RESUMO
OBJECTIVE. Fluciclovine is a synthetic radiolabeled amino acid analog used for imaging of biochemical recurrent prostate cancer. Uptake of fluciclovine is mediated by several amino acid transporters, including alanine-serine-cysteine transporter 2 and large neutral amino acid transporters, which are known to be overexpressed in other malignancies. CONCLUSION. Knowledge of the common patterns of prostate cancer recurrence, in addition to what other neoplasms can show uptake, is critical for accurate study interpretation.
Assuntos
Ácidos Carboxílicos , Ciclobutanos , Metástase Neoplásica/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Diagnóstico Diferencial , Humanos , Masculino , Compostos RadiofarmacêuticosRESUMO
Neuroendocrine neoplasms (NEN) are rare tumors arising from neuroendocrine cells. NEN are ideally suited for a theragnostic approach due to their specific expression of somatostatin receptors (SSTR). SSTR imaging of NEN dates back to the 1980s, but has evolved recently due to the introduction of more sensitive SSTR PET radiotracers. SSTR PET is a primary imaging modality for identifying NEN and characterizing SSTR expression. SSTR PET is complementary to anatomic imaging for assessing tumor response to treatment. SSTR PET is mandated to determine eligibility for peptide receptor radionuclide therapy. Here, the role of imaging to aid management of NEN is reviewed.
Assuntos
Tumores Neuroendócrinos , Receptores de Somatostatina , Humanos , Tumores Neuroendócrinos/diagnóstico por imagem , Receptores de Somatostatina/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodosRESUMO
OBJECTIVE: Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor. The purpose of this review is to provide a comprehensive description of the staging, workup, treatment, and follow-up of MCC. CONCLUSION: Sentinel lymph node mapping and PET/CT are the cornerstones of staging of MCC. MCC is a radiosensitive tumor, and hence radiotherapy plays a major role in its management. Close follow-up with PET/CT helps in detecting recurrences of MCC.
Assuntos
Carcinoma de Célula de Merkel/diagnóstico , Diagnóstico por Imagem , Carcinoma de Célula de Merkel/patologia , Carcinoma de Célula de Merkel/terapia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Biópsia de Linfonodo Sentinela , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Merkel cell carcinoma (MCC) is a rare and lethal cutaneous neuroendocrine carcinoma. Imaging is crucial for accurate staging, which remains a strong predictor of survival, as well as earlier detection of recurrence and progression, which are common despite aggressive management. There is no consensus on the role of initial and subsequent imaging for MCC. OBJECTIVE: We sought to evaluate the use of 2-fluoro-[(18)F]-deoxy-2-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the management of MCC. METHODS: In all, 270 FDG-PET/CT studies were performed in 97 patients with pathology-proven MCC at the Dana-Farber/Brigham and Women's Cancer Center, Boston, Mass, from August 2003 to December 2010. RESULTS: FDG-PET/CT scans were obtained as part of the initial (61 scans in 61 patients) and subsequent (209 scans in 79 patients) treatment strategies. MCCs were FDG-avid with a mean maximum standardized uptake value of primary lesions of 6.5 (range 1.3-12.9) and a mean maximum standardized uptake value of regional and distant metastases of 7.2 (range 1.5-9.9). FDG-PET/CT upstaged 16% of patients who underwent baseline scans. FDG-PET/CT studies showed that bone and bone-marrow metastases were more common than previously reported, and were often undetected by CT. LIMITATIONS: Our study is limited by its retrospective design, and potential referral bias associated with a tertiary care center. CONCLUSIONS: FDG-PET/CT performed as part of the initial management strategy tended to upstage patients with more advanced disease. FDG-PET/CT performed as part of the subsequent treatment strategy identified metastatic disease, particularly in bone/bone marrow, which was not seen on CT. FDG-PET/CT imaging is a valuable staging and restaging tool in MCC management.
Assuntos
Carcinoma de Célula de Merkel/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Neoplasias Cutâneas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
OBJECTIVE: PET/CT with (18)F-FDG shows metabolically active disease and is widely used for the diagnosis and follow-up of patients with cancer. Nonmetabolically active renal pathology may be missed without close attention to the CT portion of the study, whereas metabolically active pathology may be missed on PET because of physiologic tracer excretion in the kidneys. This article illustrates primary lesions of the kidney on FDG PET/CT with emphasis on key anatomic features and the appearance of tracer uptake. CONCLUSION: Close attention to both the FDG PET and CT portions of the study is essential to interpret renal pathology correctly on FDG PET/CT examinations.
Assuntos
Neoplasias Renais/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Diagnóstico Diferencial , Fluordesoxiglucose F18 , Humanos , Neoplasias Renais/patologia , Compostos RadiofarmacêuticosRESUMO
OBJECTIVE: PET/CT with (18)F-FDG is a powerful tool to evaluate patients with hematologic malignancy or to assess the burden of metastatic disease from solid tumors. Metabolically active renal pathology associated with lymphoma, leukemia, or metastatic disease can be missed without close attention to both the PET and CT portions of the study because of physiologic FDG excretion in the kidneys. This article illustrates the appearance of tracer uptake and the key anatomic features of lymphoma, leukemia, and metastatic disease involving the kidney on FDG PET/CT. CONCLUSION: Close attention to both the FDG PET and CT portions of an FDG PET/CT study is essential to evaluate the kidneys in oncology patients.
Assuntos
Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/secundário , Leucemia/diagnóstico por imagem , Leucemia/patologia , Linfoma/diagnóstico por imagem , Linfoma/patologia , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Fluordesoxiglucose F18 , Humanos , Compostos RadiofarmacêuticosRESUMO
Radiation therapy is an integral component of the treatment of breast cancer. The indications and type of radiation therapy vary depending on disease invasiveness and stage. Imaging is the cornerstone for radiation therapy planning. While conventional imaging with CT remains the primary modality for radiation treatment planning locally in the breast, molecular imaging with [18F]FDG-PET/CT identifies additional occult disease that may help alter the local radiation therapy plan or treat oligometastatic disease. The ultimate effects on long-term outcomes remain to be determined. This article reviews the role of imaging in radiation planning for breast cancer.
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Neoplasias da Mama , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Feminino , Fluordesoxiglucose F18 , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons , Compostos RadiofarmacêuticosRESUMO
Extraosseous Tc-MDP uptake on bone scans is frequently encountered and has a broad differential diagnosis. A small subset of such patients can present with intestinal Tc-MDP uptake. We present the case of a 35-year-old woman with status after right nephrectomy for renal cell carcinoma, being followed with bone scan for osseous metastases. Follow-up imaging revealed new faint Tc-MDP uptake in the right hemiabdomen. Correlation with contrast-enhanced CT localized this uptake to the ascending colon. Enteric Tc-MDP uptake and its association with iodinated contrast should be considered in the differential diagnosis of extraosseous enteric Tc-MDP uptake.
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Neoplasias Ósseas/diagnóstico por imagem , Colo/diagnóstico por imagem , Neoplasias Renais/patologia , Tomografia Computadorizada por Raios X , Adulto , Neoplasias Ósseas/secundário , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Compostos Radiofarmacêuticos , Medronato de Tecnécio Tc 99mRESUMO
177Lu-DOTATATE is a radiolabeled somatostatin analog that has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors in adults. Radionuclide therapies have been administered for many years within nuclear medicine departments in North America. However, in comparison to other radiotherapies, 177Lu-DOTATATE peptide receptor radionuclide therapy involves more planning, coordination, concomitant medication administration (antiemetic medications and amino acids), and direct patient care. To date, various methods have been used in multiple centers during the NETTER-1 trial and the provision of patient care. As participants in the phase 3 NETTER-1 trial and the subsequent expanded-access program for the administration of 177Lu-DOTATATE studies, as well as recently starting postapproval clinical care, we have administered 61 177Lu-DOTATATE therapies at the time of this manuscript submission (13 in the NETTER-1 trial, 39 in the expanded-access program, and 9 clinically) at the Dana-Farber Cancer Institute and here share our procedures, personnel training, and workflow to help other centers establish programs for this FDA-approved 177Lu-DOTATATE peptide receptor radionuclide therapy.
Assuntos
Medicina Nuclear , Octreotida/análogos & derivados , Compostos Organometálicos/uso terapêutico , Guias de Prática Clínica como Assunto , Radioterapia/métodos , Receptores de Somatostatina/metabolismo , Termos de Consentimento , Humanos , Neoplasias Intestinais/metabolismo , Neoplasias Intestinais/radioterapia , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/radioterapia , Medicina Nuclear/legislação & jurisprudência , Octreotida/uso terapêutico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/radioterapia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/radioterapiaRESUMO
OBJECTIVE: The clinical benefit of surveillance imaging in endometrial cancer remains undefined. This retrospective study was conducted to evaluate the positive predictive value (PPV) of surveillance imaging in endometrial cancer. METHODS: A total of 128 patients in first remission after treatment for endometrial cancer (uterine papillary serous, clear cell, stage III endometroid) who had surveillance imaging were retrospectively identified. The surveillance period was defined from the time of first-negative scan after treatment to the time when treatment was started for recurrent disease. Reports of surveillance scans were reviewed for the presence or absence of findings. The primary outcome was PPV of surveillance imaging. Cost and radiation exposure from surveillance imaging were also evaluated. RESULTS: A total of 128 patients had 707 surveillance scans (computed tomography, positron emission tomography-computed tomography with 2-deoxy-2-[18F]fluoro-d-glucose, magnetic resonance image, and bone scans). Median follow-up was 54 months (range: 9-173). Of all, 47 patients (37%) started therapy for recurrent endometrial cancer at the discretion of the treating physician. PPV of all surveillance imaging was 57.7%. Per patient, the mean number of surveillance scans was 5.6 (range: 2-21). The mean cost of imaging was $4200 (range: $1200-$18,700) and mean radiation exposure was 109.6mSV (range: 16-445mSv). CONCLUSIONS: Surveillance imaging detected a significant number of recurrences in patients with high-risk endometrial cancer at a reasonable cost related to the overall risk. Well-designed prospective imaging trials are warranted to assess the clinical benefit of surveillance imaging.
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Diagnóstico por Imagem/economia , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Endométrio/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Vigilância da População , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Exposição à Radiação , Indução de Remissão , Estudos RetrospectivosRESUMO
AIM: Suggested cutoff points of blood glucose levels (BGL) before F-FDG PET/CT scanning vary between 120 and 200 mg/dl in current guidelines. This study's purpose was to compare the frequency of abnormal fluorine-18-fluorodeoxyglucose (F-FDG) biodistribution on PET/CT scans of patients with various ranges of abnormal BGL and to determine the effect of BGL greater than 200 mg/dl on F-FDG uptake in various organs. PATIENTS AND METHODS: F-FDG PET/CT scans were retrospectively reviewed for 325 patients with BGL greater than 120 mg/dl at the time of scan and 112 with BGL less than or equal to 120 mg/dl. F-FDG biodistribution was categorized as normal, mildly abnormal, or abnormal by visual analysis of brain, background soft tissue, and muscle. Mean standardized uptake values (SUVmean) in brain, liver, fat (flank), gluteal muscle, and blood pool (aorta) were recorded. F-FDG biodistribution frequencies were assessed using a nonparametric χ-test for trend. Normal organ SUVs were compared using Kruskal-Wallis tests using the following BGL groupings: ≤120, 121-150, 151-200, and ≥201 mg/dl. RESULTS: Although higher BGL were significantly associated with an increased proportion of abnormal biodistribution (P<0.001), most patients with BGL less than or equal to 200 mg/dl had normal or mildly abnormal biodistribution. Average brain SUVmean significantly decreased with higher BGL groupings (P<0.001). Average aorta, gluteal muscle, and liver SUVmean did not significantly differ among groups with BGL greater than 120 mg/dl (P=0.66, 0.84, and 0.39, respectively), but were significantly lower in those with BGL less than or equal to 120 mg/dl (P≤0.001). Flank fat SUVmean was not significantly different among BGL groups (P=0.67). CONCLUSION: Abnormal F-FDG biodistribution is associated with higher BGL at the time of scan, but the effects are negligible or mild in most patients with BGL less than 200 mg/dl. Although mildly increased soft tissue uptake is seen with BGL greater than 120 mg/dl, decline in brain metabolic activity correlated the most with various BGL.
Assuntos
Glicemia/metabolismo , Fluordesoxiglucose F18/farmacocinética , Neoplasias/metabolismo , Artefatos , Humanos , Neoplasias/sangue , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Retrospectivos , Distribuição TecidualRESUMO
PURPOSE: The aim of this study was to describe FDG-PET/CT findings in extramedullary multiple myeloma (EMM) correlating them with clinical outcome. METHODS: In this institutional review board-approved HIPAA-compliant retrospective study, we reviewed the FDG-PET/CT scans of 35 patients with EMM (16 women, 19 men; mean age, 56 years; median follow-up after the diagnosis of EMM, 14 months) out of 156 patients diagnosed with MM at our institute between 2004 and 2012. The distribution and metabolic activity of EMM on the scans were reviewed. Clinical data were extracted from electronic medical records. Statistical analysis was performed to determine differences in outcome based on time of detection and distribution of EMM. RESULTS: Extramedullary multiple myeloma was present at diagnosis in 12 of 35 patients and during disease progression in 23 of 35 patients. Indications for FDG-PET/CT were initial staging (12/35), restaging for disease progression (18/23), or assessment of response to therapy (5/23). Extramedullary multiple myeloma was FDG-avid (mean SUVmax, 8.4; range, 1.2-31), solitary in 10 patients (29%) and multifocal in 25 patients (71%). Two patterns of distribution were noted: direct extension of osseous plasmacytomas in 18 (51%) of 35 patients and hematogeneous/lymphangiogenic dissemination in 33 (94%) of 35 patients. Mean SUVmax in lesions with direct osseous extension was statistically higher than hematogeneous/lymphangiogenic EMM (Mann-Whitney U test, P = 0.03). The most common sites of hematogeneous/lymphangiogenic spread of EMM were lymph nodes (21/35 [60%]), liver (10/35 [29%]), lung (9/35 [26%]), muscles away from bones (7/35 [20%]), and peritoneum/mesentery (7/35 [20%]). There was no statistically significant difference in distribution of EMM at presentation and during disease progression (χ2 test, P > 0.05); 24 (69%) of 35 patients died (median interval after diagnosis of EMM, 7 months). There was no statistically significant difference in outcome for EMM at presentation and during disease progression (log-rank test, P = 0.068). Involvement of any of the following 3 sites: liver, lung, and muscles away from bones, was associated with statistically significant shorter survival (log-rank test, P = 0.0008). CONCLUSIONS: Extramedullary multiple myeloma is more often seen on FDG-PET/CT in the context of a hematogeneous/lymphangiogenic spread pattern and less commonly as a direct extension of osseous plasmacytomas. Extramedullary multiple myeloma has poor outcome whether detected at presentation or during follow-up. Extramedullary multiple myeloma involving the liver, lung, and muscles was associated with shorter survival in our study.
Assuntos
Fluordesoxiglucose F18 , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico por imagem , Mieloma Múltiplo/patologia , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
An 84-year-old man with history of left forehead melanoma was found on a restaging F-FDG PET/CT scan with hypermetabolic lung nodules and a mildly FDG-avid soft tissue nodule posterior to the umbilicus. Biopsy of a right lower lobe nodule revealed metastatic melanoma. Follow-up posttreatment PET/CT scan showed complete resolution of lung nodules and unchanged FDG uptake at the level of the umbilicus. Review of the patient's medical history revealed a remote history of umbilical hernia repair. We present a case of postsurgical plugoma mimicking the appearance of melanoma metastasis on FDG PET/CT.
Assuntos
Hérnia Abdominal/diagnóstico por imagem , Melanoma/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Umbigo/diagnóstico por imagem , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Fluordesoxiglucose F18 , Humanos , Masculino , Melanoma/patologia , Metástase Neoplásica , Compostos RadiofarmacêuticosRESUMO
A 57-year-old man with metastatic melanoma developed colitis secondary to ipilimumab, a known immune-related adverse event (irAE). The patient then received pembrolizumab immunotherapy, an anti-programmed-death-receptor-1 (PD-1) antibody. Restaging FDG PET/CT study following 3 cycles of therapy demonstrated diffuse increased FDG uptake throughout the body of the pancreas associated with fat stranding in the peripancreatic region, suggestive of pembrolizumab-induced pancreatitis. Although the patient was clinically asymptomatic, diagnosis was biochemically confirmed with elevated amylase and lipase levels. In the era of immunotherapy, it will be critical to recognize irAEs early to allow prompt initiation of appropriate therapy and reduce the risk of long-term sequelae.
Assuntos
Anticorpos Monoclonais/efeitos adversos , Imunoterapia/efeitos adversos , Melanoma/terapia , Pancreatite/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Fluordesoxiglucose F18 , Humanos , Ipilimumab , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Pancreatite/induzido quimicamente , Compostos RadiofarmacêuticosRESUMO
FDG-PET/CT has been evaluated in a variety of gynecologic malignancies in a variety of settings and is approved by the Centers for Medicare & Medicaid Services for the initial and subsequent treatment strategies of these malignancies. Cervical cancer is typically very FDG avid, and FDG-PET/CT appears to be most valuable for initial staging, radiation therapy planning, and detection of recurrent disease. For ovarian cancer, the most value of FDG-PET/CT appears to be for detecting recurrent disease in the setting of rising CA-125 level and negative or equivocal anatomical imaging studies. Initial studies evaluating response to therapy are promising and further work in this area is needed. FDG uptake in both nonmalignant and physiological processes in the pelvis can make interpretation of FDG-PET/CT in this region challenging and knowledge of these entities and patterns can avoid misinterpretation. Some of the most common findings relate to the cyclic changes that occur as part of the menstrual cycle in premenopausal women. Mucinous tumors and low-volume or peritoneal carcinomatosis are causes of false-negative results on FDG-PET/CT studies. As new tracers are developed, comparisons with patient outcomes and standards of care (eg, FDG-PET/CT) will be needed.
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Neoplasias dos Genitais Femininos/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Fluordesoxiglucose F18 , HumanosRESUMO
Efforts have been made to minimize the damage to adjacent normal tissues during radiotherapy, primarily by shifting from the use of conventional radiotherapy to more advanced techniques. Reviewing the overall pattern on combined anatomic and functional imaging can enhance diagnostic accuracy. Several radiotracers can be used; [(18)F]fluorodeoxyglucose is the most common. Familiarity with the type and timing of previous radiation therapy, the spectrum of imaging findings after radiation injury, and the appropriate use of the different radiotracers can be crucial. This article summarizes postradiation histologic findings and multimodality imaging findings, with emphasis on PET/computed tomography.
Assuntos
Fluordesoxiglucose F18/farmacocinética , Lesões por Radiação/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Osso e Ossos/patologia , Osso e Ossos/efeitos da radiação , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/efeitos da radiação , Neoplasias Encefálicas/radioterapia , Trato Gastrointestinal/patologia , Trato Gastrointestinal/efeitos da radiação , Humanos , Pulmão/patologia , Pulmão/efeitos da radiação , Imageamento por Ressonância Magnética , Imagem Multimodal , Necrose/diagnóstico por imagem , Neoplasias/radioterapia , Lesões por Radiação/patologia , Cintilografia , Radioterapia/efeitos adversos , Medula Espinal/patologia , Medula Espinal/efeitos da radiação , Distribuição Tecidual , Tomografia Computadorizada por Raios X , Sistema Urinário/patologia , Sistema Urinário/efeitos da radiaçãoRESUMO
PURPOSE: Use of 2[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in postchemotherapy response assessment in follicular lymphoma is still a controversial issue. Here, we conducted the first systematic review and meta-analysis to determine the predictive value of FDG-PET in predicting outcome after chemotherapy of follicular lymphoma. EXPERIMENTAL DESIGN: Comprehensive literature search in Ovid-MEDLINE and EMBASE databases was performed to identify studies which evaluate predictive value of end-therapy PET and/or computed tomography (CT) in patients with follicular lymphoma. To quantitatively compare the predictive value of PET and CT, pooled hazard ratios (HRs) comparing progression-free survival (PFS) between patients with positive and negative results were adopted as the primary indicators for meta-analysis. To explore the efficiency in determining complete remission (CR), pooled CR rates of PET- and CT-based response criteria were calculated. Pooling of these parameters was based on the random-effects model. RESULTS: Review of 285 candidate articles identified eight eligible articles with a total of 577 patients for qualitative review and meta-analysis. The pooled HRs of end-therapy PET and CT were 5.1 [95% confidence interval (CI), 3.7-7.2] and 2.6 (95% CI, 1.2-5.8), respectively, which implies that PET is more predictive of PFS after chemotherapy than CT. The pooled CR rates of PET- and CT-based response criteria were 75% (95% CI, 70-79%) and 63% (95% CI, 53-73%), respectively, which implies that PET is more efficient in distinguishing CR (without residual disease) from other states with residual disease. In addition, qualitative systematic review indicates the same findings. CONCLUSIONS: Consistent evidence favoring PET-based treatment assessment should be considered in the management of patients with follicular lymphoma.