Patterns of FDG uptake in post-thoracotomy surgical scars in patients with lung cancer.

Increased (18)F-fluorodeoxyglucose ((18)F-FDG) uptake can occur in surgical scars. This study assesses the incidence, patterns and natural history of (18)F-FDG uptake in post-thoracotomy scars of non-small cell lung cancer (NSCLC) patients. 73 (18)F-FDG-PET/CT studies performed after resection of NSCLC in 61 patients (49 men, 12 women; mean age, 66.7 years) were retrospectively reviewed for the presence, pattern and intensity (maximum standardized uptake value (SUV(max))) of (18)F-FDG uptake in sites of previous thoracotomy. Increased (18)F-FDG uptake in surgical scars was found in 61% of studies (43/70) (average SUV(max), 3.6); 3 patients with recurrence at the surgical scar were excluded from the analysis of the characteristics of physiological FDG uptake in scars over time. The average time from surgery was 14.4 months in patients with, and 43.8 months in patients without, scar uptake (p<0.0002). Increased uptake was seen in 14/14 studies (100%) at 1-3 months, in 12/13 studies (92%) at 3-12 months, and in 17/43 studies (40%) at more than 12 months after surgery in patients with no evidence of disease on follow-up. (18)F-FDG uptake was diffuse in 67% of studies (29/43). Tumour recurrence in the scar was found in three studies, showing focally increased uptake (average SUV(max), 9.1 ) at 3-8 months after thoracotomy. In conclusion, increased (18)F-FDG uptake in post-thoracotomy surgical scars is mainly diffuse, and decreases in incidence and intensity with time, with 60% of studies showing no scar uptake at more than 12 months after surgery. Focally intense scar uptake should be evaluated for suspected recurrence.

Multimodality imaging of direct ureteric involvement in non-Hodgkin's lymphoma using PET/CT, CT urography and antegrade CT pyelography.

Positron emission tomography/computed tomography (PET/CT), CT urography (CTU) and antegrade CT pyelography (ACTP) findings of ureteric involvement in non-Hodgkin's lymphoma (NHL) are presented. PET/CT performed for restaging in a patient with a 2-year history of Stage 4 NHL showed increased 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) activity in a distended ureteric segment. CTU and ACTP, performed to further evaluate PET/CT findings, demonstrated diffuse, irregular and concentric thickening of the affected ureteric walls, accompanied by severe irregular narrowing of affected ureteric lumen. Tissue sampling using percutaneous CT-guided biopsy revealed NHL involvement of the ureter. To the best of our knowledge, this is the first report of PET/CT, CTU and ACTP findings of ureteric NHL.

Positron emission tomography/computed tomography with 18fluoro-deoxyglucose in the detection of local recurrence and distant metastases of pediatric sarcoma.

BACKGROUND: Combined positron emission tomography with (18)fluoro-deoxyglucose and computed tomography (FDG-PET/CT) has been used in the diagnosis and staging of various malignancies, but their use in the management of pediatric sarcomas is less well defined. The potential role of FDG-PET/CT in the diagnosis of local recurrence and distant metastases of pediatric sarcomas was investigated. PROCEDURE: Nineteen children (aged 2-21) with sarcoma (9 Ewing sarcoma, 3 osteogenic sarcoma, 7 rhabdomyosarcoma) were evaluated between January 2000 and December 2005 by FDG-PET/CT for suspected local relapse or distant metastases. The results of 21 FDG-PET studies, 16 CT scans, 9 magnetic resonance imaging (MRI) studies, and 7 bone scans (BSs) were compared with surgical pathology or clinical follow-up for at least 3 months. RESULTS: FDG-PET detected local relapse in all seven patients and distant metastases in 10/13 (77%). FDG-PET/CT and CT/MRI/BS results were discordant in eight patients. FDG-PET/CT was the only modality that detected distant metastases in two patients. PET/CT was true negative and excluded disease in three patients with abnormal CT/BSs and was false negative in three patients with distant metastases. CONCLUSION: FDG-PET/CT may be useful and complementary to other imaging modalities for the detection of recurrent pediatric sarcomas, especially at the primary site. Its potential advantages and limitations compared with conventional imaging modalities need to be further investigated in larger homogenous patient groups.

The neural correlates of understanding the other's distress: a positron emission tomography investigation of accurate empathy.

The purpose of the present study was to assess the relationship between brain metabolism and empathic response. Six right-handed healthy volunteers were scanned with PET and fluorodeoxyglucose twice: during an interview about neutral story themes and during an empathic response eliciting interview about a story of a character in distress. Metabolic values in the medial and superior frontal gyrus, occipitotemporal cortices, thalamus and the cerebellum were higher during empathic response than during the neutral theme interview. Furthermore, the subjects' empathy scores were positively correlated with metabolism in the medial aspects of the superior frontal gyrus. Our results suggest that empathy consists of both affective and cognitive components and hence may involve cortices that mediate simulation of emotional processing and mental state attribution.

Disappearance of diffuse calcinosis following autologous stem cell transplantation in a child with autoimmune disease.

A 12-year-old girl presented with arthritis, myalgia, anemia and positive ANA. Subsequently, she developed recurrent episodes of pulmonary hemorrhage, thrombocytopenia, CNS abnormalities, skin ulcers and diffuse calcinosis. This was followed by secondary antiphospholipid syndrome. Despite vigorous immunosuppression, the patient became bedridden. A peripheral blood stem cell autograft was offered when she developed pulmonary hypertension and digital ischemia at the age of 16 years. The post-transplantation course was uneventful. Liquefaction of calcinosis nodules with improvement of mobility occurred gradually. She is now 24 months post-transplant with no sign of disease activity and total disappearance of calcinosis nodules.

The value of Ga-67 scintigraphy and F-18 fluorodeoxyglucose positron emission tomography in staging and monitoring the response of lymphoma to treatment.

Gallium-67 scintigraphy (GS) has the ability to provide important diagnostic and prognostic information for the evaluation of patients with lymphoma. GS is superior to morphologic imaging techniques because of its affinity to viable lymphoma cells. The value of GS lies not in the initial diagnosis but primarily in assessing the results of treatment and in the follow-up of patients with lymphoma. Nevertheless, GS has not gained the expected wide acceptance, possibly because of the meticulous technique required and the expertise needed for optimal interpretation. The introduction of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) as a tumor-seeking agent, which provides images of superior quality, may have an impact on the current role of GS in the management of patients with lymphoma. FDG-PET seems to share with GS the advantages of a tumor viability agent. It appears to be more sensitive for detecting nodal and extranodal sites of disease than GS and may have predictive value during and after therapy for lymphoma. These potential clinical and economic advantages of FDG-PET need to be confirmed in systematic, large-scale prospective studies.

PET imaging in oncology.

The role of positron emission tomography (PET) during the past decade has evolved rapidly from a pure research tool to a methodology of enormous clinical potential. Perhaps the most striking development is the use of PET in oncology. PET imaging is approved in the United States for lung, lymphoma, colon, and melanoma cancer imaging. Data are accumulating rapidly to attest the efficacy of Fluorine-18 fluorodeoxyglucose (FDG) imaging in a wide variety of malignant tumors with sensitivities and specificities often in the high 90s. FDG uptake has been shown in tumors of the head and neck, ovary, breast, musculoskeletal system, and neuroendocrine system as well. The major role of PET has emerged as a reliable method for evaluating and staging recurrent disease. But it also has an important role in differentiating benign and malignant primary tumors. This has been shown particularly well in the differential diagnosis of solitary lung nodules. Although FDG has emerged as the dominant radiopharmaceutical for PET imaging in oncology, numerous other compounds are being evaluated. It is likely that more specific and efficacious compounds will be introduced during the next decade. F-18, because of its highly favorable physical characteristics, is likely to become the technetium of PET imaging. The next decade will witness an explosive growth of PET technology in oncologic imaging.

Aggressive non-Hodgkin lymphoma: early prediction of outcome with 67Ga scintigraphy.

PURPOSE: To evaluate use of gallium 67 scintigraphy early during chemotherapy to predict the outcome in patients with aggressive non-Hodgkin lymphoma. MATERIALS AND METHODS: Among 118 patients, 67Ga scintigraphy was performed after one cycle of chemotherapy in 51 patients, after a median of 3.5 cycles in 97 patients, and both in 30 patients. Computed tomography (CT) was performed after a median of 3.5 cycles of treatment in 87 patients. The failure-free survival was compared between patients with positive or negative 67Ga or CT scans by using the log-rank test. Multivariate analysis helped determine the relation between 67Ga scintigraphic and CT findings and the outcome. RESULTS: The differences in failure-free survival between patients with positive versus negative 67Ga scans after one cycle of treatment (P < .001) and at midtreatment (P < .001) were significant. There was no statistically significant difference in failure-free survival between patients with positive versus negative CT findings during treatment. In multivariate analysis, 67Ga scintigraphy after one cycle (P < .045) and at midtreatment (P < .006) was an independent factor associated with outcome. CONCLUSION: Gallium 67 scintigraphic findings after one cycle of chemotherapy and at midtreatment are predictive of outcome in patients with aggressive non-Hodgkin lymphoma. CT findings are not predictive. Early 67Ga scintigraphy during chemotherapy is a good indicator of patients who may benefit from a change to a more aggressive treatment. A future study is necessary to investigate the potential effect of early change of treatment.

Hodgkin disease: prediction of outcome with 67Ga scintigraphy after one cycle of chemotherapy.

PURPOSE: To investigate gallium 67 scintigraphy performed early during treatment as a means to predict outcome and thus to optimize treatment of Hodgkin disease (HD) in the future. MATERIALS AND METHODS: Ninety-eight patients with HD were examined. Thirty-one patients underwent 67Ga scintigraphy after one chemotherapy cycle and 83 patients after a mean 3.5 cycles (range, 2-5 cycles). Sixteen patients underwent 67Ga scintigraphy both after one cycle and at midtreatment. Patients underwent whole-body scintigraphy and single photon emission computed tomography of the torso. Torso computed tomography (CT) was performed after a mean 3.5 cycles (range, 2-6 cycles). Failure-free survival was compared between patients with positive and patients with negative test findings (Kaplan-Meier method), and the significance of the difference was calculated. The association of failure-free survival with various prognostic clinical factors before treatment was compared (log-rank test univariate analysis). RESULTS: Failure-free survival differed significantly (P < .002) between patients with positive and patients with negative 67Ga scintigrams after one chemotherapy cycle but not at midtreatment. Failure-free survival was not significantly different between patients with positive and patients with negative CT scans at midtreatment. Twenty-two (92%) of 24 patients with negative 67Ga scintigrams after one cycle and 64 (82%) of 78 patients with negative scintigrams at midtreatment remained in complete response. In four (57%) of seven patients with positive 67Ga scintigrams after one cycle, treatment failed. CONCLUSION: 67Ga scintigraphy after one cycle of chemotherapy is a good early predictor of outcome of HD.

Benign proliferative lesions mimicking recurrence of Hodgkin's disease.

Salvage treatment in patients with recurrent Hodgkin's disease is more effective when tumor burden is minimal. That is why more intensive follow-up strategies, including frequent imaging tests, have been recently developed for the detection of early relapse. However, as screening procedures become more sensitive, there is an increasing risk of false-positive results, demonstrating nonmalignant proliferative disorders. We describe three young patients who had lymphocyte-predominant or mixed-cellularity Hodgkin's disease and were in clinical complete remission for 2.5-3 years after a combined treatment with chemotherapy and radiation. Imaging tests revealed new gallium-avid lymphadenopathy in the chest in two cases. Pathologically enlarged pelvic lymph nodes were identified in another case, after a diagnosis of recurrent disease in axilla. Those findings were interpreted as relapse, and the patients underwent thoracotomy and laparotomy, respectively, for histologic confirmation. The results showed progressively transformed germinal centers and sarcoid-like lesions, two benign proliferative disorders. When patients with Hodgkin's disease in remission show new lymphadenopathy, even with positive gallium scan, it seems mandatory to obtain tissue for histologic examination, even through invasive procedures such as laparotomy and thoracotomy, to avoid wrong diagnosis and unnecessary treatment.

The continuing clinical role of gallium 67 scintigraphy in the age of receptor imaging.

Gallium 67 scintigraphy is useful clinically for assessment of tumor viability after treatment of Hodgkin's and nonHodgkin's lymphoma. Because more than 50% of the patients with complete response have a residual mass after treatment, computed tomography is not a good test to determine if a patient has reached a complete response. 67Ga scintigraphy, on the other hand, has a sensitivity of 76% to 100% and specificity of 75% to 96% to determine if a residual mass is a residual cancer or made up only of fibrosis and necrosis. Early diagnosis of recurrence is important in order to start therapy when the tumor can, potentially, still be controlled. The sensitivity of 67Ga for diagnosis of recurrence is 95% and the specificity 89%. Scintigraphy has been shown to diagnose recurrence sometimes months before other tests. 67Ga scintigraphy also has the potential to separate rapid from slow responders during therapy. Even when it has been known for many years, 67Ga has proved recently to be a useful test in assessing lymphoma patients after treatment.

Utility of gallium-67 scintigraphy in low-grade non-Hodgkin's lymphoma.

PURPOSE: Low-grade non-Hodgkin's lymphoma (LGNHL) has traditionally been considered non-gallium-avid. The sensitivity of gallium 67 (67Ga) scintigraphy when using modern equipment and techniques in patients with LGNHL was investigated. MATERIALS AND METHODS: Fifty-seven consecutive patients with LGNHL underwent 67Ga scintigraphy at initial presentation (n = 40), when tumor progression occurred during treatment (n = 3), and at suspected disease recurrence after continuous clinical remission (CCR) (n = 14). Planar and tomographic images were obtained with either a very large field-of-view or a dual-head digital camera. Of 45 patients with Ga-avid LGNHL, 30 underwent 93 follow-up scans (one to six studies per patient). Scan findings were correlated with clinical and computed tomographic (CT) findings and with patient outcomes. RESULTS: 67Ga scintigraphy was positive in 45 of 57 patients (sensitivity, 79%) and in 113 of 164 disease sites (sensitivity, 69%). The sensitivity was higher in the more common types of LGNHL: follicular, predominantly small cleaved cell (FSC), and follicular, mixed small cleaved and large cell (FM) (84% and 91% in patients and 72% and 71% in disease sites, respectively). Sensitivity was lower in patients with mucosa-associated lymphoid tissue lymphoma (MALT) and small lymphocytic lymphoma (SL). Among 28 patients with disease recurrence after CCR (14 with and 14 without baseline studies), 67Ga scan was positive in 25, for a sensitivity of 89% for detection of disease recurrence. CONCLUSION: When modern technology is used, 67Ga scintigraphy has good sensitivity in patients with LGNHL. It therefore can be used to monitor response to therapy and to provide early detection of disease recurrence in these patients.

Diffuse lung uptake of Ga-67 after treatment of lymphoma: is it of clinical importance?

PURPOSE: To determine if diffuse lung uptake (DLU) of gallium-67 at scintigraphy in patients with lymphoma is indicative of lymphomatous involvement of the lungs. MATERIALS AND METHODS: Thirty-eight patients (24 male, 14 female; aged 15-76 years) with DLU were examined. The relation between DLU and lymphoma was investigated. Radiographic and computed tomographic findings and the persistence of Ga-67 uptake were investigated to detect lymphomatous involvement of the lungs. The relations between chemotherapy and radiation therapy, previous lung or heart disease, and DLU were also examined. RESULTS: DLU appeared only during or after chemotherapy. No clinical, radiologic, or follow-up evidence indicated that patients with DLU had active lymphomatous involvement of the lungs. The difference in survival between patients with persistent and patients with transient DLU was not statistically significant. No statistically significant correlation between DLU and any possible inductive factor was indicated at multivariate analysis. CONCLUSION: DLU after treatment does not indicate lymphomatous involvement of the lungs.

Ga-67 scintigraphy with a dual-head camera.

High quality images are necessary for correct interpretation of Ga-67 studies in lymphoma. The authors were interested if there is a significant change in the quality of the Ga-67 images using a newly introduced dual-head camera compared with a conventional single-head camera. The tomographic spatial resolution, full width at half maximum, was found to be 9.63 mm compared with 13.7 for a single-head camera. The volume sensitivity was 380 cps/microCi/ml per axial cm as compared with 333 cps/microCi/ml, and point source sensitivity was 5.6 cps/microCi compared with 3.8. There was a significant difference (P < 0.001), when using the threshold technique, in the number of counts per pixel over a wide range of volumes and concentrations in phantoms when the two cameras were compared. There was also a significant difference (P < 0.001) in Ga-67 uptake in lymphoma lesions in patients when the same parameters were used for both cameras when using SPECT. The average uptake in lymphoma lesions, using a dual-head camera, was 529 counts/pixel with a range of 112 to 1275 counts/pixel in different tumors. With a single-head camera, the average for the same tumor was 216 counts/pixel with a range of 59 to 469 counts/pixel. The high sensitivity of the dual-head camera enabled high-quality, whole body scintigraphy, including the limbs, in 20 minutes compared with the 35 minutes necessary for the single-head camera for images which did not include the legs. Whole body Ga-67 scintigraphy is shown to be important in patients with lymphoma of the upper and lower limbs.(ABSTRACT TRUNCATED AT 250 WORDS)

Single-photon emission computed tomography quantitation of gallium citrate uptake for the differentiation of lymphoma from benign hilar uptake.

PURPOSE: To assess the role of quantitative gallium citrate (Ga 67) single-photon emission computed tomography (SPECT) in differentiating lymphoma from benign hilar uptake, concentrations of Ga 67 in 29 sites of documented lymphoma and in 75 benign lesions were compared. PATIENTS AND METHODS: One hundred seven thoracic Ga 67 SPECT studies obtained in 101 consecutive lymphoma patients were reviewed. Fifty-nine studies detected Ga 67 uptake in the hilar and or mediastinal regions. Forty-eight studies showed no such abnormality. The concentration of Ga 67 in the thoracic lesions was measured using a quantitative SPECT technique and its nature was determined by correlation with computed tomographic (CT) scans and follow-up evaluation of the sites. RESULTS: In 20 of 59 abnormal studies (34%), there was lymphoma in the hilar and or mediastinal regions. In the remaining 39 abnormal studies (66%), Ga 67 uptake was benign. There were 29 sites of lymphoma and 75 benign lesions. The concentration of Ga 67 in lymphoma was significantly higher than in benign hilar uptake (13.2 +/- 5.4 %ID/mL x 10(-3) v 5.6 +/- 1.5 % injected dose (ID)/mL x 10(-3); P < .001). A concentration value of 8.3 %ID/mL x 10(-3) was found to best separate lymphoma and benign uptake, with a sensitivity of 90%, a specificity of 93%, a positive predictive value of 84%, and a negative predictive value of 96%. CONCLUSION: Lymphoma and benign hilar uptake differ significantly in their concentration of Ga 67. The present study shows that quantitative Ga-67 SPECT reliably differentiates lymphoma and benign uptake.

Cardiac tamponade as the initial manifestation of primary pericardial mesothelioma.

Although cardiac tamponade is a known complication of malignancy, it is rarely the initial manifestation. We report a 46-year-old male who presented with malignant cardiac tamponade 6 months prior to the definitive diagnosis of primary pericardial mesothelioma. A thorough literature search has not revealed a similar care.

Gallium-67 scintigraphy in lymphoma with bone involvement.

UNLABELLED: Both Hodgkin's and non-Hodgkin's lymphoma (NHL) may involve bone. Traditionally, 99mTc-MDP bone scintigraphy has been used to detect such involvement. In recent years, 67Ga scintigraphy has shown to be useful in monitoring treatment response in lymphoma. Although 99mTc-MDP has not been found particularly useful for monitoring bone response to cancer treatment, we were interested in whether 67Ga scintigraphy and SPECT could be used to monitor bone involvement with lymphoma. METHODS: Gallium-67 and 99mTc-MDP uptake were investigated in 20 patients with lymphoma involving the bone before treatment. Gallium-67 scans were done in 16 patients for monitoring response to treatment in the bone lesions. RESULTS: Gallium-67 studies diagnosed bone lesions in 19 of the 20 patients. Technetium-99m-MDP detected bone lesions in all patients investigated. In four patients, uptake by Ga-67 was more intense than 99mTc-MDP and in another four patients 99mTc-MDP uptake was more evident. Gallium-67, however, was useful in detecting other regions of involvement in 18 of the 19 patients with soft-tissue lymphoma lesions. Gallium-67 scintigraphy also correctly monitored bone response to treatment in all but one of the 16 patients who had 67Ga scintigraphy after completing therapy. CONCLUSION: Gallium-67 uptake by lymphoma involving the bone can be used to monitor osseous response to treatment.