Mediastinal lymphoma: quantitative changes in gadolinium enhancement at MR imaging after treatment.
OBJECTIVE
To compare changes in gadolinium enhancement at magnetic resonance (MR) imaging with outcome in mediastinal lymphoma after treatment.


METHODS
Thirty-one patients with bulky mediastinal lymphoma (17 with Hodgkin disease, 14 with non-Hodgkin lymphoma) underwent serial MR imaging before and up to 50 months after treatment, with routine follow-up (including computed tomography). Signal intensity ratios between masses and muscle were calculated on T1-weighted, T2-weighted, and contrast material-enhanced T1-weighted spin-echo MR images. The percentage enhancement and signal intensity ratios of mediastinal masses on T2-weighted MR images were calculated at diagnosis and during and after treatment.


RESULTS
Twenty-one patients with persistent complete remission had a mean percentage enhancement of residual masses (4%; range, -26% to 40%) that was significantly lower than that of initial masses (78%; range, 41%-124%). Although the mean signal intensity ratio of residual masses on T2-weighted images was significantly lower than that of initial masses, an increase in this ratio was observed in four patients after treatment. In seven patients with relapse, the percentage enhancement value of the residual mass was as high as that of the initial mass.


CONCLUSIONS
Gadolinium enhancement of lymphomatous masses of the mediastinum decreased markedly after treatment in patients in continuous complete remission but not in patients with relapse.
Rahmouni
A
A
Department of Radiology, Centre Hospitalo-Universitaire Henri Mondor, 51 Avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France. alain.rahmouni@hmn.ap-hop-paris.fr
Divine
M
M
Lepage
E
E
Jazaerli
N
N
Belhadj
K
K
Gaulard
P
P
Golli
M
M
Reyes
F
F
Vasile
N
N
D000328:Adult; D003131:Combined Modality Therapy; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006689:Hodgkin Disease / Q000473:pathology* / Q000628:therapy; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008479:Mediastinal Neoplasms / Q000473:pathology* / Q000628:therapy; D008536:Meglumine; D018365:Neoplasm, Residual; D009942:Organometallic Compounds; D011446:Prospective Studies; D013997:Time Factors
D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; D005682:Gadolinium; C072417:gadoterate meglumine