CD68 staining correlates with the size of residual mass but not with survival in classical Hodgkin lymphoma.

The prognostic role of CD68 tumor-associated macrophages in classic Hodgkin lymphoma (cHL) remains controversial. We stained diagnostic biopsies and scored for CD68 using the PGM1 antibody among 98 consecutive patients with cHL from our center followed over a median of 45 months for progression-free survival (PFS). Among 79 patients we assessed interim and post-treatment positron emission tomography-computed tomography (PET-CT). Residual mass (RM) size was based on the greatest diameter of the largest mass seen in post-treatment imaging, and percent reduction was calculated by comparing RM size with its greatest pretreatment diameter. We found a significant association between CD68 positivity and absolute size of initial disease mass (p = 0.014) and residual mass at the end of therapy (p = 0.006) but no association was observed with interim PET-CT results or PFS. Our findings suggest that macrophages may influence tumor size by altering the microenvironment. This study does not support a prognostic role of CD68 positivity in predicting survival.

11C-acetate PET/CT in bladder urothelial carcinoma: intraindividual comparison with 11C-choline.

OBJECTIVE: We present a first study of the use of 11C-acetate (ACET) positron emission tomography (PET)/computed tomography (CT) in bladder urothelial carcinoma (UC) and an intraindividual comparison with 11C-choline (CHOL) PET/CT. METHODS: Fourteen patients with biopsy-proven UC (11 T2, 3 T1 refractory to treatment) were prospectively evaluated before radical cystectomy and excision of pelvic lymph nodes (LNs), with ACET and CHOL PET/CT scans performed within 1 week. Image acquisition started 5 minutes after intravenous injection of 12 to 14 mCi for both tracers. Standardized uptake values (SUVs) and tumor-to-background ratios (TBR) were calculated for all tumor and nodal findings and correlated with histopathology and follow-up. RESULTS: ACET and CHOL were taken up in all UCs, involved LNs, and prostate pathology. SUVs were on average slightly, nonsignificantly higher for CHOL uptake (SUV) in UCs and significantly higher for ACET in LNs. TBR was nonsignificantly higher with CHOL for UC and significantly higher for LNs. CONCLUSIONS: In this preliminary series, 11C-ACET and 11C-CHOL PET/CT showed equivalent results in the preoperative evaluation of UC. Both tracers have the potential to contribute to selecting patients who would benefit from combined treatment--neoadjuvant chemotherapy and surgery--by identifying pathologic LNs or from surgery only, thanks to their high negative predictive value for LN involvement.

Large vessel (Takayasu's) arteritis in a patient with myelodysplastic syndrome: is there a common pathogenesis?

Autoimmune phenomena may complicate the course of myelodysplastic syndromes (MDS) but large vessel arteritis is a rare event. We report a case of large vessel arteritis in a patient with MDS. A 62-year-old male presented with thrombocytopenia and was diagnosed with low-risk MDS, (<5% blasts in his bone marrow and a normal karyotype). Shortly thereafter he developed large vessel (Takayasu's) arteritis (TA) that responded well to oral corticosteroid and methotrexate therapy. Ten months later the MDS transformed into acute myeloid leukemia (AML). After a successful induction course with cytarabine and daunorubicin he underwent allogeneic transplantation from a matched unrelated donor with reduced-intensity conditioning. The transplantation was complicated by systemic cytomegalovirus (CMV) disease and he died 6 weeks post transplantation. Takayasu's arteritis is an uncommon form of vasculitis affecting primarily young women and is atypical for elderly males. Though autoimmune manifestations in MDS occur in 10%-18.5% of patients, usually large vessels are spared. In MDS, activated T cells are thought to mediate bone marrow failure via overproduction of proinflammatory cytokines that cause stem cell apoptosis. These T cells may also mediate the autoimmune phenomena in MDS. The prognostic significance of autoimmunity in the course of MDS is not yet determined. Some reports suggest worse prognosis. The case illustrates a possible association between MDS and large vessel vasculitis and suggests a possible relationship between the presence of autoimmune syndromes and the outcome of patients with MDS.

The role of routine imaging procedures in the detection of relapse of patients with Hodgkin lymphoma and aggressive non-Hodgkin lymphoma.

Despite improved initial therapies, a subgroup of patients with aggressive non-Hodgkin (A-NHL) and Hodgkin lymphomas (HL) will relapse after first remission. The optimal follow-up strategy for the detection of relapse has not been clarified and periodic imaging is not recommended in most written guidelines. We identified 125 patients with HL and A-NHL diagnosed between January 1993 and September 2008 who relapsed at least 1 month after the end of initial therapy. We assessed whether relapse was detected based on clinical signs or periodic computed tomography (CT), [(18)F] fluorodeoxyglucose positron emission tomography (PET), or combined PET/CT and whether the mode of detection influenced the pattern and outcome of relapsed disease. Overall, most relapses (62%) were diagnosed clinically especially in A-NHL and in patients with extranodal involvement at diagnosis (p < 0.05); however, relapses of HL occurring after 2001 when PET/CT became available were more commonly detected by routine imaging (p < 0.05). Imaging-detected relapse was not associated with improved survival. While clinical exam remains the most common mode of detecting relapse, our results suggest a potential role for routine PET/CT surveillance in HL patients; however, survival does not appear to be affected by mode of detection.

18F-fluorodeoxyglucose-PET/CT imaging of lungs in patients with cystic fibrosis.

BACKGROUND: Airway inflammation plays a critical role in the progression of cystic fibrosis (CF) lung disease, and in the destruction of airways and lung parenchyma. Current methods to assess CF lung disease (BAL, spirometry, and high-resolution CT scanning), do not always accurately reflect actual disease states. Fluorodeoxyglucose (FDG)-PET scanning has been used previously to image infection and inflammation. In this study, we assessed the use of (18)F-FDG PET/CT scanning to evaluate and monitor lung inflammation and/or infection in patients with CF. METHODS: PET/CT scans were performed in 20 patients with CF (age range, 14 to 54 years); 7 of 20 patients underwent repeat PET/CT scans during and after acute exacerbations. The results were compared with clinical information and with images from eight control subjects with no known lung disease. RESULTS: Foci of enhanced activity were observed on FDG-PET scans of patients with CF but not those of control subjects. Higher focal activity (standardized uptake value, > 3.0) was seen during disease exacerbation and infection. Coregistered CT scan images assisted in the localization of PET foci and showed corresponding CT scan findings, with many additional findings on CT scans that were not seen on PET scans. Foci seen on high-intensity PET scans during exacerbations disappeared after antibiotic therapy and the resolution of exacerbation, while corresponding CT scan findings remained unchanged. CONCLUSIONS: PET/CT imaging demonstrated the presence of foci of enhanced uptake that may reflect active focal infectious or inflammatory processes in the lungs. These foci can be cleared with antibiotic therapy. Further studies are needed to validate these results and to determine whether FDG-PET/CT scanning can predict the nature/severity of disease in patients with CF.

Added value of SPECT/CT for correlation of MIBG scintigraphy and diagnostic CT in neuroblastoma and pheochromocytoma.

OBJECTIVE: In pheochromocytoma and neuroblastoma, pathologic findings on metaiodobenzylguanidine (MIBG) scintigraphy (planar and SPECT) and on diagnostic CT are sometimes difficult to correlate. Furthermore, CT reading may be impaired by anatomic distortion after surgery or irradiation and if contrast agent is not injected. The present study evaluates the impact of SPECT/CT fusion images on correlation and image analysis of both techniques. MATERIALS AND METHODS: Eleven patients, three adults (age range, 27-64 years) with pheochromocytoma and eight children (age range, 16-72 months) with neuroblastoma, underwent 15 (123)I-MIBG scintigraphy (whole body and SPECT/CT) and diagnostic CT during follow-up after treatment, with a time interval of 2 to 30 days (mean, 12 days) between MIBG scintigraphy and diagnostic CT. The diagnostic CT scans were read twice: blindly and with knowledge of the SPECT/CT findings. The scintigraphic and anatomic data were subsequently compared and were verified by clinical outcome. RESULTS: Of 15 imaging studies, there were nine cases of discordance between SPECT/CT and diagnostic CT, whereas concordant findings of planar MIBG and diagnostic CT were observed in six studies. Overall, SPECT/CT provided additional information in eight of the 15 cases (53%) and in eight of nine discordant studies (89%). In one case of pheochromocytoma in which anatomy was distorted by previous surgery and contrast agent was not injected, SPECT/CT findings guided the diagnostic CT that had initially misinterpreted the right adrenal gland as the inferior vena cava. In three of 11 studies performed for neuroblastoma, SPECT/CT facilitated the diagnostic CT reading: in one study, a small paravertebral thickening was overlooked at blind CT reading and in another case, SPECT/CT localized and characterized a soft-tissue mass medial to the iliac bone, which was missed on diagnostic CT in an area of difficult differential anatomy (bowel loops and eventual involved lymph nodes). In the third case, SPECT/CT directed the diagnostic CT to the MIBG abnormality after multiple surgical procedures. In these four cases, MIBG SPECT/CT allowed for localization of the pathologic site that was difficult to visualize on diagnostic CT. In four additional neuroblastoma studies in which a residual mass was present on diagnostic CT, planar MIBG scintigraphy was negative. SPECT/CT, focused on the area of the diagnostic CT abnormality, showed no focal MIBG uptake, thus increasing the diagnostic certainty of remission. CONCLUSION: In cases of equivocal diagnostic CT, SPECT/CT bridges the gap between MIBG scintigraphy and diagnostic CT, with guidance of the diagnostic CT and characterization of its findings. In this small series, MIBG SPECT/CT increased the diagnostic certainty in 89% of discordant studies.

Contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of advanced transitional cell carcinoma.

PURPOSE: Current imaging modalities for preoperative staging of advanced transitional cell carcinoma of the bladder or upper urinary tract are not sensitive for detection of metastases. This study examines the contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of transitional cell carcinoma. MATERIALS AND METHODS: We prospectively evaluated 18 patients with 19 advanced transitional cell carcinomas (17 bladder tumors and 2 upper tract transitional cell carcinomas). All patients had computerized tomography of the chest, abdomen and pelvis negative for metastases. 11C-choline positron emission tomography/computerized tomography was performed on a Discovery ST(R) positron emission tomography/computerized tomography system. Finally 16 patients underwent radical surgery and positron emission tomography/computerized tomography images were compared to histopathological findings. Two patients were not operated on due to the findings on 11C-choline positron emission tomography/computerized tomography. RESULTS: 11C-choline uptake was found in all primary transitional cell carcinomas, with a maximum standardized uptake value of 7.3 +/- 3.2 (mean +/- SD). The series included 3 patients with refractory bladder carcinoma in situ, which was visualized in all 3, with a standardized uptake value of 6.9 +/- 5.6. In 6 patients uptake of 11C-choline in lymph nodes as small as 5 mm was visualized (standardized uptake value 3.8 +/- 1.4). Of these patients 4 underwent surgery and histopathology confirmed malignancy in 3 of 4. No additional patients with positive lymph nodes were found on histopathology. Metastases were visualized in bones with normal architecture on computerized tomography in 4 patients (standardized uptake value 5.2 +/- 1.1) and were confirmed by followup computerized tomography. CONCLUSIONS: In this small series 11C-choline positron emission tomography/computerized tomography was highly sensitive for primary and metastatic transitional cell carcinoma. Carcinoma in situ, lymph node metastases and early bony metastases were visualized. 11C-choline positron emission tomography/computerized tomography is a promising tool for preoperative staging of advanced transitional cell carcinoma.

Crosslinked chitosan implants as potential degradable devices for brachytherapy: in vitro and in vivo analysis.

Compared with conventional external beam radiation, brachytherapy offers a superior therapeutic regimen. However, some major constraints are associated with its implementation, including the need of complicated procedures for device placement and removal. The purpose of this study was to examine whether crosslinked chitosan (Ct) implants could serve as potential biodegradable devices for brachytherapy. Ct was reacted with increasing amounts of glutaraldehyde to obtain hydrogels with different crosslinking densities, which were characterized chemically, thermally and mechanically. The effect of the dialysis medium conditions (ionic strength, osmolarity and pH) on the gel hydration and in vivo degradation was assessed. Two types of implants, slow and fast degrading gel (SDG and FDG, respectively), were prepared and implanted with or without Sudan Black (SB) in the rat. While SDG withstood for over a month, the FDG degraded within two weeks after implantation. The release kinetics of SB from the hydrogels verified their in vivo degradation properties. The incorporation of the radioactive compound (131)I-norcholesterol ((131)I-NC) into the SDG altered the degradation kinetics of the gel as reflected by the release kinetics of the radioactive marker. Eighty percent of (131)I-NC was released within a month after implantation, after which time, radioactivity was detected in the regional lymph nodes. Histological examination of the tissues surrounding the implants demonstrated negligible tissue response to the implants, when compared to biodegradable surgical sutures. It is concluded that hydrogels made of crosslinked Ct are potential novel, safe, degradable devices for brachytherapy.