Tom in Tech Support Tidbit:

Did a QA Alert appear when starting an acquisition? If yes, then click here.

Did the Monthly QC Suite not complete? If yes, then click here.

Many Siemens MI-SPECT Symbia scanners have an AQC (Automatic Quality Control) option. Most systems with the AQC option have a 50 micro-curie Cobalt-57 point source and and a 10 milli-curie Gadolinium-153 line source installed in the Front Bed. That said, the Symbia Pro.Specta is an exception; it uses a 25 micro-curie Cobalt-57 point source and a 10 milli-curie Gadolinium-153 line source.

The part numbers for replacement sources are:

PHI-0124 Co-57 Point Source (if not Symbia Pro.Specta)

NOTES: This is a 50 microcurie Co-57 point source, which is used to tune the detectors and acquire Intrinsic Calibration and Intrinsic Verification Floods. The half-life of Co-57 is 271 days. Siemens recommends replacing this source every 12 months.. If the point source is allowed to decay past 18 months, tuning will fail due to an insufficient court rate.

PHI-0138 Co-57 Point Source (Symbia Pro.Specta only)

NOTES: This is a 25 microcurie Co-57 point source, which is used to tune the detectors and acquire Intrinsic Calibration and Intrinsic Verification Floods. The half-life of Co-57 is 271 days. Siemens recommends replacing this source every 12 months.. If the point source is allowed to decay past 12 months, tuning will fail due to an insufficient court rate.

HEGL-0133 Gd-153 Line Source (all systems unless AutoQC Premium Source Kit was purchased)

NOTES: This is a 10 milli-curie Gadolinium-153 line source, which is used to acquire Extrinsic Sweep Verification Floods. This source is also used with an AQC MHR Sleeve for Head Alignment Calibrations and Head Alignment Verifications. This source is not used to acquire Extrinsic Calibration and Extrinsic Verification Floods (other than Extrinsic Sweep). The half-life of Gd-153 is 241.6 days. Siemens recommends replacing this source every 24 months rather than every 12 months due to its cost. After the line source has decayed 18 months or longer, the Monthly QC Suite takes a long time to complete. For more info, see the chart shown below.

????-??? Gd-153 Line Source (all systems with AutoQC Premium Source Kit)

NOTES: This is a 20 milli-curie Gadolinium-153 line source, which is used to acquire Extrinsic Sweep Verification Floods. This source is also used with an AQC MHR Sleeve for Head Alignment Calibrations and Head Alignment Verifications. This source is not used to acquire Extrinsic Calibration and Extrinsic Verification Floods (other than Extrinsic Sweep). The half-life of Gd-153 is 241.6 days. Siemens recommends replacing this source every 24 months rather than every 12 months due to its cost. Since SPECT/CT systems acquire a Head Alignment Calibration and a Head Alignment Verification immediately afterwards, after the line source has decayed 18 months or longer, the Monthly QC Suite takes a long time to complete.

For systems covered by a Siemens Service Agreement with the "Source Replenishment Option," the Siemens Source Order Team orders a replacement Point Source every 12 months and a replacement Line Source every 24 months. Orders are placed three months prior to the recommended replacement date. Approximately 90 days later, source(s) arrive onsite, and a Siemens CSE is dispatched to install them.

For systems without a Source Replenishment Agreement, replacement sources are available from either Siemens Healthineers, or directly from source manufacturers Eckert & Ziegler or Pinestar.

Below is the contact information for the Siemens Source Order Team, Eckert & Ziegler, and Pinestar. All three suppliers use the same Model Numbers for the Co-57 and Gd-153 sources. Prices vary.

mailto:sourceorder.team@siemens-healthineers.com

https://www.ezag.com/home/products/isotope_products/

Then select Medical Imaging Sources.

Use the search tool to find PHI-0124.

Use the search tool to find PHI-0138.

Use the search tool to find HEGL-0133.

https://www.pinestar.com/categories/5

Then select Symbia AutoQC.

Once a replacement AQC source is onsite, step-by-step instructions for replacing that source are shown in the Operators Manual that was shipped with the gamma camera. In short…

[1] On the MI APPS tab, register a patient and then select the workflow category labeled, “All”.
[2] Double-click on the workflow labeled, “Source Replenishment ACQ”.
[3] Click on the tab labeled, “AutoQC Start”.
[4] Click on button labeled, “Update QC Source(s)”.
[5] Extend sources and/or edit dates as necessary.

Be advised that a #6 Driller Spanner Driver (see below) was shipped with the camera system, and that anti-tamper tool is needed to remove and reinstall each radioactive source. Therefore, this anti-tamper tool should already be onsite, but the local service team may have stashed it out of sight to prevent its disappearance. A Siemens service engineer is not needed to install replacement sources.

Since the half-life of Gd-153 is approximately 8 months, the time needed to acquire AQC nearly doubles every 8 months.

When the Gd-153 source is new, Extrinsic Sweep Verification Flood only takes 45 minutes using LEHR collimators. However, 16 months later, that flood takes over 2 hours and obviously the time needed continues to increase each month. This rarely causes a problem, since the Extrinsic Sweep usually has all night to complete.

When the Gd-153 source is new, the Head Alignment Calibration or Verification takes 135 minutes using LEHR collimators. However, 16 months later, that same acquisition takes over 8 hours and obviously the time needed continues to increase each month.

If you did the math after reading the last two paragraphs, then you noticed that 16 months after a Gd-153 line source is installed, the combination of the Head Alignment followed by the Extrinsic Sweep takes over 10 hours. And as you probably know, prior to those acquisitions, the Monthly QC Suite also includes removing collimators, tuning both detectors, acquiring an Intrinsic Calibration Flood and an Intrinsic Verification Flood, and then reinstalling collimators.

The table shown below is a work in progress. On September 3, 2021, a new Gd-153 line source was installed at a customer site, and the initial Head Alignment and Extrinsic Sweep acquisitions were performed using LEHR collimators on the same day as the Reference Date for the AQC line source. Afterwards, each month Tom in Tech Support has been documenting how long those acquisitions take to complete. I will attempt to update the chart each month until the times for all 24 months have been documented. Be advised the times shown for months 18 thru 24 are estimated.

NOTE: In the chart below, be advised the acquisitions for months 0 thru 17 were not performed exactly one month apart. For example, one acquisition was performed on 12/03/21 and the next on 01/22/22, and then one was performed on 3/22/22 and the next on 04/02/22. Obviously, I do not control when a customer performs the Monthly QC Suite.

The chart shown below does not apply to systems with the AutoQC Premium Source Kit.