FDG PET/CT (Oncology)

What it does

FDG PET/CT (Oncology) reads the highest-volume PET exam: whole-body staging and response assessment in lymphoma, lung, head-and-neck, oesophageal, colorectal and other cancers. Upload the attenuation-corrected PET with its CT; the run computes SUV from the injection metadata, segments every FDG-avid lesion and places it on the CT anatomy.

The result is a structured oncologic read. Each lesion carries SUVmax, SUVpeak, metabolic tumour volume (MTV) and an anatomical site, measured against liver and mediastinal blood-pool references. For lymphoma it adds the Lugano stage, total metabolic tumour volume and, on interim or end-of-treatment scans, the Deauville score. With a prior study it matches lesions over time and returns a PERCIST or Lugano response category.

Intended use

Decision support for the physician who reports oncologic PET/CT: a quantified lesion table and reference values to check a Deauville call, a consistent PERCIST comparison between two time points, and a TMTV baseline for the lymphoma team. Physiological uptake (brain, myocardium, brown fat, bowel, urinary tract), post-treatment inflammation and G-CSF marrow activation are the classic mimics; every lesion is shown with its mask, SUV and anatomical site.

Who it is for

Nuclear-medicine physicians and radiologists, including fellows and general radiologists in centres without a dedicated PET reader; haematologists and oncologists who need a standardised answer; radiation oncologists planning head-and-neck treatment. Developers use the organ and lesion masks for PET quantification pipelines.

Accepted input

• PET: DICOM PET Image or Enhanced PET Image, whole-body and attenuation-corrected.
• CT: the paired low-dose or diagnostic CT series of the same PET/CT study.
• Prior study (optional, in prior_files): an earlier FDG PET/CT for response assessment.
• MIP screenshots and secondary captures are not read; the run needs the reconstructed volumes.

Requirements

Requirement	Why
Radiopharmaceutical Information Sequence (0054,0016): total dose, start time, half-life	SUV needs the injected activity decayed to scan time
Patient's Weight (0010,1030)	Body-weight SUV (SUVbw)
Patient's Size (0010,1020)	Lean-body-mass SUL used by PERCIST
Units (0054,1001), Decay Correction (0054,1102), Corrected Image (0028,0051)	Checks that the voxel values can be converted to SUV
CT covering the PET field of view	Reference regions and anatomical labelling of lesions

Vendor-specific SUV scale factors are handled. A quantitation check flags missing injection times, implausible dose or uptake time, blood glucose out of range, extravasation, low counts, attenuation-correction artefacts and PET–CT misregistration; affected numbers are flagged rather than silently reported.

Optional context

The indication (lymphoma or solid tumour) and the treatment time point (baseline, interim, end of treatment) in clinical_context determine which lymphoma sections and which response criteria apply.

The result

Section	Content
Lesions	FDG-avid lesion masks with SUVmax, SUVpeak, MTV and anatomical site; stable lesion IDs across time points
SUV and reference regions	SUVbw and SUL, SULpeak, liver and mediastinal blood-pool reference values, quantitation QC
Lymphoma stage	Involved nodal and extranodal regions, bulky disease and stage I–IV (Lugano 2014, modified Ann Arbor)
Total metabolic tumour volume	TMTV, total lesion glycolysis (TLG) and Dmax for lesion dissemination, with the threshold stated
Deauville score	Deauville 5-point score per target lesion and overall, against liver and blood-pool references
Metabolic response	Matched lesions versus the prior; PERCIST category (CMR, PMR, SMD, PMD) or Lugano category (CMR, PMR, NMR, PMD)
Organ segmentation	Whole-body organ masks from the CT with per-organ SUV statistics
Head-and-neck GTV contours	Primary (GTVp) and nodal (GTVn) tumour contours for radiotherapy planning
Draft report	Opt-in (options.report): an English narrative that interprets the result for the reader (findings, impression, limitations); every number is checked against the findings

Lesions are shown on the MIP and on fused PET/CT slices, so every SUV can be traced back to its mask.

Standards

• DICOM: Segmentation for lesion, organ and GTV masks; RTSTRUCT for GTV contours; SR TID 1500 Measurement Report for SUV, MTV and TLG, with units from CID 85 SUV Unit (g/ml{SUVbw}, g/ml{SUVlbm}); Parametric Map for SUV; Key Object Selection; Encapsulated PDF.
• Guidelines and criteria: EANM FDG PET/CT tumour-imaging guideline v2.0; Lugano 2014 staging and response with the Deauville 5-point scale; PERCIST 1.0 for solid tumours.
• Volumes: TMTV with SUV 4.0 or 41 % SUVmax segmentation thresholds, reported with the method used.

Response criteria

PERCIST 1.0 applies to solid tumours, using SULpeak and the liver reference. Lugano 2014 applies to lymphoma and uses the Deauville score: at interim or end of treatment, a score of 1–3 usually indicates complete metabolic response, while a score of 4 or 5 is read together with the change from baseline. The criteria and version applied are named in the result.