Bone scintigraphy

A report skeleton for whole-body, three-phase and SPECT/CT bone scintigraphy with 99mTc-labelled bisphosphonates, following the documentation and reporting section of the EANM bone scintigraphy guideline. The optional prostate block applies the PCWG3 progression rule used in castration-resistant prostate cancer.

Based on: EANM practice guidelines for bone scintigraphy (Van den Wyngaert 2016); PCWG3 bone-scan progression criteria for castration-resistant prostate cancer (Scher 2016)

BONE SCINTIGRAPHY

CLINICAL INDICATION:
  [Staging / restaging / response assessment / pain / trauma / infection / prosthesis / other]
  Clinical question: [ ]
  Relevant history: [primary tumour, surgery, fractures, arthroplasty]
  Relevant results: [PSA / ALP / tumour markers; radiographs, CT, MRI]
  Treatment affecting bone: [ADT / ARPI / chemotherapy / bisphosphonate / denosumab / radiotherapy field / G-CSF]

TECHNIQUE:
  Radiopharmaceutical: [99mTc-MDP / 99mTc-HDP (HMDP) / 99mTc-DPD]
  Administered activity: [ ] MBq IV, [site], at [time]
  Protocol: [whole-body anterior and posterior at [ ] h / three-phase: flow, blood pool at [ ] min, delayed at [ ] h / spot views / late (6–24 h) images]
  SPECT/CT: [not performed / region(s): [ ]; CT for attenuation correction and localisation / diagnostic CT]; DLP [ ] mGy·cm, CTDIvol [ ] mGy
  Preparation, incidents and limitations: [analgesia, catheter, extravasation, motion / none]

COMPARISON:
  [Prior bone scan dated [ ] / CT / MRI / PSMA PET / none]

FINDINGS:
  Image quality: [adequate / limited by [ ]]
  Flow and blood pool (if performed): [normal / increased at [ ]]
  Skeleton: [normal distribution, symmetrical and homogeneous uptake]
  Abnormal foci (for each: site, size, shape, intensity, number):
    [site]: [increased / decreased / photopenic with rim] uptake; SPECT/CT correlate [sclerotic / lytic / mixed / fracture / degenerative / no CT abnormality]
  Pattern: [none / solitary / multiple scattered / diffuse]
  Superscan: [not present / present: diffusely increased skeletal uptake with low or absent renal and soft-tissue activity]
  Kidneys and urinary tract: [normal / [ ]]
  Soft tissues: [no abnormal uptake / [ ]]
  CT-only findings: [skeletal or non-skeletal findings seen on CT only / none]

PROSTATE CANCER (PCWG3), if applicable:
  Scan: [baseline / first post-treatment scan / later scan]
  New lesions compared with [baseline / first post-treatment scan]: [number]
  Assessment: [no new lesions / new lesions, confirmation required / progression confirmed / possible flare]

IMPRESSION:
  1. [Answer to the clinical question: e.g. no scintigraphic evidence of skeletal metastases / findings consistent with metastases at [ ] / benign aetiology: [ ]]
  2. [Change from prior scan: improved / stable / new lesions / progression]
  3. [Differential diagnosis with likelihood, if nonspecific]
  4. [Recommendation, e.g. targeted MRI / CT / biopsy / confirmatory scan]

Before you sign

• State whether a superscan is present: diffusely increased skeletal uptake with faint or absent kidneys and soft tissue can pass for a normal scan.
• In the first weeks to months after starting a new treatment (PCWG3 treats the first 12 weeks as the flare window), brighter or more numerous foci may be progression but can also be a flare in patients who are responding. Name the possibility rather than calling progression on one scan.
• PCWG3 (the 2+2 rule): if the first post-treatment scan shows ≥2 new lesions compared with baseline, progression is confirmed only when a later scan shows ≥2 further new lesions. After that, ≥2 new lesions compared with the first post-treatment scan must persist on a confirmatory scan.
• Small (under 2 cm) purely lytic lesions, such as myeloma, infarction, osteonecrosis, haemangioma and lytic metastases, can be barely visible on planar images. Use SPECT/CT for equivocal foci and for patients with a high pretest probability of metastases.
• Urinary contamination is the most common artefact, especially after urological surgery. Also look for a urinary diversion reservoir and for bladder activity that changes during pelvic SPECT.
• Report findings seen only on the CT part of SPECT/CT, both skeletal and non-skeletal, and give the DLP and CTDI.
• End the report with an answer to the referring question. If the findings are nonspecific, give a differential diagnosis with likelihoods and suggest the next test.

Sources

1. Van den Wyngaert T, Strobel K, Kampen WU, et al. The EANM practice guidelines for bone scintigraphy. Eur J Nucl Med Mol Imaging. 2016;43:1723–38.
2. Scher HI, Morris MJ, Stadler WM, et al. Trial design and objectives for castration-resistant prostate cancer: updated recommendations from the Prostate Cancer Clinical Trials Working Group 3. J Clin Oncol. 2016;34:1402–18.
3. Anand A, Heller G, Fox J, et al. Automated bone scan index to optimize Prostate Cancer Working Group radiographic progression criteria for men with metastatic castration-resistant prostate cancer. Clin Genitourin Cancer. 2022;20:270–7.