A case of primary malignant lymphoma of the brain with high uptake of 123I-IMP

The diagnostic value of 123I-IMP SPECT in ocular adnexal lymphoma

BACKGROUND

N-isopropyl- (¹²³I) p-iodoamphetamine (¹²³I-IMP) is specifically accumulated in primary central nervous system lymphoma (PCNSL) during single-photon emission tomography (SPECT) and contributes to its diagnostic imaging. However, whether ¹²³I-IMP is accumulated in ocular adnexal lymphoma (OAL), one of the malignant intraorbital tumors, remains unclear. This study aimed to evaluate the diagnostic value of ¹²³I-IMP SPECT in OAL.

METHODS

Between August 2005 and June 2020, 26 patients with intraorbital tumors underwent neurosurgery at the tertiary care center. Of these, 15 patients who underwent ¹²³I-IMPSPECT before surgery were retrospectively examined. The region of interest was set in the cerebellum ipsilateral to the intraorbital tumor on ¹²³I-IMP SPECT, and the tumor-to-cerebellum ratio (T/C ratio) was calculated using the following formula: T/C ratio = [accumulation of tumor (count/pixel)]/[accumulation of ipsilateral normal cerebellar hemisphere (count/pixel)].

RESULTS

Six patients were included in the OAL group, who were pathologically diagnosed with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), diffuse large B-cell lymphoma (DLBCL), and plasmacytoma. The T/C ratio in the OAL group was statistically higher than that in the non-OAL group (p < 0.01). The optimal cutoff values for both groups were between 0.76 and < 0.93. The sensitivity and specificity were 1.00, respectively.

CONCLUSIONS

¹²³I-IMP SPECT is useful as one of the examinations in the differential diagnoses of OAL, because it showed a significantly higher accumulation in OAL group than in non-OAL group.

Combined 201Tl and 67Ga brain SPECT in patients with suspected central nervous system lymphoma or germinoma: clinical and economic value

BACKGROUND

Surgical resection is costly and an unfavorable prognostic factor for primary central nervous system (CNS) lymphoma and germinoma patients.

OBJECTIVE

To assess the diagnostic and economic impact of combined 201Tl and 67Ga brain SPECT on the management of patients suspected of having CNS lymphoma or germinoma.

METHODS

Sequential 201Tl and 67Ga brain SPECT was performed in 40 patients with cranial tumors to assess the diagnostic and economic impact of combined 201Tl and 67Ga SPECT on the management of patients suspected of having CNS lymphoma or germinoma. All intracranial masses were pathologically confirmed. The final diagnoses of a total of 47 foci were: 11 non-Hodgkin's lymphomas in 10 patients, 3 germinomas in 2 patients, 10 glioblastomas in 9 patients, 10 cerebral metastases in 8 patients, 13 meningiomas in 11 patients. Decision-tree sensitivity analysis for pretest probability regarding expected cost saving was performed for introduction of the combined study.

RESULTS

All but one focus of CNS lymphomas or germinomas (92.9%, 13/14) exhibited more intense uptake of 67Ga than of 201Tl (p < 0.001). All foci of glioblastomas (10/10) and meningiomas (13/13), and 60% of metastatic foci (6/10) exhibited higher uptake of 201Tl than of 67Ga (p < 0.035). Expected cost saving in the 1% to 50% range of pretest probability of CNS lymphoma or germinoma would be from minus dollars 842US to plus dollars 2,047US per patient for introduction of the combined study, because of substitution of stereotactic biopsy for craniotomy. The pretest probability was the key factor for cost saving of the combined study.

CONCLUSIONS

A 67Ga-positive and 201Tl-positive pattern with more intense uptake of 67Ga than 201Tl probably suggests CNS lymphoma or germinoma. This combination study appears to be cost-effective only in patients highly suspected of having CNS lymphoma or germinoma.

High 123I-IMP retention on SPECT image in primary central nervous system lymphoma

The purpose of this study is to characterize the time course of N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) uptake of primary central nervous system lymphomas (PCNSL) comparing with those of other common brain tumors such as malignant gliomas and meningioma. Ten patients with PCNSL, 14 with malignant gliomas and 7 with meningioma underwent 123I-IMP single photon emission computerized tomography (SPECT). Four (40%), 7 (70%) and 9 cases (90%) of PCNSL showed IMP index more than 1 on early (15 min), delayed (6 h) and extra-delayed (24 h) SPECT images, respectively. In contrast with those IMP index was less than 1 on any image of both malignant gliomas and meningioma. The PCNSL cases with IMP index more than 1 could be distinguished from malignant gliomas and meningioma visually. The mean value of IMP index of PCNSL was increased time-dependently and was higher than those of the other two brain tumor groups on SPECT images of any time phases, and statistically different from those of malignant gliomas, however, not from those of meningioma. Interestingly, the retention rates of 123I-IMP from early to extra-delayed image and delayed to extra-delayed image in PCNSL were significantly higher than those of both malignant gliomas and meningioma. The high 123I-IMP retention on SPECT image is regarded as characteristic in PCNSL and the evaluation of this character is suggested to be more useful for diagnosis of this tumor than that of 123I-IMP up-take on a single SPECT image.

Increased uptake of 99Tcm-ethyl cysteinate dimer in patients with brain tumours

We performed 229 99Tcm-ethyl cysteinate dimer (ECD) single photon emission tomography (SPET) studies in 185 patients with brain tumour. Increased uptake of the tracer was observed in 11 cases. In six of these 11 patients, focal intense activity was seen in the area surrounding the tumour. Five of these six patients had episodes of seizure, and ictal SPET showed further increased uptake in the area of hyperperfusion in one patient. Hyperperfusion surrounding the tumour might be related to seizure. In the remaining five patients, increased accumulation was seen in the tumour. Three of these five patients had a discrepancy between 99Tcm-ECD SPET and 201Tl SPET imaging. There could be some difference in the mechanism of accumulation in the tumour between 99Tcm-ECD and 201Tl.

Malignant lymphoma of the central nervous system with delayed increased accumulation on I-123 IMP SPECT

Ga-67 citrate scintigraphy in the management of malignant lymphomas is well established. It cannot, however, differentiate malignant from benign lesions because this agent also accumulates in benign inflammatory lesions. The authors present a case of increased I-123 IMP uptake on both early and delayed SPECT images in a patient with malignant lymphoma of the central nervous system. Results show that I-123 IMP SPECT can help differentiate malignant lymphoma from benign lesions and other malignant brain tumors.

Adenocarcinoma mimicking primary gastric lymphoma demonstrated by I-123 IMP scintigraphy

A poorly differentiated adenocarcinoma of the stomach showed an unusual type of diffuse wall thickening of the entire stomach, similar to that seen in malignant lymphoma. The pathologic specimen revealed a "lymphoepithelioma"-like pattern of undifferentiated carcinoma with intense lymphocyte and plasma cell infiltration. I-123 IMP scintigraphy incidentally demonstrated increased uptake in the entire stomach on early imaging and moderate washout on delayed studies. SPECT images demonstrated diffusely increased accumulation in the entire gastric wall.

Primary central nervous system involvement of the so called 'peripheral T-cell lymphoma'. Report of a case and review of the literature

Primary central nervous system (CNS) involvement of non-Hodgkin's lymphoma is uncommon and a vast majority of reported cases are of B-cell origin. We present a 52-year-old woman with primary peripheral T-cell lymphoma of the brain. Immunostaining of paraffin-embedded sections proved tumor cells to be positive for T-cell markers MT1 and UCHL1, and negative for B-cell markers MB1, and 4KB5. Radiotherapy combined with steroid therapy rendered neurologic recovery and complete tumor remission confirmed by computed tomography and magnetic resonance imaging. From a review of documented 19 cases of primary CNS T-cell lymphoma including the present case, this disease is characterized by poor prognosis among CNS lymphomas.

Secondary malignant lymphoma of the central nervous system with delayed high uptake on 123I-IMP single-photon emission computerized tomography. Case report

A case of secondary central nervous system (CNS) lymphoma with high uptake in the delayed image of N-isopropyl-[123I]-p-iodoamphetamine (125I-IMP) single-photon emission computerized tomography (SPECT) is presented. Previous to this report, only six cases of brain tumor with high uptake on the delayed 123I-IMP SPECT scan have been reported, two of which were CNS malignant lymphomas. Of 19 brain tumors examined with 123I-IMP SPECT at Kameda General Hospital, this case was the only one that showed high uptake in the delayed image. These data imply that 123I-IMP SPECT, which has now become rather obsolete as a tumor-imaging method, can be useful in diagnosing CNS malignant lymphoma.