Knowledge Hub · Saxsons Shielded Infusion Pump Shield
The administration step dominates PRRT staff dose —and the bremsstrahlung order has to be right.
Riveira-Martin et al. (EJNMMI Physics 2023) measured 32 administrations of 7.4 GBq Lu-177 DOTATATE: the administration phase alone accounted for 69 % of total staff dose while occupying only 19 % of procedure time. Peak dose-rates at the operator position were 93 µSv/h (physicians) and 113 µSv/h (nurses). This page is why the cabinet exists, why the Perspex sits inside the lead for Lu-177 and Y-90 work, and how the variant matrix maps onto the AERB 500 mSv/year extremity-dose envelope.
Why this matters
Six things the cabinet delivers, sourced inline
Administration dominates
69 % of staff dose in 19 % of procedure time
Riveira-Martin et al. measured 32 administrations of 7.4 GBq Lu-177 DOTATATE across 2 physicians and 4 nurses with simultaneous active + passive dosimetry. The administration step alone — patient-side, infusion pump running — accounted for 69 % of total staff dose, despite being only 19 % of procedure time. Peak dose-rates at the operator position were 93 ± 31 µSv/h (physicians) and 113 ± 56 µSv/h (nurses). The dispensary phase is the shorter, lower-dose phase. Designing a shielded radiopharmacy that stops at the dispensing hot cell leaves the dominant dose pathway unprotected. The cabinet wraps the infusion pump and syringe across exactly the phase that drives the per-administration dose.
Based on: Riveira-Martin M et al., EJNMMI Physics 10:84 (2023). PMC10645926.
Read source ↗Bremsstrahlung-ordering
Why the Perspex sits inside the lead, not outside
Lu-177 emits β (E_max ~ 498 keV) with a small γ branching ratio at 113 / 208 keV. Y-90 is essentially pure β at much higher energy (E_max 2.28 MeV). When a high-Z absorber (lead) is in the β path, the β electrons decelerate and produce bremsstrahlung — secondary γ photons spread across a broad continuum, which then transmit through the same lead at the lead-attenuation rate. The correct shielding order: a low-Z absorber (Perspex / PMMA / acrylic) on the inside stops the β with minimal bremsstrahlung; high-Z (lead) on the outside catches the primary γ (Lu-177 113 / 208 keV) and the residual bremsstrahlung. Inverting the order — lead inside — turns the lead from a γ-absorber into a bremsstrahlung source. The Perspex + lead hybrid variant is built in the correct order; the Perspex is the inner wall, the lead is the outer wall.
Based on: NCRP Report 49 bremsstrahlung-shielding guidance; AAPM Report 88 hybrid-shielding for β-emitters.
Read source ↗Lu-177 photon shielding
Why the 208 keV line drives the lead-tier choice
Lu-177 emits two γ lines — 113 keV and 208 keV — with the 208 keV photon being the dose-rate-driving line at the dispensing bench. The lead outer layer of the β/γ hybrid variant is sized to bring transmitted dose-rate at the syringe surface into the same order of magnitude as the dispensary lead-vial-shield envelope. The published treatment-room shielding work for Lu-177 (Oumano 2025) frames the lead-tier choice against patient throughput and dose-per-administration; the cabinet sizing follows the same framework applied to the source-side rather than the room-side.
Based on: NIST XCOM photon-attenuation database; Oumano M et al. J Appl Clin Med Phys 26(5): e70062 (2025). PMC12059296.
Read source ↗Lead apron limits
Why room shielding does not replace the cabinet
Riveira-Martin 2023 measured the dose reduction from a standard PRRT lead apron during administration: 71 % dose reduction for physicians, 56 % for nurses, with cumulative-dose reductions of 69 % and 68 % respectively. The apron is meaningful but partial: it shields the torso, not the hands, not the eye lens, not the patient-side approach geometry where the operator leans in to start the pump. The cabinet attacks the source side — the syringe and the pump — rather than the operator side. The two are complementary, not substitutes. The published apron-only protection is the lower bound on what the cabinet should add.
Based on: Riveira-Martin M et al., EJNMMI Physics 10:84 (2023). PMC10645926.
Read source ↗IV-pole-cut variant
Why the transport step is part of the dose budget
The infusion does not start in the radiopharmacy and finish in the radiopharmacy. The syringe pump, source syringe and patient-side tubing move from the dispensary to the patient bedside or the ward corridor. The IV-pole-cut variant rides on a standard ward IV pole — the cabinet remains shielded across the entire patient transport. Without the pole-mount cut, the staff member walking the syringe across the corridor is the unshielded link in the chain. Riveira-Martin's administration-phase dose number includes that walk; eliminating it from the dose chain matters as much as the bremsstrahlung-ordering inside the cabinet.
Based on: Riveira-Martin M et al. (procedure-phase analysis); AERB Safety Code for Nuclear Medicine Facility — patient-transport shielding expectations.
Read source ↗AERB extremity-dose envelope
How the variant matrix maps onto the 500 mSv/year limit
ICRP Publication 103 sets the occupational extremity-dose limit (Hp(0.07)) at 500 mSv/year, which the AERB Safety Code for Nuclear Medicine Facility carries through. Riveira-Martin's normalized dominant-hand Hp(0.07) for Lu-177 DOTATATE administration: 45.2 µSv/GBq for physicians, 13.9 µSv/GBq for nurses (per dose, per 7.4 GBq administration ≈ 335 µSv physician, 103 µSv nurse without additional source-side shielding). A high-volume PRRT centre running 4 patients/week = 200 administrations/year — without source-side shielding the unshielded physician hand dose would approach 67 mSv/year, well inside the limit but climbing. Adding the cabinet pulls the source-side contribution to a small fraction of that; the per-tier specification is the audit trail the AERB inspection reads.
Based on: ICRP Publication 103; AERB Safety Code for Nuclear Medicine Facility; Riveira-Martin et al. (2023) per-GBq Hp(0.07) data.
Read source ↗Standards + peer-reviewed references
EJNMMI Physics, J Appl Clin Med Phys, AAPM, NCRP, ICRP and AERB documents that anchor PRRT infusion-shielding selection.
Riveira-Martin et al. 2023 — EJNMMI Physics
Active + passive dosimetry across 32 administrations of 7.4 GBq Lu-177 DOTATATE. The source paper for the "administration step = 69 % of staff dose in 19 % of procedure time" finding.
Oumano et al. 2025 — J Appl Clin Med Phys
Shielding resources for Tc-99m, F-18, I-131 and Lu-177. Treatment-room shielding-design framework for the four common radiopharmaceuticals.
AAPM Report 88 — Quality Assurance for Radiopharmacy
AAPM framework for radiopharmacy QC including hybrid (low-Z + high-Z) shielding for β-emitters and the bremsstrahlung-ordering principle.
NCRP Report 49 — Structural Shielding Design and Evaluation
NCRP foundational shielding-design report; covers bremsstrahlung-shielding for β-emitters and the half-value-layer framework.
ICRP Publication 103 — Recommendations of the ICRP
Current ICRP framework defining the 500 mSv/year occupational extremity-dose limit (Hp(0.07)) referenced by AERB.
AERB Safety Code for Nuclear Medicine Facility
Indian regulatory framework for nuclear-medicine facility licensing — patient-administration shielding and extremity-dose expectations.
Where next
Two more pages, depending on what you need.
Product page →
Infusion pump shield specs + variant matrix
Multiple lead-only tiers across the chassis form factors, plus the Perspex + lead β/γ hybrid variant with IV-pole cut.
For the radiopharmacist →
PRRT administration-step SOP
Per-isotope tier selection, transport workflow, infusion-pump deck SOP, AERB dose-log expectations.