The current trend is towards resection of suspected Stage 1(cT1N0M0 on PET) lung cancer when biopsies (CTFNA) are inconclusive, given the limitations of sampling. In case the decision is taken for interval imaging rather than resection (eg by VATS), are there any features of the nodule that would favour such an approach? I would presume lower SUV and slow growth as the most obvious. The situation usually arises in patients with WHO PS2 with comorbidities, who may be suitable for radical treatment at Stage 1 but not at Stage 2 or beyond. The concern of course is that the interval scan may show metastatic or incurable disease and you don't want the patient to "miss the boat". Remember also "Primum non nocere".
You are correct in general terms that low SUVmax and long doubling times are both indicators of reduced aggressiveness of the tumour. Unfortunately, nothing is 100%, but seems to me that this would be a reasonable approach to take.
I would assume any change in size to be the sign of malingancy and propose therapy. The therapy of choice would be surgery and resection (lobectomy or segmentectomy) with exploration of mediastinal lymph nodes. If, for any reason patient can't undergo the surgery radical radiotherapy is the best alternative.
Only in case of low SUV and no sign of growth would I recomend follow up as a choice.
Dear Lawrence, this is an interesting question for which there are some (but not all) answers.
As you indicate there is a balance of risk between "primum non nocere" and early resection resulting in cure of a malignant process.
I would refer you to the attached papers
a. Fleischner Society recommendations for the management of a solid nodule - Radiology (2013)
b. Furman et al (2013) Future Oncol. 2013;9(6):855-865.
c. American Association for Thoracic Surgery guidelines for lung cancer screening
In addition to growth rate and SUV on PET, which you mention, there are other the factors:
1. Those which increase pre- test probability, namely smoking burden, current and remote history of malignancy, family history, exposure to radon gas, asbestos and certain metals (e.g., chromium, cadmium and arsenic), pulmonary fibrosis, HIV infection, asbestosis, haemoptysis and constitutional symptoms.
2. Shape (Spiculation)
3. Contrast enhancement
4. Location - upper lobe increases risk
5. Ground glass opacity
6. Absence of a polygonal shape, Thickness of a cavity wall > 15mm
There are separate guidelines for ground glass opacities
Hope this helps
Best wishes
Thanks to the respondents. I will look at the references again.