SPECT-only — Tc-99m / I-131
Drums · 2–3 drums
Pb tiers · 3 mm Pb × 2 (Tc-99m daily-cycle) + 6 mm Pb × 1 (I-131 60-day hold)
Chassis · 321 × 450 mm standard
Why · Tc-99m clears in 60 h — daily-cycle drum rotates; I-131 holds for 60–80 days so the 6 mm drum stays static. Two-drum-per-isotope minimum to avoid daily swap.
Routine PET — FDG / Ga-68
Drums · 3–4 drums
Pb tiers · 12 mm Pb × 3 (rotating F-18 + Ga-68 cycle)
Chassis · 321 × 450 mm standard or 400 × 500 mm mid-range
Why · F-18 clears in 18 h, Ga-68 in 11 h — daily rotation keeps cumulative hold-volume low. The 12 mm Pb tier keeps drum-side dose-rate inside envelope during the rotation cycle.
High-throughput PET radiopharmacy
Drums · 4–6 drums
Pb tiers · 12 mm Pb × 3 (routine) + 25 mm Pb × 2 (multi-dose source-vial)
Chassis · Mix of 321 × 450 mm + 530 × 800 mm large
Why · 30+ dispenses per shift, multi-dose source-vial workflow produces higher per-shift solid-waste volume. The 25 mm tier handles cumulative source-vial waste activity.
Lu-177 theranostic centre
Drums · 3–5 drums
Pb tiers · 25 mm Pb × 2–4 (PRRT / PSMA-617 / FAPI)
Chassis · 530 × 1100 mm 100 L high-volume × at least 2
Why · Lu-177 holds for 67 days. The 100 L drum gives the multi-week buffer needed; minimum 2 drums to rotate weekly fill cycles without overflow.
Mixed SPECT + PET + therapy
Drums · 5–8 drums
Pb tiers · Full range 3 / 6 / 12 / 25 mm Pb
Chassis · Mix from 321 × 381 mm compact to 530 × 1100 mm large
Why · Multi-modality hot lab needs the full per-isotope segregated decay-store. Each isotope gets dedicated drums; one drum per shift × isotope.
Beta-emitter compatible (Y-90 / P-32 / Sr-89)
Drums · 1–2 drums
Pb tiers · 6 mm Pb + 6 mm Perspex inner (β-γ hybrid build)
Chassis · 321 × 450 mm
Why · Pure-beta isotopes need Perspex inner to prevent bremsstrahlung against the lead. Activity per dispense is lower than PET; standard chassis size suffices.
