PET/CT IS MORE HELPFUL THAN CONVENTIONAL TECHNIQUES IN REVEALING METASTASES OF BREAST CANCER

Louai Al-Qatawna*, Ahmed Albtoush, Dogan Atiyat, Ala'a Al-Zub'i, Bashar Shamayleh, Amany Al-Ja'afreh, Khaled Al-Khawaldeh

ABSTRACT

Background: Breast cancer with extensive tumours have a risk of 8.3-15.1% for metastasis. Positron emission tomography/computed tomography (PET/CT) can precisely reveal metastases during staging of breast cancer. Aim: To compare the sensitivity and specificity of PET/CT versus conventional techniques for revealing metastases in breast cancer. Methods: Our prospective and double-blind investigation included 167 subjects with breast cancer, aged 49.6 years (31-75) at King Hussein hospital, KHMC, Amman, Jordan, during the period 2010-2020. For stage II or III breast cancer, CXR, scintigraphy and CT of the abdomen were used. For stage IV breast cancer, CXR, scintigraphy, CT of the abdomen and PET/CT were used. PET/CT when conventional techniques were unclear and for staging of inflammatory breast cancer. PET/CT was compared with conventional techniques. Sensitivity and specificity in revealing metastases were recorded for PET/CT and conventional techniques. Metastases were recorded according to consecutive MRI, ultrasound or plain radiography. If there were no metastases, follow-up was done for 24 months. Fisher’s exact test was used to assess differences in sensitivity and specificity between PET/CT and conventional techniques. Results: 58 subjects had metastases according to pathological (20), radiological (22) or clinical (16) criteria. Of the 109 subjects with no metastases, 15 subjects relapsed and 94 subjects were disease-free. The locations of relapse in these 15 subjects were the local lymph nodes (3), distant lymph nodes (2), bone (2), brain (3), lung (3) and liver (2). Regarding the conventional techniques, 86 subjects (51.5%) had doubtful metastases and 50 (58.1%) of 86 subjects were positive for metastases. Metastases by location were in the bone (48), thoracic lymph nodes (18), lung (7) and liver (13). The sensitivity and specificity of PET/CT in revealing metastases were 91.9% and 85.7%, respectively, and those of conventional techniques were 80.4% and 61.8%, respectively. The sensitivity and specificity of PET/CT were remarkably higher than conventional techniques (P < 0.005, for both). Eight subjects with metastases revealed by PET/CT were clinically occult and metastases had not been revealed by conventional techniques. Conclusion: PT/CT has better sensitivity and specificity than conventional techniques in revealing metastases of breast cancer.

Keywords: PET/CT; conventional techniques; breast cancer; metastases; sensitivity; specificity.