18F‐Fluorodeoxyglucose positron emission tomography/computed tomography for the detection of recurrent bone and soft tissue sarcoma

BACKGROUND:

The clinical utility of modern hybrid imaging modalities for detecting recurrent bone or soft tissue sarcoma remains to be determined. In this report, the authors present a clinical study on the diagnostic accuracy and incremental value of integrated ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in patients with a history of sarcoma who have clinically suspected disease recurrence.

METHODS:

Forty‐three patients who had a history of bone or soft tissue sarcoma and had documented complete remission underwent ¹⁸F‐FDG PET/CT. Image analysis was performed independently for ¹⁸F‐FDG PET (n = 43) and for contrast‐enhanced spiral CT (CE‐CT) (n = 30) by 2 separate readers, whereas combined ¹⁸F‐FDG PET/CT (n = 43) images were analyzed in consensus by both readers. Imaging findings were rated on a 5‐point scale and finally were reported as malignant, benign, or equivocal. Imaging findings were validated either by histopathology (n = 24) or by clinical follow‐up (n = 19).

RESULTS:

¹⁸F‐FDG PET/CT had greater sensitivity and specificity compared with CE‐CT alone (94% and 92% vs 78% and 67%, respectively), resulting in significantly greater accuracy (93% vs 73%; P = .03). ¹⁸F‐FDG PET/CT was particularly superior regarding detection of local recurrence or soft tissue lesions (sensitivity and specificity: 83% and 100% vs 50% and 100%, respectively) or bone metastases (100% and 100% vs 85% and 88%, respectively).

CONCLUSIONS:

¹⁸F‐FDG PET/CT had greater diagnostic accuracy in the detection of recurrent bone or soft tissue sarcoma compared with CE‐CT alone. The detection of local recurrence was the most evident advantage of ¹⁸F‐FDG PET/CT over CE‐CT. Cancer 2013. © 2012 American Cancer Society.     

Successful administration of rituximab-bendamustine regimen in the relapse of Hodgkin lymphoma after autologous hemopoietic stem cell transplantation

Objectives. Treatment options for relapsing Hodgkin lymphoma (HL) are controversial after autologous hemopoietic stem cell transplantation (HSCT). Nevertheless, allogeneic HSCT may be curative if it is performed in complete remission. Case report. In 2007, a 22‐year‐old female patient was diagnosed with nodular sclerosis subtype of classical HL. Her clinical stage was IIAX with unfavorable prognosis. Eight courses of doxorubicin, bleomycin, vinblastine and dacarbazine chemotherapy and involved field irradiation were applied, but after 3 months of complete remission, disseminated relapse was recognised by ¹⁸FDG‐PET/CT. After two cycles of salvage dexamethasone, cisplatinum, and cytosine arabinoside therapy, further progression was noticed, so the treatment was modified to ifosfamide, gemcitabine, vinorelbine, and prednisone (IGEV) regimen. After two cycles of IGEV regimen, she achieved a complete metabolic remission, which was confirmed by a ¹⁸FDG‐PET/CT scan again. She was referred for autologous‐HSCT, and a successful stem cell collection was performed in August 2008. However, a rapid progression was detected again, so total body irradiation was applied before the conditioning therapy with R‐mini‐BEAM regimen. The ¹⁸FDG‐PET/CT scan performed 100 days after the autologous‐HSCT was still positive. In December 2009, multiple nodal and extranodal progression was detected, so ifosfamide, carboplatine, etoposide, mesna protection rescue treatment was started, but it was ineffective. Based on sporadic data of the literature, rituximab–bendamustine therapy was started in March 2010. After four cycles, she achieved complete metabolic remission, which was verified by ¹⁸FDG‐PET/CT. The patient has been referred for an allogeneic HSCT with reduced intensity conditioning. Conclusions. Based on our experience, bendamustine–rituximab salvage therapy can be a suitable option for the treatment of post‐transplant progression or relapse of HL. Copyright © 2011 John Wiley & Sons, Ltd.     

Relevance of monitoring metabolic reduction in patients with relapsed or refractory follicular and mantle cell lymphoma receiving bendamustine: a multicenter study

The aim of the present study was to investigate the relevance of monitoring metabolic reduction evaluated by (18) F-fluorodeoxyglucose ((18) F-FDG) PET/CT in relapsed or refractory patients with follicular lymphoma (FL) and mantle cell lymphoma (MCL) who received bendamustine. We conducted a phantom study of 18F-FDG PET/CT to ensure quality control for performing a multicenter clinical study. We analyzed 49 patients with relapsed or refractory FL and MCL who received bendamustine (120 mg/m(2)) on days 1-2 of a 21-day cycle for up to six cycles as a licensing phase II study. 18F-FDG PET/CT scans were acquired before the first and after the last cycle. In a total of 175 target lesions, the maximum perpendicular diameter (Max PD), minimum PD (Min PD), sum of the products of the Max PD (SPD), maximum standardized uptake value (SUVmax), and the percentage reduction rates of Max PD (%Max PD), SPD (%SPD) and SUVmax (%SUVmax) were evaluated for the response to treatment. The therapeutic response was assessed after the last cycle of treatment according to the revised response criteria for malignant lymphoma (revised RC). We evaluated 134 lesions in 39 patients (76%) achieving complete response (CR) and 41 lesions in 10 patients (24%) not achieving CR. The Max PD, Min PD, SPD and SUVmax of the lesions after the last cycle were significantly higher in patients with non-CR than in patients with CR. The %MPD, %SPD and %SUVmax of the lesions were significantly greater in patients with CR than in patients with non-CR (P < 0.0001). Metabolic reduction was observed in all target lesions of relapsed or refractory patients with FL and MCL who achieved CR after bendamustine therapy.     

Midtreatment 18F-fluorodeoxyglucose positron-emission tomography in aggressive non-Hodgkin lymphoma

BACKGROUND:

The use of ¹⁸F‐fluorodeoxyglucose positron‐emission tomography (PET) scan has increased considerably in the clinical management of non‐Hodgkin lymphoma patients, and its role as a prognostic factor during chemotherapy has been established recently.

METHODS:

Between May 2003 and May 2009, 91 newly diagnosed patients with primary mediastinal large B‐cell lymphoma (PMLBCL) and diffuse large B‐cell lymphoma (DLBCL) were treated with 12 weekly cycles of rituximab‐MACOP‐B (n = 12 patients with PMLBCL), 6 cycles of rituximab‐CHOP21 (n = 65 patients with DLBCL, aged < 60 years and 1 patient with PMLBCL), or 8 weekly cycles of rituximab‐VNCOP‐B (n = 13 DLBCL patients, aged ≥ 60 years). All patients underwent a staging PET examination at baseline and a midtreatment (interim) PET examination after 6 weeks of rituximab‐MACOP‐B treatment, 3 cycles of rituximab‐CHOP21 treatment, or 4 weeks of rituximab‐VNCOP‐B treatment and again at the end of the chemo‐immunotherapy regimen.

RESULTS:

At midtreatment evaluation, 35 patients showed a persistently positive PET scan; only 6 (17%) of these patients achieved a continuous complete response (CCR). However, 56 patients presented with a negative interim PET, and 50 (89%) of these patients achieved and maintained a CCR. Comparison between the 2 PET groups indicated a statistically significant association between PET findings and event‐free survival (P = .0001) and overall survival (P = .0001).

CONCLUSIONS:

The results of this study indicated that midtreatment PET may represent a significant step forward in helping physicians make crucial decisions on further treatment. Cancer 2011. © 2010 American Cancer Society.     

18F‐FDG uptake and its clinical relevance in primary gastric lymphoma

We studied the clinical relevance of ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG) uptake in patients with primary gastric lymphoma underwent positron emission tomography (PET)/ computed tomography (CT) scan. Forty‐two patients with primary gastric lymphoma were analysed: 32 diffuse large B‐cell lymphomas (DLBCL) and 10 extranodal marginal zone B‐cell lymphomas of mucosa‐associated lymphoid tissue (MALT lymphomas). The PET/CT scans were compared with clinical and pathologic features, and the results of CT and endoscopy. Nine patients were up‐staged based on the results of their PET/CT scan compared to CT (seven DLBCLs, two MALT lymphomas) while six patients were down‐staged by the PET/CT scan. The standard uptake value (SUV) was used as an indicator of a lesion with a high metabolic rate. The high SUVmax group, defined as an SUVmax ≥ median value, was significantly associated with an advanced Lugano stage (p < 0.001). Three patients with DLBCL, who showed an initially high SUVmax, died of disease progression. Among 24 patients for whom follow‐up PET/CT scan with endoscopy was performed, 11 patients with ulcerative or mucosal lesions showed residual ¹⁸F‐FDG uptake. All of these gastric lesions were grossly and pathologically benign lesions without evidence of lymphoma cells. In conclusion, PET/CT scan can be used in staging patients with primary gastric lymphoma; however, the residual ¹⁸F‐FDG uptake observed during follow‐up should be interpreted cautiously and should be combined with endoscopy and multiple biopsies of the stomach. Copyright © 2009 John Wiley & Sons, Ltd.     

Role of fluorine‐18‐fluorodeoxyglucose positron emission tomography/computed tomography in evaluating breast mucosa‐associated lymphoid tissue lymphoma: A case series

Mucosa‐associated lymphatic tissue (MALT) lymphoma of the breast is an extremely rare disease; its pathogenesis is not clear because of the rarity of disease, and the best diagnostic method has yet to be established. The metabolic behavior of this lymphoma is not still clear because only a few case reports are present in literature describing the possible role of fluorine‐18‐fluorodeoxyglucose positron emission tomography/computed tomography (18F‐FDG PET/CT) in this field. This report presents 4 cases of women with histologically proven breast MALT lymphoma who underwent 7 18F‐FDG PET/CT throughout the course of disease. All patients underwent staging PET/CT showing in all cases an FDG avid lesion corresponding to breast lymphoma; 3 patients underwent 18F‐FDG PET/CT also after chemotherapy. Our results suggest that breast MALT lymphomas are 18F‐FDG‐avid lymphomas. Positron emission tomography/computed tomography showed heterogeneous but high FDG uptake (mean maximum standardized uptake value 7.9), suggesting that it could be part of diagnostic workup and restaging process.     

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non–small‐cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non–small‐cell lung cancer (NSCLC) patients. The aim of this meta‐analysis was to assess the diagnostic value of ¹⁸F‐FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta‐analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver‐operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65–0.78] and 0.91 (95% CI: 0.86–0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60–0.80) and 0.83 (95% CI: 0.77–0.88) in intrathoracic staging; 0.78 (95% CI: 0.64–0.87) and 0.90 (95% CI: 0.84–0.94) in intrathoracic staging on a per‐node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.77 (95% CI: 0.47–0.93) and 0.95 (95% CI: 0.92–0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80–0.97) and 0.98 (95% CI: 0.94–0.99) for bone metastases. ¹⁸F‐FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. ¹⁸F‐FDG PET/CT confers significantly higher sensitivity and specificity than contrast‐enhanced CT (both p < 0.01) and higher sensitivity than ¹⁸F‐FDG PET in staging NSCLC (p < 0.05).     

Ability of integrated positron emission and computed tomography to detect significant colonic pathology

BACKGROUND:

The ability of integrated positron emission tomography and computed axial tomography (PET‐CT) to detect colonic pathology is not fully defined. The purpose of this study was to assess the ability of PET‐CT to detect colonic pathology and to determine the significance of (¹⁸F)2‐fluoro‐2‐deoxyglucose (¹⁸F‐FDG) activity noted incidentally in the colon on PET‐CT.

METHODS:

Records for all patients who underwent PET‐CT and colonoscopy at our institution were reviewed. Patients with history of colonic malignancy or colon surgery were excluded.

RESULTS:

Fifty‐eight patients had incidental colonic ¹⁸F‐FDG activity on PET (Group A) and 272 had none (Group B). In Group A, 65% of patients had pathologic findings detected on colonoscopy that corresponded to the site of PET activity. Standardized uptake value (SUV) readings were not helpful in distinguishing true‐positives from false‐positives. In Group B, 11.8% of patients were found to have significant colonic findings. Lesions not detected by PET‐CT included 4 colon cancers, 7 advanced adenomas, and 10 patients with colonic lymphoma. Overall, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET‐CT for detecting significant pathology were 53%, 93%, 65%, 89%, and 85%, respectively. For detecting colon cancer and adenomas 10 mm or more, the sensitivity, specificity, PPV, NPV, and accuracy of PET‐CT were 72%, 90%, 45%, 96%, and 88%, respectively.

CONCLUSIONS:

Incidental colonic activity detected by PET‐CT warrants further evaluation with colonoscopy. However, negative PET‐CT does not rule out significant colonic pathology including colon cancer, advanced adenomas, or lymphoma. Cancer 2010. © 2010 American Cancer Society.     

Detection rate of fluorine‐18‐fluorodeoxyglucose positron emission tomography in patients with marginal zone lymphoma of MALT type: a meta‐analysis

The aim of this article is to meta‐analyse published data about the detection rate (DR) of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the evaluation of patients with marginal zone lymphoma of the mucosa‐associated lymphoid tissue (MALT). A comprehensive literature search of studies published through February 2014 was performed. Pooled DR of ¹⁸F‐FDG PET or PET/CT including 95% confidence intervals (95% CI) was calculated on a per‐patient‐based analysis. Twenty studies including 376 patients with MALT lymphoma were selected. The pooled DR of ¹⁸F‐FDG PET or PET/CT was 71% (95% CI: 61–80%). A significant difference between the DR of PET/CT (69%; 95% CI: 61–80%) and that of PET alone (73%; 95% CI: 60–84%) was not demonstrated. A better DR of ¹⁸F‐FDG PET or PET/CT in bronchial (94%; 95% CI: 85–99%) and head‐and‐neck (90%; 95% CI: 78–98%) MALT lymphomas compared with gastric (62%; 95% CI: 46–77%) and ocular (49%; 95% CI: 36–63%) MALT lymphomas was found. This meta‐analysis demonstrates that MALT lymphoma is an ¹⁸F‐FDG‐avid tumour in most of the cases, suggesting a potential clinical role of ¹⁸F‐FDG PET or PET/CT in the initial evaluation of these patients. In particular, the DR of ¹⁸F‐FDG PET or PET/CT is related to the primary site of the MALT lymphoma. Copyright © 2014 John Wiley & Sons, Ltd.     

Prognostic role of baseline 18F‐FDG PET/CT parameters in MALT lymphoma

Mucosa‐associated lymphoid tissue (MALT) lymphoma is an indolent lymphoma with good prognosis and variable fluorine‐18 fluorodeoxyglucose (¹⁸F‐FDG) avidity. Many possible prognostic factors have been investigated with controversial results, but the possible prognostic role of ¹⁸F‐FDG positron emission tomography/computed tomography (PET/CT) remains unclear. Our aim was to evaluate the prognostic impact of qualitative and semiquantitative baseline PET/CT parameters on outcome of MALT lymphoma. We retrospectively enrolled 161 patients with histologically confirmed MALT lymphoma who underwent ¹⁸F‐FDG PET/CT before any treatment. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan‐Meier method was used to estimate the progression‐free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determine the relation between PET/CT features and OS and PFS. Ninety‐eight patients had positive ¹⁸F‐FDG PET/CT showing ¹⁸F‐FDG uptake (mean SUVbw, 10.1; SUVlbm, 7.2; SUVbsa, 2.7; MTV, 88.8; and TLG, 526); the remaining 63 were not ¹⁸F‐FDG avid. ¹⁸F‐FDG avidity was significantly correlated with tumor size and Ki‐67 score. Relapse/progression of disease occurred in 47 patients with an average time of 40.2 months; death occurred in 12 patients with an average of 59 months. At a median follow‐up of 62 months, median PFS and OS were 52 and 62 months, respectively. Advanced tumor stage and extragastric site were demonstrated to be independent prognostic factors for PFS, while only tumor stage for OS. Instead, PET/CT parameters were not related to survival, despite positive correlation at univariate analysis between MTV and TLG with PFS and positive PET/CT with PFS and OS. In conclusion, a 61% rate of PET avidity in biopsy‐confirmed MALT lymphoma was found, and it was correlated with tumor size and Ki‐67 score. Only tumor stage and localization were independently correlated with PFS and OS.     

High‐dose chemotherapy in relapsed or refractory Hodgkin lymphoma patients: a reappraisal of prognostic factors

High‐dose chemotherapy (HDCT) has a consolidated role in the treatment of patients with refractory or relapsed Hodgkin lymphoma (HL). We report clinical results of 97 HL patients who underwent HDCT for refractory (62 patients) or relapsed (35 patients) diseases in Istituto Europeo di Oncologia, from 1995 to 2009. Treatment included high‐dose carmustine, etoposide, cytarabine and melphalan in 84 patients and high‐dose idarubicin and melphalan in 13 patients with subsequent peripheral hemopoietic stem cells transplant. Outcomes were evaluated in terms of progression‐free survival (PFS) and overall survival (OS). In order to identify prognostic factors for outcome, a multivariate analysis for age, sex, disease status (refractory/relapsed), disease stage, B symptoms, presence of extranodal involvement, bulky disease, elevated lactate dehydrogenase, number of previous chemotherapy lines, remission status before transplant, 18F‐fluoro‐deoxy‐d ‐glucose positron emission tomography (¹⁸FDG‐PET) status before and after transplant was done. A clinical response was achieved in 91% of patients, with complete remissions in 76/97 patients. With a median follow‐up of 45 months (range 1–164 months), 5‐year PFS and OS were 64% and 71%, respectively. Remission status after induction therapy, 18F‐fluoro‐deoxy‐d ‐glucose positron emission tomography status before and after transplant were the most important prognostic factors for PFS and OS in univariate or multivariate analyses. HDCT is able to induce a high remission rate and a prolonged PFS in more than 50% of the patients with refractory and relapsed HL. Copyright © 2012 John Wiley & Sons, Ltd.     

Comparison of magnetic resonance spectroscopy and positron emission tomography in detection of tumor recurrence in posttreatment of glioma: A diagnostic meta‐analysis

It is important to distinguish between tumor recurrence and treatment effects in posttreatment patients with high‐grade gliomas. Several imaging modalities have been reported in differentiating between tumor recurrence and treatment effects. However, there were no consistent conclusions between different studies. We performed a meta‐analysis of 23 studies that compared the diagnostic values of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) and ¹¹C‐methionine (¹¹C‐MET) PET (positron emission tomography) or PET/CT (computed tomography) and magnetic resonance spectroscopy (MRS) in predicting tumor recurrence of gliomas. The pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios and summary receiver operating characteristic curves of ¹⁸F‐FDG and ¹¹C‐MET PET or PET/CT and MRS in detecting tumor recurrence were calculated. In conclusion, MRS is highly sensitive in the detection of tumor recurrence in glioma.¹⁸F‐FDG PET or PET/CT is highly specific in recurrence diagnosis. ¹¹C‐MET does not have noticeable advantage over ¹⁸F‐FDG. The current evidence shows no statistical difference between MRS and PET on the accuracy.     

Evaluation of thoracic tumors with 18F‐FMT and 18F‐FDG PET‐CT: A clinicopathological study

L‐[3‐¹⁸F]‐α‐methyltyrosine (¹⁸F‐FMT) is an aminoacid tracer for positron emission tomography (PET). The aim of this study was to determine whether PET‐CT with ¹⁸F‐FMT provides additional information for the preoperative diagnostic workup as compared with ¹⁸F‐FDG PET. PET‐CT studies with ¹⁸F‐FMT and ¹⁸F‐FDG were performed as a part of the preoperative workup in 36 patients with histologically confirmed bronchial carcinoma, 6 patients with benign lesions and a patient with atypical carcinoid. Expression of L‐type amino acid transporter 1 (LAT1), CD98, Ki‐67 labeling index, VEGF, CD31 and CD34 of the resected tumors were analyzed by immunohistochemical staining, and correlated with the uptake of PET tracers. For the detection of pulmonary malignant tumors, ¹⁸F‐FMT PET exhibited a sensitivity of 84% whereas the sensitivity for ¹⁸F‐FDG PET was 89% (p = 0.736). ¹⁸F‐FMT PET‐CT and ¹⁸F‐FDG PET‐CT agreed with pathological staging in 85 and 68%, respectively (p = 0.151). ¹⁸F‐FMT uptake was closely correlated with LAT1, CD98, cell proliferation and angiogenesis. The specificity of ¹⁸F‐FMT PET for diagnosing thoracic tumors was higher than that of ¹⁸F‐FDG PET. Our results suggest that coexpression of LAT1 and CD98 in addition to cell proliferation and angiogenesis is relavant for the progression and metastasis of lung cancer. © 2008 Wiley‐Liss, Inc.     

Evaluation of pulmonary nodules and lung cancer with one‐inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT

Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d‐PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using NaI detectors in coincidence mode (g‐PET) have been compared to d‐PET but reported usefulness has been variable when gamma cameras with half‐inch to three‐fourth‐inch thick crystals have been used without CT. Our aim was to compare g‐PET with a 1‐in.‐thick crystal and inbuilt CT for lesion localization and attenuation correction (g‐PET/CT) and d‐PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after ¹⁸F‐fluorodeoxyglucose (FDG), patients underwent BGO d‐PET/CT from jaw to proximal thigh. This was followed by one to two bed position g‐PET/CT 194 ± 27 min after FDG. Each study pair was independently analysed with concurrent CT. d‐PET/CT was interpreted by a radiologist experienced in both PET and CT, and g‐PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist. A TNM score was assigned and studies were then unblinded and compared. Fifty‐seven patients underwent 58 scan pairs over 2 years. Eighty‐nine per cent concordance was shown between g‐PET/CT and d‐PET/CT for the assessment of intrapulmonary lesions, with 100% concordance for intrapulmonary lesions >10 mm (36 of 36). Eighty‐eight per cent (51 of 58) concordance was shown between g‐PET/CT and d‐PET/CT for TNM staging. Coincidence imaging using an optimized dual‐head 1‐in.‐thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some value when d‐PET/CT is not readily available.     

Early 18F‐2‐fluoro‐2‐deoxy‐d‐glucose positron emission tomography may identify a subset of patients with estrogen receptor‐positive breast cancer who will not respond optimally to preoperative chemotherapy

BACKGROUND:

A pathologic complete response (pCR) and minimal residual disease (pMRD) after preoperative chemotherapy (PCT) for early stage or locally advanced breast cancer (BC) correlates with a good prognosis.

METHODS:

Patients who received from 6 to 8 cycles of PCT for BC were monitored by ¹⁸F‐2‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography (¹⁸F‐FDG‐PET), and the maximal standardized uptake value (SUVmax) was calculated at baseline, after 2 cycles, after 4 cycles, and at the end of PCT. SUVmax percentage changes (Δ‐SUV) were compared with the pathologic response rate. Patients who had a pCR or pMRD in the tumor and an absence of cancer cells in ipsilateral axillary lymph nodes were defined as having obtained an optimal pathologic response (pR), whereas all the other conditions were classified as a pathologic nonresponse (pNR).

RESULTS:

Of 34 patients, 7 (21%) achieved a pR (3 patients had a pCR, and 4 patients had pMRD). After the second cycle, the Δ‐SUV threshold with optimal negative predictive value to predict a pR was 50%. Twenty‐six patients (76%) had a Δ‐SUV >50%, including all 7 patients who had a pR and 19 patients who had a pNR. Conversely, all 8 patients who had a Δ‐SUV ≤50% had a pNR. All 8 of those patients had estrogen recepetor‐positive tumors.

CONCLUSIONS:

Early evaluation of metabolic response by ¹⁸F‐FDG‐PET during PCT was able to identify 30% of patients, all with estrogen receptor‐positive tumors, who would not obtain pR after completion of chemotherapy program. Cancer 2010. © 2010 American Cancer Society.     

Dual‐tracer PET/CT scan after injection of combined [18F]NaF and [18F]FDG outperforms MRI in the detection of myeloma lesions

The detection rates of whole‐body combined [¹⁸F]NaF/[¹⁸F]FDG positron emission tomography combined with computed tomography (PET/CT), CT alone, whole‐body magnetic resonance imaging (WB‐MRI), and X‐ray were prospectively studied in patients with treatment‐requiring plasma cell disorders The detection rates of imaging techniques were compared, and focal lesions were classified according to their anatomic location. Twenty‐six out of 30 initially included patients were assessable. The number of focal lesions detected in newly diagnosed patients (n = 13) and in relapsed patients (n = 13) were 296 and 234, respectively. The detection rate of PET/CT was significantly higher than those of WB‐MRI (P < 0.05) and CT (P < 0.0001) both in patients with newly diagnosed and in those with relapsed multiple myeloma (MM). The X‐ray detection rate was significantly lower than those of all other techniques, while CT detected more lesions compared with WB‐MRI at diagnosis (P = 0.025). With regard to the infiltration patters, relapsed patients presented more diffuse patterns, and more focal lesions located in the limbs compared with newly diagnosed patients. In conclusion, the detection rate of [¹⁸F]NaF/[¹⁸F]FDG PET/CT was significantly higher than those of CT, MRI, and X‐ray, while the detection rate of X‐rays was significantly lower than those of all other imaging techniques except for focal lesions located in the skull.     

Brentuximab vedotin administered to platinum‐refractory,transplant‐naïve Hodgkin lymphoma patients can increase the proportion achieving FDG PET negative status

Normalization of fluorodeoxyglucose positron emission tomography (FDG PET) imaging prior to high‐dose therapy and autologous stem cell transplantation (ASCT) improves outcomes in relapsed and refractory (RR) Hodgkin lymphoma (HL), but many patients refractory to platinum‐based salvage regimens are unable to achieve this goal. We therefore investigated whether brentuximab vedotin (BV) could normalize FDG PET in platinum‐refractory HL prior to ASCT. Fifteen consecutive patients with RR HL and FDG PET positive disease after platinum‐based salvage therapy were treated with a median of 4 cycles of BV. Normalization of FDG PET (Deauville ≤2) occurred in 8/15 (53%) patients but was only observed in patients that had achieved partial remission or stable disease after platinum‐based salvage therapy. All patients eventually proceeded to ASCT, regardless of FDG PET status. Our data suggest that BV can normalize FDG PET in a subset of patients with platinum‐refractory HL prior to ASCT. Copyright © 2014 John Wiley & Sons, Ltd.     

Standardized uptake value based evaluation of lymphoma by FDG and FLT PET/CT

Although ¹⁸F‐FDG PET/CT imaging is the conventional method for evaluating lymphoma, PET/CT imaging with radiopharmaceuticals other than FDG is being investigated. We evaluated the utility of different standardized uptake value (SUV) measurements in ¹⁸F‐FLT PET/CT scans compared with PET/CT scans performed with FDG. Two scans, each using one of the radiopharmaceuticals, were performed on each of 114 patients with histologically proven lymphoma. Maximum and mean SUV (SUVmax) and (SUVmean) of all visualized lesions, with backgrounds of mediastinal blood pool, liver, spleen and vertebra were calculated. The ratios of the SUVs of the lesions to those of each reference region were statistically analyzed. Using receiver operating characteristic curves, we analyzed the differences in uptake of the two agents in aggressive and indolent B‐cell non‐Hodgkin lymphoma. We found that the SUVmax measurements of FDG were significantly different between aggressive and indolent B‐cell non‐Hodgkin lymphoma. The receiver operating characteristic curve of SUVmax of tumour/liver for FDG studies resulted in the most area under the curve. The SUVmax of the tumour/mediastinum ratio for FLT studies resulted in the most area under the curve (0.781). There was no significant correlation between FDG and FLT uptake in most types of lymphoma we studied. Further studies of the characteristics of ¹⁸F‐FLT should employ the tumour/mediastinum SUVmax ratio for accurate uptake measurement. Copyright © 2013 John Wiley & Sons, Ltd.     

Functional imaging of neuroendocrine tumors with combined PET/CT using 68Ga-DOTATATE (DOTA-DPhe1,Tyr3-octreotate) and 18F-FDG

BACKGROUND.

The aim was to assess the relevant distribution of the novel PET tracer ⁶⁸Ga‐DOTATATE in neuroendocrine tumors (NETs) with combined positron emission tomography / computed tomography (PET/CT) and compare its performance with that of ¹⁸F‐FDG PET/CT.

METHODS.

The imaging findings with ⁶⁸Ga‐DOTATATE and ¹⁸F‐FDG on 38 consecutive patients with a diagnosis of primary or recurrent NET were compared and correlated with tumor grade on histology based on ki67 and mitotic index.

RESULTS.

The sensitivity of ⁶⁸Ga‐DOTATATE PET/CT was 82% (31 of 38) and that of ¹⁸F‐FDG PET/CT was 66% (25 of 38). The sensitivity of combined ⁶⁸Ga‐DOTATATE and ¹⁸F‐FDG PET/CT was 92% (35 of 38). There was greater uptake of ⁶⁸Ga‐DOTATATE than ¹⁸F‐FDG in low‐grade NET (median SUV 29 vs 2.9, P < .001). In high‐grade NET there was higher uptake of ¹⁸F‐FDG over ⁶⁸Ga‐DOTATATE (median SUV 11.7 vs 4.4, P = .03). There was a significant correlation with predominant tumor uptake of ⁶⁸Ga‐DOTATATE or ¹⁸F‐FDG and tumor grade on histology (P < .0001).

CONCLUSIONS.

⁶⁸Ga‐DOTATATE PET/CT is a useful novel imaging modality for NETs and is superior to ¹⁸F‐FDG for imaging well‐differentiated NET. Functional imaging with both ⁶⁸Ga‐DOTATATE and ¹⁸F‐FDG has potential for a more comprehensive tumor assessment in intermediate‐ and high‐grade tumors. Cancer 2008. ©2008 American Cancer Society.     

Higher response to lenalidomide in relapsed/refractory diffuse large B-cell lymphoma in nongerminal center B-cell-like than in germinal center B-cell-like phenotype

BACKGROUND:

There is a need to develop novel therapies for relapsed/refractory diffuse large B‐cell lymphoma (DLBCL) and to identify biomarkers predictive for therapeutic response. Lenalidomide was previously shown to induce an overall response rate (ORR) of 28% in patients with relapsed/refractory DLBCL. It is currently unknown if response rates differ between patients with different DLBCL subtypes.

METHODS:

The authors retrospectively evaluated clinical outcomes of patients with germinal center B‐cell–like versus nongerminal center B‐cell–like DLBCL treated with salvage lenalidomide at 4 academic institutions.

RESULTS:

Forty patients with relapsed/refractory DLBCL were included (24 men; 16 women; median age, 66 years; median of 4 prior treatments, including rituximab chemotherapy). Patients were classified as germinal center B‐cell–like (n = 23) or nongerminal center B‐cell–like (n = 17) DLBCL according to the Hans algorithm. The subgroups were similar in terms of stage, international prognostic index score, prior number of treatments, and rituximab resistance. A significant difference in clinical response to lenalidomide was observed in nongerminal center B‐cell–like versus germinal center B‐cell–like patients. ORR was 52.9% versus 8.7% (P = .006); complete response rate was 23.5% versus 4.3%. Median progression‐free survival was 6.2 versus 1.7 months (P = .004), although no difference in OS was observed between nongerminal center B‐cell–like and germinal center B‐cell–like DLBCL patients.

CONCLUSIONS:

The data suggest that the 2 major subgroups of patients with DLBCL (germinal center B cell and nongerminal center B cell) have different antitumor responsiveness to lenalidomide in the relapsed/refractory setting. A large international trial (NCT01197560) has been opened to enrollment in an attempt to prospectively validate these retrospective observations. Cancer 2011;. © 2011 American Cancer Society.