BACKGROUND: Aim ot the study was to assess the role of
planar lymphoscintigraphy and fusion imaging of SPECT/CT
in sentinel lymph node (SLN) detection in patients with various
types of tumours and to estimate some factors influencing
detection success — age and body mass index.
MATERIAL AND METHODS: Planar scintigraphy and hybrid
modality SPECT/CT were performed in 550 consecutive patients
(mean age 58.1 ± 13.1 years): 69 pts with gynaecological
tumours (37 pts with cervical cancer, 25 pts with endometrial
cancer, 7 pts with vulvar carcinoma; mean age 54.4 ± 13.2
years), 161 consecutive patients with melanomas (mean age
57.1 ± 14.8 years), and 320 consecutive women with breast
cancer (mean age 59.4 ± 12.0 years). The radiopharmaceutical
was injected around the tumour (gynaecologic and breast
cancers, melanomas), subareolarly (in some breast cancers), or around the scar (in melanomas after their removal). Planar and
SPECT/CT images were interpreted separately by two nuclear
medicine physicians.
RESULTS: Planar scintigraphy did not show SLN in 77 patients
(14.0%): in 8 pts with gynaecologic tumours, in 23 pts with melanomas
and in 46 pts with breast cancer. SPECT/CT was negative
in 49 patients (8.9%): in 4 pts with gynaecologic tumours, in 12
pts with melanomas and in 33 pts with breast cancer. In 199
(36.2%) patients the number of SLNs captured on SPECT/CT
was higher than on planar imaging. 35 foci of uptake (3.1% from
totally visible 1134 foci on planar images) interpreted on planar
images as hot LNs were found to be false positive non-nodal
sites of uptake when further assessed on SPECT/CT. SPECT/CT
showed the exact anatomical location of all visualized sentinel
nodes. Influence of the age and BMI: The group of patients with
higher number of detected SLN on SPECT/CT than on planar
scintigraphy had lower average age than the group of patients
with the same number of detected SLN on SPECT/CT and on
planar scintigraphy, the difference was statistically significant
(P=0.008). BMI did not differ between the two groups.
CONCLUSION: In some patients with gynaecologic and breast
cancers and melanomas, SPECT/CT improves detection of
sentinel lymph nodes. It can image nodes not visible on planar
scintigrams, exclude false positive uptake and exactly localize
axillary, inguinal, pelvic and paraaortic SLNs. It improves
anatomical localization of SLNs. We have found the influence
of the age on the difference in the number of SLNs detected by
the fusion of SPECT/CT and planar lymphoscintigraphy. On the
other hand, this difference was not influenced by BMI.