Long-term follow-up of residual mediastinal-hilar Ga-67 uptake after treatment for Hodgkin's and non-Hodgkin's lymphomas: what degree of Ga-67 uptake is significant?
OBJECTIVE
Ga-67 planar and SPECT images of 85 patients after treatment for mediastinal-hilar (M-H) lymphoma were reviewed retrospectively. Forty-seven patients had Hodgkin's disease and 38 patients had non-Hodgkin's lymphoma. The entire period was 7 years after diagnosis. The main goal was visual assessment of the significance of mild (grades 1 or 2) Ga-67 uptake in the M-H area as compared with Ga-67 uptake in bone marrow.


METHODS
Residual Ga-67 mediastinal uptake after a complete course of chemotherapy or other treatments was defined as normal (no residual) M-H uptake, borderline (M-H residual uptake with intensity less than that or equal to the sternum, spine, or both), and abnormal (M-H residual uptake with intensity greater than that of the sternum or spine).


RESULTS
Among the 38 patients (45%) with no residual M-H uptake, four (one Hodgkin's disease and three non-Hodgkin's lymphoma) experienced recurrence: two in the mediastinum and two in the abdomen. Among the 45 patients (53%) with borderline M-H uptake, five experienced recurrence: two in the mediastinum and three in other sites. The two patients (2%) with abnormal (M-H) uptake never responded to treatment. No significant statistical difference in tumor recurrence was found between no residual and borderline uptake (P = 0.21).


CONCLUSIONS
Visual assessment of M-H Ga-67 uptake (without quantification) could be useful to differentiate active residual tumor from nonactive residual uptake.
Nikpoor
N
N
Brigham and Women's Hospital, Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Aliabadi
P
P
Diaz
L
L
Mannting
F
F
D005260:Female; D005500:Follow-Up Studies; D005710:Gallium Radioisotopes; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000628:therapy; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
D005710:Gallium Radioisotopes