is proposed that having tomato juice containing monosodium glutamate (MSG) may reduce radiotracer uptake in the salivary glands and kidneys and reduce damage to these tissues.

Detailed Description
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This is a prospective single cohort study to evaluate the utility of MSG in reducing salivary gland radiotracer uptake, in patients who undergo an 18F-DCFPyL Positron Emission tomography / Computer Tomography (PET/CT) scan. 18F-DCFPyL PET/CT scans Each participant will receive 2 18F-DCFPyL PET/CT scans at the BC Cancer - Vancouver Centre, as part of this research sub-study. Each participant will receive tomato juice before each appointment. One visit they will have tomato juice containing MSG and the other will be a placebo (standard tomato juice). Each study participant will receive a bolus intravenous dose of 18F-DCFPyL. The participant will rest in a comfortable chair for 120 minutes and will then be taken to the PET/CT scanner for images. 24 hour follow-up All participants will be requested to either return to the functional imaging department approximately 24 hours (acceptable range 16-28 hours) after the injection of 18F-DCFPyL and tomato juice consumption or agree to be contacted by phone. The participants will be asked if they experienced any undesirable effects following the administration of 18F-DCFPyL and tomato juice, or in the intervening 24 hours. The local site attending nuclear medicine physician will then make an assessment as to whether these effects are likely related to 18F-DCFPyL and/or tomato juice administration. The study is expected to take approximately 1 year for accrual.

Official Title
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Evaluation of Monosodium Glutamate (MSG) to Reduce Salivary Gland and Renal Accumulation of PSMA-binding Radiopharmaceuticals

Conditions
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Prostate Cancer, Prostate Cancer Metastatic, Prostatic Neoplasm

Intervention / Treatment
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* Diagnostic Test: 18F-DCFPyL PET/CT scan
* Other: Placebo drink
* Other: MSG drink


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Known prostate cancer with biochemical recurrence after initial curative therapy with radical prostatectomy, presenting with a prostate specific antigen (PSA) greater than 0.4 ng/mL. Subjects with findings on other examinations (such as plain x-ray, CT, MRI or bone scintigraphy and others) that are suspicious for metastatic disease but not conclusively diagnostic of metastatic disease, within 3 months of PET scan. Known prostate cancer with biochemical recurrence after initial curative therapy with radiation therapy (including brachytherapy), with a PSA level >2 ng/mL above the nadir after radiation therapy. Castration resistant prostate cancer with a minimum PSA of 2.0 ng/mL with 2 consecutive rises above the nadir and castrate levels of testosterone (<1.7 nmol/L). Treatment does not need to be discontinued before the 18F-DCFPyL scan. Eastern Cooperative Oncology Group (ECOG) performance status of 2 or less. Exclusion Criteria: Medically unstable (eg. acute illness, unstable vital signs) Unable to lie supine for the duration of imaging Unable to provide written consent Exceeds safe weight limit of the PET/CT bed (204.5 kg) or unable to fit through the PET/CT bore (diameter 70 cm) Severe uncontrolled hypertension (systolic blood pressure above 140 mm Hg and diastolic blood pressure above 90 mm Hg, or systolic blood pressure above 180 mm Hg, or diastolic blood pressure above 110 mg Hg). Patients with controlled hypertension under medication are eligible History of severe asthma that has led to hospitalizations or emergency room visits History of intolerance to MSG History of severe headaches or migraines triggered by food or MSG Participants on a sodium/salt restricted diet due to other medical conditions No new treatment has started between the first and second 18F-DCFPyL PET/CT

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: This is a prospective double blind intra-participant comparison of [18F]-DCFPyL PET/CT scans performed after orally administered MSG or placebo. The participants will receive oral administration of MSG or placebo, in two different examination sessions, 30 minutes before [18F]-DCFPyL injection.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 18F-DCFPyL PET/CT scan with MSG drink<br>Food grade MSG will be dissolved in low sodium tomato juice, and administered orally before 18F-DCFPyL administration. | Diagnostic Test: 18F-DCFPyL PET/CT scan<br>* Participants will have their weight recorded and baseline vital signs (blood pressure, heart rate, and oxygen saturation level) measured prior to the tomato juice ingestion, immediately prior to 18F-DCFPyL injection and 5 to 15 minutes after injection. The participant will receive a bolus intravenous dose of 18F-DCFPyL. After 60 min, the vital signs will be recorded and again two hours after 18F-DCFPyL. Immediately before scanning, the participants will be taken to a designated washroom and asked to void. The PET/CT image acquisition time will be approximately 30 minutes.<br>Other: MSG drink<br>* Participants will consume 300mL of tomato juice with MSG 30 minutes prior to 18F-DCFPyL injection.<br>|
| Placebo Comparator: 18F-DCFPyL PET/CT scan with placebo drink<br>Regular tomato juice will be used, and administered orally before 18F-DCFPyL administration. | Diagnostic Test: 18F-DCFPyL PET/CT scan<br>* Participants will have their weight recorded and baseline vital signs (blood pressure, heart rate, and oxygen saturation level) measured prior to the tomato juice ingestion, immediately prior to 18F-DCFPyL injection and 5 to 15 minutes after injection. The participant will receive a bolus intravenous dose of 18F-DCFPyL. After 60 min, the vital signs will be recorded and again two hours after 18F-DCFPyL. Immediately before scanning, the participants will be taken to a designated washroom and asked to void. The PET/CT image acquisition time will be approximately 30 minutes.<br>Other: Placebo drink<br>* Participants will consume 300mL of tomato juice 30 minutes prior to 18F-DCFPyL injection.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Salivary Gland Maximal Standardized Uptake Values Corrected for Lean Body Mass (SULmax) for 18F-DCFPyL | Comparison of MSG and placebo 18F-DCFPyL salivary gland (submandibular) accumulation measured by the maximal standardized uptake values corrected for lean body mass (SULmax). For determination of salivary gland uptake, regions of interest will be drawn around the salivary glands, using a standardized contouring method, to measure the SULmax. The average SULmax in the organs will be used for this analysis. | scan with MSG and 3-7 days later, scan with Placebo (or vice versa) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Renal Maximal Standardized Uptake Values Corrected for Lean Body Mass (SULmax) for 18F-DCFPyL | Comparison of MSG and placebo 18F-DCFPyL renal accumulation measured by the maximal standardized uptake values corrected for lean body mass (SULmax). For determination of renal uptake, regions of interest will be drawn around the kidneys, using a standardized contouring method, to measure the SULmax. The average SULmax in the organs will be used for this analysis. | scan with MSG and 3-7 days later, scan with Placebo (or vice versa) | 
| Tumour Maximal Standardized Uptake Values Corrected for Lean Body Mass (SULmax) for 18F-DCFPyL | Comparison of MSG and placebo 18F-DCFPyL tumour accumulation measured by the maximal standardized uptake values corrected for lean body mass (SULmax). For determination of tumour uptake, all malignant lesions, the SULmax were measured using the PET Edge tool running on MIM. All regions of interest were created in one dataset by a blinded observer, and then saved and compared to the identical location in the second dataset for matched comparisons of activity. The median SULmax in the malignant lesions will be used for this analysis. | scan with MSG and 3-7 days later, scan with Placebo (or vice versa) | 
| Number of Participants With Tomato Juice (Containing Either MSG or Placebo) Related Adverse Events as Assessed by Abnormal Vital Sign Measurement. | Vital signs (blood pressure, heart rate and pulse oximetry) will be measured at two time points (before tomato juice and 2 hours after radiotracer injection). All values that fall outside of the normal parameters will be assessed by a physician and reported as an adverse event. | 2 hours |