Role of fluorine-18 fluoro-deoxyglucose positron emission tomography scan in the evaluation and follow-up of patients with low-grade lymphomas

BACKGROUND: Fluorine-18 fluoro-deoxyglucose positron emission tomography (FDG-PET) scanning has excellent sensitivity and specificity for staging non-Hodgkin lymphomas, but to the authors' knowledge few studies to date have evaluated FDG-PET in low-grade lymphomas only. METHODS: A retrospective study was performed on patients with biopsy-proven nontransformed and transformed follicular lymphoma (FL), B-cell small-cell lymphocytic lymphoma (SLL/CLL), or marginal zone lymphoma (MZL) who underwent PET and computed tomography (CT) scans within 3 weeks. Standard uptake values (SUV) of all abnormal foci were measured. RESULTS: In FL, PET demonstrated 94% sensitivity and 100% specificity for staging. PET was more specific than CT for detecting recurrence or assessing therapeutic responses (91% vs. 50%). FDG avidity among patients with WHO Grades 1, 2, and 3 disease was not significantly different (analysis of variance [ANOVA]). For MZL staging, PET had moderate sensitivity (71%) and outperformed CT alone in the depiction of extranodal sites (85% vs. 57% sensitivity). In SLL/CLL, PET sensitivity was 53% and underestimated disease extent in 5 of 19 patients (26%) compared with CT. PET did not affect initial management but confirmed suspected recurrences in 75% of patients. Nontransformed FL had a higher SUV (ANOVA, P < .05) compared with MZL and SLL/CLL. SUV was higher in transformed than in nontransformed tumors (P < .001, Student t test). CONCLUSIONS: PET usefulness in staging low-grade lymphomas varies depending on histology. PET sensitivity is excellent in FL and moderate in MZL. PET is more specific than CT for follow-up in all types. PET has limited usefulness for SLL/CLL staging. However, a suggestive pattern of hazy and mild uptake was often noted in positive scans. In all low-grade lymphomas, the emergence of foci of intense uptake should raise suspicion of conversion to high-grade disease.     

18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) for staging and follow-up of marginal zone B-cell lymphoma

OBJECTIVE: According to recent reports, nodal marginal zone lymphoma (MZL) appears to be a distinctive lymphoma entity rather than a more advanced stage of extranodal MZL of mucosa-associated lymphoid tissue (MALT). We have therefore retrospectively evaluated all patients diagnosed with nodal or extranodal MZL who have been referred to our unit for imaging using (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET). PATIENTS AND METHODS: A total of 21 patients with a diagnosis of MZL upon referral for imaging with (18)F-FDG-PET were identified. Histological reassessment of biopsy specimens confirmed the diagnosis of extranodal MZL of MALT in 14 patients, while a diagnosis of nodal MZL was verified in 6 patients. Lymphoma cell proliferation was assessed immunohistochemically using a Ki-67 antibody. Whole-body (18)F-FDG-PET scans were performed on a GE advanced PET scanner 40 min after intravenous injection of 300-380 MBq (18)F-FDG. RESULTS: None of the patients with extranodal MZL showed focal tracer uptake within verified tumor sites. In contrast, 5 of the 6 patients with nodal MZL showed significant FDG uptake within the affected lymph nodes. These results did not simply reflect the different growth fractions of the two lymphoma entities since the proliferation indices of the two groups did not differ significantly. CONCLUSION:(18)F-FDG-PET visualizes nodal MZL in a high proportion of patients whereas FDG uptake is undetectable in extranodal MZL. Although limited by the small number of patients, this study suggests that imaging with (18)F-FDG-PET might play a potential role in the diagnostic workup of patients with nodal MZL involvement.     

PET/CT in Disease Detection and Follow-up of Subcutaneous Involvement in Marginal Zone Lymphoma

BackgroundThe value of positron emission tomography/computed tomography (PET/CT) in the staging and assessment of treatment response in marginal zone lymphoma (MZL) lymphomas remains controversial. We investigated radiologic characteristics of subcutaneous MZL as imaged on PET/CT scans.Patients and MethodsFrom the records of a single medical center, for the years 2008 and 2017, we identified subcutaneous lesions in PET/CT scans of patients with histopathologically confirmed MZL in sites other than subcutaneous tissue.ResultsOf 571 scans of 178 patients, subcutaneous lesions were found in 20 (11%). Lesions were located in soft tissue structures, mainly along the lateral aspects of the buttocks, thighs and lower and upper back areas, the flank, and the shoulders. Median lengths of the long and short axes of the lesions were 2.0 (range, 1.1-6.0) cm and 0.8 (range, 0.3-2.0) cm, respectively. Median standardized maximum uptake value was 2.3 (range, 0.9-7.6). In 12 patients (60%), MZL was diagnosed at an early stage; 15 (75%) had lymph node involvement and 10 (50%) extranodal involvement. One had spleen and 2 had cutaneous involvement; none had gastric findings.ConclusionThe findings of this study support the usefulness of PET/CT in the detection of subcutaneous MZL as well as in staging and treatment decisions.     

Frequent impact of [18F]fluorodeoxyglucose positron emission tomography on the staging and management of patients with indolent non-Hodgkin's lymphoma

[18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful in staging aggressive non-Hodgkin's lymphoma (NHL). However, its role in indolent NHL has not been established. This retrospective study assessed the sensitivity and clinical impact of PET findings in patients with indolent NHL. Patients with indolent NHL who underwent FDG-PET scanning between May 1997 and August 2001 were identified. Case records were reviewed for FDG-PET and conventional staging/restaging results and compared for concordance. Forty-seven patients were identified. Twelve staging FDG-PET scans and 37 restaging FDG-PET scans were obtained. The FDG-PET case sensitivity rate was 98%. Forty-two percent of staging FDG-PET scans were concordant with conventional staging, with the remaining patients exhibiting more extensive disease on PET. At progression, FDG-PET and conventional assessments were discordant in 46% of cases. Positron emission tomography findings downstaged disease in 30% of these patients and upstaged disease in 16%. Computed tomography (CT) and FDG-PET identified 150 and 146 individual sites of disease, respectively. Among "definite" sites on structural imaging, 74% were also seen on PET. For equivocal lesions, only 19% were seen on both modalities. Clinical management was changed in 34% of patients as a result of FDG-PET findings. Of 22 discordant lesions in which true disease status could be evaluated, the PET findings were confirmed to be correct in 21 (95%; P < 0.0001). These findings demonstrate that FDG-PET has a high sensitivity for indolent NHL and often leads to alteration of disease staging and management. This high accuracy of FDG-PET in assessing discordant lesions suggests a greater diagnostic utility compared with CT.     

Initial experience of FDG-PET/CT guided IMRT of head-and-neck carcinoma

PURPOSE: The purpose of this study is to evaluate the impact of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) fused with planning computed tomography (CT) on tumor localization, which guided intensity-modulated radiotherapy (IMRT) of patients with head-and-neck carcinoma. METHODS AND MATERIALS: From October 2002 through April 2005, we performed FDG-PET/CT guided IMRT for 28 patients with head-and-neck carcinoma. Patients were immobilized with face masks that were attached with five fiducial markers. FDG-PET and planning CT scans were performed on the same flattop table in one session and were then fused. Target volumes and critical organs were contoured, and IMRT plans were generated based on the fused images. RESULTS: All 28 patients had abnormal increased uptake in FDG-PET/CT scans. PET/CT resulted in CT-based staging changes in 16 of 28 (57%) patients. PET/CT fusions were successfully performed and were found to be accurate with the use of the two commercial planning systems. Volume analysis revealed that the PET/CT-based gross target volumes (GTVs) were significantly different from those contoured from the CT scans alone in 14 of 16 patients. In addition, 16 of 28 patients who were followed for more than 6 months did not have any evidence of locoregional recurrence in the median time of 17 months. CONCLUSION: Fused images were found to be useful to delineate GTV required in IMRT planning. PET/CT should be considered for both initial staging and treatment planning in patients with head-and-neck carcinoma.     

Detection of unsuspected distant metastases and/or regional nodes by FDG-PET [corrected] scan in apparent limited-disease small-cell lung cancer

We retrospectively investigated the clinical usefulness of fluorodeoxyglucose positron emission tomography (FDG-PET) for evaluation of patients with limited-disease small-cell lung cancer (LD-SCLC) diagnosed by conventional staging procedures. Sixty-three patients received whole body FDG-PET scans after routine initial staging procedures. The findings of FDG-PET scans suggesting extensive-stage disease were confirmed by other imaging tests or by the patient's clinical course. FDG-PET scan findings indicated distant metastases in 6 of 63 patients. Metastatic disease was confirmed in five of these six patients (8%, 95% confidence interval: 3-18%). FDG-PET scan also detected regional lymph node metastases even in nine patients (14%) in whom computed tomography images had been negative, including contralateral lymph node metastasis in three patients. FDG-PET scan detected additional lesions in patients diagnosed as having LD-SCLC by conventional staging procedures. The therapeutic strategies were changed in 8% of patients based on the results of FDG-PET. FDG-PET scan is recommended as an initial staging tool for patients with this disease.     

The potential role of circulating tumor DNA (ctDNA) in the further investigation of colorectal cancer patients with nonspecific findings on standard investigations

Early detection of metastatic colorectal cancer, at initial diagnosis or during routine surveillance, can improve survival outcomes. Current routine investigations, including CEA and CT, have limited sensitivity and specificity. Recent studies of colorectal cancer cohorts under post surgery surveillance indicate circulating tumor DNA (ctDNA) evidence of recurrence can occur many months before clinical detection. Another possible role for ctDNA is in the further assessment of indeterminate findings on standard CEA or CT investigations. To further explore this potential, we undertook a prospective study. Further investigation, including FDG-PET imaging, was at clinician discretion, blinded to ctDNA analysis. Forty-nine patients were enrolled. Analyzed here are the 45 patients with an evaluable blood sample of whom 6 had an isolated elevated CEA, 30 had indeterminate CT findings, and 9 had both. FDG-PET scans were performed in 30 patients. Fourteen of 45 patients (31%) had detectable ctDNA. At completion of the planned 2 year follow-up, recurrence has occurred in 21 (47%) patients. Detectable ctDNA at study entry was associated with inferior relapse free survival (HR 4.85, p < 0.0001). Where FDG-PET scan was normal/equivocal (n = 15, 50%) 1 of 1 with detectable ctDNA versus 3 of 14 with undetectable ctDNA ultimately had recurrence confirmed. In summary, for colorectal cancer patients with indeterminate findings on routine investigations, ctDNA detection increases the probability that the findings indicate metastatic disease, including in a nonpredefined subset that also underwent FDG-PET imaging. Further studies of the value of ctDNA analysis during patient surveillance are warranted.     

2-(fluorine-18)fluoro-2-deoxy-D-glucose positron emission tomography in the detection and staging of malignant lymphoma. A bicenter trial

BACKGROUND: The authors undertook a prospective evaluation of the clinical value of 2-fluoro [18-]-2-deoxyglucose positron emission tomography (FDG-PET) in the detection and staging of malignant lymphoma compared with computed tomography (CT) and bone marrow biopsy (BMB). METHODS: Fifty-two consecutive patients with untreated malignant lymphoma were evaluated prospectively in a bicenter study. FDG-PET, CT, and BMB were performed for investigating lymph node/extranodal manifestations and bone marrow infiltration. Thirty-three percnt of the discrepant results were verified by biopsy, magnetic resonance imaging, or clinical follow-up (range, 4-24 month). RESULTS: Altogether, 1297 anatomic regions (lymph nodes, organs, and bone marrow) were evaluated. FDG-PET and CT scans were compared by receiver operating characteristic (ROC) curve analysis. The area under the ROC curve were as follows: lymph nodes, 0.996 (PET) and 0.916 (CT); extranodal, 0.999 (PET) and 0.916 (CT); supradiaphragmatic, 0.996 (PET) and 0.905 (CT); and infradiaphragmatic, 0.999 (PET) and 0.952 (CT). In these analyses, FDG-PET was significantly superior to CT (P < 0.05), except in infradiaphragmatic regions, in which the two methods produced equivalent results. In detecting bone marrow infiltration, FDG-PET was superior to CT and was equivalent to BMB. In 4 of 52 patients (8%), FDG-PET led to an upstaging and a change of therapy. CONCLUSIONS: Noninvasive FDG-PET is very accurate in the staging of malignant lymphoma. Compared with standard staging modalities (CT and BMB), PET was significantly superior and led to changes in the therapy regimen for 8% of patients.     

FDG-PET/CT in the evaluation of anal carcinoma

PURPOSE: Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. METHODS AND MATERIALS: Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was with standard Nigro regimen. RESULTS: [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. CONCLUSION: [(18)F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.     

Improvement in preoperative staging of gastric adenocarcinoma with positron emission tomography

BACKGROUND: Positron emission tomography (PET) with 18- fluorodeoxyglucose (FDG) has been used to both detect and stage a variety of malignancies. The current study examined the value of PET for preoperative staging of gastric adenocarcinoma. METHODS: Sixty-eight patients (49 males and 19 females) with gastric adenocarcinoma, who were referred for preoperative FDG-PET scans, were enrolled in this study. The patients underwent spiral-computed tomography (CT) within 1 week of referral. The final diagnosis in all patients was made by histologic and surgical findings. For quantitative PET analysis, the regional tumor FDG uptake was measured by the standardized uptake value (SUV). RESULTS: For the primary tumor of a gastric adenocarcinoma, PET demonstrated an increased uptake in 64 of 68 patients (sensitivity, 94%), with a mean SUV of 7.0 (range, 0.9-27.7). A comparison of FDG uptake and clinicopathologic features showed significant association between FDG uptake and macroscopic type, tumor size, lymph node metastasis, histologic type, and TNM stage. The PET scan had a similar accuracy with that of CT for diagnosing local and distant lymph node metastases as well as peritoneal status. In assessing local lymph node status, however, PET had a higher specificity than CT (92% vs. 62%, P = 0.000). Moreover, PET had additional diagnostic value in 10 (15%) of 68 patients by upstaging 4 (6%) and downstaging 6 (9%) patients. PET combined with CT was more accurate for preoperative staging than either modality alone (66% vs. 51%, 66% vs. 47%, respectively; P = 0.002). CONCLUSIONS: FDG-PET improves the preoperative TNM staging of gastric adenocarcinoma. Based on its superior specificity, FDG-PET can facilitate the selection of patients for a curative resection by confirming a nodal status identified by CT.     

Use of positron emission tomography in localized extremity soft tissue sarcoma treated with neoadjuvant chemotherapy

BACKGROUND: Patients with high-grade soft tissue sarcomas are at high risk of developing local disease recurrence and metastatic disease. [F-18]-fluorodeoxy-D-glucose (FDG) positron emission tomography (PET) scans are hypothesized to detect histopathologic response to therapy and to predict risk of tumor progression in patients with various malignancies. Serial FDG-PET scans were taken to determine the correlation between FDG uptake and patient outcomes in patients receiving multimodality treatment of extremity sarcomas. METHODS: Forty-six patients with high-grade localized sarcomas were studied. The maximum standardized uptake values (SUVmax) of tumors were measured before receipt of neoadjuvant chemotherapy and again before surgery. Resected specimens were examined for residual viable tumor. Patients were followed up at least annually for evidence of local and distant recurrence of disease and survival. RESULTS: Patients with a baseline tumor SUVmax >/= 6 and < 40% decrease in FDG uptake were at high risk of systemic disease recurrence estimated to be 90% at 4 years from the time of initial diagnosis. Patients whose tumors had a >/= 40% decline in the SUVmax in response to chemotherapy were at a significantly lower risk of recurrent disease and death after complete resection and adjuvant radiotherapy. CONCLUSIONS: The FDG-PET scan was found to be a useful method with which to predict the outcomes of patients with high-grade extremity soft tissue sarcomas treated with chemotherapy. The pretreatment tumor SUVmax and change in SUVmax after neoadjuvant chemotherapy independently identified patients at high risk of tumor recurrence. The FDG-PET scan showed promise as a tool to identify the patients with sarcoma who are most likely to benefit from chemotherapy.     

Inefficacy of F-18 fluorodeoxy-D-glucose-positron emission tomography scans for initial evaluation in early-stage cutaneous melanoma

BACKGROUND: The purpose of the current study was to determine the sensitivity and specificity of initial F-18 fluorodeoxy-D-glucose-positron emission tomography (FDG-PET) scanning for detection of occult lymph node and distant metastases in patients with early-stage cutaneous melanoma. METHODS: The authors conducted a prospective nonrandomized clinical trial. Inclusion criteria were patients with cutaneous melanoma tumors > 1.0 mm Breslow thickness, local disease recurrence, or solitary intransit metastases without regional lymph or distant metastases by standard clinical evaluation. All patients underwent whole-body FDG-PET scanning before surgical therapy. Abnormal PET findings were studied by targeted conventional imaging and/or biopsy. FDG-PET scans were interpreted in a blinded fashion. Regional lymph node basins were staged by sentinel lymph node biopsy (SLNB). PET scan findings in regional lymph nodes were compared with histology of SLNB specimens. Abnormal distant PET scan findings were studied with repeat conventional scan imaging at 3-6 months and were correlated with the first site(s) of clinical disease recurrence. Blinded PET scan findings were correlated with all information to determine sensitivity and specificity. RESULTS: There were 144 assessable patients with a mean tumor depth of 2.8 mm. The median follow-up for these patients was 41.4 months. Blinded interpretations of FDG-PET scan images showed that 31 patients (21%) had signs of metastatic disease, 13 patients had probable regional lymph node metastases, and 18 patients had 23 sites of possible distant metastases. SLNB and/or follow-up demonstrated regional lymph node metastases in 43 of 184 lymph node basins in 40 patients (27.8%). Compared with all clinical information, FDG-PET scan sensitivity for detection of regional lymph node metastases was 0.21 (95% confidence [CI], 0.10-0.36) and specificity was 0.97 (95% CI, 0.93-0.99). No distant sites were confirmed to be true positive by targeted conventional imaging/biopsy at the time of presentation. Thirty-four patients (23.6%) presented with 54 foci of metastatic disease at initial disease recurrence. FDG-PET scan sensitivity for prediction of the first site(s) of clinical disease recurrence was 0.11 (95% CI, 0.04-0.23). Excluding patients with brain metastases, FDG-PET scan sensitivity for detection of occult Stage IV disease in patients was 0.04 (95% CI, 0.001-0.20) and specificity was 0.86 (95% CI, 0.79-0.92). CONCLUSIONS: FDG-PET scanning did not impact the care of patients with early-stage melanoma already staged by standard techniques. Routine FDG-PET scanning was not recommended for the initial staging evaluation in this population.     

18F]fluorodeoxyglucose positron emission tomography scanning for staging, response assessment, and disease surveillance in patients with mantle cell lymphoma

BackgroundPositron emission tomography (PET) is an important imaging modality in the staging and response assessment of patients with lymphoma, but data on its specific use in mantle cell lymphoma (MCL) are lacking.Patients and MethodsThe records of 28 patients with MCL who had a total of 123 [¹⁸F]fluorodeoxyglucose (FDG) PET scans between March 1999 and November 2005 were reviewed. Nine patients had staging scans. The other scans were performed for response assessment or relapse surveillance.ResultsFDG-PET sensitivity was 100% for nodal disease in the 9 patients studied at baseline. Positron emission tomography scans performed for response assessment were concordant with conventional imaging in 47% and discordant in 53% of cases. Positron emission tomography scanning led to earlier diagnosis of relapse in 1 of 17 patients but produced a high rate of false-negative findings in the evaluation of gastrointestinal involvement.ConclusionFDG-PET appears to be a sensitive modality for staging and for response assessment in MCL but was not found to be useful in relapse surveillance or in the evaluation of gastrointestinal disease.     

18F-FDG positron emission tomography staging and restaging in rectal cancer treated with preoperative chemoradiation

PURPOSE: To assess the information supplied by FDG-PET in patients with locally advanced rectal cancer both in the initial staging and in the evaluation of tumor changes induced by preoperative chemoradiation (restaging). METHODS AND MATERIALS: Twenty-five consecutive patients with rectal cancer were included, with tumor stages (c)T(2-4)N(x)M(0), during the period 1997-1999. We prospectively performed two FDG-PET scans in all patients to assess disease stage (1) at initial diagnosis and (2) presurgically, 4 to 5 weeks after protracted chemoradiation. Protracted chemoradiation was carried out during 5-6 weeks with 45-50 Gy, plus concurrent oral tegafur 1200 mg/day or 5-fluorouracil 500-1000 mg/m(2) administered as a 24-h continuous i.v. infusion on Days 1-4 and 21-25 of the radiotherapy treatment. Tumors were staged with CT in 95% of patients, whereas endorectal ultrasound was used in 90% of patients. Maximum standardized uptake value (SUVmax) was used as the quantitative parameter to estimate the tumor:tissue metabolic ratio. RESULTS: Preoperative chemoradiation significantly decreased the SUVMAX: 5.9 (mean SUVmax at initial staging) vs. 2.4 (mean SUVmax after chemoradiation) with p < 0.001. Unknown liver metastases were detected by FDG-PET in 2 patients, in 1 of them with the initial staging FDG-PET scan, and with the restaging FDG-PET scan in the other. After an average follow-up of 39 months, the value of SUVmax > or =6 allowed us to discriminate for survival at 3 years: 92% vs. 60% (p = 0.04). T downstaging (total 62%) was significantly correlated with SUVmax changes: 1.9 vs. 3.3 (p = 0.03). The degree of rectal cancer response to chemoradiation, established as mic vs. mac categories, was not associated with SUVmax differences (mean values of 2.0 vs. 2.7). CONCLUSION: Preliminary results observed suggest the potential utility of FDG-PET as a complementary diagnostic procedure in the initial clinical evaluation (8% of unsuspected liver metastases) as well as in the assessment of chemoradiation response (any T downstaged event) of locally advanced rectal cancer. Initial SUVmax might be of prognostic value related to long-term patient outcome.     

18F-脱氧葡萄糖正电子发射计算机断层显像对淋巴瘤分期和预后评估的作用

 【摘要】　目的　探讨18F-脱氧葡萄糖正电子发射计算机断层显像（FDG-PET）对淋巴瘤患者分期及预后评估的作用。 方法 对初诊的41例淋巴瘤患者,化疗前和化疗4个疗程后行FDG-PET,中位随访30个月,比较化疗前FDG-PET分期和化疗4个疗程后FDG-PET结果对预后的影响。 结果 41例患者治疗前结内、外病灶的最大标准摄取值（SUVmax）分别为9.7±6.9和8.4±6.8。侵袭性非霍奇金淋巴瘤（NHL）和惰性NHL比较,结内、外病灶的SUVmax值差异有统计学意义（侵袭性NHL分别为10.3±7.5和9.1±6.5,惰性NHL分别为4.7±2.1和2.4±0.6,均P<0.05）。NHL和霍奇金淋巴瘤（HL）、B细胞和T细胞NHL、活化B与生发中心来源弥漫大B细胞淋巴瘤治疗前FDG-PET的SUVmax差异无统计学意义（P>0.05）。化疗前 22例（54 ％）患者FDG-PET检出结外器官病变;6例（15 ％）因FDG-PET发现CT等其他检查未显示的淋巴结或结外病变而提高临床分期。治疗前经FDG-PET分期为Ⅰ、Ⅱ期的患者15例（37 ％）,Ⅲ、Ⅳ期的患者26例（63 ％）。随访期间,FDG-PET分期Ⅰ、Ⅱ期的患者中1例（7 ％）因疾病进展死亡,Ⅲ、Ⅳ期的患者中6例（23 ％）因疾病进展死亡。41例患者化疗4个疗程后行FDG-PET检查,FDG-PET阴性的患者17例（41 ％）中,随访期间1例（6 ％）因疾病复发死亡,FDG-PET阳性的患者24例（59 ％）中,随访期间6例（25 ％）因疾病进展死亡。 结论　化疗前FDG-PET检查有助于对淋巴瘤患者进行准确的临床分期,化疗4个疗程后FDG-PET检查有助于评估淋巴瘤患者的预后,指导进一步治疗。     

Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease

Background: Staging of Hodgkin's disease (HD) is accomplished by a variety of invasive and non-invasive modalities. This prospective study was undertaken to investigate the value of whole-body positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in defining regions involved by lymphoma compared with conventional staging methods in patients with HD.Patients and methods: Fourty-four newly diagnosed patients with HD underwent FDG-PET as part of their initial staging work-up. PET findings were correlated with findings of conventional staging including computed tomography, ultrasound, bone scanning, bone marrow biopsy, liver biopsy and laparotomy. When results of FDG-PET differed to those obtained by conventional methods reevaluation was performed by biopsy, if possible, or magnetic resonance imaging.Results: The results of FDG-PET were compared with three hundred twenty-one conventional staging procedures performed in 44 patients. FDG-PET was positive in 38 of 44 (86%) patients at sites of documented disease. PET detected additional lesions in five cases previously not identified by conventional staging methods. In another case a nodal lesion suspect on CT was negative at FDG-PET and was settled as true negative by biopsy. As a consequence of PET findings five patients had to be upstaged and one patient had to be downstaged, resulting in changes in treatment strategy in all six cases (14%). FDG-PET failed to visualize sites of HD in four patients. In two of our patients a false positive PET result was obtained.Conclusions: Our data indicate that FDG-PET provides an imaging technique that appears to visualize involved lesions in most patients with HD and is useful in the managment of these patients.     

Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and Ga-67 scintigraphy in evaluation of lymphoma

BACKGROUND: The accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET; dual-head camera with attenuation correction) and Ga-67 scintigraphy was compared to identify disease sites in patients with Hodgkin disease (HD) and intermediate and high-grade non-Hodgkin lymphoma (NHL) at initial diagnosis or clinical recurrence. METHODS: Fifty-one contemporaneous FDG-PET and Ga-67 scintigraphies were performed on patients with NHL (35 intermediate grade, 3 high grade) or HD (13 patients). Sites of disease were correlated on a site-by-site basis on FDG-PET and Ga-67 images. Tumor-to-background (T/B) ratios were obtained for both techniques. Discordant FDG-PET and Ga-67 findings were correlated with computed tomography findings or clinical evaluation including repeat FDG-PET scans obtained after therapy. RESULTS: Fluorodeoxyglucose positron emission tomography was positive at all 158 sites in 51 patients compared with 113 sites in 41 positive studies with Ga-67 scintigraphy (single positron emission computed tomography [SPECT] and/or planar images). In 44 patients who had complete Ga-67 SPECT data on all tumor sites, FDG-PET was positive at 126 sites and Ga-67 SPECT was positive at 81 sites. Ga-67 SPECT failed to demonstrate disease at 45 sites (35.7%). In 10 of 44 patients, Ga-67 SPECT completely failed to detect any disease at 22 of 45 sites (17.5%) and partially identified disease sites at 23 of 45 sites (18.2%) in 11 patients regardless of the tumor site and histology. In these patients, the lesions measured between 0.6 and 14.0 cm by CT. Fluorodeoxyglucose positron emission tomography revealed higher stage disease in 13 patients compared with Ga-67 imaging. Tumor-to-background ratios were statistically different between the two techniques with higher ratios obtained with FDG-PET (P < 0.0001). CONCLUSIONS: In imaging aggressive lymphoma and HD before therapy, FDG-PET has significantly higher site and patient sensitivity than Ga-67 scintigraphy (100% vs. 71.5% and 100% vs. 80.3%, respectively). The change in disease stage by FDG-PET may result in a change in therapy strategy.     

Prognostic value of the Follicular Lymphoma International Prognostic Index score in marginal zone lymphoma

BACKGROUND:

In marginal zone lymphoma (MZL), clinical and follow‐up data on large cohorts of patients are difficult to obtain. The objective of this single‐center, retrospective analysis of a large cohort of 144 patients with MZL was to elucidate the role of prognostic markers, treatments, and outcomes in this disease.

METHODS:

In total, 144 patients were identified who were diagnosed with MZL at the authors' institution between 2003 and 2010. Data on clinical parameters, treatments, response, and survival were analyzed. In addition, the validity of the International Prognostic Index (IPI) and Follicular Lymphoma International Prognostic Index (FLIPI) prognostic scores were tested in patients with MZL.

RESULTS:

Among 144 patients with MZL, 96 patients (67%) had extralymph node (extranodal) MZL, 32 patients (22%) had lymph node (nodal) MZL, and 16 patients (11%) had splenic MZL. The 5‐year progression‐free survival rate was 82% in the nodal MZL group, 88% in the extranodal MZL group, and 74% in the splenic MZL group and did not different between the 3 groups (P = .60). The 5‐year overall survival rate was excellent in all 3 MZL groups (nodal MZL, 89%; extranodal MZL, 92%; splenic MZL, 82%; P = .46). In our cohort, the FLIPI score was a significant prognostic marker: The 5‐year progression‐free survival rate for patients who had FLIPI scores of 0 to 2 (low or intermediate risk) was excellent at 92%, whereas it was only 62% for patients who had FLIPI scores of 3 to 5 (poor risk; P = .003). Similarly, the 5‐year overall survival rate for patients who had FLIPI scores of 0 to 2 was 95%, whereas it was only 62% for patients who had FLIPI scores of 3 to 5 (P = .0009).

CONCLUSIONS:

The FLIPI score had strong prognostic value in patients with MZL. Patients who have low‐risk or intermediate‐risk FLIPI scores have an excellent prognosis, whereas patients with poor‐risk FLIPI scores are candidates for novel treatment approaches. Cancer 2013. © 2012 American Cancer Society.     

Comparison between positron emission tomography and computed tomography in the use of the assessment of esophageal carcinoma

BACKGROUND: The role and potential value of positron emission tomography (PET) scanning in certain tumors has been widely investigated in recent years. The authors retrospectively assessed the performance of 18-F-fluorodeoxyglucose (FDG)-PET in the assessment of esophageal squamous cell carcinoma (SCC). METHODS: The results using PET were compared with those using computed tomography (CT), and these were correlated with the pathologic findings. The authors studied 32 patients with thoracic esophageal SCC who had undergone radical esophagectomy. RESULTS: Uptake of FDG in the primary tumor was found in 25 of the 32 (78.1%) cases. Comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between the FDG uptake and each of the depth of tumor invasion (P < 0.05), occurrence of lymph node metastasis (P < 0.01), and lymphatic invasion (P < 0.01). The survival rate in cases with high FDG uptake (standardized uptake value [SUV], >3) was significantly lower than that in cases with low FDG uptake (SUV, < 3; P < 0.05). In the evaluation of lymph node staging by the detection of lymph node metastasis, FDG-PET showed 77.8% sensitivity, 92.9% specificity, and 84.4% accuracy, and CT scanning showed 61.1% sensitivity, 71.4% specificity, and 65.6% accuracy. Positron emission tomography scanning showed a high degree of accuracy in the neck, upper thoracic, and abdominal regions. However, in the mid- and lower thoracic regions, the sensitivity was very low. The smallest lymph node metastasis that was detected by FDG-PET imaging was 6 mm. The average size of lymph node metastasis that was undetected by FDG-PET scanning was 7.3 mm (range, 1-17 mm). CONCLUSIONS: In conclusion, FDG-PET may be used as a noninvasive diagnostic technique in assessing the aggressiveness of the tumor and the prognosis in patients with esophageal SCC. During the preoperative diagnostic procedures, the sensitivity, specificity, and accuracy of lymph node staging is higher with FDG-PET than with CT imaging. In view of the high specificity of FDG-PET, it also gives useful information to guide the choice of treatment of esophageal carcinoma.     

Diagnostic value of (18)F-fluorodeoxyglucose positron emission tomography for pancreatic neuroendocrine tumors with reference to the World Health Organization classification

The 2004 classification of the World Health Organization (WHO) has demonstrated an efficacy for prediction of the prognosis of pancreatic neuroendocrine tumors. This study aimed to assess the predictive value of preoperative (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in relation to the 2004 WHO criteria. The histology of 21 pancreatic endocrine tumors resected at our hospital was reviewed and the tumors were classified according to the 2004 WHO criteria. FDG-PET findings were analyzed by comparing the findings with CT scans. FDG uptake was positive in 10 primary endocrine tumors (47%), but no uptake was seen in 11 tumors. In relation to the 2004 WHO classification, 1 out of 8 well-differentiated tumors with benign behavior was positive by PET (12.5%), 4 out of 7 well-differentiated tumors with uncertain behavior were positive (57%) and 4 low-grade malignant tumors were positive (100%). According to the WHO criteria, the rate of positive FDG uptake increased as the malignant potential increased. The metastases of low-grade malignant tumors also showed a positive FDG uptake. In conclusion, from our limited experience, FDG-PET appears to be useful for identifying pancreatic neuroendocrine tumors with a higher malignant potential. In addition, FDG-PET can detect distant metastases and may contribute to better staging of advanced disease.