Prognostic value of tumor 18F-FDG uptake in patients with untreated extranodal natural killer/T-cell lymphomas of the head and neck

Extranodal nasal-type NK/T lymphoma treated with chemotherapy and radiotherapy: case series from a European tertiary referral center and review of the literature

PURPOSE

Extranodal nasal-type NK/T-cell lymphoma (ENKTL) is very rare in western countries and few data are available regarding the prognosis and the outcome of patients treated for this disease. We aimed to evaluate the prognosis, the pattern and risk factors of disease failure after combined therapy and also performed a review of the literature.

PATIENTS AND METHODS

We retrospectively analyzed 20 patients with (ENKTL) who underwent L‑Asparaginase based chemotherapy followed by (chemo-) radiotherapy between 2010 and 2020 in our center. Data on clinical characteristics and irradiation were collected. Failure patterns were recorded as local (tumor site), regional (regional lymph nodes) or distant failure (metastasis and/or nonregional lymph nodes).

RESULTS

During a median follow-up period of 46 months, disease failure was observed in 8 patients (40%). The 3‑year progression-free survival (PFS) and overall survival (OS) rates were 62.5 and 83.0%, respectively. The failure patterns were local (n = 6, 30%), regional (n = 3, 15%) and distant (n = 4, 20%). Among patients with local failure, all failures occurred within the radiation fields (100%). Univariate analysis showed that bilateral regional lymph node involvement (p = 0.0002), initial circulating EBV viral load ≥ 3.5 log (p = 0.03) and no negativation of EBV PCR after induction CT (p = 0.0497) were independent predictors of PFS.

CONCLUSION

Patients with bilateral lymph node involvement and/or high EBV viral load have a significant recurrence rate despite multimodal therapy. These results need to be confirmed by larger studies. Given the high rate of local recurrence within radiotherapy fields, the value of dose escalation should be considered. Patients at risk of relapse should be included in dedicated trials.

Diagnostic and prognostic value of pretreatment PET/CT in extranodal natural killer/T-cell lymphoma: a retrospective multicenter study

PURPOSE

The objective of this research was to assess the utility of positron emission tomography combined with computed tomography (PET/CT) to detect bone marrow invasion (BMI) and the predictive value of PET/CT in extranodal natural killer/T-cell lymphoma (ENKTL) patients.

PATIENTS AND METHODS

This multicentre study enrolled ENKTL patients who underwent pretherapy PET/CT and bone marrow biopsy (BMB). The specificity, sensitivity, negative predictive value (NPV), and positive predictive value (PPV) of PET/CT and BMB for BMI were evaluated. Multivariate analysis was used to identify predictive parameters for constructing a nomogram.

RESULTS

Seven hundred and forty-eight patients were identified from four hospitals, with eighty (10.7%) having focal skeletal lesions on PET/CT and fifty (6.7%) having positive BMB. When BMB is considered as the gold standard, the specificity, sensitivity, PPV, and NPV of PET/CT for diagnosing BMI were found to be 93.8%, 74.0%, 46.3%, and 98.1%, respectively. PET/CT-positive individuals showed significantly worse OS than PET/CT-negative patients in the subgroup of BMB-negative cases. The nomogram model created according to the significant risk factors from multivariate analysis performed well in predicting survival probability.

CONCLUSION

PET/CT offers a superior degree of precision for determining BMI in ENKTL. A nomogram model including the parameters of PET/CT can predict survival probability and may help in applying appropriate personalized therapy.

Dynamic evaluation of the prognostic value of 18F-FDG PET/CT in extranodal NK/T-cell lymphoma, nasal type

Extranodal natural killer/T-cell lymphoma, nasal-type (ENKTL) is a type of rare and distinct entity of non-Hodgkin lymphoma with poor prognosis. It is important to evaluate the early treatment response accurately to decide further treatment strategy. ¹⁸F-FDG PET/CT plays an important role in response evaluation and prognostic prediction in some kinds of lymphomas. However, data available regarding patients with ENKTL are limited. Thus, in this prospective study, we analyzed the prognostic value of ¹⁸F-FDG PET/CT in ENKTL. Thirty-four patients with newly diagnosed ENKTL were enrolled in this phase 2 study (NCT02825147, July 7, 2016). The patients received pre-, mid-, and end-treatment ¹⁸F-FDG PET/CT scans. Deauville score (DS), maximal standardized uptake values (SUVmax), and the change in SUVmax (ΔSUVmax) were recorded for response assessment. The median follow-up period was 42.2 months. The 2-year overall survival (OS) and progression-free survival (PFS) were 82.4% and 73.5%, respectively. Univariate analysis revealed that Ann Arbor stage (P < 0.002), mid-treatment DS (P = 0.005), mid-SUVmax (P = 0.001), mid-∆SUVmax (P = 0.004), end-treatment DS (P < 0.001), and end-SUVmax (P = 0.014) were prognostic factors for OS. Ann Arbor stage (P = 0.001), mid-treatment DS (P = 0.008), mid-SUVmax (P = 0.029), mid-∆SUVmax (P < 0.001), and end-treatment DS (P =0.021) were of prognostic significance for PFS. Multivariate analysis showed that mid-SUVmax (P = 0.042) and DS at the middle (P = 0.050) and end (P = 0.044) of treatment were significant independent predictors of PFS. ¹⁸F-FDG PET/CT is useful for predicting the prognosis of ENKTL.

Weakly supervised deep learning for determining the prognostic value of 18F-FDG PET/CT in extranodal natural killer/T cell lymphoma, nasal type

Purpose

To develop a weakly supervised deep learning (WSDL) method that could utilize incomplete/missing survival data to predict the prognosis of extranodal natural killer/T cell lymphoma, nasal type (ENKTL) based on pretreatment ¹⁸F-FDG PET/CT results.

Methods

One hundred and sixty-seven patients with ENKTL who underwent pretreatment ¹⁸F-FDG PET/CT were retrospectively collected. Eighty-four patients were followed up for at least 2 years (training set = 64, test set = 20). A WSDL method was developed to enable the integration of the remaining 83 patients with incomplete/missing follow-up information in the training set. To test generalization, these data were derived from three types of scanners. Prediction similarity index (PSI) was derived from deep learning features of images. Its discriminative ability was calculated and compared with that of a conventional deep learning (CDL) method. Univariate and multivariate analyses helped explore the significance of PSI and clinical features.

Results

PSI achieved area under the curve scores of 0.9858 and 0.9946 (training set) and 0.8750 and 0.7344 (test set) in the prediction of progression-free survival (PFS) with the WSDL and CDL methods, respectively. PSI threshold of 1.0 could significantly differentiate the prognosis. In the test set, WSDL and CDL achieved prediction sensitivity, specificity, and accuracy of 87.50% and 62.50%, 83.33% and 83.33%, and 85.00% and 75.00%, respectively. Multivariate analysis confirmed PSI to be an independent significant predictor of PFS in both the methods.

Conclusion

The WSDL-based framework was more effective for extracting ¹⁸F-FDG PET/CT features and predicting the prognosis of ENKTL than the CDL method.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05232-3.

Baseline SUVmax of 18F-FDG PET-CT indicates prognosis of extranodal natural killer/T-cell lymphoma

To evaluate the prognostic value of the baseline SUVmax of F-FDG PET-CT in extranodal natural killer/T-cell lymphoma (NKTCL) patients.From January 2010 to December 2015, 141 extranodal NKTCL patients with staging F-FDG PET-CT scan were divided into two group based on SUVmax cutoff value obtained from operating characteristic (ROC) curves. All the patients received radiotherapy, chemotherapy or chemoradiation. Survival analysis was performed on the basis of SUVmax.The median baseline SUVmax of the tumors was 11.67 (range 2.6-34.6). The ROC curves showed that the optimal cutoff of the baseline SUVmax was 9.65. The patients were divided into two groups: low SUV group (SUVmax < 9.65) and high SUV group (SUVmax ≥ 9.65). Patients in high SUV group were more likely to have invasive disease outside the nasal cavity (P < .001), poorer ECOG scores (P = .012) and higher LDH levels (P = .034). The univariate survival analyses indicated that high SUVmax was a poor prognostic factor for overall survival (OS, P = .038), progression free survival (PFS, P = .006) and distant relapse free survival (DRFS, P = .001), but not for local recurrence free survival (LRFS, P > .05). These results were consistent with that of the survival analyses using the Kaplan-Meier method. The multivariate survival analyses showed that the baseline SUVmax was no longer a prognostic factor for OS (HR 1.99, 95% CI 0.81-4.88, P = .135), but it still indicated worse PFS (HR 2.6, 95% CI 1.24-5.46, P = .012) and DRFS (HR 4.58, 95% CI 1.83-11.46, P = .001) independent of other variables.For extranodal NKTCL patients, a higher baseline SUVmax of F-FDG PET-CT was associated with more aggressive clinical features. An SUVmax ≥ 9.65 was an independent poor prognostic factor for DRFS and PFS. Thus, the baseline SUVmax may be a valuable tool to help identify patients with a high risk of disease progression.

The predictive value of pre-treatment 18F-FDG PET/CT on treatment outcome in early-stage extranodal natural killer/T-cell lymphoma

The diagnostic value of pretreatment ¹⁸F-FDG PET/CT in early-stage extranodal natural killer/T-cell lymphoma (ENKTL) is established, but its prognostic value is still unclear. We conducted ¹⁸F-FDG PET/CT-based quantitative and qualitative analysis as well as assessed related clinical parameters in 50 patients with recently diagnosed ENKTL and treated with methotrexate, etoposide, dexamethasone, and pegaspargase (MESA)-based therapy. Patients were followed-up for 38.6 ± 17.8 months. Six patients died of tumor-related disease, and six patients presented with persistence or recurrence. The estimates of the 2-year OS and PFS for the patients were 90.0% (SE: 4.0%) and 82.0% (SE: 5.0%), respectively. Survival curves were obtained using Kaplan-Meier analysis and compared using log rank test. Based on signifiacnt results of univariate analysis, we selected Epstein-Barr virus DNA (EB-DNA), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for multivariate analysis. Finally, MTV was found to be the significant independent predictor of both OS (p = .038) and PFS (p = .039).

18F-FDG PET/CT imaging findings in anaplastic large cell lymphoma, a rare subtype of lymphoma

OBJECTIVE

To investigate the 18F-FDG PET/CT imaging manifestations for anaplastic large cell lymphoma (ALCL), a rare subtype of T/NK cell lymphoma.

METHODS

Fifty patients with ALCL, including 32 anaplastic lymphoma kinase (ALK)-positive patients and 18 ALK-negative patients, were enrolled. The positive detection, maximal standardized uptake value (SUVmax), and distribution of nodal and extranodal involvement were recorded and analysed. Fifty patients with diffuse large B cell lymphoma (DLBCL) were collected as a control group.

RESULTS

ALCL lesions were demonstrated to be 18F-FDG-avid tumours with a mean SUVmax of 19.4 ± 12.6. Most (76%) ALCL patients presented with stage III-IV disease, and nodal and extranodal involvement occurred in 74.0 and 72.0% of the patients, respectively. ALCL and DLBCL showed many similarities in tumour stage, 18F-FDG uptake and tumour involvement (P > 0.05), although the preferred extranodal organs of involvement (bone and the gastrointestinal tract, respectively) were different (P < 0.05). Compared to ALK-negative lesions, a higher uptake of 18F-FDG was found in the ALK-positive lesions (SUVmax: 22.1 ± 14.3 vs. 15.1 ± 6.6, t = 2.354, P = 0.023). ALK-positive ALCL was more likely to involve the lymph nodes than ALK-negative ALCL (84.3% vs. 55.5%, χ2 = 4.973, P = 0.043), while ALK-negative ALCL was more prone to involve the extranodal organs compared to ALK-positive ALCL (88.9% vs. 62.5%, χ2 = 3.979, P = 0.046).

CONCLUSION

The present study demonstrated that ALCL is a systemic 18F-FDG-avid lymphoma with many imaging manifestations similar to DLBCL on PET/CT. The present study also showed that ALK expression actually influenced tumour 18F-FDG uptake and lesion distribution. These findings may be useful to improve the understanding of the biological characteristics of ALCL.

Baseline FDG Uptake And Peripheral Lymphocyte-Monocyte Ratio For Predicting Chemoradiotherapy Response In Patients With Esophageal Squamous Cell Carcinoma

Purpose

To explore he predictive values of both the baseline SUVmax of ¹⁸F-fluorodeoxy-glucose by the primary tumor in positron emission tomography/computed tomography (PET/CT) and the lymphocyte-monocyte ratio (LMR) in peripheral blood in inoperable treated esophageal squamous cell carcinoma (ESCC) patients who received concurrent chemoradiotherapy (CCRT).

Patients and methods

Between January 2011 and December 2016, 138 newly diagnosed ESCC patients from our institution were retrospectively recruited. The optimal cut-off values for baseline SUVmax and peripheral LMR were determined by individual receiver operating characteristic curves. The predictive values of baseline SUVmax and peripheral LMR for primary tumor response were examined by chi-square and Fisher’s exact tests, as was their combined predictive value.

Results

The objective response rate (ORR) was significantly different between the high-SUVmax group and the low-SUVmax group (61.9% vs 87.8%; P=0.004), as well as between the high-LMR group and the low-LMR group (80.7% vs 52.0%; P=0.001). Furthermore, the low-SUVmax-high-LMR group achieved the best ORR (100%), which was significantly different from the ORRs of the high-SUVmax-high-LMR group (ORR: 72.1%, P=0.002), the high-SUVmax-low-LMR group (ORR: 45.7%, P=0.001), and the low-SUVmax-low-LMR group (ORR: 45.7%, P=0.001).

Conclusion

Baseline SUVmax of the primary tumor and the peripheral LMR are independent predictors of CCRT response in the primary tumors of ESCC patients. Patients who have lower FDG uptake accompanied by a higher peripheral LMR are more likely to have a better primary tumor response after CCRT.

18F-FDG PET/CT for Prognostic Stratification of Patients With Extranodal Natural Killer/T-Cell Lymphoma

PURPOSE

The prognostic value of PET/CT for extranodal natural killer/T-cell lymphoma (ENKTL) patients is controversial. We sought to investigate the use of pretreatment and interim PET/CT in this disease.

METHODS

Sixty-five patients diagnosed with ENKTL who underwent pretreatment (n = 53) and/or interim PET/CT scans (after 2-4 cycles of chemotherapy and/or radiotherapy, n = 33) were retrospectively enrolled. Interim PET/CT images were interpreted according to the Deauville 5-point scale. PET/CT results were assessed for their predictive value of progression-free survival (PFS) and overall survival (OS). Kaplan-Meier estimates were generated to evaluate the predictive value of clinical parameters and PET/CT scans for prognosis evaluation. The Cox proportional hazards model was performed to assess the potential independent predictors for PFS and OS.

RESULTS

Patients with a high score (4/5) according to the Deauville scale had heavier tumor burdens and tended to have elevated serum LDH and β2-microglobulin (β2-MG). In univariate analysis, the following parameters were predictive of PFS: age (≤60 vs > 60 years), stage (I/II vs III/IV), lesion location (nasal vs extranasal), LDH (normal vs elevated), β2-MG (normal vs elevated), SUVmax before treatment (≤8.3 vs > 8.3), and interim PET/CT results. For OS, the predictive factors were composed of stage, lesion location, LDH, β2-MG, and interim PET/CT results. However, in multivariate analysis, only interim PET/CT scan interpreted by the Deauville scale remained as an independent predictor for both PFS and OS.

CONCLUSIONS

Interim PET/CT scan displayed potential predictive value for ENKTL patients. Response assessment according to the Deauville 5-point scale may help to improve the accuracy of prediction. Patients with advanced stage (III/IV), elevated LDH or β2-MG, and a high Deauville score of 4 to 5 on the interim PET/CT scan were more likely to have reduced PFS and OS.

Positron emission tomography/computed tomography in the diagnosis, staging, and prognostic evaluation of natural killer/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTL) is a rare subtype of non-Hodgkin's lymphoma that is associated with Epstein-Barr virus infection. The clinicopathological features of NKTL are unique among lymphomas. NKTL is an aggressive disease with a poor prognosis in the absence of effective treatment. Accurate diagnosis and staging are essential to ensure an appropriate treatment strategy and accurate prognosis of NKTL. ¹⁸F-Fluorodexoyglucose-positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is a valuable technique in the diagnosis, staging, and prognostic evaluation of various types of malignant tumors, including NKTL. PET/CT imaging studies of patients with NKTL have shown that NKTL is ¹⁸F-FDG-avid and that PET/CT is superior to conventional methods in detecting cutaneous and extracutaneous lesions. We herein review recent PET/CT studies that have provided considerable insight into the diagnosis, staging, prognostic evaluation, and treatment effectiveness in patients with NKTL.

Prognostic value of baseline, interim and end-of-treatment 18F-FDG PET/CT parameters in extranodal natural killer/T-cell lymphoma: A meta-analysis

METHODS

We searched the PubMed, EMBASE, Cochrane Library and Medline databases for eligible articles. SUVmax, MTV, and TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT were regarded as efficacy data. Combined hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were estimated using RevMan 5.3 software.

RESULTS

Nine trials with a total of 535 ENKTL patients were included. SUVmax, MTV and TLG on B-PET/CT were significantly associated with PFS with HRs of 2.78 (95%CI 1.54-5.03), 3.61 (95%CI 1.96-6.65) and 5.62 (95%CI 1.94-16.33), respectively, and with OS with HRs of 4.78 (95%CI 2.29-9.96), 3.20 (95%CI 1.55-6.60) and 7.76 (95%CI 1.79-33.58), respectively. For the DS on I-PET/CT, the HRs for PFS and OS were 5.15 (95%CI 2.71-9.80) and 5.80 (95%CI 2.28-14.73), respectively. Similarly, the DS on E-PET/CT was a significant predictor of PFS and OS with HRs of 3.65 (95%CI 2.13-6.26) and 3.32 (95%CI 1.79-6.15), respectively.

CONCLUSION

Our results suggest that SUVmax, MTV, TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT may be significant prognostic indicators for PFS and OS in ENKTL patients. Moreover, TLG tends to be superior to SUVmax and MTV on B-PET/CT for predicting survival of ENKTL patients. Therefore, response monitoring and prognostication assessments based on multiple PET/CT parameters should be considered in the management of ENKTL patients.

Prognostic significance of standardized uptake value on F18-FDG PET/CT in patients with extranodal nasal type NK/T cell lymphoma: A multicenter, retrospective analysis

OBJECTIVES

The purpose of this study was to evaluate the value of parameters assessed with F18-flurodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in predicting relapse free survival and overall survival in patients with extranodal nasal type NK/T cell lymphoma.

METHODS

Thirty-six patients with extranodal nasal type NK/T cell lymphoma, and who underwent PET/CT prior to curative treatment, were enrolled at five institutions. Volumes of interest covering the entire tumor volume were delineated on PET/CT images, and the maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using thresholds of 40% of SUVmax. Furthermore, we compared the difference in F18-FDG avidity according to Epstein-Barr virus (EBV) infection status.

RESULTS

The SUVmax (p=0.041) and SUVmean (p=0.049) in patients who died were higher than the respective values of those who survived. A higher TLG (>45.8) was associated with relapse free survival (HR 7.856, p=0.034). Ann Arbor stage (III-IV, HR 14.12, p=0.004), and a higher SUVmax (>12.6, p=0.024) and SUVmean (>6.4, p=0.024) were associated with poor survival. However, neither the MTV nor the TLG (volumetric parameters) were significant predictors of death. The PET parameters SUVmax (p=0.181), SUVmean (p=0.237), MTV (p=0.636), and TLG (p=0.469) did not differ significantly between patients with and without EBV infections.

CONCLUSIONS

High TLG was the only significant predictive factor on relapse free survival. The SUVmax and SUVmean measured by F18-FDG PET/CT could be significant prognostic factors in patients with extranodal nasal type NK/T cell lymphoma.

Evaluating the Predictive Ability of Initial Staging F-18 FDG PET/CT for the Prognosis of Non-Hodgkin Malignant Lymphoma Patients Who Underwent Stem Cell Transplantation

Objectives

This study aimed to determine the value of clinical prognostic factors and semiquantitative metabolic parameters from initial staging fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in non-Hodgkin lymphoma (NHL) patients treated with stem cell transplantation (SCT).

Methods

A total of 39 malignant lymphoma patients who underwent initial staging F-18 FDG PET/CT were enrolled in this study. SUVmax, MTV_wb, and TLG_wb were measured during the initial staging PET/CT. Receiver operating characteristic curve (ROC) analysis was adopted to dichotomize continuous variables. Log-rank test and Cox proportional hazard regression analysis were used to evaluate disease-free survival (DFS) rate.

Results

Among the 39 patients with malignant lymphoma, 17 (43.6%) had a relapse. For several clinical factors such as age, ECOG performance score, AMC/ALC score, stages, and revised International Prognostic Index score, differences between the two dichotomized groups were statistically insignificant. In univariate analysis, DFS estimates were 71.0 ± 7.8 months and 18.0 ± 5.9 months in high-SUVmax and low-SUVmax group, respectively (P < 0.01). For MTV_wb, DFS estimates were 46.6 ± 12.4 months and 69.1 ± 8.5 months in high-MTV_wb and low-MTV_wb group, respectively (P = 0.12). For TLG_wb, DFS estimates were 65.3 ± 7.5 months and 13.7 ± 8.6 months in high-TLG_wb and low-TLG_wb group, respectively (P = 0.02). In Cox proportional hazard regression analysis, only MTV_wb showed statistical significance (HR 3.01, 95% CI 1.04-8.74, P = 0.04).

Conclusion

In NHL patients treated with SCT, the MTV_wb of initial staging F-18 FDG PET/CT was an independent prognostic factor.

Tumor necrosis and complete resection has significant impacts on survival in patients with limited-stage upper aerodigestive tract NK/T cell lymphoma

Tumor necrosis (TN) is associated with worse prognosis in several solid cancers. Whether TN predicts poor outcome in natural killer cell / T cell lymphoma (NKTCL) is unclear. We investigated the clinical impact of TN on survival and other novel prognostic parameters in upper aero-digestive tract (UAT) NKTCL of 100 patients with limited stage. TN was significantly associated with poor performance status (p = 0.049), high Korean Prognostic Index score (p = 0.024), high C-reactive protein/albumin ratio (p = 0.003), higher maximum standard uptake value on positron emission tomography/computed tomography (PET/CT) (p = 0.008) and higher metabolic tumor volume (MTV) on PET/CT (p < 0.001). In univariate and multivariate analyses, progression-free survival and overall survival were independently associated with High MTV status (p = 0.001, p = 0.032), TN (p = 0.018, p = 0.009), local tumor invasiveness (p = 0.007, p = 0.035), complete resection (p = 0.020, p = 0.028) and regional lymph node involvement (p < 0.001, p < 0.001). TN and complete resection are concluded to be novel independent prognostic factors in patients with UAT NKTCL.

Pathogenesis and FDG-PET/CT findings of Epstein-Barr virus-related lymphoid neoplasms

Epstein-Barr virus (EBV) is one of the most common viruses, infecting more than 90% of the adult population worldwide. EBV genome is detected in some lymphoid neoplasms. Not only their histopathological subtypes, but also their backgrounds and their clinical courses are variable. A number of B-cell lymphoproliferative disorders associated with the immunocompromised state are related to EBV infection. The incidences of these disorders have been increasing along with generalization of organ transplantations and use of immunosuppressive treatments. Furthermore, some EBV-positive lymphoma can also occur in immunocompetent patients. While evaluating patients with generalized lymphadenopathy of unknown cause by positron emission tomography/computed tomography with 2-deoxy-2-[¹⁸F]fluoro-D-glucose (FDG-PET/CT), the possibility of lymphoid neoplasms should be considered in some patients, and a careful review of the background and previous history of the patients is necessary. In this review article, we describe the pathogenesis of EBV-related lymphoid neoplasms and then present FDG-PET/CT images of representative diseases. In addition, we also present a review of other EBV-related diseases, such as infectious mononucleosis and nasopharyngeal carcinoma.

SUV navigator enables rapid [18F]-FDG PET/CT image interpretation compared with 2D ROI and 3D VOI evaluations

PURPOSE

Positron emission tomography (PET) and the maximum standardized uptake value (SUV_max) is a useful technique for assessing malignant tumors. Measurements of SUV_max in multiple lesions per patient frequently require many time-consuming procedures. To address this issue, we designed a novel interface named SUV Navigator (SUVnavi), and the purpose of this study was to investigate its utility.

MATERIALS AND METHODS

We measured SUV_max in 661 lesions from 100 patients with malignant tumors. Diagnoses and SUV_max measurements were made with SUVnavi, 2D, and 3D measurements. SUV measurement accuracy in each method were also evaluated.

RESULTS

The average reduction in time with SUVnavi versus 2D was 53.8% and 3D was 37.5%; time required with SUVnavi was significantly shorter than with 2D and 3D (P < 0.001 and P < 0.001, respectively). The time reduction and lesion number had a positive correlation (P < 0.001 and P < 0.001, respectively). SUV_max agreed with precise SUV_max in all lesions measured with SUVnavi and 3D but in only 466 of 661 lesions (70.5%) measured with 2D.

CONCLUSION

SUVnavi may be useful for rapid [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]-FDG PET/CT) image interpretation without reducing the accuracy of SUV_max measurement.

The Correlation Between Pre-treatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters and Clinical Prognostic Factors in Pediatric Hodgkin Lymphoma

Objective:

To compare standardized uptake values (SUV) derived from pre-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and clinical prognostic factors in pediatric patients with Hodgkin lymphoma (HL).

Methods:

Pre-treatment FDG PET/CT findings of 28 children with HL were evaluated in this retrospective study. Metabolic tumor volume (MTV), SUV_max normalized by weight (SUVw_eight), lean body mass (SUV_lbm), body surface area (SUV_bsa) and plasma glucose levels of tumors (SUV_glucose) were calculated using pre-treatment FDG PET/CT scan images. These metabolic parameters were correlated with clinical factors [age, sex, number of lymph node groups, presence of splenic involvement, bulky mediastinal disease, Ann Arbor stage, serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum albumin and hemoglobin levels].

Results:

SUV_bsa, SUV_lbm, SUV_weight, SUV_glucose and MTV were higher in patients with stage III-IV disease, bulky tumor and ≥3 lymph node groups (p<0.05). SUV_bsa and SUV_glucose were higher in patients with splenic involvement (p<0.05). There was no significant correlation between these metabolic parameters and sex, ESR, levels of albumin and WBC (p>0.05). SUV_bsa and SUV_lbm were higher in patients with anemia (p<0.05). Additionally, significant increases were detected in SUV_weight, MTV, and SUV_glucose with increasing age (p=0.005, p=0.027, and p=0.009, respectively). SUV_bsa and SUV_lbm had no significant correlation with age (p>0.05).

Conclusion:

Metabolic parameters derived from pre-treatment FDG PET/CT may have an important role in predicting high-risk disease in patients with HL. Also, SUV_bsa and SUV_lbm may be better markers than SUV_weight in the quantitative evaluation of FDG PET/CT scans in pediatric patients.

Utility of baseline, interim and end-of-treatment 18F-FDG PET/CT in extranodal natural killer/T-cell lymphoma patients treated with L-asparaginase/pegaspargase

Positron emission tomography-computed tomography (PET/CT) is widely used for initial staging and monitoring treatment responses in Hodgkin and diffuse large B-cell lymphoma. However, its prognostic value in extranodal natural killer (NK)/T-cell lymphoma (ENKL) remains unclear. Here, we conducted a retrospective study to determine the impact of PET/CT in ENKL. Fifty-two patients newly diagnosed with ENKL were enrolled. Baseline maximum standardized uptake values (SUVmax), whole-body metabolic tumor volume (WBMTV) and whole-body total lesion glycolysis (WBTLG) were recorded. Additionally, interim PET/CT (I-PET) and end-of-treatment PET/CT (E-PET) results were scored using a 5-point scale. Patients were divided into groups using baseline parameter cut-off values; significant differences were found in overall survival (OS) and progression-free survival (PFS) between the high and low WBMTV and WBTLG groups and in OS between the two SUVmax groups. Positive I-PET and E-PET results predicted inferior PFS and OS. A multivariate analysis showed that baseline WBTLG, I-PET and E-PET results were associated with PFS and OS, and baseline SUVmax was an independent predictor of OS. Thus, baseline WBTLG, I-PET and E-PET results are good predictors of PFS and OS in ENKL patients who received L-asparaginase/pegaspargase in their first-line treatment, and baseline SUVmax is a valuable tool for assessing OS.

Prognostic value of whole-body SUVmax of nodal and extra-nodal lesions detected by 18F-FDG PET/CT in extra-nodal NK/T-cell lymphoma

We analyzed data from 54 newly-diagnosed persons with extra-nodal natural killer/T-cell (NK/T) lymphoma, who had a pretreatment 18F-FDG PET/CT study, to determine whether the sum of SUVmax of all the nodal and extra-nodal lesions predicted progression-free survival (PFS) and/or overall survival (OS). Three models (WB1SUVmax, WB2SUVmax, WB3SUVmax) based on the basis of the sum of SUVmax of the whole-body SUVmax of 11 nodal and 10 extra-nodal lesions were tested. The discrimination value of these models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC) in training and validation cohorts. Findings were validated in an independent cohort of 15 subjects. ROC curve analysis showed the optimal cut-off values for WB1SUVmax, WB2SUVmax and WB3SUVmax were 15.8 (sensitivity 92%, specificity 67%, AUC 0.811; P<0.001), 12.7 (sensitivity 96%; specificity 57%; AUC 0.785; P<0.001) and 15.8 (sensitivity 88%; specificity 70%; AUC 0.793; P<0.001). Multivariate analyses indicated WB3SUVmax was independently associated with PFS (hazard ratio [HR]=3.67, 95% confidence interval [95% CI]=1.19, 11.29; P=0.023) and OS (HR= 4.51 [1.02, 19.91]; P=0.047). WB3SUVmax calculated based of the sum of the SUVmax of 3 nodal and 10 extra-nodal lesions was significantly associated with PFS and OS.

Diagnostic value of 18F-FDG PET/CT for cutaneous extranodal natural killer/T-cell lymphoma, nasal type

OBJECTIVE

To evaluate the use of fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in the diagnosis of cutaneous extranodal natural killer/T-cell lymphoma, nasal type (C-ENK/T-NT).

METHODS

A total of 39 patients with newly diagnosed C-ENK/T-NT were enrolled between May 2006 and November 2013. Anatomic regions (n=429; five cutaneous and six extracutaneous regions per patient) were assessed using an F-FDG PET/CT scan and conventional staging methods (CSMs). F-FDG PET/CT and CSMs were compared and evaluated for their ability to detect tumor lesions and their influence on the staging and treatment strategies. Biopsy and clinical follow-up were used as the gold standard for diagnosis.

RESULTS

In total, 139 lesions were detected by CSMs and F-FDG PET/CT, of which there were 50 cutaneous and 89 extracutaneous-positive regions. F-FDG PET/CT detected 48 cutaneous and 88 extracutaneous regions. CSMs, however, detected only 34 cutaneous lesions and 61 extracutaneous lesions that were positive for malignancy (cutaneous comparison of PET/CT vs. CSMs, P<0.001; extracutaneous comparison of PET/CT vs. CSMs, P<0.05). Using F-FDG PET/CT, 8 (42%) patients were in stage I-II and 31 patients (58%) were in stage III-IV. F-FDG PET/CT staging was consistent with the final stage determination in 94.9% (37/39) of patients, whereas CSMs staging was correct in final stage determination in 74.4% (29/39) of patients (P=0.025).

CONCLUSION

Our study showed that F-FDG PET/CT scanning is a valuable modality for the detection of cutaneous and extracutaneous lesions of C-ENK/T-NT. F-FDG PET/CT may therefore influence future staging and treatment strategies.

Three-dimensional texture analysis of contrast enhanced CT images for treatment response assessment in Hodgkin lymphoma: comparison with F-18-FDG PET

PURPOSE

To determine the diagnostic performance of three-dimensional (3D) texture analysis (TA) of contrast-enhanced computed tomography (CE-CT) images for treatment response assessment in patients with Hodgkin lymphoma (HL), compared with F-18-fludeoxyglucose (FDG) positron emission tomography/CT.

METHODS

3D TA of 48 lymph nodes in 29 patients was performed on venous-phase CE-CT images before and after chemotherapy. All lymph nodes showed pathologically elevated FDG uptake at baseline. A stepwise logistic regression with forward selection was performed to identify classic CT parameters and texture features (TF) that enable the separation of complete response (CR) and persistent disease.

RESULTS

The TF fraction of image in runs, calculated for the 45° direction, was able to correctly identify CR with an accuracy of 75%, a sensitivity of 79.3%, and a specificity of 68.4%. Classical CT features achieved an accuracy of 75%, a sensitivity of 86.2%, and a specificity of 57.9%, whereas the combination of TF and CT imaging achieved an accuracy of 83.3%, a sensitivity of 86.2%, and a specificity of 78.9%.

CONCLUSIONS

3D TA of CE-CT images is potentially useful to identify nodal residual disease in HL, with a performance comparable to that of classical CT parameters. Best results are achieved when TA and classical CT features are combined.

Management of advanced NK/T-cell lymphoma

NK/T-cell lymphomas are aggressive malignancies, and the outlook is poor when conventional anthracycline-containing regimens designed for B-cell lymphomas are used. With the advent of L-asparaginase-containing regimens, treatment outcome has significantly improved. L-asparaginase-containing regimens are now considered the standard in the management of NK/T-cell lymphomas. In advanced diseases, however, outcome remains unsatisfactory, with durable remission achieved in only about 50% of cases. Stratification of patients with advanced NK/T-cell lymphomas is needed, so that poor-risk patients can be given additional therapy to improve outcome. Conventional presentation parameters are untested and appear inadequate for prognostication when L-asparaginase-containing regimens are used. Recent evidence suggests that dynamic factors during treatment and interim assessment, including Epstein-Barr virus (EBV) DNA quantification and positron emission tomography computed tomography findings, are more useful in patient stratification. The role of high-dose chemotherapy and haematopoietic stem cell transplantation requires evaluation in an overall risk-adapted treatment algorithm.

Utility of ¹⁸fluoro-deoxyglucose positron emission tomography for prognosis and response assessments in a phase 2 study of romidepsin in patients with relapsed or refractory peripheral T-cell lymphoma

BACKGROUND

For patients with peripheral T-cell lymphoma (PTCL), the value of (18)fluoro-deoxyglucose positron emission tomography (FDG-PET) scans for assessing prognosis and response to treatment remains unclear. The utility of FDG-PET, in addition to conventional radiology, was examined as a planned exploratory end point in the pivotal phase 2 trial of romidepsin for the treatment of relapsed/refractory PTCL.

PATIENTS AND METHODS

Patients received romidepsin at a dose of 14 mg/m(2) on days 1, 8, and 15 of 28-day cycles. The primary end point was the rate of confirmed/unconfirmed complete response (CR/CRu) as assessed by International Workshop Criteria (IWC) using conventional radiology. For the exploratory PET end point, patients with at least baseline FDG-PET scans were assessed by IWC + PET criteria.

RESULTS

Of 130 patients, 110 had baseline FDG-PET scans, and 105 were PET positive at baseline. The use of IWC + PET criteria increased the objective response rate to 30% compared with 26% by conventional radiology. Durations of response were well differentiated by both conventional radiology response criteria [CR/CRu versus partial response (PR), P = 0.0001] and PET status (negative versus positive, P < 0.0001). Patients who achieved CR/CRu had prolonged progression-free survival (PFS, median 25.9 months) compared with other response groups (P = 0.0007). Patients who achieved PR or stable disease (SD) had similar PFS (median 7.2 and 6.3 months, respectively, P = 0.6427). When grouping PR and SD patients by PET status, patients with PET-negative versus PET-positive disease had a median PFS of 18.2 versus 7.1 months (P = 0.0923).

CONCLUSIONS

Routine use of FDG-PET does not obviate conventional staging, but may aid in determining prognosis and refine response assessments for patients with PTCL, particularly for those who do not achieve CR/CRu by conventional staging. The optimal way to incorporate FDG-PET scans for patients with PTCL remains to be determined.

TRIAL REGISTRATION

NCT00426764.

Prognostic CT and MR imaging features in patients with untreated extranodal non-Hodgkin lymphoma of the head and neck region

OBJECTIVE

To determine the prognostic CT and MR imaging features of extranodal non-Hodgkin lymphoma in the head and neck region.

METHODS

The clinical data and CT and MR imaging features of 59 patients with histologically confirmed extranodal non-Hodgkin lymphoma in the head and neck region were retrospectively reviewed. Subjects included 27 male and 32 female patients between 13 and 81 years of age, with a mean age of 60.3 years. The clinical outcomes were categorized according to whether relapse or metastasis occurred within 2 years after therapy. The association between the clinical outcome and radiologic factors including tumour size, margin, shape, local tumour invasiveness, regional lymph node involvement, number of involvement sites, and contrast enhancement patterns was determined using univariate and multiple logistic regression analysis.

RESULTS

Radiologic factors including tumour size, margin, shape, and local tumour invasiveness were associated with poor clinical outcomes, as determined by univariate analysis (P < 0.05). Only the lesion margin category (ill-defined) remained an independent risk factor for clinical outcome in multivariate logistic regression analysis, with an OR of 8.14 (P < 0.05).

CONCLUSION

Ill-defined margin of the primary lesion was indicative of unfavourable survival outcome for patients with extranodal non-Hodgkin lymphoma of the head and neck region.

KEY POINTS

• Tumour size, margin, shape and local tumour invasiveness were prognostically relevant. • Tumour margin was an independent risk factor for clinical outcome. • Ill-defined margin of primary lesion was indicative of unfavourable survival outcome.

Utility of PET/CT in the diagnosis and staging of extranodal natural killer/T-cell lymphoma: a systematic review and meta-analysis

The role of 18F-fuorodexoyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) in the staging of Hodgkin lymphoma (HL) and aggressive B-cell non-Hodgkin lymphomas (NHL) has been demonstrated extensively. Nevertheless, the role of PET/CT in the diagnosis, staging, prognosis, and treatment evaluation of natural killer (NK)/T-cell lymphoma remains indeterminate. To systematically review and meta-analyze the publications on the value of 18F-FDG-PET/CT in the diagnosis and staging of NK/T-cell lymphoma. Pubmed, Embase, Cochrane Library, and some other database were searched for initial studies (last updated on May 8th, 2014).The eligibility criteria were studies assessing the usefulness of PET/CT in the staging of NK/T-cell lymphoma, patients were diagnosed as NK/T-cell lymphoma through pathology, or clinical and imaging follow-up. Sensitivities and specificities of 18F-FDG-PET/CT in individual studies were assessed. The summary receiver operating characteristic curve (sROC) and the area under the curve (AUC) were calculated. The "Meta-Disc 1.4" software was used for data analysis. Eight studies, with a total of 135 NK/T-cell lymphoma patients, were included in this meta-analysis. In terms of the 6 studies with patient based data, the pooled sensitivity and specificity of PET/CT in the diagnosis of NK/T-cell lymphoma were 0.95 (95% CI: 0.89-0.98) and 0.40 (95% CI: 0.09-0.78), respectively. For lesion-based analysis, with 1546 lesions included, the pooled sensitivity and specificity of PET/CT in the staging of NK/T-cell lymphoma were 0.98 (95% CI: 0.96-0.99) and 0.99 (95% CI: 0.99-1.00), respectively. For the patient based data, the AUC and Q index were 0.8537 and 0.7847, respectively. For lesion based data, the AUC and Q index were 0.9959 and 0.9755, respectively. The results of this current meta-analysis indicated that PET/CT could be used as a valuable diagnostic and staging tool for NK/T-cell lymphoma.

Abnormal immunophenotype provides a key diagnostic marker: a report of 29 cases of de novo aggressive natural killer cell leukemia

Aggressive natural killer (NK) cell leukemia (ANKL) is a systemic neoplastic proliferation of NK cells with an aggressive clinical course. Currently, the diagnosis of ANKL remains challenging. In the current study, we report the clinical, laboratory, immunophenotypic, and genetic findings from 29 cases of de novo ANKL in a single center and evaluate the relative contribution of these features to the diagnosis of ANKL. Clinical features, laboratory findings, morphologic, cytogenetic features, and Epstein-Barr virus status were important factors for diagnosing aggressive NK cell leukemia. On the other hand, ANKL displays a strikingly abnormal immunophenotype in contrast to nonneoplastic NK cells. The immunophenotype of ANKL cells may differ from reactive NK cells in 4 respects. First, the CD45/linear side scatter gating of flow cytometry allows the initial identification of neoplastic subpopulations for additional immunophenotypic analysis in half of ANKL cases. Second, unusual expression of surface antigens in ANKL cells was a prominent feature. Third, the clonality of ANKL cells could be identified using antibodies against CD158a/h, CD158b, or CD158e. Last, the positive rate of Ki-67 expression in ANKL cells was generally high. Based on these findings, we provide an objective marker based on clinical data for the definite diagnosis of ANKL.

Prognostic value of interim positron emission tomography in patients with peripheral T-cell lymphoma

The definition of the role of positron emission tomography (PET) in peripheral T-cell lymphomas (PTCLs) is still under investigation. The purpose of the present observational retrospective study was to assess the early prognostic value of PET after the first three cycles of therapy (PET+3), evaluating visual data in de novo PTCL patients treated in first line with standard chemotherapy and followed by both PET and computed tomography scan. Of 27 PET+3-negative patients, 19 also had a negative PET at the end of treatment (PET+6), whereas 8 of 27 had a positive final one; 6 of 7 PET+3-positive patients had a positive PET+6, whereas only 1 patient had a negative PET+6. Estimated overall survival plotted according to PET+3 results showed 78.6% for negative patients and 21.4% for positive patients at 88.7 months with a significant difference. Patients with negative PET+3 had superior progression-free survival of 72.6% compared with 16.7% of PET+3-positive patients. At the time of this analysis, 17 of 19 (89.5%) patients with negative PET+3 are in continuous complete response (CCR) and only 1 of 7 (14.2%) patients with positive PET+3 is still in CCR. In conclusion, our results indicate that positive PET+3 is predictive of a worse outcome in PTCL, and this significant statistical difference between the two curves could be clinically informative. Larger and prospective studies and harmonization of PET reading criteria are needed.

Extranodal natural killer/T cell lymphomas with extranasal disease in non-endemic regions are disseminated or have nasal primary: a study of 84 cases from India

Abstract We report a study of 84 extranodal natural killer/T cell lymphomas (ENKTCLs) from India to understand the disease pattern. Sixty-one patients had nasal disease and three had Waldeyer's ring tumors, while 20 had extranasal sites of presentation, namely: cervix (n = 1), oral cavity (n = 3), orbit (n = 3), liver (n = 1), ileum (n = 1), and soft tissue and lymph nodes (n = 9). Staging of patients with extranasal disease revealed that either they had disseminated disease or the nasal mass was missed during the initial staging. Extranasal presentation, performance status (PS), international prognostic index (IPI), Korean prognostic index, marrow involvement, radiotherapy and type of chemotherapy affected overall survival, while lymphopenia, performance status, radiotherapy and type of chemotherapy impacted disease-free survival. In the multivariate analysis, IPI and response to chemotherapy emerged as significant prognostic factors. Thus most patients with extranasal ENKTCL have a nasal lesion or disseminated disease and pure extranasal disease is uncommon in non-endemic regions.

Extranodal natural killer/T-cell lymphoma: advances in the management

PURPOSE OF REVIEW

Extranodal natural killer (NK)/T-cell lymphoma, nasal-type is a highly aggressive disease more frequent in Asia than in Western countries. There is no consensus treatment. The outcome depends on disease stage. Localized NK/T-cell lymphomas often respond to radiotherapy. In contrast, patients who have extensive disease or who relapse after radiotherapy have a very poor prognosis. Overall, long-term survival in these lymphomas tends to be inferior to that for other aggressive lymphomas. This review focuses on the new management modalities in light of advances in risk stratification, patient monitoring and treatment strategies.

RECENT FINDINGS

Many parameters have been reported to correlate with prognosis and new staging systems have been elaborated. Detecting Epstein-Barr virus (EBV) in the bone marrow is important for staging and measuring EBV DNA in the serum improved monitoring response to therapy. Radiation modalities have been precised and new strategies combining radiation and chemotherapy have been proposed for patients with localized disease. The particular efficacy of L-asparaginase in this disease has been confirmed and L-asparaginase-based regimens have been studied in prospective trials for patients with refractory, relapsing or disseminated disease with good results. Laboratory studies may point the way toward new therapeutic approaches.

SUMMARY

Early-stage disease is treated by involved-field radiotherapy with adjuvant chemotherapy. L-Asparaginase-containing regimens are the mainstay of treatment for advanced or disseminated disease. The role of targeted therapies, autologous and allogeneic haematopoietic stem cell transplantation is yet to be clearly defined.

(18)F-FDG PET in Patients with Primary Systemic Anaplastic Large Cell Lymphoma: Differential Features According to Expression of Anaplastic Lymphoma Kinase

PURPOSE

Primary systemic anaplastic large cell lymphoma (ALCL) is divided into two entities according to the expression of anaplastic lymphoma kinase (ALK). We investigated (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) findings in primary systemic ALCL according to ALK expression.

METHODS

Thirty-seven patients who had baseline PET before CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone)-based chemotherapy were enrolled. Among them, patients who underwent interim and/or post-therapy PET were further investigated for the treatment response and survival analysis. Baseline PET was analyzed visually and semi-quantitatively using peakSUV, and interim and post-therapy PETs were visually analyzed.

RESULTS

All cases were (18)F-FDG-avid on baseline PET. The peakSUV of ALK-positive ALCL (n = 16, 18.7 ± 10.5) was higher than that of ALK-negative ALCL (n = 21, 10.0 ± 4.9) (P = 0.006). In ALK-negative ALCL, complete response (CR) rate in negative-interim PET was higher than positive-interim PET (100 % vs 37.5 %, P = 0.02); however, there was no such difference in ALK-positive ALCL (100 % vs 75 %, P = 0.19). The 3-year progression-free survival (PFS) was not significantly different between ALK-positive and ALK-negative ALCL (72.7 % vs 47.6 %, P = 0.34). In ALK-negative ALCL, negative interim and post-therapy PET patients had better 3-year PFS than positive interim (83.3 % vs 25.0 %, P = 0.06) and post-therapy PET patients (70.0 % vs 20.0 %, P = 0.04). In contrast, ALK-positive ALCL had no such differences between PFS and PET results.

CONCLUSIONS

On baseline PET, all cases showed (18)F-FDG-avidity, and ALK expression was related to higher (18)F-FDG uptake. ALK-positive patients tend to have better PFS than ALK-negative patients. Negative-interim PET was a good indicator of CR, and interim or post-therapy PET was helpful for predicting the prognosis only in the ALK-negative group.

Dynamic observation of the radiosensitive effect of irisquinone on rabbit VX2 lung transplant tumors by using fluorine-18-deoxyglucose positron emission tomography/computed tomography

OBJECTIVE

We studied the radiosensitizing effect of irisquinone on a VX2 lung transplant tumor model during three-dimensional radiotherapy using fluorine-18-deoxyglucose ((18)F-FDG) PET/computed tomography (PET/CT).

MATERIALS AND METHODS

Thirty VX2 tumor-bearing rabbits were randomized into three groups: the radiotherapy group, the irisquinone+radiotherapy group, and the control group, each comprising 10 rabbits. (18)F-FDG PET/CT images were obtained to monitor the tumor/muscle (T/M) ratio of F-FDG uptake and the retention index (RI) before treatment, when the radiation dose reached 6, 12, and 18 Gy, and 1 week after radiotherapy. Tumor volume changes were also assessed. The management of the control group followed the same procedure.

RESULTS

At all treatment time points, the tumor volume was significantly smaller in the treatment groups than in the control group. The 1 and 2 h T/M ratios and RIs decreased gradually when the radiation dose reached 12 or 18 Gy in the treatment groups, whereas these values increased continuously in the control group. One week after treatment, the 1 and 2 h T/M ratios increased in the treatment groups, although these values remained lower than those in the control group. The RIs of the radiotherapy and irisquinone+radiotherapy groups were 0.329±0.133 and 0.137±0.036, respectively. Histological evaluation revealed that tumor F-FDG uptake was strongly related to tumor cell density.

CONCLUSION

F-FDG PET/CT was sensitive and noninvasive and could be used to monitor the radiosensitizing effects of irisquinone and the therapeutic efficacy of radiotherapy.

18F-FDG PET for diagnosis and response assessment for aggressive NK cell leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare malignant disorder of mature NK cells characterized by aggressive clinical course and poor outcome. The commonly involved sites are peripheral blood, bone marrow, liver, and spleen, but any organ can show involvement. We report a case of ANKL diagnosed and assessed the clinical response with 18F-FDG PET. Pretreatment and posttreatment FDG PET/CT showed a high correlation with pathologic diagnosis and staging as well as in the follow-up assessment of the clinical response. FDG PET could be a valuable tool enabling comprehensive staging and follow-up of ANKL.

Prognostic value of whole-body metabolic tumour volume and total lesion glycolysis measured on ¹⁸F-FDG PET/CT in patients with extranodal NK/T-cell lymphoma

PURPOSE

The aim of this study was to determine whether maximum standardized uptake value (SUVmax), whole-body metabolic tumour volume (WBMTV), and whole-body total lesion glycolysis (WBTLG) measured on pretreatment ¹⁸F-FDG PET/CT can predict prognosis in patients with extranodal natural killer/T-cell lymphoma (ENKTL).

METHODS

We conducted a retrospective analysis of 20 patients with newly-diagnosed ENKTL who underwent pretreatment ¹⁸F-FDG PET/CT. WBMTV and WBTLG were measured automatically using the boundaries of voxels presenting SUV>3.0. Uni- and multivariate analyses for survival and disease progression were performed using clinical variables and PET parameters (SUVmax, WBMTV, and WBTLG).

RESULTS

During the follow-up period (median 26.3 months), 12 patients showed disease progression and 10 patients died from the disease. Receiver operating characteristic curve analysis showed cut-off values for SUVmax, WBMTV and WBTLG of 8.1, 14.4 cm³ and 52.7, respectively. Univariate analysis showed that the International Prognostic Index (IPI) score and PET parameters were significant predictors of overall survival (OS) and progression-free survival (PFS). Multivariate analysis, even after adjustment for the IPI score, showed that high WBMTV was the best predictor of OS and PFS, and high SUVmax and WBTLG were significant predictors of PFS.

CONCLUSION

Our results suggested that the use of PET parameters together with the IPI score may be useful for detailed prediction of prognosis in ENKTL patients. Therefore, despite a lower IPI score, patients with high PET parameter values might be considered candidates for aggressive therapy to improve clinical outcomes.

18F-fluorodeoxyglucose positron emission tomography in the staging and prognosis of T cell lymphoma

We previously reported that (18)F-fluorodeoxyglucose positron emission tomography scan (FDG-PET) is almost universally positive in patients with T cell lymphoma. In the present analysis we examined the impact of FDG-PET on the initial staging of peripheral T cell lymphomas (PTCLs), and the prognostic value of interim FDG-PET. This retrospective analysis identified patients with mature T or natural killer (NK) lymphomas who had PET scans as part of initial staging or staging at relapse [(n = 95) (staging cohort)] in the PTCL database at Memorial Sloan-Kettering Cancer Center. A subset of these patients had repeat PET for interim restaging during initial therapy with curative intent [(n = 50) (interim restaging cohort)]. The frequency of specific T cell histologies included in this analysis were: PTCL not otherwise specified (NOS) (n = 35); angioimmunoblastic T cell lymphoma (AITL) (n = 17); anaplastic large cell lymphoma (ALCL), ALK-1+ (n = 11) and ALK-1- (n = 12); adult T cell lymphoma/leukemia (ATLL) (n = 7); NK/T cell lymphoma (NKTCL) (n = 10); and enteropathy-associated T cell lymphoma (EATL) (n = 3). In the staging cohort, 77 patients were newly diagnosed, and 18 had relapsed disease. Pretreatment FDG-PET was positive in 96% of patients. PET identified additional disease sites in 47/95 patients (50%) when added to conventional staging. Most frequently identified additional sites were: other nodal (n = 24); bone (n = 10); skin (n = 8); nasopharynx (n = 4); spleen (n = 3); and lung (n = 2). However, FDG-PET modified computed tomography (CT)-based staging in only 5/95 patients (5.2%): two patients were upstaged and three patients were downstaged. FDG-PET-based staging did not alter planned treatment for any patient. Interim restaging with PET was performed after a median of 4 cycles of chemotherapy. In this cohort, treatment regimens included cyclophosphamide, doxorubicin, vincristine and prednisone CHOP (n = 19); CHOP/ifosfamide, carboplatin and etoposide (ICE) (n = 26); and other (n = 7). Subsequently, 29 patients were consolidated with either autologous (n = 22) or allogeneic (n = 7) stem cell transplant. After a median follow-up of 3.4 years for surviving patients, those with negative interim PET had superior progression-free survival (PFS) compared to patients with positive interim PET (p = 0.03). There were no differences in overall survival (OS). In PTCL, FDG-PET commonly identifies additional sites of disease but infrequently impacts CT-based staging and does not influence therapy. Interim FDG-PET may predict for PFS. FDG-PET should be integrated into prospective trials to confirm these findings.

Predictive value of pretreatment positron emission tomography/computed tomography in patients with newly diagnosed extranodal natural killer/T-cell lymphoma

The role of (18)Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in extranodal natural killer/T-cell lymphoma (ENKL) is not well established. This study aimed to investigate the prognostic role of the pretreatment maximum standardized uptake value (SUV(max)) on PET/CT in patients with newly diagnosed ENKL. Among 364 consecutive patients with newly diagnosed ENKL, 81 patients were included and reviewed. The impact of SUV(max) on survival and the relationship between SUV(max) and other clinicopathological parameters were analyzed. The median SUV(max) was 14.6 (range 2.0-45.4). The optimal cutoff value of SUV(max) to predict overall survival (OS) was 15. Patients with high SUV(max) (SUVmax >15) were associated with bulky disease (P < 0.001), local invasion (P = 0.030), high score of Korean Prognostic Index (KPI, P = 0.046), resistance to primary treatment (P = 0.014), poor OS (P < 0.001), and unfavorable progression-free survival (P < 0.001). With a median follow-up of 25.0 months, the median OS was 63.0 months (range 2.0-99.0 months). Multivariate analyses revealed the following independent prognostic factors for OS: age >60 years (P = 0.001), stage III-IV (P = 0.023), SUV(max) >15 (P = 0.020), and bulky disease (>5 cm) (P = 0.002). By using the SUV(max), patients in most subgroups stratified by the KPI or the International Prognostic Index (IPI) were further discriminated in OS with significant statistical difference. Our results suggest the pretreatment SUV(max) is predictive of prognosis in patients with newly diagnosed ENKL. The SUV(max) may provide additional prognostic information for IPI and KPI.

Clinical value of metabolic tumor volume by PET/CT in extranodal natural killer/T cell lymphoma

This study investigated whether metabolic tumor volume (MTV) by PET/CT as indicator of extent of lymphoma burden would be a prognostic factor in stage I(E)/II(E) extranodal natural killer/T cell lymphoma (ENKTCL). Eighty patients with stage I(E)/II(E) ENKTCL in the upper aerodigestive tract underwent PET/CT at diagnosis were enrolled and 32 patients received upfront radiotherapy (RTx). MTV was measured on PET/CT images by the extranodal region above SUV, 2.5. Receiver operating curve analyses indicated that an MTV of 35.2 cm(3) was the ideal cut-off to distinguish between low and high MTV groups. Clinical outcomes were compared according to several prognostic factors (age, stage, high performance status [PS], high International Prognostic Index, elevated lactate dehydrogenase [LDH], local tumor invasiveness [LTI], high MTV and up-front RT). High PS, elevated LDH, LTI, high MTV and upfront RT were associated with survivals. In multivariate analysis, high MTV (PFS, HR=4.170, 95% CI=1.714-10.147, p=0.002; OS, HR=4.102, 95% CI=1.617-10.408, p=0.003) and up-front RT (PFS, HR=0.410, 95%CI=0.178-0.946, p=0.037; OS, HR=0.365, 95% CI=0.152-0.872, p=0.023) were significant independent prognostic factors. Upfront RTx and extent of tumor burden, as measured by the MTV, had significant prognostic value in patients with ENKTCL.

PET in T-Cell Lymphoma

Most non-Hodgkin lymphomas (NHL) are of B-cell origin; only about 10% are T-cell or NK-cell lymphomas. The clinical features of T/NK-cell lymphomas differ from those of B-cell lymphomas: advanced stage and extranodal disease are more common and the prognosis is worse. Several studies have confirmed that 2-[fluorine-18]fluoro-2-deoxy-D-glucose (18FDG) uptake varies among different subtypes of lymphoma, a disparity that can be explained by the differences in histology, proliferation of tumor cells, and the ratio of viable tumor and reactive cells in the environment. These observations are based on investigation of B-cell lymphomas. Positron emission tomography (PET)/computed tomography (CT) was found to be useful both at staging and at measuring the therapeutic outcome after two to three cycles of chemotherapy (interim PET/CT). Several meta-analyses have confirmed the role of PET in evaluating the viability of the residual tumor mass after treatment. 18FDG-PET has been proved to have an excellent negative predictive value. Conversely, only a few studies have investigated the role of FDG-PET in T/NK-cell lymphomas. This paper summarizes the current information regarding the potential use of PET/CT in patients with T-cell lymphoma.

PET/CT aids the staging of and radiotherapy planning for early-stage extranodal natural killer/T-cell lymphoma, nasal type: a case series

Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is a rare form of non-Hodgkin lymphoma. Treatment of ENKTL primarily relies on radiation; thus, proper delineation of target volumes is critical. Currently, the ideal modalities for delineation of gross tumor volume for ENKTL are unknown. We describe three consecutive cases of localized ENKTL that presented to the Nova Scotia Cancer Centre in Halifax, Nova Scotia. All patients had a planning CT and MRI as well as a planning FDG-PET/CT in the radiotherapy treatment position, wearing immobilization masks. All patients received radiation alone. In two patients, PET/CT changed not only the stage, but also the target volume requiring treatment. The third patient was unable to tolerate an MRI, but was able to undergo PET/CT, which improved the accuracy of the target volume. PET/CT aided the staging of and radiotherapy planning for our patients and appears to be a promising tool in the treatment of ENKTL.

Use of 18F-FDG PET/CT as a predictive biomarker of outcome in patients with head-and-neck non-squamous cell carcinoma

OBJECTIVE

The purpose of this article is to establish whether pretreatment (18)F-FDG uptake predicts disease-free survival (DFS) and overall survival in patients with head-and-neck non-squamous cell carcinoma (SCC).

MATERIALS AND METHODS

Eighteen patients (six women and 12 men; mean [± SD] age at diagnosis, 57.89 ± 13.54 years) with head-and-neck non-SCC were included. Tumor FDG uptake was measured by the maximum standardized uptake value (SUV(max)) and was corrected for background liver FDG uptake to derive the corrected SUV(max). Receiver operating characteristic analyses were used to predict the optimal corrected SUV(max) cutoffs for respective outcomes of DFS (i.e., absence of recurrence) and death.

RESULTS

The mean corrected SUV(max) of the 18 head-and-neck tumors was 5.63 ± 3.94 (range, 1.14-14.29). The optimal corrected SUV(max) cutoff for predicting DFS and overall survival was 5.79. DFS and overall survival were significantly higher among patients with corrected SUV(max) < 6 than among patients with corrected SUV(max) ≥ 6. The mean DFS for patients with corrected SUV(max) < 6 was 25.7 ± 11.14 months, and the mean DFS for patients with corrected SUV(max) ≥ 6 was 7.88 ± 7.1 months (p < 0.018). Among patients with corrected SUV(max) < 6, none died, and the mean length of follow-up for this group was 35.2 ± 9.96 months. All of the patients who died had corrected SUV(max) ≥ 6, and the overall survival for this group was 13.28 ± 12.89 months (p < 0.001).

CONCLUSION

FDG uptake, as measured by corrected SUV(max), may be a predictive imaging biomarker for DFS and overall survival in patients with head-and-neck non-SCC.