Analysis of Local Control in Patients with Non-Hodgkin’s Lymphoma According to the WHO Classification

PURPOSE: To analyze the influence of radiotherapy doses, chemotherapy doses, and clinical parameters on in-field disease control to assess the optimal radiation doses for treatment of non-Hodgkin's lymphoma according to the newly proposed WHO classification. PATIENTS AND METHODS: Subjects consisted of 35 extranodal marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type, 75 diffuse large B-cell lymphomas (DLBCL), 14 follicular lymphomas, 17 extranodal natural killer (NK)/T-cell lymphomas, nasal type, eight unclassified peripheral T-cell lymphomas, four anaplastic large-cell lymphomas, T/null cell type, and five others. 59 patients received radiotherapy alone. 98 patients received CHOP, modified CHOP, or more intensive chemotherapy, and six patients were treated with other combination. RESULTS: No patients with MALT lymphoma had in-field local recurrence. There were no recurrences in DLBCL patients who received chemotherapy in which the doses of adriamycin were > 200 mg/m(2), nor in DLBCL patients who were treated with > 45 Gy. Only nine of 15 patients with T-cell lymphoma treated with < or = 50 Gy and three of five patients treated with > 50 Gy had local control. The dose of adriamycin had no influence on local control of T-cell lymphoma. CONCLUSION: T/NK-cell lymphomas were more radioresistant than B-cell lymphomas. The prognosis for peripheral T/NK-cell lymphomas is poor even when treated by irradiation combined with chemotherapy.     

Analysis of Local Control in Patients with Non-Hodgkin’s Lymphoma According to the WHO Classification

Purpose:   

To analyze the influence of radiotherapy doses, chemotherapy doses, and clinical parameters on in-field disease control to assess the optimal radiation doses for treatment of non-Hodgkins lymphoma according to the newly proposed WHO classification.     

FDG PET/CT Response Assessment Criteria for Patients with Hodgkin’s and Non-Hodgkin’s Lymphoma at End of Therapy: A Multiparametric Approach

Purpose

Based on the International Harmonization Project (IHP) criteria, positron emission tomography (PET) response assessment of residual nodal masses in patients with lymphoma after completion of therapy is performed visually using mediastinal blood pool as the reference. The primary objective of this study was to define the optimal reference for PET response assessment. Secondary aim was to assess if morphological criteria on computed tomography (CT) may improve performance of PET.

Methods

This institutional review board approved retrospective study included 137 patients, with Hodgkin’s (n = 43) or non-Hodgkin’s lymphoma (n = 94) assessed for residual masses (n = 180) after completion of therapy with pathology and clinical and imaging surveillance data (mean, 19 months) as the standard of reference. Two readers independently assessed response by IHP and Deauville criteria. The addition of morphological parameters on CT was assessed in relation to therapy response.

Results

Based on the standard of reference, 36 patients (26.3 %) had residual lymphoma. For IHP and Deauville criteria, sensitivity, specificity and accuracy were 97.2 %, 97.2 % (p = 1); 79.2 %, 92.1 % (p < 0.001); and 83.9 %, 93.4 % (p = 0.001), respectively. Of the morphological parameters assessed, only change in size over course of therapy was significant (p < 0.003) and improved specificity for IHP-based interpretation to 90.4 % (p = 0.008).

Conclusions

Using liver as the visual reference to determine PET positivity for lymphoma patients being assessed for residual masses at the end of therapy improves specificity, yet maintains the high sensitivity of PET in identifying residual disease. The addition of change in size after therapy improves specificity of PET when using IHP-based but not Deauville-based interpretation.     

A case of non-Hodgkin’s lymphoma of the ovary: Usefulness of18F-FDG PET for staging and assessment of the therapeutic response

Primary ovarian lymphoma as the initial manifestation is rare. A 27-year-old woman presented to our hospital with the symptoms of lower abdominal fullness and pollakisuria. CT scan and MRI revealed bilateral ovarian tumors, which showed heterogeneous masses. 18F-FDG PET revealed strong uptake by the abdominal masses, and the maximum standardized uptake value (SUVmax) was 12.5. Abnormal uptake was not shown by other regions. An exploratory laparotomy was performed. Histological findings revealed diffuse large B-cell lymphoma. The clinical stage was IV according to the Ann Arbor system. International prognostic index (IPI) was 3 (high-intermediate risk). Chemotherapy was administered consisting of three courses of an R-CHOP regimen, and 18F-FDG PET and CT scan revealed no signs of involvement 3 months after initiation of the chemotherapy. 18F-FDG PET was a useful method for staging and assessment of the therapeutic response in primary ovarian lymphoma.     

Usefulness of Combined Metabolic–Volumetric Indices of 18F-FDG PET/CT for the Early Prediction of Neoadjuvant Chemotherapy Outcomes in Breast Cancer

Purpose

The purpose of this study was to investigate the usefulness of metabolic-volumetric indices of ¹⁸F- fluorodeoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) for the evaluation of neoadjuvant chemotherapy outcomes in breast cancer.

Methods

Twenty-four patients with locally advanced breast cancer were enrolled in the study. They underwent baseline ¹⁸F-FDG PET/CT scan and received four or six cycles of neoadjuvant chemotherapy, interim ¹⁸F-FDG PET/CT was done after second cycle of chemotherapy. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesions were calculated. Reduction rates of these parameters were obtained between baseline and interim ¹⁸F-FDG PET/CT. Chemotherapy outcomes were assessed using tumor size reduction rate and histological grading system (Miller and Payne system). Reduction rates of SUVmax, MTV, and TLG correlated with chemotherapy outcomes.

Results

MTV and TLG reduction rates showed significant correlation with tumor size reduction rate (R = 0.68, P = 0.0004; R = 0.62, P = 0.002, respectively). However, SUVmax reduction rate showed no significant correlation. MTV and TLG reduction rates were significantly higher in responders than nonresponders, as determined by Miller and Payne system (P < 0.0007, P < 0.002). However, SUVmax reduction rate showed no significant difference. On ROC analysis, the area under the MTV and TLG curves was 0.886, and that of SUVmax was 0.743. Sensitivity, specificity, positive predictive value, and negative predictive value to predict histopathologic response were the same for MTV and TLG, and the values were 100 %, 85.7 %, 83.3 %, and 100 %, respectively (at the reduction rate of 93.2 % for MTV, and 95.8 % for TLG).

Conclusion

Changes of metabolic–volumetric indices successfully reflected the neoadjuvant chemotherapy outcomes. MTV and TLG could be robust indices in discriminating pathologic responder as SUVmax, after neoadjuvant chemotherapy.     

Clinical significance of 18F-α-methyl tyrosine PET/CT for the detection of bone marrow invasion in patients with oral squamous cell carcinoma: comparison with 18F-FDG PET/CT and MRI

Objective

L-3-[¹⁸F]-fluoro-α-methyl tyrosine (¹⁸F-FAMT) is an amino acid tracer for positron emission tomography/computed tomography (PET/CT) which specifically transported into cancer cells by L-type amino acid transporter 1 (LAT1). LAT1 overexpression in tumors is significantly correlated with cell proliferation and angiogenesis. ¹⁸F-FAMT PET/CT, fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT and magnetic resonance imaging (MRI) were compared for their diagnostic performance in the detection of bone marrow invasion in patients with oral squamous cell carcinoma (OSCC).

Methods

Twenty-seven patients with OSCC on the upper or lower alveolar ridge underwent staging by MRI, ¹⁸F-FDG PET/CT and ¹⁸F-FAMT PET/CT studies before surgery. Post-surgical pathologic examination was used as the standard to determine the final diagnoses. The possibility of bone marrow invasion on MRI, ¹⁸F-FDG PET/CT and ¹⁸F-FAMT PET/CT were usually graded retrospectively into five-point score. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated according to the obtained scores.

Results

As the sensitivity of ¹⁸F-FDG PET/CT was highest (100 %) among that of MRI (95 %) and ¹⁸F-FAMT PET/CT (90 %), the specificity of ¹⁸F-FAMT PET/CT was highest (85.7 %) among that of MRI (57 %) and ¹⁸F-FDG PET/CT (14.3 %). The size of pathological tumor was accorded with that detected by ¹⁸F-FAMT PET/CT and was smaller than that detected by ¹⁸F-FDG PET/CT (P < 0.01). Significant difference was not found between ¹⁸F-FAMT PET tumor volume and pathological tumor volume.

Conclusions

¹⁸F-FAMT PET/CT was useful and more specific than MRI or ¹⁸F-FDG PET/CT in the detection of bone marrow invasion of OSCC and may contribute to minimize the extent of resection in oral surgery patient.     

Feasibility of PET Template-Based Analysis on F-18 FP-CIT PET in Patients with De Novo Parkinson’s Disease

Purpose

The aim of this study was to evaluate the feasibility of FP-CIT PET template-based quantitative analysis on F-18 FP-CIT PET in patients with de novo Parkinson’s disease (PD), compared with MR-based and manual methods. We also assessed the correlation of quantitative parameters of those methods with clinical severity of the disease.

Methods

Forty patients with de novo PD underwent both MRI and F-18 FP-CIT PET. Images were spatially normalized to a standardized PET template. Mean counts of 4 ROIs: putamen, caudate, occipital cortex and cerebellum, were obtained using the quantification program, Korean Statistical Probabilistic Anatomical Map (KSPAM). Putamen-to-caudate ratio (PCR), asymmetry index (ASI), specific-to-nonspecific ratios with two different references: to occipital cortex (SOR) and cerebellum (SCR) were compared. Parameters were also calculated from manually drawn ROI method and MR-coregistrated method.

Results

All quantitative parameters showed significant correlations across the three different methods, especially between the PET-based and manual methods. Among them, PET-based SOR and SCR values showed an excellent correlation and concordance with those of manual method. In relationship with clinical severity, only ASI achieved significantly inverse correlations with H&Y stage and UPDRS motor score. There was no significant difference between the quantitative parameters of both occipital cortex and cerebellum in all three methods, which implied that quantitation using PET-based method could be reproducible regardless of the reference region.

Conclusions

Quantitative parameters using FP-CIT PET template-based method correlated well with those using laborious manual method with excellent concordance. Moreover, PET-based quantitation was less influenced by the reference region than MR-based method. It suggests that PET-based method can provide objective and quantitative parameters quickly and easily as a feasible analysis in place of conventional method.     

A Case of Meigs’ Syndrome: The 18F-FDG PET/CT Findings

The findings of an ovarian mass with marked ascites and pleural effusion are highly suggestive of malignancy, especially in a postmenopausal female with an elevated level of CA-125. However, benign conditions such as Meigs’ syndrome should be considered in the differential diagnosis if the primary mass shows benign features. ¹⁸F-FDG is known to be useful to differentiate between malignant and benign diseases, and this utility is also promising in the case of ovarian tumor. We present here a case of Meigs’ syndrome that was evaluated by ¹⁸F-FDG PET/CT, and this helped the preoperative diagnosis be made. ¹⁸F-FDG PET/CT is a promising modality to diagnose the pathological character of an ovarian tumor preoperatively, which can lead to a proper therapeutic plan.     

Radiography,Bone Scan,and F-18 FDG PET/CT Imaging Findings in a Patient with Paget’s Disease

Background

A 52-year-old female patient sought evaluation at our hospital for an incidental abnormal finding on an abdominal radiograph.

Methods

The initial radiograph showed irregular sclerotic changes involving the right pelvic bone. At the same time, bone scintigraphy showed intense hot uptake in the right iliac and pubic bones. CT images showed characteristic thickening of the pelvic brim, suggesting the mixed phase of Paget’s disease.

Results

The level of alkaline phosphatase (ALP) was 266 IU/l. ¹⁸F-FDG PET/CT images also showed diffusely increased ¹⁸F-FDG uptake in the right pelvic bone. However, the findings of ¹⁸F-FDG PET/CT were less notable than those of bone scintigraphy.

Conclusion

We report the imaging findings of a patient with Paget’s disease evaluated by radiography, bone scintigraphy, and ¹⁸F-FDG PET/CT.     

Whole-body 18F-FDG PET/CT for M staging in the patient with newly diagnosed nasopharyngeal carcinoma: Who needs?

ObjectiveAlthough whole-body fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) (¹⁸F-FDG PET/CT) is commonly used for M staging of newly diagnosed nasopharyngeal carcinoma (NPC), some patients may not benefit from this procedure. The present study investigated which patients require this modality for M staging.MethodsWhole-body ¹⁸F FDG PET/CT results and clinical data were collected for 264 patients with newly diagnosed NPC. The relationships between distant metastasis and age, gender, pathological type, lesion size, SUVmax-T, T staging, N staging, SUVmax-N and Epstein-Barr virus (EBV) quantity were retrospectively analysed to identify factors associated with increased risk.ResultsOf the 264 patients, only 37 (14.0%) were diagnosed with distant metastasis. Using multiple logistic regression analysis, EBV-positivity (OR = 13.1; 95% CI:1.61,106.80), N staging (OR = 3.05; 95% CI:1.41,6.63) and T staging (OR = 2.16; 95% CI:1.10, 4.24) were significantly related to distant metastasis (all P < 0.05). EBV DNA levels ≥ 9000 copies/ml, N3 stage and T4 stage were identified as high risk factors. A low risk of distant metastasis was found in patients with 0–1 risk factors and in those with 2 specific risk factors, T3/T4 and N2/N3 staging. Patients with EBV DNA levels ≥9000 copies/ml and N3 or T4 staging and those with 3 risk factors had a medium or high risk, with a much higher incidence of distant metastasis (χ² = 29.896, P = 0.000), and needed a whole-body ¹⁸F FDG PET/CT for M staging.ConclusionsDue to the low incidence of distant metastasis, only patients with medium or high risk need to undergo a whole-body scan.     

Usefulness of PET–CT in the assessment of suspected recurrent colorectal carcinoma

Purpose

To evaluate the usefulness of PET/CT in detecting recurrent colorectal carcinoma (CRCR) in patients subsequent to colonic resection or rectal amputation and to compare it with the PET part of integrated FDG-PET/CT.

Materials and methods

PET/CTs from 32 patients with suspected CRCR were studied. Histology, clinical follow-up and additional imaging served as the gold standard. The sensitivity, specificity, positive and negative predictive values (PPV, NPV), and accuracy of PET as well as integrated PET/CT were calculated and compared for each of (a) intra-abdominal extra-hepatic recurrences, (b) extra-abdominal and/or hepatic recurrences, and (c) any form of CRCR.

Results

PPV, sensitivity, NPV, specificity and accuracy of PET in detecting intra-abdominal extra-hepatic CRCR were, respectively, 85.7%, 85.7%, 88.9%, 88.9%, and 87.5% compared with 92.9%, 92.9%, 94.5%, 94.5%, and 93.8%, respectively, for PET/CT. The corresponding values for the detection of extra-abdominal and/or hepatic CRCR were 84.6%, 84.6%, 89.5%, 89.5%, and 87.5% for PET versus 100%, 92.3%, 95%, 100%, and 96.9% for PET/CT. For all forms of recurrence, the corresponding values for PET were 80%, 80%, 66.7%, 66.7%, and 75%, respectively, compared with 94.5%, 90%, 84.6%, 91.7%, and 90.6%, respectively, for PET/CT.

Conclusion

PET/CT enhances the accuracy and specificity of diagnosis of CRCRa. PET/CT grows to reach prominent roles for imaging and restaging of patients after colorectal carcinoma resection.     

Role of 18F-FDG PET/CT for detection of recurrence and metastases in renal cell carcinoma—are we underusing PET/CT?

PURPOSEThe aim of this study was to compare ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography (¹⁸F-FDG PET/CT) scan with computed tomography (CT) scan for detecting recurrence and metastasis in renal cell carcinoma patients.METHODSThis retrospective study included patients from October 2013 to April 2017. Contrast-enhanced CT and PET/CT scans were compared and correlated with histopathology or/and follow-up studies.RESULTSSeventy-six patients, 60 males, were included. Lesions included primary renal, recurrent renal fossa lesions, lymph nodes, and distant metastatic lesions. Of 176 malignant lesions, CT detected 157 lesions; of which, 154 were true positive. Twenty-two false-negative lesions showed abnormal FDG uptake. CT scan had positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity, and accuracy of 98.0%, 37.1%, 87.5%, 81.2%, and 86.9%, respectively. All 176 lesions were PET/CT-positive. PET/CT had PPV, NPV, sensitivity, specificity, and accuracy of 100% each. The specificity and NPV of PET/CT were superior (P < .05). CONCLUSIONPET/CT appears more accurate than CT scan for detecting metastasis and recurrence in renal cell carcinoma patients.

Main points

• Positron emission tomography–computed tomography (PET/CT) has a significantly higher specificity and negative predictive value than CT scan for detection of metastasis and recurrence in patients with renal cell carcinoma.
• PET/CT scan is a better imaging technique compared to CT scan for follow-up imaging.

Renal cell carcinoma (RCC) is the most common solid kidney cancer. The incidence in Asian population is 1.1-6.0/100 000. World over, the 5-year survival rate is 68.4%.¹Localized RCC patients treated surgically usually have favorable outcomes. However, about 20%-40% patients later develop distant metastases. The main aim of postoperative follow-up is early detection of local recurrence and/or distant metastases. Post-surgery follow-up imaging is commonly done with conventional imaging modalities (CIM), mainly computerized tomography (CT) scan. These have certain limitations in assessing local recurrence due to postoperative changes such as fibrosis, adjacent organs occupying the space of the renal fossa, the presence of surgical clips causing metallic artifacts, and other such changes.About one-fourth of the patients are found to be metastatic at initial presentation, with very few (<5%) having single-site metastasis.²¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography scan (¹⁸F-FDG PET/CT) provides both anatomical details and functional information. PET/CT has better specificity (83%-100%) and sensitivity (80%-100%) as compared with CT scan or PET scan alone.^2-5 PET/CT is particularly useful for detection of involvement of lymph nodes. These are often not identified on CT scan (even though they are involved), which uses the 1 cm size criteria. CT interpretation of the renal fossa (post-nephrectomy) is difficult due to post-treatment changes. However, the metabolic activity of the tumor is not affected by these factors. Therefore, PET/CT can identify renal bed recurrence earlier and better than CT scan.³During the initial staging of RCC, contrast-enhanced CT scan of the chest, abdomen, and pelvis is the modality of choice. However, PET/CT scan images the whole body (head to toe) along with a contrast-enhanced CT examination in one procedure non-invasively. Since PET/CT relies on changes in metabolic activity of tissues, early detection of pathological areas is possible even before anatomic changes are apparent.³In cases with impaired renal function, a regional abdomino pelvic magnetic resonance imaging (MRI) is the preferred imaging choice due to its high soft-tissue resolution as many lesions can be missed on a non-contrast CT scan. Now in such cases, whole-body PET/CT scan can also be performed with non-contrast CT. Current guidelines do not recommend PET/CT as the initial diagnostic imaging modality of choice in RCC. However, studies have shown PET/CT to be better than conventional imaging like CT for detecting local recurrence and distant metastases.² Detection of distant metastases and accurate restaging of RCC are important because this can lead to changes in the treatment plan.We conducted this study to compare CT scan with PET/CT for detecting recurrence and metastasis in RCC patients.     

Unusual Horner’s Syndrome in Recurrent Breast Cancer: Evaluation Using <Superscript>18</Superscript>F-FDG PET/CT

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner’s syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner’s syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner’s syndrome using FDG PET/CT.