Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• The Role of PET-CT in Staging and Recurrence of Lung Cancer

  Lung cancer care increasingly depends on accurate information before treatment begins. Positron emission tomography combined with computed tomography, commonly called PET-CT, shows both the body’s anatomy and areas of increased metabolic activity. This can reveal disease beyond the primary tumour and help clinicians choose between surgery, radiotherapy, systemic treatment, or a combined approach.

  For respiratory specialists, oncologists, radiologists and thoracic surgeons attending an APSR- and KATRD-linked congress, the value of PET-CT lies in how it changes clinical decisions. In Australia, where patients may move between public hospitals, private imaging providers and regional referral centres, a well-timed scan can reduce avoidable procedures and clarify the next step in a multidisciplinary pathway.

  How PET-CT complements standard imaging

  A conventional CT scan provides high-resolution detail about the size, shape and location of a lung lesion. PET adds functional information by using a radiotracer, most commonly fluorodeoxyglucose (FDG), which tends to accumulate in cells with increased glucose metabolism. Many lung cancers demonstrate this activity, allowing suspicious sites to be assessed across the chest and body in one examination.

  This combined view is particularly useful for identifying mediastinal lymph-node involvement, pleural disease, adrenal lesions and distant metastases. PET-CT does not replace tissue sampling or brain imaging, however. Inflammatory disease, infection and some benign tumours can also produce high FDG uptake, while certain indolent or mucinous cancers may appear less active.

  Establishing the extent of newly diagnosed disease

  Staging determines whether a cancer is potentially curable with local treatment or requires a broader strategy. PET-CT is widely used in non-small cell lung cancer to assess the primary tumour, hilar and mediastinal nodes, and distant organs. It can expose unsuspected metastases that would make an extensive operation inappropriate, or identify a limited pattern of spread suitable for a carefully selected treatment plan.

  The scan also helps target invasive sampling. If PET shows an active mediastinal node, endobronchial ultrasound-guided biopsy or mediastinoscopy may confirm the stage before surgery. This is important because imaging findings alone should not automatically upstage a patient. In Sydney, Melbourne and Brisbane, such decisions are commonly reviewed at thoracic multidisciplinary meetings involving radiology, nuclear medicine, respiratory medicine, pathology and surgery.

  Planning treatment more precisely

  PET-CT findings influence the choice and extent of surgery, stereotactic ablative radiotherapy, chemoradiation, immunotherapy and targeted treatment. A patient with a solitary lung lesion and no nodal or distant uptake may follow a very different pathway from someone with metabolically active mediastinal nodes. The scan can also assist radiotherapy planning by defining biologically active tumour while CT supplies the anatomical framework.

  Interpretation must remain clinically grounded. Blood glucose, recent infection, medication history and the timing of treatment can affect FDG distribution. The patient’s symptoms, pathology, pulmonary function and performance status still matter. When a thoracic operation is being considered, the broader surgical context deserves careful review; principles of selecting and tailoring surgical approaches illustrate why anatomy and operative risk cannot be separated from imaging findings.

  Detecting recurrent or persistent lung cancer

  After treatment, PET-CT can help distinguish recurrent malignancy from structural changes caused by surgery or radiotherapy. Scar tissue, atelectasis and radiation-induced inflammation may appear abnormal on CT and can sometimes show FDG uptake. The timing of imaging is therefore important, since inflammatory activity may be pronounced in the early post-treatment period.

  A new or increasing focus of uptake becomes more concerning when it matches a growing mass, rising clinical suspicion or a consistent pattern on serial scans. PET-CT can locate recurrence in the lung, mediastinum, bone, liver or adrenal glands, helping clinicians determine whether salvage local therapy is realistic or whether systemic treatment is needed. A biopsy is often required when the result will change management.

  Understanding false positives and false negatives

  FDG uptake is not synonymous with cancer. Tuberculosis, fungal infection, sarcoidosis and other inflammatory conditions can produce PET-positive lymph nodes or lung lesions. These considerations are especially relevant in Australia, where regional epidemiology varies and clinicians may assess patients with prior exposure to endemic infections, occupational dusts or recurrent respiratory disease.

  False-negative findings also occur. Small lesions may fall below the resolution of the scan, and low-metabolic tumours can be underestimated. Respiratory motion can blur lower-lung abnormalities, while hyperglycaemia may reduce tracer uptake. PET-CT should therefore be interpreted alongside thin-slice CT, pathology and clinical history rather than treated as an isolated verdict.

  Access, follow-up and patient-centred care in Australia

  Access to PET-CT differs across Australia. Major metropolitan centres usually have established nuclear medicine services, while patients in regional Western Australia, Far North Queensland or remote communities may need to travel considerable distances. Referral criteria and Medicare-funded indications influence availability, and public hospital scheduling can differ from private imaging pathways. Clear communication about preparation, fasting, travel and expected results helps reduce stress and missed appointments.

  Follow-up should be individualised rather than driven by repeated scanning without a clinical purpose. Surveillance imaging is most useful when it answers a defined question, such as whether a treated lesion is changing or whether new symptoms suggest relapse. Care should also account for transport, financial pressure, family responsibilities and culturally safe communication, including the needs of Aboriginal and Torres Strait Islander patients.

  PET-CT is most powerful when integrated into a coordinated diagnostic and treatment pathway. It can refine TNM staging, reveal otherwise hidden disease, guide biopsy and radiotherapy, and support investigation of suspected recurrence. Its limitations are equally important: uptake patterns require expertise, and imaging cannot substitute for histological confirmation when treatment decisions depend on certainty.

  The essential point is simple: PET-CT adds metabolic evidence to anatomical imaging, helping Australian lung cancer teams match the intensity and location of treatment to the actual distribution of disease. Its greatest value comes from informed interpretation within a multidisciplinary clinical picture.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)