The application of ultrasound and PET techniques in cancer diagnosis and treatment is an emerging field with potential for resource-limited settings such as South Africa. A comparative study was conducted to assess the effectiveness of ultrasound imaging versus PET scans in diagnosing early-stage cancers. The sample size included 50 patients, with a focus on breast cancer cases. Ultrasound proved superior in identifying small lesions compared to PET, with an accuracy rate of 87% for detecting breast cancer at stage I and II. The study highlights the potential of ultrasound as a cost-effective alternative to PET, particularly in resource-limited settings where both technologies are available. Further research should be conducted to validate these findings across different types of cancers and healthcare facilities. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.