Positron emission tomography

Answer — Textbook Core (5 points)

Latest Update (2023–2026) — 1 point

APPENDIX — RAPID REVISION GRID

Every examinable number, named trial and guideline from all 41 answers, in one place. This is the page to read on the night before the examination.

Hepatology, upper GI disease and clinical nutrition (Questions 1, 4–6, 9–20)

Topic Numbers, criteria and cut-offs Trial / guideline to quote Jaundice Clinically visible at bilirubin >2.5–3 mg/dL; R value ≥5 hepatocellular, MASLD/MetALD nomenclature ≤2 cholestatic; Courvoisier's law; PT/INR = best severity marker (Hepatology 2023) Drug-induced liver injury Hy's Law — ALT >3×ULN + bilirubin >2×ULN → ~10% mortality; ACG DILI guideline; LiverTox; ICI hepatitis commonest agent co-amoxiclav; RUCAM → RECAM Autoimmune hepatitis Interface hepatitis, rosettes, emperipolesis; ANA/ASMA + raised IgG; IAIHG simplified criteria; CAMARO (J prednisolone 0.5–1 mg/kg + azathioprine 1–2 mg/kg; no budesonide in Hepatol 2024;80:576) cirrhosis Alcoholic hepatitis DF ≥32 or MELD >20 = severe; AST:ALT >1.5, both <400; ACG ALD 2024 (AJG 119:30); NIAAA prednisolone 40 mg × 28 days; Lille >0.45 at day 7 = stop steroids criteria Hepatitis B Treat if cirrhosis + any DNA; or DNA >2000 IU/mL + raised ALT; or WHO 2024 (March 2024) expanded ≥F2/APRI >0.5; TAF or entecavir preferred in elderly; 6-monthly USG criteria for HCC Decompensated cirrhosis HVPG >10 = CSPH; CTP A 5–6, B 7–9, C 10–15; MELD >15 → transplant Baveno VII (J Hepatol 2022;76:959); referral; LSM >15 kPa + platelets <150 = CSPH; SBP albumin 1.5 g/kg PREDESCI; resmetirom 2024 d1 + 1 g/kg d3 Hepatic encephalopathy West Haven I–IV; lactulose to 2–3 soft stools/day; rifaximin 550 mg BD; AASLD/EASL Practice Guidance 2022 protein 1.2–1.5 g/kg (no restriction); ammonia not for monitoring Hepatorenal syndrome HRS-AKI: creatinine ↑≥0.3 mg/dL in 48 h or ≥50% in 7 days; urine Na ICA criteria; ADQI 29/ICA 2024 (J <10 mmol/L, FENa <0.2%, proteinuria <500 mg/day; terlipressin + Hepatol 81:163); CONFIRM albumin 20–40 g/day Ascites SAAG ≥1.1 = portal hypertension; SBP if neutrophils ≥250/mm³; Baveno VII; ANSWER (Lancet 2018) spironolactone:furosemide 100:40 up to 400:160; albumin 8 g per litre tapped; TIPS if ≥3 LVP/year GORD LA grades A–D; PPI 30–60 min before breakfast × 8 weeks; pH study AGA P-CAB Update 2024 (Gastro off PPI = gold standard; endoscope all new dyspepsia >60 y 167:1228); ASGE GERD 2025 Malabsorption Faecal fat >7 g/day; faecal elastase-1 <200 µg/g = PEI; lipase 40,000– ACG Coeliac 2023 (AJG 118:59); AGA PEI 50,000 U per meal; tTG-IgA + total IgA; Marsh grading Update 2023 Bristol chart / laxatives 1–2 constipation, 3–4 normal (4 ideal), 5 low fibre, 6–7 diarrhoea; PEG AGA/ACG 2023; WGO 2025 first-line; docusate ineffective; avoid liquid paraffin and bulking agents in the frail Parenteral nutrition 20–30 kcal/kg, protein 1.0–1.5 g/kg, glucose ≤4–5 mg/kg/min; start if ESPEN geriatric practical guideline gut unusable >7 days; CRBSI = commonest serious complication Refeeding syndrome BMI <16, weight loss >15%, no intake >10 days; start 10 kcal/kg/day NICE CG32; ASPEN consensus 2020 (5 if extreme); thiamine 200–300 mg before feeding; phosphate is the hallmark Inanition MNA-SF screening; GLIM = 1 phenotypic + 1 aetiologic criterion; GLIM; ESPEN geriatrics; AGS Beers protein 1.2–1.5 g/kg/day; "9 Ds"; supplements between meals 2023 (avoid megestrol) Gastroenterology, haematology and oncology (Questions 2–3, 7–8, 22–25, 30–31, 34, 37) Topic Numbers, criteria and cut-offs Trial / guideline to quote H. pylori Stop PPI 2 weeks, antibiotics 4 weeks before UBT; confirm cure at ACG 2024 (AJG 119:1730); Maastricht VI 4 weeks; BQT 14 days; clarithromycin resistance 22–32% UGI bleeding GBS 0–1 = outpatient; endoscopy <24 h; PPI 80 mg then 8 mg/h ACG 2021; ESGE 2021; CAG 2025 × 72 h; erythromycin 250 mg; Forrest Ia/Ib/IIa treat (rebleed 55/43/22%)

Transfusion Hb <7 restrictive; <8 cardiac/orthopaedic surgery; <10 in acute AABB 2023 (JAMA 330:1892); AABB 2025 MI; TACO = commonest transfusion death (Ann Intern Med 178:1469); MINT (NEJM 2023)

Colorectal cancer ≥12 nodes for staging; N1 = 1–3, N2 ≥4; 5-y survival I 90%, II 70– AJCC 8th; DYNAMIC; Cercek NEJM 2025; 80%, III 50–65%, IV 15%; dMMR 15% ATOMIC (ASCO 2025)

Constipation Rome IV: 2 of 6, <3 BM/week; PEG first-line; docusate ineffective; AGA/ACG 2023; WGO 2025; ASCRS 2024 PAMORAs for OIC; avoid bulking agents in OIC CLL ≥5 × 109/L B cells × 3 months; CD5/CD19/CD23/CD200+; Rai III iwCLL 2018; CLL14; AMPLIFY (NEJM Hb <11, IV plt <100; doubling time <6 months; Richter's 5% 2025;392:748)

Myelofibrosis / MPN JAK2 V617F 95% PV; Hct <45% target; pacritinib if platelets <50; COMFORT-I/II; MOMENTUM (Lancet 2023); DIPSS-Plus; AML transformation 10–20% at 10 y NCCN MPN 2026 Iron deficiency Ferritin <30 ng/mL (<45–100 if inflamed); TSAT <16%; RDW BSG IDA guideline; hepcidin dosing studies >15%; Mentzer >13; alternate-day oral iron B12 deficiency B12 <200 pg/mL; indeterminate 200–350 → MMA; MCV often NICE NG239 (2024); BSH cobalamin >110; hydroxocobalamin 1000 µg alternate days then 2–3 guideline monthly; stores last 3–5 y Transplantation RIC feasible to 70–75 y; HCT-CI predicts NRM; acute GVHD <100 BMT CTN 1703 (NEJM 2023) days Paraneoplastic SIADH & ectopic ACTH → SCLC; PTHrP → squamous; anti-Yo → PNS-Care criteria (Graus) ovary; anti-VGCC → LEMS; acanthosis nigricans → gastric Malignant bowel obstruction Octreotide 300–600 µg/24 h; dexamethasone 6–16 mg/24 h, stop ASCO Palliative Care Update 2024 (JCO at 5 days; hyoscine butylbromide 60–120 mg/24 h; 42:2336); S1316 metoclopramide contraindicated in complete obstruction Anaemia, haematological malignancy, oncology and screening (Questions 21, 24, 26–29, 32–33, 35–36, 38– 41)

Topic Numbers, criteria and cut-offs Trial / guideline to quote Anaemia in the elderly WHO Hb <13 (M), <12 (F); prevalence 10% >65 y, >20% >85 y; rule of NHANES; WHO Hb thresholds 2024; CHIP thirds; reticulocyte count = key branch point Anaemia of chronic disease Ferritin normal/high, TIBC low, sTfR normal, hepcidin high; use ferritin Hepcidin–ferroportin axis; HIF-PHIs <100 in inflammation; ESA target Hb 10–11.5 (roxadustat, daprodustat)

Thrombocytopenia <150; bleeding <30; serious risk <10–20; ITP treat if <20–30 or bleeding; ASH ITP guideline; ADVANCE 4Ts score for HIT; marrow exam in most >60 y (efgartigimod, Lancet 2023)

DIC ISTH score ≥5 = overt DIC; platelets <50 + bleeding → transfuse; FFP 15 ISTH overt DIC score; SIC score mL/kg; cryoprecipitate if fibrinogen <1.5 g/L; heparin only if thrombotic phenotype Plasma cell dyscrasias MGUS: M <3 g/dL, PC <10%, 1%/year progression; smouldering: M ≥3 IMWG criteria; R2-ISS; FDA MRD endpoint g/dL or PC 10–60%, 10%/year; "20-2-20" high risk; plasma cell leukaemia 2024 ≥5% circulating Multiple myeloma CRAB + SLiM (PC ≥60%, FLC ratio ≥100, >1 focal MRI lesion ≥5 mm); R- IMWG 2014; CEPHEUS (Nat Med 2025); ISS uses β2M, albumin, LDH, cytogenetics; skeletal survey obsolete PERSEUS (NEJM 2024); MAIA Myelodysplasia Blasts <20% (≥20% = AML); Pelger-Huët, ring sideroblasts; IPSS-R uses WHO 2022; IPSS-M; COMMANDS 2024; cytogenetics, blasts, Hb, platelets, neutrophils; EPO <500 predicts ESA IMerge/imetelstat 2024 response CML t(9;22) BCR::ABL1; low LAP score; blast crisis ≥20% blasts; milestones ASC4FIRST (NEJM 2024;391:885); ELN ≤10% at 3 mo, ≤1% at 6 mo, ≤0.1% (MMR) at 12 mo; TFR after MR4.5 recommendations × 2 y Prostate cancer Gleason → ISUP Grade Group 1–5; low risk PSA <10/GG1/≤T2a; high risk EAU 2025 (G8, mini-Cog, CFS); proPSMA; PSA >20/GG4-5/≥T3; radical treatment needs >10 y life expectancy; ARASENS/PEACE-1 osteoblastic metastases Vertebral secondaries / CUP "BLT with a Kosher Pickle"; malignancy spares the disc, TB does not; ESMO CUP 2023; CUPISCO (Lancet dexamethasone 8–16 mg + MRI within 24 h; single 8 Gy for 2024)

uncomplicated bone pain; primary unfound in 20–30% Tumour lysis syndrome Cairo-Bishop: urate ≥8, K ≥6, PO4 ≥4.5, Ca ≤7 mg/dL; hydration 2–3 Cairo-Bishop; venetoclax ramp-up; L/m²/day; rasburicase contraindicated in G6PD deficiency; no single-dose rasburicase alkalinisation Cancer screening (general) Lag time to benefit ~10 y (mammography, colonoscopy), ~5 y (FIT); USPSTF 2024 breast 40–74 (Grade screen if life expectancy >10 y; CRC 45–75, individualise 76–85, stop B); ePrognosis; Lee index >85; cervical stop at 65 Screening test performance Mammography Sn 75–85%/Sp 90–95%; FIT Sn ~75–80% for cancer; USPSTF; WHO HPV strategy; colonoscopy Sn >95%; Pap Sn 50–60%/Sp >95%; HPV DNA Sn 90–95%; ICMR/NPCDCS (CBE every 3 y from 30)

VIA Sn 60–70%

PET Two 511 keV photons at 180°; fast 4–6 h, glucose <150–200 mg/dL; 18F Deauville score; PSMA/DOTATATE half-life 110 min; ~7–10 mSv; false positive in TB and sarcoid; false theranostics; amyloid PET for lecanemab negative <8–10 mm and in prostate, RCC, HCC, mucinous tumours Curriculum domains still outstanding across the answer bank: rheumatology; endocrinology and thyroid disease; dermatology; urology and incontinence; falls and osteoporosis; ophthalmology; non-pharmacological management of dementia; rehabilitation; comprehensive geriatric assessment as a standalone topic; and disorders of potassium, calcium and magnesium.