PET Scan Surveillance in Small Cell Lung Cancer on Observation
PET/CT scans should NOT be used for routine surveillance in patients with small cell lung cancer after curative-intent treatment. 1
Recommended Surveillance Strategy
The NCCN explicitly states that "PET/CT is not recommended for routine follow-up" in SCLC patients after completing initial therapy. 1 This recommendation is echoed by ASCO guidelines, which specify that fluorodeoxyglucose positron emission tomography/computed tomography imaging should not be used as a surveillance tool in lung cancer patients after definitive curative-intent therapy. 1
Surveillance Schedule for SCLC
For Limited-Stage SCLC:
- Oncology follow-up visits every 3 months during years 1-2 1
- Every 6 months during year 3 1
- Annually thereafter 1
- At each visit: history, physical examination, and CT chest/abdomen 1
For Extensive-Stage SCLC:
- Oncology follow-up visits every 2 months during year 1 1
- Every 3-4 months during years 2-3 1
- Every 6 months during years 4-5 1
- Annually thereafter 1
Optimal Imaging Modality
CT imaging is the recommended surveillance modality, not PET/CT. 1 The ASCO guideline specifically recommends chest computed tomography imaging as the optimal imaging modality for surveillance every 6 months for 2 years and then annually for detection of new primary lung cancers. 1
Rationale Against Routine PET Surveillance
The evidence against routine PET surveillance is compelling:
High false-positive rate: Studies consistently demonstrate numerous false-positive and equivocal findings with PET imaging in post-treatment surveillance. 1 The ESMO guidelines note "a high number of false-positive findings on PET" requiring biopsy confirmation whenever possible. 1
No survival benefit demonstrated: Research comparing PET/CT to conventional imaging at 6-month intervals showed no significant differences in sensitivity (0.73 vs 0.82), specificity (0.91 vs 0.89), or accuracy (0.89 vs 0.88) for detecting recurrence. 1
Cost-effectiveness concerns: Given the expense of PET imaging and the need for follow-up of incidental findings without proven survival benefit, routine use is not justified. 1
When PET May Be Appropriate
PET imaging should be reserved for specific clinical scenarios:
- When recurrence is suspected based on symptoms or CT findings 1
- For investigation of specific areas of concern rather than routine surveillance 1
- When biopsy confirmation should follow positive findings in patients suitable for salvage therapy 1
Special Consideration: Brain Surveillance
Brain MRI may be used for surveillance in SCLC patients who have undergone curative-intent treatment:
This differs from NSCLC, where routine brain MRI surveillance is not recommended. 1
Common Pitfalls to Avoid
Do not order routine PET/CT scans at predetermined intervals for asymptomatic SCLC patients in surveillance—this increases false-positive findings and healthcare costs without improving outcomes. 1
Do not rely on PET alone if obtained for suspected recurrence—biopsy confirmation is essential due to high false-positive rates, particularly in patients who are candidates for salvage therapy. 1
Do not confuse NSCLC and SCLC surveillance protocols—while some principles overlap, SCLC requires more frequent early surveillance given its aggressive biology and higher recurrence risk. 1