VASD Siemens PET CT 2 Rm 4503 Final2 Shield Design.pdf

Memorandum

Date: 13 October 2020

From: Medical Physicist, Radiology Service

Subj: Shielding Evaluation for Siemens Biograph Vision PET/CT 2 Scanner Room 4503

To: Ernest Belezzuoli, M.D., Nuclear Medicine Service (115) cc: Amilcare Gentili, MD

Sara Johnson, MS Michael Degnan

Floor plan drawings (AE-104 FLOOR PLAN and AE-204 RCP1) were received from Engineering Services on 10/1/2020 for the proposed installation of the new Siemens Biograph Vision PET/CT Scanner in Room 4503. Siemens x-ray scatter specifications (A-102) were also received.

Workload data and sample protocols were obtained from Nuclear Medicine Service and Biomedical Engineering.

The shielding requirements are summarized below and on the attached room sketch. This report should be maintained for the life of this facility to ensure adequate documentation of the shielding design criteria. Please ensure that a copy of this report is given to the owner/operator. The Radiation Shielding Plan is based on the requirements of the Nuclear Regulatory Commission, AAPM Task Group 108, California Radiation Control Regulations Title 17, Report 147 of the National Council on Radiation Protection & Measurements and applicable provisions of Chapter 31C, California Building Code (Title 24, California Code of Regulations) relating to radiation protection.

It is highly recommended that the lead materials be physically inspected at the time of installation and documentation be made. The Qualified Medical Physicists shall perform radiation scatter measurements during Acceptance Testing of the scanner after its installation.

The following criteria were applied in the shielding calculations and radiation safety specifications based on information supplied by Nuclear Medicine personnel, Siemens and Engineering Services. If there are any changes in the workload values, the scanner model, the room layout or area occupancy the shielding calculations may no longer be valid. Please contact me immediately if there are any changes or revisions contemplated for this room layout or its proposed use. These calculations reflect conservative shielding criteria consistent with good practice. Shielding is rated for a workload with 100% positron emitters using the half-life (110 min) of F-18 FDG 10 mCi and F-18 Furibapiz 2 doses 15 mCi total. Use of shorter-lived isotopes (N-13, O-15, C-11, Rb- 82, Ga-88 5 mCi) will not affect these requirements. I further declare that I am a Medical Radiation Physicist certified by the American Board of Radiology and registered with the State of California.

Lead thickness greater than the minimum specified may be used. All lead equivalent barriers (walls, doors and windows) must be rated at 511 keV.

Shielding Criteria:

1. Total Workload: 40 pats/wk, 8 hrs/day, 40 hrs/wk, mixture of 2D and 3D acquisitions, whole body 65%

2. Administered activity: 10-15 mCi (366-555 MBq)

3. Patients will void (~15% of administered activity) after the 60 min uptake before scanning

4. Average imaging time: 30-60 min

5. 1 hour integrated dose from patient at 1 m: 3.0 μGy/hr/37 MBq

6. Body absorption factor for PET: 0.34,

7. CT techniques: 120 kVp, 166 mAs body, 362 mAs head (per PET/CT 1), 96,140 mAs/wk

8. All Use Factors are 0 for primary beam, 1 for scattered radiation

9. Uncontrolled areas: <0.02 mSv (2 mR) per week

10. Controlled areas: Target value of < 0.02 mSv (2 mR) per week SDVA ALARA Level 1

11. Floor-to-Floor Distance: 17 ft

12. Concrete floors: 5.1 inches. No additional barrier required for ceiling or floor (occupancy 1.0 for each). The interstitial space above the scan room must be restricted during use.

13. Attenuation of x-rays and photons in the scanner gantry was included in barrier calculations.

14. A thicker lead barrier than that specified in this Report may be installed. If this is done, full documentation in the permanent record is required.

Thank you for the opportunity to review this project and to be of service. Please contact us at your convenience for any questions about this report.

Sincerely, Michael P. André, Ph.D., FAIUM, FAAPM David J. Hall, Ph.D.

Certified, American Board of Radiology Certified, American Board of Radiology

Corridor

Corridor

PET/CT

SPECT/CT

Corridor

VASD SIEMENS BIOGRAPH VISION PET/CT SCANNER RECOMMENDED BARRIERS

Room 4503

Barrier Location Or Wall

(Ref. Drawing)

Type of Area

Distance ft (m)

Occupancy Factor

XUT CT

Scatter

(mSv/wk)

PET

(mSv/wk) at barrier

CT Required Minimum

Barrier

PET Barrier Recommended Total Barrier

(A1) Shared Control Rm wall, door, window

Controlled

0.1 mSv/wk

(4.9)

1 T

0.11 23 0.4 mm Pb 1 lb

1.3 mm 3#

1.6 mm 4# 8 ft high

(B) Control Rm doorway, open

Controlled

0.1 mSv/wk

1/5 T

0.06 23 No additional No additional

(C1) East Corridor wall, former door

Uncontrolled

0.02 mSv/wk

(5.5)

0.06 18 No additional No additional --

(C2) East Corridor wall

Uncontrolled

0.02 mSv/wk

0.08 26 0.3 mm Pb 1 lb

0.3 mm Pb 0.8 mm 2# 8 ft high

(D) East Corridor wall

(1.8)

0.65 32 0.8 mm Pb 2 lb

3.7 mm Pb 10#

3.9 mm 10# 8 ft high

(E) East Corridor wall

Uncontrolled

0.02 mSv/wk

(1.8)

1/5 T 0.39 32 0.67 mm Pb 2 lb

3.7 mm Pb 10#

3.9 mm 10# 8 ft high

(F1) South Corridor wall

Uncontrolled

0.02 mSv/wk

(1.5)

1/5 T 0.85 47 0.9 mm Pb

2.5 lb

6 mm Pb 16#

6.3 mm 16# 8 ft high

(F2) Receptionist alcove 4076 southeast

Uncontrolled

0.02 mSv/wk

(3.7)

1 T 0.77 40 0.8 mm Pb 2 lb

5.5 mm Pb 16#

6.3 mm 16# 8 ft high

(F3) Reading Room south Uncontrolled

0.02 mSv/wk

(4)

1 T 0.63

34 0.8 mm Pb 2 lb

4.2 mm Pb 12#

No additional F1 satisfies

(G) Reading Room west

Uncontrolled

0.02 mSv/wk

(2.1)

1 T 0.43 118 0.7 mm Pb

1.5 lb

3 mm Pb 8#

3 mm 8# 8 ft high

(H1) Equipment Rm 4520 west

Uncontrolled

0.1 mSv/wk

(1.8)

1/20 T 0.12 8 0.5 mm Pb 2 lb

2.3 mm Pb 6#

3 mm 8# 8 ft high

(H2) Corridor 4521 beyond Equip Rm

Uncontrolled

0.1 mSv/wk

(3.7)

1/5 T 0.17 24 0.5 mm Pb 2 lb

2.3 mm Pb 6#

H1 satisfies

(I) West Door 4503.1 Uncontrolled

0.1 mSv/wk

(4.9)

1/5 T <0.02 <0.02 No additional No additional No additional

(J) Corridor wall Uncontrolled

0.1 mSv/wk

(4.9)

1/5 T 0.12 5 0.4 mm Pb 0.4 mm Pb 0.8 mm 2# 8 ft high

(K) Control Doorway 4504.1

Uncontrolled

0.1 mSv/wk

(5.5)

1/5 T <0.02 <0.02 No additional No additional No additional barrier required

(L) Control wall west Uncontrolled

0.1 mSv/wk

(5.8)

1/5 T <0.02 <0.02 No additional No additional No additional barrier required

Ceiling

14 1 T 0.38 29.7 2.6” concrete

2.2” concrete

5.1” concrete existing

No additional Floor

14 1T 0.38 29.7 2.6” concrete 2.2” concrete

5.1” concrete existing

No additional Workload: 40 pats/wk

1 HVL broad beam geometry at 511 keV = 5 mm Pb (12 lb/sq ft)

CT Radiation Scatter Plots

Or Wall