What is a typical doubling time for lung cancer?

Lung adenocarcinomas often have doubling times of 400–600 days, while squamous cell carcinomas tend to be faster at 60–200 days. Very slow-growing lesions (DT > 600 days) are more likely benign, although this is not definitive.

Does the calculator assume the tumor is a perfect sphere?

Yes — when you enter diameter, the tool converts it to volume using V = (4/3)π(d/2)³. For non-spherical lesions, entering directly measured volumetric data (if available from your imaging software) gives a more accurate result.

What does a negative doubling time mean?

A negative result means the second measurement is smaller than the first — the lesion shrank. This may indicate treatment response or measurement variability. The tool flags this case and reports it as regression.

What is specific growth rate (SGR)?

SGR = ln(V2/V1) / t, expressed as a percentage per day. It is a linear measure that handles rapidly doubling tumors more accurately than DT alone and is preferred in research settings.

How accurate are these calculations?

Mathematical accuracy is exact, but real-world precision is limited by measurement variability between scans (inter-observer error, slice selection, contrast timing). Small lesions are especially susceptible — a 1 mm error on a 5 mm nodule changes volume by ~75%.

Tumor Doubling Time Calculator

Name: Tumor Doubling Time Calculator
Availability: InStock
Author: Nham Vu

Enter two tumor measurements and the interval between scans to calculate doubling time and specific growth rate.

Measurements

Measurement type

Diameter (mm) Volume (cm³)

First measurement (mm)

Measurement from the earlier / baseline scan

Second measurement (mm)

Measurement from the follow-up scan

Days between scans

Results

Enter measurements and click Calculate

Summary

Enter two tumor measurements and the interval between scans to calculate doubling time and specific growth rate.

How it works

Enter the first measurement (diameter in mm, or volume in cm³) from the earlier scan.
Enter the second measurement from the later scan.
Enter the number of days between the two scans.
Choose whether you entered diameter or volume.
The calculator applies the exponential growth formula: DT = (t × ln 2) / ln(V2/V1).
Results show doubling time in days and specific growth rate (SGR) in % per day.

Use cases

Assess aggressiveness of a pulmonary nodule on serial CT scans.
Evaluate whether a liver lesion grew significantly between two MRI studies.
Estimate how long a lesion may have been growing based on current size.
Compare pre- and post-treatment lesion sizes to gauge response.
Distinguish fast-growing from slow-growing lesions in a surveillance program.

Frequently Asked Questions

Last updated: 2026-07-26 · Reviewed by Nham Vu