CompletedNot Applicable

Catheterization to Locate Mesenchymal Tumors in Patients With Tumor-Induced Osteomalacia or Oncogenic Osteomalacia

United States45 participantsStarted 2004-12-15

Plain-language summary

This study will use a procedure called selective venous catheterization in patients with tumor-induced osteomalacia (TIO) or oncogenic osteomalacia (OOM) to try to locate very small tumors that produce proteins called phosphatonins. Too much phosphatonin in the blood causes the kidneys to allow large amounts of phosphorus to be excreted in the urine, leading to low blood levels of phosphorus and, in turn, to osteomalacia (a condition of soft bones). Osteomalacia can cause bone fractures requiring many surgical procedures that can leave patients in pain. Patients may also feel weak and can lose height from massive bone loss. Selective venous catheterization is a way to measure the amount of phosphatonin in the blood and may be used as a way to locate phosphatonin-producing tumors that cannot be found using standard imaging techniques. Patients with TIO or OOM are screened under NIDR Protocol 01-D-0184 with a medical history, review of medical records and routine physical examination. Other procedures may include blood tests, urine tests, and imaging tests, such as x-rays, bone densitometry, bone scan, computed tomography (CT) and magnetic resonance imaging (MRI). This study will include mostly patients whose tumors were not able to be located through imaging procedures, but also a few patients whose tumors were located. All participants, regardless of whether or not their tumor was located, undergo selective venous catheterization. For this procedure, a radiologist inserts a catheter (thin flexible tube) into the body and uses fluoroscopy (a type of x-ray) to guide the tip of the catheter to different places in the body to collect small amounts of blood from the different areas. After the procedure, the patient lies flat for 2 hours and avoids moving his or her leg on the side where the catheter was placed. The blood is analyzed to measure the amount phosphatonin is in each sample, and the amounts are compared to the average amount of phosphatonin in the general blood circulation. If a higher level of phosphatonin is found in one area and the location of the tumor is unknown, the patient undergoes imaging in that area. If a tumor is found and it is in an area where it can be removed surgically, the patient is given the option to have the surgery. If the tumor is not found by imaging done after the first catheterization procedure, the patient has the option to have a second catheterization, taking samples of blood only from the area where the phosphatonin was found to be the highest during the sampling procedure.

Who can participate

Age range

8 Years – 100 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

* INCLUSION CRITERIA: Patients must have the clinical diagnosis of TIO/OOM to be considered for enrollment in this study. The diagnosis will be based upon a clinical history including some or all of: rickets (children), pathological fractures, bone pain, muscle weakness, low serum phosphorus with concomitant inappropriately high urine phosphorus, low or inappropriately low-normal serum vitamin 1,25 (OH)(2)-vitamin D3, and an elevated FGF-23 level in the absence of a family history of a phosphate wasting syndrome. Along with the clinical symptoms listed above, the patient must have undergone routine clinical imaging. Inclusion will be limited to all patients in whom a likely lesion was not localized by imaging, plus five patients for whom a likely lesion has been identified by imaging. Patients with a likely lesion identified will serve as positive controls. Patients must be able to give informed consent. EXCLUSION CRITERIA: Patients with co-morbidities that would increase the risk of selective venous catheterization will be excluded from the study. This includes but is not limited to medical conditions such as: poorly controlled diabetes, renal insufficiency, chronic obstructive pulmonary disease, anemia, hypertension, clotting disorders, etc. Pregnancy is a contraindication to this venous catheterization procedure. A serum Beta-Hcg will be required for all eligible women of childbearing age unless documentation of a hysterectomy or other condition that makes pregnancy …

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

Trial details

NCT IDNCT00099762

SponsorNational Institute of Dental and Craniofacial Research (NIDCR)

Sponsor typeNIH

Study typeOBSERVATIONAL

Primary completion2009-09-02

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