PET/CT in leukemia: utility and future directions

2-Deoxy-2-[18F]fluoro-d-glucose PET/computed tomography ([18F]FDG PET/CT) has proven to be a sensitive method for the detection and evaluation of hematologic malignancies, especially lymphoma. The increasing incidence and mortality rates of leukemia have raised significant concerns. Through the utilization of whole-body imaging, [18F]FDG PET/CT provides a thorough assessment of the entire bone marrow, complementing the limited insights provided by biopsy samples. In this regard, [18F]FDG PET/CT has the ability to assess diverse types of leukemia The utilization of [18F]FDG PET/CT has been found to be effective in evaluating leukemia spread beyond the bone marrow, tracking disease relapse, identifying Richter's transformation, and assessing the inflammatory activity associated with acute graft versus host disease. However, its role in various clinical scenarios in leukemia remains unacknowledged. Despite their less common use, some novel PET/CT radiotracers are being researched for potential use in specific scenarios in leukemia patients. Therefore, the objectives of this review are to provide a thorough assessment of the current applications of [18F]FDG PET/CT in the staging and monitoring of leukemia patients, as well as the potential for an expanding role of PET/CT in leukemia patients.

Synchronous Colorectal and Prostate Cancer: Dual PET/CT Approach for Detecting and Distinguishing Metastatic Patterns

Prostate cancer (PC) and colorectal cancer (CRC) are two of the leading causes of cancer-related mortality. The incidence of synchronous neoplasms in patients with CRC is increasing, though synchronous PC and CRC remains a rare occurrence in clinical practice. Early diagnosis, accurate staging, and characterization of tumors are essential for selecting patient-tailored therapy. The origin of metastatic disease in synchronous cases presents a challenge for conventional imaging modalities, but advances in molecular imaging have addressed this limitation. Positron emission tomography/computed tomography (PET/CT) is now the preferred modality for assessing synchronous cases. The authors present a 72-year-old male patient with the rare occurrence of two coexisting primary cancers. At first, fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT detected the first colorectal primary tumor extension along with evidence of heterogeneous 18F-FDG activity within an enlarged prostate, warranting further evaluation. Subsequently, gallium-68 prostate-specific membrane antigen (68 Ga-PSMA) PET/CT imaging revealed the second prostate primary cancer with evidence of bone metastases. Adoption of a dual PET/CT approach in cases where biopsy is impractical can achieve accurate staging results during the initial diagnostic workup.

Degenerative lumbar changes have a statistically significant but small effect on trabecular bone score (TBS)-adjusted fracture risk (FRAX)

Trabecular bone score (TBS) assesses trabecular microarchitecture at the lumbar spine and was shown to improve fracture risk prediction compared to bone mineral density (BMD) alone. We investigated whether lumbar degenerative changes (DC) affect TBS and TBS-adjusted 10-year fracture risk assessment (tool) (FRAX) estimates. All patients who underwent BMD and TBS measurements via dual-energy X-ray absorptiometry at our institution between 1/7/2020 and 1/10/2020 were retrospectively evaluated. We identified all patients who had DC in 1 or 2 vertebrae (out of L1-L4) with a BMD T score > 1 unit higher than the remaining 2 to 3 adjacent vertebrae. TBS and BMD were compared between the vertebrae with and without DC. Change in TBS as well as FRAX estimates for major osteoporotic (MOP) and hip fractures after exclusion of the degenerative vertebrae were also determined. Of the 356 eligible patients, 94 met the inclusion criteria. The mean TBS of vertebrae without DC was not significantly different from that of L1 to L4 (1.31 ± 0.12 vs 1.32 ± 0.12, respectively, P = .11). The FRAX estimates after exclusion of the degenerative vertebrae were statistically significantly higher than for L1 to L4 for both MOP and hip fractures (P = .04 and P = .01, respectively). However, the differences were very small. The mean 10-year MOP FRAX estimate after exclusion of degenerative vertebrae was 7.67% ± 4.50% versus 7.55% ± 4.36% for L1 to L4 and the mean 10-year hip FRAX estimate after exclusion of degenerative vertebrae was 2.06% ± 2.01% versus 2.02% ± 1.98% for L1 to L4. Lumbar DC have a statistically significant but only small effect on TBS-adjusted FRAX making it unnecessary to exclude the degenerative vertebrae when computing TBS.

Long-Term Survival Analysis and Prognostic Factors of Arabic Patients with Differentiated Thyroid Carcinoma: A 20-Year Observational Study at the King Hussein Cancer Center (KHCC) Involving 528 Patients

DTC accounts for the majority of endocrine tumors. While the incidence of thyroid cancer has been increasing globally over the past few decades, papillary thyroid carcinoma (PTC) generally shows an excellent prognosis, except in cases with aggressive clinicopathological features. This study aimed to assess the 5- and 10-year overall survival (OS) and progression-free survival (PFS) of 528 Arabic patients diagnosed with primary DTC from 1998 to 2021. Additionally, the study aimed to analyze the impact of various factors on both OS and PFS. An univariable survival analysis was conducted using Kaplan-Meier curves. The 5- and 10-year OS for patients with DTC have exceeded 95%. Additionally, PFS showed very good rates (ranging between 96.5 and 85% at 5 and 10 years, respectively). Age, male gender, risk of recurrence, and distant metastasis were identified as the main negative prognostic factors for both OS and PFS, while RAI treatment was found to be a significant factor in improving OS. Moreover, adherence to the King Hussein Cancer Center's (KHCC) CPG demonstrated significant improvement in PFS. These findings highlight common prognostic factors and favorable outcomes in Arabic patients with DTC treated at a tertiary cancer center using standard of care approaches.

The Prognostic and Diagnostic Value of [18F]FDG PET/CT in Untreated Laryngeal Carcinoma

This study aims to determine the diagnostic accuracy of staging PET/CT and neck MRI in patients with laryngeal carcinoma and to assess the value of PET/CT in predicting progression-free survival (PFS) and overall survival (OS). Sixty-eight patients who had both modalities performed before treatment between 2014 and 2021 were included in this study. The sensitivity and specificity of PET/CT and MRI were evaluated. PET/CT had 93.8% sensitivity, 58.3% specificity, and 75% accuracy for nodal metastasis, whereas MRI had 68.8%, 61.1%, and 64.7% accuracy, respectively. At a median follow-up of 51 months, 23 patients had developed disease progression and 17 patients had died. Univariate-survival analysis revealed all utilized PET parameters as significant prognostic factors for OS and PFS (p-value < 0.03 each). In multivariate analysis, metabolic-tumor volume (MTV) and total lesion glycolysis (TLG) predicted better PFS (p-value < 0.05 each). In conclusion, PET/CT improves the accuracy of nodal staging in laryngeal carcinoma over neck MRI and adds to the prognostication of survival outcomes through the use of several PET metrics.

PET/CT in Hodgkin Lymphoma: An Update

¹⁸F-FDG-PET/CT is now an integral part of the workup and management of patients with Hodgkin's lymphoma (HL). PET/CT is currently routinely performed for staging and for response assessment at the end of treatment. Interim PET/CT is typically performed after 1-4 of 6-8 chemo/chemoimmunotherapy cycles ± radiation for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics such as the standardized uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and their changes with treatment are being investigated as more reproducible and, potentially, more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value. This review highlights the most relevant applications of PET/CT in HL, its strengths and limitations, as well as recent efforts to implement PET/CT-based metrics as promising tools for precision medicine. Finally, the value of PET/CT for response assessment to immunotherapy is discussed.

FDG-PET/CT in the Monitoring of Lymphoma Immunotherapy Response: Current Status and Future Prospects

Cancer immunotherapy has been extensively investigated in lymphoma over the last three decades. This new treatment modality is now established as a way to manage and maintain several stages and subtypes of lymphoma. The establishment of this novel therapy has necessitated the development of new imaging response criteria to evaluate and follow up with cancer patients. Several FDG PET/CT-based response criteria have emerged to address and encompass the various most commonly observed response patterns. Many of the proposed response criteria are currently being used to evaluate and predict responses. The purpose of this review is to address the efficacy and side effects of cancer immunotherapy and to correlate this with the proposed criteria and relevant patterns of FDG PET/CT in lymphoma immunotherapy as applicable. The latest updates and future prospects in lymphoma immunotherapy, as well as PET/CT potentials, will be discussed.

Incidence Trends of Melanoma and Nonmelanoma Skin Cancers in Jordan From 2000 to 2016

PURPOSE

Skin cancers are among the commonest cancers worldwide, and the incidence of melanoma and non-melanoma skin cancer (NMSC) continues to rise worldwide. However, there are no comprehensive reports on skin cancer incidence in Jordan during the past two decades. This report investigates the incidence of skin cancers in Jordan, in particular their time trends for the period 2000-2016.

MATERIALS AND METHODS

Data on malignant melanomas (MMs), squamous cells carcinomas (SCCs), and basal cell carcinomas (BCCs) were extracted from the Jordan Cancer Registry for the period between 2000 and 2016. Age-specific and overall age-standardized incidence rates (ASIRs) were computed.

RESULTS

Two thousand seventy patients were diagnosed with at least one BCC, 1,364 with SCC, and 258 with MM. ASIRs were 28, 19, and 4 per 100,000 person-years for BCC, SCC, and MM, respectively. The BCC:SCC incidence ratio was 1.47:1. The risk of men developing SCCs was significantly higher than women (relative risks [RRs], 1.311; 95% CI, 1.197 to 1.436), but significantly lower for BCCs (RR, 0.929; 95% CI, 0.877 to 0.984) or melanomas (RR, 0.465; 95% CI, 0.366 to 0.591). Persons older than 60 years were at a significantly higher risk of developing SCCs (RR, 1.225; 95% CI, 1.119 to 1.340) or melanomas (RR, 2.445; 95% CI, 1.925 to 3.104), but at a significantly lower risk of developing BCCs (RR, 0.885; 95% CI, 0.832 to 0.941). The overall incidence rates of SCCs, BCCs, and melanomas increased over the 16-year study period, but this was not statistically significant.

CONCLUSION

To our knowledge, this is the largest epidemiologic study regarding skin cancers in Jordan and in the Arab world. Despite low incidence rates in this study, rates are higher than reported regional figures. This is likely due to standardized, centralized, and mandatory reporting of skin cancers, including NMSC.

The development and validation of a novel COVID19 stigma scale among healthcare workers (COVISS-HCWs)

BACKGROUND AND AIM

Fear of coronavirus disease 2019 (COVID-19) and its complications may result in stigmatization of individuals who may carry the virus. This is of special concern to healthcare workers who tolerate additional physical and emotional stress at times of pandemic. The aims of this study are to (1) develop and validate the COVID-19 Stigma Scale (COVISS-HCWs) survey; and (2) investigate the experience of stigma among healthcare workers possibly dealing with COVID-19 patients in five major public hospitals in Damascus, Syria.

METHODS

We divided the sample into two parts and then underwent EFA on the first 350 participants, dividing the 14 questions into two dimensions. Furthermore, CFA was conducted on the other 350 participants to confirm how correctly a hypothesized model matched the factor structure by EFA, as described above. Moreover, the coefficient of determination (R2) and item-scale correlations (standardized factor loading) were estimated to establish the acceptability of the final structure of the COVISS-HCWs. Through a cross-sectional study, a convenience sample of 700 healthcare workers participated in a self-administered questionnaire containing a section for demographic variables and another for newly designed COVISS-HCWs. The scale comprises 14 adapted and novel items that measure two subscales: feelings of perceived harm and inferiority, and avoidance. Descriptive statistics, reliability, and validity were evaluated.

RESULTS

The 14 COVISS-HCWs items were reduced to 11 items with a high Cronbach's α of 0.909. A significant correlation was observed between the responses to each COVISS-HCWs item and the corresponding subscale, and between each subscale and the overall scale. Feeling stigmatized was reported by 9.86% of the participants. Younger age, low socioeconomic status, and higher intensity of contact with COVID-19 patients significantly correlated with higher stigmatization.

CONCLUSIONS

The novel COVISS-HCWs is a reliable and valid tool to evaluate stigma among healthcare workers during the COVID-19 pandemic. The Stigma prevalence among healthcare workers was 9.86%. Therefore, this must be addressed to prevent possible psychosocial and public health repercussions.

Facemask wearing does not impact neuro-electrical brain activity

Given the massive use of facemasks (FMs) during the covid-19 pandemic, concerns have been raised regarding the effect of FMs wearing on overall health. This study aimed at evaluating the effect of surgical FM on brain neuro-electrical activity. Electroencephalography (EEG) background frequency (BGF) and background amplitude (BGA) was performed on 30 volunteers before (baseline), during and after wearing a FM for 60 min. Measurements were done during normal ventilation, hyperventilation and post-hyperventilation (PHVR). Blood gas levels were assessed at baseline and after FM use. EEG analysis concerning baseline (without FM) (BGA), was 47.69 ± 18.60 µV, wearing FM, BGA was 48.45 ± 17.79 µV, post FM use BGA was 48.08 ± 18.30 µV. There were no statistically significant differences between baseline BGA and BGA under FM and post FM. BGF, Baseline data were 10.27 ± 0.79, FM use 10.30 ± 0.76 and post FM use was 10.33 ± 0.76. There were no statistically significant differences between baseline BGF and BGF under FM and post FM. Venous blood gases, and peripheral oxygen saturation were not significantly affected by FM use. Short-term use of FM in young healthy individuals has no significant alteration impact on brain's neuro-electrical activity

68Ga-DOTATOC Embolus Manifestation and Spontaneous Resolution by PET/CT

⁶⁸Ga-labeled somatostatin receptor analogs physiologic distribution patterns have become recognizable among nuclear medicine physicians because of the increasing routine clinical use of this modality in the work-up of neuroendocrine tumors. Some pitfalls during ⁶⁸Ga-labeled somatostatin receptor PET/CT have recently been reported as causes of misdiagnoses. Iatrogenic microembolism as a cause of ¹⁸F-FDG embolus is well-established; however, 68Ga-DOTATOC embolus is not well documented in the literature. In the current case, the presence and the spontaneous resolution of the ⁶⁸Ga-labeled somatostatin receptor analogs embolus during sequential PET/CT are nicely demonstrated. Awareness of this incidental finding would avoid misdiagnosis and unnecessary investigations.

A Striking Case of Perfusion-Metabolism "Flip-Flop" in a Patient With Left Anterior Descending Artery Total Occlusion

ABSTRACT

A 57-year-old man diagnosed with left anterior descending artery chronic total occlusion underwent rest gated 99mTc-MIBI scan showing moderately to markedly decreased perfusion with abnormal wall motion in the apex, anterior, anteroseptal, and apical anterolateral walls. 18F-FDG PET showed a "flip-flop" phenomenon with markedly increased FDG uptake in the hypoperfused regions and absent/markedly decreased uptake in the normally perfused, normokinetic myocardium, presumably due to the predominant use of free fatty acids under normoxic conditions. After coronary artery bypass grafting, left ventricular motion normalized except for surgery-related paradoxical septal motion and the left ventricular ejection fraction improved from 52% to 68%.

Bone Scan in Identification, Assessment of Initial Extent and Response to Therapy in Polymyositis

This is a 51-year-old male who presented with abdominal pain, bilateral proximal upper and lower extremities pain and weakness, and decreased urine output with abnormal kidney function test; Urea and creatinine levels were elevated at 231.5 mg/dl and 11.05 mg/dl, respectively. Initial bone scan showed increased uptake within several muscles suspicious for polymyositis, this was confirmed by biopsy of the right triceps, identified by bone scan as the best superficial biopsy site. Pelvis and thigh MRI demonstrated diffuse hyperintense signal on fluid sensitive sequences involving several muscles. Renal biopsy showed acute tubular injury. He was treated with steroids resulting in significant improvement. A repeat bone scan showed near complete resolution of the muscular uptake seen at presentation. This case nicely illustrates the role of bone scanning in the initial recognition and determination of the extent of polymyositis with identification of a suitable biopsy site as well as assessment of response to treatment.

Assessing potential impact of 2015 American Thyroid Association guidelines on community standard practice for I-131 treatment of low-risk differentiated thyroid cancer: case study of Jordan

OBJECTIVES

The 2015 American Thyroid Association (ATA) guidelines called for significantly more selective ¹³¹I therapy in patients with low-risk differentiated thyroid cancer (DTC). We hypothesized that application of these guidelines would significantly reduce the ¹³¹I activity utilized by an academic tertiary hospital in Jordan.

METHODS

All DTC patients managed at Jordan University Hospital (JUH) between 1/2009 and 6/2019 were classified according to the 2015 ATA risk category and ¹³¹I activity was assigned accordingly. The actual ¹³¹I activity administered was compared with that recommended by the 2015 ATA guidelines.

RESULTS

In total, 135/182 DTC patients (74.2%) managed at JUH underwent ¹³¹I therapy. Of those, 58 (43%) had ATA low-, 58 (43%) intermediate-, and 19 (14%) high-risk disease. The low-, intermediate-, and high-risk DTC patients received an average (±SD) initial ¹³¹I activity of 3.53 ± 0.95, 4.40 ± 1.49, and 5.06 ± 2.52 GBq, respectively. Withholding ¹³¹I therapy altogether in the 2015 ATA low-risk patients would result in decreasing the ¹³¹I activity in the overall patient population by 37%. Withholding ¹³¹I therapy only in low-risk papillary thyroid microcarcinomas while administering 1.11 GBq of ¹³¹I to other low-risk patients would result in 28% reduction of ¹³¹I.

CONCLUSION

This study demonstrates a significant reduction in ¹³¹I therapeutic activity that would be given to DTC patients in an academic tertiary setting in Jordan, following acceptance of the 2015 ATA recommendations. Institutions that adopted the 2015 ATA guidance should measure outcomes in comparison to their historical controls and report those findings, while long-term results of randomized controlled trials are forthcoming.

Positron emission tomography/computed tomography in the management of Hodgkin and B-cell non-Hodgkin lymphoma: An update

¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is now an integral part of lymphoma staging and management. Because of its greater accuracy compared with CT alone, PET/CT is currently routinely performed for staging and for response assessment at the end of treatment in the vast majority of FDG-avid lymphomas and is the cornerstone of response classification for these lymphomas according to the Lugano classification. Interim PET/CT, typically performed after 2 to 4 of 6 to 8 chemotherapy/chemoimmunotherapy cycles with or without radiation, is commonly performed for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-adapted or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics, such as the standardized uptake value, changes (Δ) in the standardized uptake value, metabolic tumor volume, and total lesion glycolysis, are being investigated as more reproducible and potentially more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value, emphasizing the need for more specific molecular probes. This review highlights the most relevant applications of PET/CT in Hodgkin and B-cell non-Hodgkin lymphoma, its strengths and limitations, as well as recent efforts at implementing PET/CT-based metrics as promising tools for precision medicine.

18F-Fluorothymidine PET is an early and superior predictor of progression-free survival following chemoimmunotherapy of diffuse large B cell lymphoma: a multicenter study

Purpose

To determine whether interim 3′-deoxy-3′-[¹⁸F]fluorothymidine (iFLT) PET/CT is a superior predictor of progression-free survival (PFS) compared with interim ¹⁸F-fluorodeoxyglucose (iFDG) PET/CT in patients with diffuse large B cell lymphoma (DLBCL) treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (R-EPOCH).

Methods

Ninety-two prospectively enrolled patients with DLBCL underwent both FLT-PET/CT and FDG-PET/CT 18–24 days after two cycles of R-CHOP/R-EPOCH. Deauville-criteria, PERCIST1.0, standardized uptake value (SUV), total lesion glycolysis (TLG), and metabolic tumor volume were used to interpret iFDG-PET/CT while dichotomous visual interpretation was used to interpret iFLT-PET/CT and the results were compared with the 3- and 5-year PFS.

Results

iFLT-PET/CT was negative in 67 (73%) and positive in 25 (27%) patients. iFDG-PET/CT by Deauville criteria was negative (Deauville scores [DS] of 1–3) in 53 (58%) and positive (DS = 4–5) in 39 (42%) patients. Of the 67 iFLT-PET/CT-negative patients, 7 (10.4%) progressed at a median of 14.1 months whereas 14/25 (56.0%) iFLT-PET/CT-positive patients progressed at a median of 7.8 months (P < .0001). Of the 53 Deauville-negative patients, 9 (17.0%) progressed at a median of 14.1 months whereas 12/39 (30.8%) Deauville-positive patients progressed at a median of 5.6 months (P = .11). In multivariate analysis, including iFLT-PET/CT, PERCIST, interim TLG, and interim SUV_max, only iFLT-PET/CT was an independent predictor for 3- and 5-year PFS (P < .0001 and P = .001, respectively).

Conclusions

In patients with DLBCL given R-CHOP/R-EPOCH, iFLT-PET/CT is a superior independent predictor of outcome compared with iFDG-PET/CT.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05353-9.

Transient ischemic dilatation with adenosine 99mTc-sestamibi stress: prognostic significance in patients with normal myocardial perfusion

OBJECTIVE

To determine the significance of transient ischemic dilatation (TID) in patients with normal perfusion on adenosine stress/rest.

METHODS

We analyzed 430 consecutive patients with normal perfusion on 2-day adenosine stress/rest ^99mTc-sestamibi. A group of 70 patients with Framingham 10-year coronary heart disease risk < 10% was used to derive abnormal TID thresholds (derivation group). The significance of TID at these thresholds was validated in the remaining 360 patients (validation group) followed for cardiac events for 31.2 ± 9.7 (mean ± SD) months.

RESULTS

Transient ischemic dilatation in the derivation group was 1.05 ± 0.13. Three definitions of an abnormal TID were used: > mean + 2SD (TID ≥ 1.32), > mean + 1SD (TID ≥ 1.19) and a TID in the group's highest quartile (TID ≥ 1.15). Of the 360 validation group patients, 12 (3.3%), 48 (13.3%) and 70 (19.4%) had TID ≥ 1.32, 1.19 and 1.15, respectively. Age, gender, family history of coronary artery disease (CAD), known CAD, smoking, hypertension, diabetes, dyslipidemia, rest LVEF, post-stress LVEF, ΔLVEF, ≥ 5% or 10% decrease in LVEF did not predict TID ≥ 1.32. However, TID ≥ 1.19 was predicted by rest LVEF and ≥ 5% decrease in LVEF (P = 0.04 and 0.02, respectively) and TID ≥ 1.15 was predicted by ≥ 5% decrease in LVEF (P = 0.02). Cardiac event-free survivals were similar in patients with a TID ≥ and < 1.32 (P = 0.68), ≥ and < 1.19 (P = 0.40) and ≥ and < 1.15 (P = 0.79).

CONCLUSIONS

Transient ischemic dilatation does not confer adverse prognosis in patients with normal perfusion on adenosine stress/rest ^99mTc-sestamibi irrespective of the threshold used for its definition.

Rupture of De Novo Middle Cerebral Artery Aneurysm 8 Years After the Clipping of Ruptured M1 Middle Cerebral Artery Aneurysm

BACKGROUND Development and rupture of a de novo intracranial aneurysm is rare. Little is known regarding its etiology and the appropriate timing of follow-up angiograms after surgical clipping or coiling. CASE REPORT We present a case report of a 39-year-old male smoker with history of hypertension who developed a de novo aneurysm 8 years after surgical clipping of an aneurysm in the middle cerebral artery in the same segment. He presented with neck rigidity and drowsiness. Laboratory analysis did not show blood dyscrasia. Brain computerized tomography showed right temporal lobe hematoma and 4-vessel angiogram demonstrated de novo aneurysm in the same segment of the M1 middle cerebral artery, which was confirmed by intraoperative microsurgical findings. We review the literature on such cases and discuss the pathophysiology, diagnosis, and treatment of this condition. De novo aneurysm, although rare, can develop within days to as long as 10 years after surgical clipping or coiling. CONCLUSIONS This rare case of de novo aneurysm supports follow-up imaging of patients after initial surgical clipping for up to 10 years.

Microsurgical Fenestration of Intracranial Arachnoid Cysts: Volumetric Analysis and Clinical Outcome

INTRODUCTION

There is paucity of data regarding change in arachnoid cyst (AC) volume following surgery. This study aimed at investigating the clinical outcome of ACs and applying 2 volumetric methods for determination of their volume change post microsurgical fenestration.

METHODS

Twenty-one ACs in 20 patients that underwent microsurgical fenestration were analyzed using 2 volumetric methods; the modified McDonald equation and the picture archiving and communication (PAC) system-based method. Patients were followed up for 23 ± 40.3 months.

RESULTS

The majority of the patients (13 or 65%) were children. Preoperative symptoms in children were mainly seizures and less commonly headache. Of the 20 patients, 12 (60%) had complete resolution of their preoperative symptoms with 8 (40.0%) showing partial improvement. Volumetric studies showed a mean reduction in AC size of 73.7% in children and 64.4% in adults using the PAC system versus 67.9% in children and 70.5% in adults using the modified McDonald equation method. There was no correlation between the percentage decrease in AC volume post surgery and degree of symptom improvement (49.2 ± 34.3% in patients with complete vs. 60.9 ± 40.3% in patients with only partial resolution of symptoms, p = 0.57).

DISCUSSION/CONCLUSION

Microsurgical fenestration is an effective approach for ACs with an excellent clinical outcome apparent in the complete or partial improvement of symptoms in all patients. Volumetric estimates of ACs and their change following surgery are feasible using the modified McDonald or PAC system methods. However, there is no correlation between the percentage decrease in AC volume after surgery and degree of clinical improvement.

Prognostic significance of post-stress reduction in left ventricular ejection fraction with adenosine stress in Jordanian patients with normal myocardial perfusion

BACKGROUND

The significance of post-stress reduction in left ventricular ejection fraction (LVEF) in patients with normal perfusion on adenosine stress/rest imaging remains controversial.

METHODS

Consecutive patients who underwent 2-day adenosine gated stress/rest 99mTc-sestamibi imaging and had normal perfusion were analyzed. LVEF was quantified at rest and 1 hour post-adenosine. Patients were followed up for hard (cardiac death or nonfatal MI) and soft (coronary revascularization or congestive heart failure) cardiac events for 24.1 ± 11.0 months.

RESULTS

Of 560 patients included in the study, 135 (24.1%) had a post-stress reduction in LVEF of ≥ 5%. Rest LVEF (P < 0.001), known history of CAD (P = 0.01) and transient ischemic dilatation ratio (P = 0.02) were independent predictors of LVEF reduction. Event-free survivals were similar in patients with and without ≥ 5% LVEF reduction (P = 0.8). The unadjusted hazard ratio (95% CI) for cardiac events for ≥ 5% LVEF reduction was 1.09 (0.55-2.15), P = 0.81, while the hazard ratio adjusted for known history of CAD, smoking, post-stress LVEF and peak heart rate was 0.87 (0.44-1.75), P = 0.71.

CONCLUSIONS

Significant post-adenosine reduction in LVEF occurs in about one-fourth of patients with normal perfusion but does not confer adverse prognosis compared with patients without such reduction.

Esophageal 99mTc-pertechnetate uptake mimicking an autonomous thyroid adenoma in a patient with subacute thyroiditis: a case report

Subacute thyroiditis (SAT) is one of the most common causes of thyrotoxicosis. Thyroid scans with radioiodine or technetium-99m pertechnetate (99mTc) are often performed in the workup of patients with thyrotoxicosis, particularly to differentiate between SAT and Graves’s disease. Although very helpful, thyroid scans are prone to pitfalls that may occasionally lead to misdiagnosis. These pitfalls are largely related to physiologic uptake of radioiodine or 99mTc in non-thyroidal tissue, such as salivary gland and stomach that may result in false-positive findings. We present herein a very rare case of SAT misdiagnosed as an autonomous thyroid adenoma most likely due to focal 99mTc uptake in the esophagus. This case may have implications for the management of patients with suspected SAT, who undergo a radioiodine or 99mTc thyroid scan.

Additive evidence of the competence of pregnancy-adapted YEARS algorithm in reducing the need for CTPA, Q and/or V/Q scintiscan

OBJECTIVE

To determine whether a pregnancy-adapted clinical and D-dimer-based algorithm, termed the "YEARS algorithm," can reduce the need for radiological imaging, including lung scintigraphy in pregnant women with suspected pulmonary embolism (PE).

PATIENTS AND METHODS

This retrospective study included all pregnant women with suspected PE between January 2014 and September 2019 who have undergone D-dimer testing and radiological imaging (computed tomography pulmonary angiography or lung perfusion scans) at presentation. Three criteria from the YEARS algorithm were assessed: clinical signs of deep vein thrombosis, haemoptysis, and whether PE was clinically considered as the most likely diagnosis. Patients who did not have to undergo imaging per the YEARS algorithm were defined as those with no YEARS criteria and a D-dimer of <1μg/mL (group 1) and those with 1-3 YEARS criteria and a D-dimer of <0.5μg/mL (group 2). Patients who had to undergo imaging were those with no YEARS criteria and a D-dimer ≥1μg/mL (group 3) and those with 1-3 YEARS criteria and a D-dimer ≥0.5μg/mL (group 4). Women with symptoms of deep-vein thrombosis had to undergo Doppler ultrasound: If positive, they were anticoagulated and excluded from this analysis, and if negative, they were evaluated further for the need of imaging based on other YEARS criteria and D-dimer level.

RESULTS

Of 117 pregnant women with suspected PE analyzed according to the YEARS algorithm five had confirmed deep-vein thrombosis by Doppler ultrasound, were anticoagulated and excluded from the analysis. Of the remaining 112 women (mean age; 30.4±5.7 years), 50 underwent computed tomography pulmonary angiography (CTPA), 54 lung perfusion or ventilation-perfusion (V/Q) scan and eight both; PE was diagnosed in 7 (6.25%), two by CTPA, two by lung perfusion or V/Q scan and three by both. Thirty-three of the 112 women (29.5%) were in groups 1+2 and could, therefore, have avoided CTPA or lung perfusion scans per the YEARS algorithm. None of those 33 women had PE by CTPA or lung perfusion scans vs. 7/79 patients (8.9%) who required CTPA or lung perfusion scans per the YEARS algorithm.

CONCLUSION

The pregnancy-adapted YEARS algorithm can safely rule out PE in about one-third of pregnant women with suspected PE without the need for radiological imaging.

Psychometric testing of a short form, 11-item Tampa Scale of Kinesiophobia-Arabic version: TSK-AV-11

To examine the psychometric properties of a short form TSK-AV in Arabic-speaking patients with chronic low back pain (CLBP).One hundred one CLBP patients recruited from Jordan University Hospital provided demographic information and completed the TSK-AV full version and measures of pain severity and disability. Explorative factor analysis was used to determine whether a generally accepted 2-factor model consisting of fewer TSK items applies to the TSK-AV and exhibits acceptable psychometric properties.A 2-factor model provided an adequate-to-good fit to our data, explaining 46.54% of the variance. Factor 1 (labeled as "activity avoidance") comprised items 1, 2, 7, 9, 14, 15, and 17. Factor 2 was labeled as "somatic focus" and comprised items 3, 6, 11, and 13. The 11-item TSK-AV comprised of the 2 factors (TSK-AV-11) as well as its subscales all remained independent significant (P < .001) predictors of pain disability in Jordanian patients with CLBP after accounting for factors such as age, gender, pain duration, and pain severity.The short, 11-item TSK-AV (TSK-AV-11) appears to be an ideal clinical and research tool for measuring fear of movement/re (injury) in Arabic-speaking patients.

Contemporary considerations in adjuvant radioiodine treatment of adults with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of ¹³¹ I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the ¹³¹ I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low ¹³¹ I activity. ¹³¹ I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of ¹³¹ I activity for adjuvant treatment is controversial, but experts reached a consensus that the ¹³¹ I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for ¹³¹ I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current ¹³¹ I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment.

Diagnosis of mesenteric panniculitis in the multi-detector computed tomography era. Association with malignancy and surgical history

OBJECTIVES

To assess the prevalence and associations of mesenteric panniculitis (MP) using multi-detector CT (MDCT).

METHODS

This retrospective study included 4758 consecutive patients who underwent abdomino-pelvic MDCT between January 2012 and December 2014 at Jordan University Hospital, Amman, Jordan. Radiological database was searched for MP diagnosis and patients with suspected MP were re-evaluated by an experienced radiologist to confirm the diagnosis. Data on all patients with confirmed MP diagnosis were subsequently collected and analyzed.

RESULTS

Computed tomography features of MP were identified in 90 patients (41 males, 49 females), a prevalence of 1.9%. Mesenteric panniculitis was identified in both asymptomatic and symptomatic patients. Malignancy was found in 28 MP patients (31%) and 44 of the MP patients (49%) had prior history of abdomino-pelvic surgery. Mesenteric panniculitis was significantly more frequently associated with prior abdomino-pelvic surgery (p=0.0001) and the likelihood of associated malignancy in patients with MP was 2.1-fold higher than in patients without MP (p=0.0013). Conclusion: Mesenteric panniculitis can be reliably diagnosed by MDCT due to its typical CT appearance. Its identification is important because of its significant association with malignancy and because it represents one of the differential diagnoses in patients with nonspecific symptoms referred for abdomino-pelvic CT.

Testicular microlithiasis: Correlation with doppler sonography of testicular arteries and sperm function

PURPOSE

To determine the prevalence of testicular microlithiasis and its correlation with Doppler parameters of testicular arteries and sperm function.

METHODS

Reports of 1,200 consecutive scrotal sonographic examinations performed at our hospital were reviewed. Patients diagnosed with testicular microlithiasis were recalled for detailed scrotal sonographic examination, including Doppler sonography and sperm function. The same examinations were performed in an age-matched control group and the findings compared.

RESULTS

Testicular microlithiasis was found in 64 cases (5.3%). Doppler sonography showed mean resistance index, Vmax, and Vmin of 61.1 ± 9.3%, 18.2 ± 4.7 cm/s, and 7.7 ± 2.3 cm/s, respectively, in the testicular microlithiasis group versus 62.4 ± 10.4%, 18.4 ± 5.7 cm/s, and 7.3 ± 2.4 cm/s, respectively, in the control group (p = 0.49, 0.84 and 0.35, respectively). Sperm function tests demonstrated sperm count, motility, and normal morphology (normal oval head) of 29.6 ± 20.4 × 10(6) /mL, 35.3 ± 16.2%, and 44.4 ± 12%, respectively, in patients with testicular microlithiasis versus 54.3 ± 22.4 × 10(6) /mL, 50.2% ± 14.4%, and 66.4 ± 11.6% in control subjects (p < 0.02).

CONCLUSIONS

Prevalence of testicular microlithiasis of 5.3% in Jordanian patients is similar to what has been reported in the literature. Testicular microlithiasis does not have a significant effect on Doppler parameters of testicular arteries. The apparent impairment of sperm function in patients with testicular microlithiasis warrants further studies. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:474-479, 2016.

18 F-fluorothymidine uptake in follicular lymphoma and error-prone DNA repair

Background

We observed a disproportional 18 F-fluorothymidine (F-FLT) uptake in follicular lymphoma (FL) relative to its low cell proliferation. We tested the hypothesis that the ‘excess’ uptake of 18 F-FLT in FL is related to error-prone DNA repair and investigated whether this also contributes to 18 F-FLT uptake in diffuse large B cell lymphoma (DLBCL).

Methods

We performed immunohistochemical stainings to assess the pure DNA replication marker MIB-1 as well as markers of both DNA replication and repair like PCNA, TK-1 and RPA1 on lymph node biopsies of 27 FLs and 35 DLBCLs. In 7 FL and 15 DLBCL patients, 18 F-FLT-PET had been performed.

Results

18 F-FLT uptake was lower in FL than in DLBCL (median SUVmax 5.7 vs. 8.9, p = 0,004), but the ratio of 18 F-FLT-SUVmax to percentage of MIB-1 positive cells was significantly higher in FL compared with DLBCL (p = 0.001). The median percentage of MIB-1 positive cells was 10% (range, 10% to 20%) in FL and 70% (40% to 80%) in DLBCL. In contrast, the median percentages of PCNA, TK-1 and RPA1 positive cells were 90% (range, 80 to 100), 90% (80 to 100) and 100% (80 to 100) in FL versus 90% (60 to 100), 90% (60 to 100) and 100% (80 to 100) in DLBCL, respectively.

Conclusions

This is the first demonstration of a striking discordance between 18 F-FLT uptake in FL and tumour cell proliferation. High expression of DNA replication and repair markers compared with the pure proliferation marker MIB-1 in FL suggests that this discordance might be due to error-prone DNA repair. While DNA repair-related 18 F-FLT uptake considerably contributes to 18 F-FLT uptake in FL, its contribution to 18 F-FLT uptake in highly proliferative DLBCL is small. This apparently high contribution of DNA repair to the 18 F-FLT signal in FL may hamper studies where 18 F-FLT is used to assess response to cytostatic therapy or to distinguish between FL and transformed lymphoma.

The influence of aging on the association between adiposity and bone mineral density in Jordanian postmenopausal women

The objective of this study was to assess the relative association between body weight, body mass index (BMI), lean mass (LM) and fat mass (FM), and bone mineral density (BMD) in a group of Jordanian postmenopausal women and investigate if this possible association changes with age. A total of 3256 patients had dual-energy X-ray absorptiometry (DXA) scan in the period from January 2009 till January 2012 at the Radiology and Nuclear Medicine Department of Jordan University Hospital. Only 584 women met the selection criteria. Age has been recorded, and patients were divided into subgroups according to age. Body weight and height were measured, and BMI was calculated. Body composition (LM, FM, percentage of android fat, and percentage of gynoid fat) was assessed by DXA. BMD of the lumbar spine (L1-L4) and femoral neck was measured by DXA. Weight, BMI, FM, LM, percentage of android fat, and percentage of gynoid fat were positively correlated to BMD at both lumbar spine and femoral neck. However, this correlation disappeared at the age of 70 yr at lumbar spine and 75 yr at femoral neck. This study suggests that both FM and LM are important determinants of BMD in Jordanian postmenopausal women, and this correlation disappears after the age of 70 yr at lumbar spine and 75 yr at femoral neck.

Is there a correlation between symptoms and bone scintigraphic findings in patients with complex regional pain syndrome?

BACKGROUND

Complex regional pain syndrome (CRPS) is characterized by pain in combination with sensory, vasomotor, sudomotor, trophic and motor abnormalities. The diagnosis of CRPS is based primarily on clinical criteria and the presence of distinct signs and symptoms. The role of bone scintigraphy in the diagnosis of these patients has been limited by its variable sensitivity. In this study, we aim to look if the presence of specific symptoms or symptom subgroups in patients with clinically diagnosed CRPS correlates with scintigraphic findings in bone scan.

MATERIALS AND METHODS

We retrospectively reviewed clinical records of patients referred for bone scintigraphy with the clinical diagnosis of CRPS during the period December 2006 until February 2011. Patients were classified into 4 distinct subgroups according to the presence of specific symptoms namely sensory subgroup, sudomotor and/or edema subgroup, vasomotor subgroup and finally motor and/or trophic changes subgroup. We looked specifically for the correlation between these specific symptoms and scintigraphic bone findings.

RESULTS

37 patients were referred for bone scintigraphy with the clinical diagnosis of CRPS and were enrolled in the study. The presence of vasomotor symptoms and (motor and/or trophic changes) was significantly higher in patients with positive bone scintigraphy (P value 0.0133, 0.018 respectively). There was no other statistically significant correlation between the presence of specific symptoms or symptom subgroups on one hand and the result of bone scintigraphy on the other hand.

CONCLUSIONS

The probability of positive bone scintigraphy increased significantly in patients with vasomotor symptoms and in patients with motor and/or trophic changes. This may contribute to the reported variability of the diagnostic performance of bone scintigraphy in CRPS patients.

Modeling Combined Radiopharmaceutical Therapy: A Linear Optimization Framework

In this paper, we investigate a previously proposed mathematical model describing the effects that an innovative combined radiopharmaceutical therapy might have on the delivery of radiation to the tumor and limiting critical organs. While focused on a specific dual agent therapy, this investigation will prove mathematically that for any two therapeutic radiopharmaceuticals with different limiting critical organs the model provides patient specific conditions under which combination therapy is superior to single agent therapy. In addition, this paper outlines general methods for calculating the amounts of administered radioactivity for each drug required to optimize tumor radiation dose. We also consider extensions of this model to include an arbitrary number of independent radiopharmaceuticals and/or other treatment factors.

First demonstration of leukemia imaging with the proliferation marker 18F-fluorodeoxythymidine

Acute myeloid leukemia (AML) is a neoplasm of hematopoietic stem cells with partial or complete loss of the ability to differentiate but with preserved proliferation capacity. The aim of our study was to evaluate if the in vivo proliferation marker 3'-deoxy-3'-18F-fluorothymidine (FLT) is suitable for visualizing leukemia manifestation sites and if 18F-FLT is a surrogate marker for disease activity.

METHODS

In this pilot study, 10 patients with AML underwent pretherapeutic imaging with 18F-FLT PET or 18F-FLT PET/CT. The biodistribution of 18F-FLT was assessed 60 min after intravenous injection of the radiotracer. Standardized uptake values were calculated for reference segments of bone marrow, spleen, and normal organs. 18F-FLT PET in 10 patients with benign pulmonary nodules and the absence of malignant or inflammatory disease served as controls.

RESULTS

Retention of 18F-FLT was observed predominantly in bone marrow and spleen and was significantly higher in AML patients than in controls (mean 18F-FLT SUV in bone marrow, 11.5 and 6.6, P < 0.05; mean 18F-FLT SUV in spleen, 6.1 and 1.8, P < 0.05). Outside bone marrow, focal 18F-FLT uptake showed extramedullary manifestation sites of leukemia in 4 patients (meningeal disease, pericardial, abdominal, testicular, and lymph node), proven by other diagnostic procedures.

CONCLUSION

This pilot study indicated that PET using 18F-FLT is able to visualize extramedullary manifestation sites of AML and reflects disease activity. Because 18F-FLT uptake in bone marrow is caused by a combination of both neoplastic and normal hematopoietic cells, the correlation of 18F-FLT uptake in bone marrow and leukemic blast infiltration did not reach statistical significance.

The role of FDG-PET scans in patients with lymphoma

18-Fluoro-deoxyglucose positron emission tomography (FDG-PET) is a noninvasive, 3-dimensional imaging modality that has become widely used in the management of patients with malignant lymphomas. This technology has been demonstrated to be more sensitive and specific than either (67)gallium scintigraphy or computerized tomography, providing a more accurate distinction between scar or fibrosis and active tumor. PET scans have been evaluated in pretreatment staging, restaging, monitoring during therapy, posttherapy surveillance, assessment of transformation, and, more recently, as a surrogate marker in new drug development. Data to support these various roles require prospective validation. Moreover, caution must be exercised in the interpretation of PET scans because of technical limitations, variability of FDG avidity among the different lymphoma histologic subtypes, and in the large number of etiologies of false-negative and false-positive results. Recent attempts to standardize PET in clinical trials and incorporation of this technology into uniformly adopted response criteria will hopefully lead to improved outcome for patients with lymphoma.

Revised Response Criteria for Malignant Lymphoma

Purpose

Standardized response criteria are needed to interpret and compare clinical trials and for approval of new therapeutic agents by regulatory agencies.

Methods

The International Working Group response criteria (Cheson et al, J Clin Oncol 17:1244, 1999) were widely adopted, but required reassessment because of identified limitations and the increased use of [18F]fluorodeoxyglucose-positron emission tomography (PET), immunohistochemistry (IHC), and flow cytometry. The International Harmonization Project was convened to provide updated recommendations.

Results

New guidelines are presented incorporating PET, IHC, and flow cytometry for definitions of response in non-Hodgkin's and Hodgkin's lymphoma. Standardized definitions of end points are provided.

Conclusion

We hope that these guidelines will be adopted widely by study groups, pharmaceutical and biotechnology companies, and regulatory agencies to facilitate the development of new and more effective therapies to improve the outcome of patients with lymphoma.

Use of positron emission tomography for response assessment of lymphoma: consensus of the Imaging Subcommittee of International Harmonization Project in Lymphoma

PURPOSE

To develop guidelines for performing and interpreting positron emission tomography (PET) imaging for treatment assessment in patients with lymphoma both in clinical practice and in clinical trials.

METHODS

An International Harmonization Project (IHP) was convened to discuss standardization of clinical trial parameters in lymphoma. An imaging subcommittee developed consensus recommendations based on published PET literature and the collective expertise of its members in the use of PET in lymphoma. Only recommendations subsequently endorsed by all IHP subcommittees were adopted.

RECOMMENDATIONS

PET after completion of therapy should be performed at least 3 weeks, and preferably at 6 to 8 weeks, after chemotherapy or chemoimmunotherapy, and 8 to 12 weeks after radiation or chemoradiotherapy. Visual assessment alone is adequate for interpreting PET findings as positive or negative when assessing response after completion of therapy. Mediastinal blood pool activity is recommended as the reference background activity to define PET positivity for a residual mass > or = 2 cm in greatest transverse diameter, regardless of its location. A smaller residual mass or a normal sized lymph node (ie, < or = 1 x 1 cm in diameter) should be considered positive if its activity is above that of the surrounding background. Specific criteria for defining PET positivity in the liver, spleen, lung, and bone marrow are also proposed. Use of attenuation-corrected PET is strongly encouraged. Use of PET for treatment monitoring during a course of therapy should only be done in a clinical trial or as part of a prospective registry.

Potential increased tumor-dose delivery with combined 131I-MIBG and 90Y-DOTATOC treatment in neuroendocrine tumors: a theoretic model

(131)I-Metaiodobenzylguanidine (MIBG) and (90)Y-DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) have been used as radiotherapeutic agents for treating neuroendocrine tumors. The tumor dose delivered by these agents is often insufficient to control or cure the disease. However, these 2 agents used together could potentially increase tumor dose without exceeding the critical organ dose because the dose-limiting tissues are different. In this paper, we investigate the conditions in which combined-agent therapy is advantageous and we quantify the expected tumor-dose gain.

METHODS

A series of equations was derived that predicted the optimal combination of agents and the fractional increase in tumor dose available from combined-agent therapy with respect to either (131)I-MIBG or (90)Y-DOTATOC. The results obtained from these derivations were compared with direct dose calculations using published dosimetric organ values for (131)I-MIBG and (90)Y-DOTATOC along with critical organ-dose limits. Tumor dose was calculated as a function of the tumor-dose ratio, defined as the (90)Y-DOTATOC tumor dose per megabecquerel divided by the (131)I-MIBG tumor dose per megabecquerel. Comparisons were made between the dose delivered to tumor with single-agent therapy and the dose delivered to tumor with combined-agent therapy as a function of the tumor-dose ratio and the fraction of activity contributed by each agent.

RESULTS

The dose model accurately predicted the optimal combination of agents, the range at which combined-agent therapy was advantageous, and the magnitude of the increase. For the published organ dosimetry and critical organ-dose limits, combined-agent therapy increased tumor dose when the tumor-dose ratio was greater than 0.67 and less than 5.93. The maximum combined-agent tumor-dose increase of 68% occurred for a tumor-dose ratio of 2.57, using 92% of the maximum tolerated (90)Y-DOTATOC activity supplemented with 76% of the maximum tolerated activity of (131)I-MIBG. Variations in organ dose per megabecquerel and dose-limiting values altered both the magnitude of the increase and the range at which combined-agent therapy was advantageous.

CONCLUSION

Combining (131)I-MIBG and (90)Y-DOTATOC for radiotherapy of neuroendocrine tumors can significantly increase the delivered tumor dose over the dose obtained from using either agent alone. Prior knowledge of the normal-organ and tumor dosimetry of both agents is required to determine the magnitude of the increase.

Utility of positron emission tomography (PET) scanning in managing patients with Hodgkin lymphoma

Use of positron emission tomography (PET) or PET/ computed tomography (CT) in Hodgkin lymphoma (HL) continues to expand worldwide. PET is currently widely utilized for response assessment after completion of therapy and, to a lesser extent, for pretreatment staging and assessment of response during therapy (therapy monitoring). In pretreatment staging, PET cannot replace CT or bone marrow biopsy (BMB); however, it can provide complementary information to both CT and BMB, potentially resulting in a modification of disease stage (usually upstaging) in about 15-20% of patients with impact on management in about 5-15%. PET for response assessment at the conclusion of treatment is substantially more accurate than CT because of its ability to distinguish between viable tumor and necrosis or fibrosis in posttherapy residual mass (es) that are present in about two-thirds of patients with HL without any other clinical or biochemical evidence of disease. PET, therefore, provides more accurate response classifications compared with CT-based assessment. The role of PET for therapy monitoring is still evolving but may prove to be the most exciting with potentially high impact on patient management and outcome. PET evaluation during therapy appears to be at least as accurate for predicting patient outcome as evaluation after completion of therapy and its use is clearly justified if the purpose is to provide an early and yet accurate assessment of response with the clear intent of tailoring therapy according to the information provided by the scan. The role of PET scanning for post-therapy surveillance without clinical, biochemical or radiographic evidence of disease remains controversial, primarily because of the potential for a disproportionate fraction of false-positive findings, potentially resulting in increasing cost without proven benefit from earlier PET detection of disease compared to standard surveillance methods. Large prospective studies are therefore needed to determine whether routine surveillance by PET is both cost-effective and whether it results in meaningful changes in patient management and/or outcome.

Response assessment of aggressive non-Hodgkin's lymphoma by integrated International Workshop Criteria and fluorine-18-fluorodeoxyglucose positron emission tomography

PURPOSE

To determine whether a response classification based on integration of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) into the International Workshop Criteria (IWC) provides a more accurate response assessment than IWC alone in patients with non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Fifty-four patients with aggressive NHL who underwent FDG-PET and computed tomography 1 to 16 weeks after four to eight cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone were assessed for complete response (CR), unconfirmed CR (CRu), partial response (PR), stable disease (SD), and progressive disease (PD) by the IWC and by integrated IWC and FDG-PET (IWC+PET). Progression-free survival (PFS) was also compared between IWC- and IWC+PET-assigned response designations.

RESULTS

By IWC, 17 patients had a CR, seven had a CRu, 19 had a PR, nine had SD, and two had PD. In comparison, by IWC+PET, 35 patients had a CR, 12 had a PR, six had SD, one had PD, and zero had a CRu. In separate multivariate models, PFS was significantly shorter in patients with PR than in those with a CR using IWC (hazard ratio [HR], 8.9; P = .021) or IWC+PET (HR, 29.7; P = .0003). However, when the two classifications were included in the same multivariate model, only IWC+PET was a statistically significant independent predictor for PFS (P = .008 v P = .72 for IWC). In addition, when patients with a PR by IWC and a CR by IWC+PET were compared with those with a CR by IWC and a CR by IWC+PET, there was no significant difference in PFS (HR, 1.6; P = .72), indicating that IWC+PET identified a subset of IWC-PR patients with a more favorable prognosis.

CONCLUSION

Compared with IWC, the IWC+PET-based assessment provides a more accurate response classification in patients with aggressive NHL.