Radiopharmacist · Variant selection workflow
The PET L-bench family is ten configurations across two lead tiers, four footprint sizes, two outer materials, two lead-glass densities, the base-lead option and the side-shielding pack. Each decision has a rule, a physics reason and a citable reference. Here is the sheet the radiopharmacist and the hot-lab planner work through.
Rule · If per-shift cumulative dispensed activity exceeds ~ 25 GBq (typical busy FDG hot lab) OR the workflow includes Lu-177 theranostic prep, pick the 60 mm tier. Otherwise 50 mm is sufficient.
Why · At 511 keV the 60 mm wall delivers ~ 14.6 HVL vs ~ 12 HVL at 50 mm — a measurable difference at the operator-face dose rate during a high-activity dispense. The shielding mass also covers Lu-177's 511 keV pair-production contribution.
Reference: NCRP Report 49 HVL framework; AAPM Report 88 radiopharmacy QA.
Rule · For high-throughput PET dispensing benches (30+ doses per shift) pick the premium lead-glass tier. For lower-throughput SPECT-and-PET shared benches the standard tier is adequate. Full per-tier specifications shared on request under NDA.
Why · The lead-glass window is the operator-face weak point. Stepping up the lead-glass tier translates to a meaningful cumulative-dose reduction over a hundred-shift year.
Reference: NCRP Report 147 shielding-design framework.
Rule · If the L-bench is the central dispensing station and shares the worktop with the dose calibrator + dispense tray + sharps shield, pick 24″×24″×24″. If the L-bench is auxiliary (parallel to a primary dispensing station) the 14″×14″×24″ or 18″×15″×21″ compact tiers fit the gap.
Why · The 24″×24″×24″ envelope is the workhorse PET dispensing footprint — the standard 2′×2′×2′ that the Saxsons Dose Calibrator + dispense tray + L-bench layout assumes.
Reference: Saxsons hot-lab fit-out reference layouts; AAPM Report 88 radiopharmacy workflow design.
Rule · If the hot-lab cleaning protocol includes daily wet wipe-down OR the lab is built to clean-room / GMP-grade surface specs, pick SS 304. Otherwise MS painted (epoxy decontaminable) is the cost-optimised choice.
Why · Same lead-shielding mass inside either outer. SS 304 withstands repeated wet wipe-down without coating degradation; MS painted is cheaper and adequate for the standard cleaning cycle.
Reference: EU GMP Annex 1 (revised 2022) clean-room surface specifications; AAPM Report 88 cleaning-validation guidance.
Rule · If the hot-lab sits over an occupied basement / lower floor, pick the base-lead variant ("B" suffix — e.g. RPLB-50-18-15-21-MS-A-B-0). For ground-floor hot-labs over a concrete slab with no occupied space below, base-lead is optional.
Why · Base lead covers the floor-side scatter path. The structural-floor calculation includes the L-bench mass, the base-lead mass and the dispense activity — the radiation-safety officer signs off based on the cumulative.
Reference: NCRP Report 49 shielding-design framework (floor / ceiling scatter chapters); AERB Safety Code structural-shielding clauses.
Rule · For multi-station hot-lab layouts where the L-bench abuts another shielded workstation, add the 50 mm side-shielding pack (RPLBA-01-50-B-0 for MS, RPLBA-02-50-C-0 for SS 304 outer). For standalone L-bench installations the pack is optional.
Why · The side wall closes the lateral scatter path between two adjacent shielded benches. The MS / SS choice on the side pack matches the outer of the L-bench it pairs with.
Reference: Saxsons hot-lab fit-out reference layouts; NCRP scatter-path analysis.
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