Post-therapy Scan Research Articles

Increased 131I Accumulation in the Polyacrylamide Hydrophilic Gel Used for Breast Augmentation

A 37-year-old woman with papillary thyroid cancer received repeat 131I therapy. The first posttherapy scan revealed only activity in the neck. However, both the second and third posttherapy scans showed intense activity in the anterior lower chest bilaterally, suggestive of breast uptake. However, the SPECT/CT images demonstrated that the iodine activity was not located in the breast tissue. Instead, the activity was inside the polyacrylamide hydrophilic gels she received 10 years ago for breast augmentation.

Examining recombinant human TSH primed 131I therapy protocol in patients with metastatic differentiated thyroid carcinoma: comparison with the traditional thyroid hormone withdrawal protocol

Purpose Recombinant human thyroid-stimulating hormone (rhTSH)-based protocol is a promising recent development in the management of differentiated thyroid carcinoma (DTC). The objectives of this prospective study were: (1) to assess the feasibility and efficacy of the rhTSH primed 131I therapy protocol in patients with DTC with distant metastatic disease, (2) to perform lesional dosimetry in this group of patients compared to the traditional protocol, (3) to document the practical advantages (patient symptoms and hospital stay) of the rhTSH protocol compared to the traditional thyroid hormone withdrawal protocol, (4) to document and record any adverse effect of this strategy, (5) to compare the renal function parameters, and (6) to compare the serum TSH values achieved in either of the protocols in this group of patients.

Is there a role for therapy response assessment with 2-[fluorine-18] fluoro-2-deoxy-d-glucose–positron emission tomography/computed tomography in mantle cell lymphoma?

2-[Fluorine-18] fluoro-2-deoxy-d-glucose–positron emission tomography/computed tomography (FDG-PET/CT) scanning is used for response assessment in mantle cell lymphoma (MCL). However, its ability to predict outcome is debatable. We retrospectively evaluated the prognostic impact of interim and post therapy FDG-PET/CT scan on outcome of 58 consecutive MCL patients. Scans performed at diagnosis, mid-therapy, post-chemotherapy and post-transplant were reviewed and outcome analyzed. Median age was 59; MCL International Prognostic Index (MIPI) was low in 45%, intermediate in 41% and high in 14%. Thirty-four patients (58%) received R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone) or R-CHOP-like chemotherapy, 24 (42%) underwent upfront autologous stem-cell transplant (ASCT). Three-year overall (OS) and progression-free-survival (PFS) were 81% and 45%, respectively. No differences in OS or PFS between PET-positive and PET-negative groups both for interim and post-therapy scans were observed. We conclude that in patients treated with R-CHOP, using the International-Harmonization-Project criteria for FDG-PET/CT interpretation, there is no role for interim or post-therapy PET.

Skin Recurrence of Transformed Mycosis Fungoides Postumbilical Cord Blood Transplant despite Complete Donor Chimerism.

Background. Allogeneic stem cell transplant is the treatment of choice for systemic cutaneous T-cell lymphoma (CTCL) which provides graft-versus-lymphoma effect. Herein we discuss a case of recurrence of CTCL skin lesions after cord blood transplant in a patient who continued to have 100% donor chimerism in bone marrow. Case Presentation. A 48-year-old female with history of mycosis fungoides (MF) presented with biopsy proven large cell transformation of MF. PET scan revealed multiple adenopathy in abdomen and chest suspicious for lymphoma and skin biopsy showed large cell transformation. She was treated with multiple cycles of chemotherapy. Posttherapy PET scan showed resolution of lymphadenopathy. Later she underwent ablative preparative regimen followed by single cord blood transplant. Bone marrow chimerism studies at day +60 after transplant showed 100% donor cells without presence of lymphoma. However 5 months after transplant she had recurrence of MF with the same genotype as prior skin lesion. Bone marrow chimerism study continued to show 100% donor cells. Conclusion. A differential graft-versus-lymphoma effect in our case prevented lymphoma recurrence systemically but failed to do so in skin. We hypothesize that this response may be due to presence of other factors in the bone marrow and lymph node microenvironments preventing recurrence in these sites.

Value of SPECT/CT in Cervical Vertebra Metastasis Mimicking Residual Thyroid Tissue on Planar I-131 Scan

A total thyroidectomy was performed on a 62 year-old male patient with 3.5 cm cold nodule and diagnosis of differentiated thyroid carcinoma was made. He received 200 mCi of I-131 because pulmonary metastases were founded on computed tomography and his serum thyroglobulin level was high (>300 ng/ml). Post-therapy planar whole body scan showed diffuse pulmonary tracer accumulation consistent with pulmonary metastases, 3 foci of activities in the thyroid region of neck and physiological tracer uptake in the liver. Initially, it was considered that high serum thyroglobulin level was caused by pulmonary metastases and activities in the neck were due to residual thyroid tissue. But, single photon emission computed tomography/computed tomography (SPECT/CT) images demonstrated that the activity in the midline of the neck was originated in the cervical (C5-6) vertebra due to bone metastasis. Cervical vertebra metastasis in the same level with probable residual thyroid tissue in planar I-131 whole body scan can be easily overlooked. We considered that the complementary SPECT/CT for head and neck region should be used not only in the selected differentiated thyroid patients with unexpected abnormal activity but also in patients with expected residual thyroid tissue, salivary gland or mouth activity in planar I-131 whole body scan.

Differences in the sensitivity of pretherapy and post-therapy scans in patients undergoing peptide receptor radionuclide therapy

Minutoli, Fabio; Sindoni, Alessandro; Cardile, Davide; Baldari, Sergio Author Information

Necessity of performing I-131 MIBG post-therapy scans in patients with metastatic neuroblastoma

aDepartment of Nuclear Medicine, Beijing Friendship Hospital of Capital Medical University, Beijing, People’s Republic of China bDepartment of Radiology, Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA Correspondence to Hongming Zhuang, MD, PhD, Department of Radiology, Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA Tel: +1 267 425 7134; fax: +1 267 425 7095; e-mail: [email protected] Received June 7, 2013 Accepted June 24, 2013

Clinical significance of diffuse intrathoracic uptake on post-therapy I-131 scans in thyroid cancer patients.

The purpose of this study was to identify the frequency and possible cause of diffuse intrathoracic uptake on post-therapy I-131 scans in thyroid cancer patients. We retrospectively reviewed 781 post-therapy scans of 755 thyroid cancer patients who underwent total thyroidectomy and radioactive iodine therapy between January and December 2010. Diffuse intrathoracic uptake on post-therapy scans was examined, and clinical patient characteristics including sex, age, regimen for thyroid-stimulating hormone (TSH) stimulation (thyroid hormone withdrawal or recombinant human TSH injection), TSH, thyroglobulin (Tg) and anti-thyroglobulin antibody (anti-Tg Ab) levels, therapeutic dose of radioactive iodine therapy and prior history of radioactive iodine therapy were recorded.Scan findings were correlated with chest CT, chest radiographs, laboratory tests and/or clinical status. Diffuse intrathoracic uptake without evidence of pathologic condition was categorized as indeterminate. The association between clinical characteristics and intrathoracic uptake were analyzed for negative intrathoracic uptake and indeterminate uptake groups. Diffuse intrathoracic uptake on post-therapy scans was demonstrated in 39 out of 755 (5.2%) patients, among which 3 were confirmed as lung metastasis. The 14 patients that showed high Tg or anti-Tg Ab levels were considered to be at risk of having undetected micrometastasis on other imaging modalities. The remaining 22 were indeterminate (2.9%).Upon comparison of negative intrathoracic uptake and indeterminate uptake groups, TSH stimulation by thyroid hormone withdrawal was shown to be significantly correlated with diffuse intrathoracic uptake (p < 0.05). The frequency of diffuse intrathoracic uptake on post-therapy scans was 5.2% and could be seen in thyroid cancer patients with underlying lung metastasis as well as those without definite pathologic condition. In the latter, there was a higher frequency for diffusely increased intrathoracic uptake in those who underwent thyroid hormone withdrawal rather than recombinant human TSH injection.

131I SPECT/CT: a one-station imaging modality in the management of differentiated thyroid cancer

In patients with differentiated thyroid carcinoma (DTC), single-photon emission computed tomography/computed tomography (SPECT/CT) applied to diagnostic or therapeutic radioiodine (131I) whole-body scintigraphy (WBS) may accurately localize and help to distinguish benign from malignant sites of 131I uptake, with the potential to alter the management plan. 131I SPECT/CT is increasingly being used to evaluate patients with DTC and shows promise for improving imaging specificity and reducing false-positive results. Pre-ablation scans with 131I SPECT/CT contribute to the staging of thyroid cancer and the identification of regional and distant metastases prior to radioiodine therapy. Post-therapy scans with 131I SPECT/CT improve detection and localization of 131I accumulation in lymph node metastases and distant metastases compared with planar WBS and reduce the number of equivocal diagnoses and the need for additional cross-sectional imaging.

Liver and lymph node metastases of prostate cancer visualized on post-therapy imaging after treatment with 188Re-HEDP

A 76-year-old man with bone metastases of prostate cancer diagnosed a year ago was admitted for relief of bone pain (visual analogue scale: 90%) most markedly in cervical spine and upper extremities due to skeletal metastases. His serum prostate specific antigen level was markedly increased (351 ng/ml). After documentation of sufficient tracer uptake in multiple bone metastases on whole-body 99mTc-MDP bone scan, we treated him with a single intravenous injection of 2.4 GBq 188Re-HEDP. Quality control of 188Re-HEDP was performed with TLC within 30 min prior to injection, radiochemical purity was >95%, free rhenium and colloid ratios were less than 3%. For pain, he was taking Novalgin 30 drops t.i.d. and used Fentanyl patch 50 g/72 h. Fig. 1 shows increased activity localization in multiple bone metastases and the liver lesion after treatment with 188Re-HEDP, as well as on the whole-body scans obtained a week prior to treatment. This metastatic liver lesion was diagnosed on a conventional CT scan 6 months before treatment. The SPECT/CT study (obtained at 24 h after injection) shows tracer accumulation in the liver lesion, in abdominal lymph nodes (in the hepatoduodenal ligament) and in stomach (Fig. 2A and B). An abdominal section of the SPECT/CT study shows that the area of activity localization on right side of abdomen on whole body image corresponds to intestinal contents (Fig. 2C). Liver metastases of various malignant tumors such as breast cancer have been reported to show accumulation on bone scintigraphy with 99mTc-MDP. Limouris and Skukla reported 186Re-HEDP uptake in the stomach in two patients with osseous metastases because of prostate and breast cancer1; however, we could not find any reports on visualization of lymph node metastases on posttherapy scan after administration of 188Re-HEDP. Accumulation of

Utility of post-therapy surveillance scans in DLBCL.

8504 Background: Diffuse large B-cell lymphoma (DLBCL) is an aggressive lymphoma. The optimal follow-up strategy for patients (pts) in remission is not clear. The goal of this study is to determine the utility of surveillance scans in a large, prospective, multi-institutional cohort of DLBCL pts. Methods: Patients were enrolled in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), a prospective cohort of newly diagnosed lymphoma pts. All pts were followed for events including relapse, re-treatment, and death with events verified by medical records. Patients eligible for this study had biopsy proven DLBCL and were treated with anthracycline based immunochemotherapy (IC). Initial and post-treatment management was per treating physician. Medical records were re-reviewed in pts with events for clinical details at relapse and relationship to planned follow-up visits and surveillance scans. Results: 644 pts with DLBCL treated with IC were enrolled in MER from 2002-2009. Median age was 63 years (range 18-92), 54% were men, and median f/u was 59 months (range 8-116). 537 pts entered post-treatment observation; 109 (20%) of the 537 pts relapsed and 41 died from other causes. 42% of relapses were in the first 12 months following diagnosis, 27% between 12-24 months, and 31% &gt;24 months. In the 109 who relapsed, 62% of pts (62/100, 9 unknown) presented to their physician earlier than a planned follow-up visit due to symptoms. At the time of relapse, 68% were symptomatic, 42% of pts had abnormal physical exam, and 55% had elevated LDH; 87% of pts had ≥1 of these features. Of the 38 pts with relapse detected at a planned visit, 26 had clinical features of relapse and 12 pts had relapse detected solely by planned surveillance scan; 4 pts had relapse of low-grade or other subtype and 8 had DLBCL relapse (4 of whom had equivocal/positive PET at the end of IC). Thus, surveillance scanning detected DLBCL relapse prior to clinical manifestations in only 8/537 pts (1.5%) observed post DLBCL therapy. Conclusions: The vast majority of DLBCL relapses occur outside of planned follow-up visits and are accompanied by symptoms, physical exam, or laboratory abnormalities. Routine surveillance scans post-therapy add little to detection of DLBCL relapse.

Peptide receptor imaging in neuroendocrine tumors: comparison between diagnostic scintigraphy and post-therapy whole-body scan

Several different somatostatin analogs labeled with gamma or positron-emitting radionuclides exist for diagnostic imaging of neuroendocrine tumors (NETs). Differences between standard diagnostic scintigraphy (SDS) and post-therapy whole-body scan (PTWBS) at peptide receptor radionuclide therapy in lesion detection are known; such differences have been correlated with the varying degree of receptor subtype expression and the varying receptor affinity profile of the different ligands. The aim of this study is to investigate differences between SDS and PTWBS obtained using the same radiopharmaceutical. We retrospectively reviewed clinical records of 53 patients with a diagnosis of NET, who underwent both SDS and PTWBS using (111)In-Pentetreotide. We compared the number of lesions for each body region detected by SDS and PTWBS. In 14/53 patients (26.4%) discrepancies between SDS and PTWBS were found. PTWBS detected 68 additional lesions with respect to SDS that were distributed as follows: head and neck, 6; mediastinum, 1; liver, 10; abdomen/pelvis, 1; bone, 44; other localizations, 6. The number of lesions detected by SDS was significantly different from that revealed by PTWBS (Wilcoxon matched pairs test, P = 0.0313). The regions that contributed significantly to reach this difference were head and neck (McNemar test, P = 0.0412), liver (McNemar test, P = 0.0044), bone (McNemar test, P < 0.0001) and other localizations (McNemar test, P = 0.0412). PTWBS shows more lesions than SDS with a significant discrepancy. We suppose that administration of higher radiopharmaceutical activity, use of larger peptide amount and the different time interval between radiopharmaceutical administration and scan execution can determine a higher sensitivity of PTWBS.

Flip-flop pattern of skeleton after treatment in a patient with Hodgkin's lymphoma

18F-FDG PET/CT is a well-established method used both for staging and follow-up examinations of patients with lymphoma. In addition, it provides valuable information considering bone marrow infiltration.1 We present a case of 46-year-old female with lymphocyte-depleted Hodgkin’s lymphoma who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for initial staging and for response evaluation to chemotherapy. Evaluation of preand post-therapy scans side by side revealed an unusual flip-flop pattern of skeleton as reversing FDG uptake (Fig. 1).

A Low Postoperative Nonstimulated Serum Thyroglobulin Level Does Not Exclude the Presence of Radioactive Iodine Avid Metastatic Foci in Intermediate-Risk Differentiated Thyroid Cancer Patients

Postsurgical thyrotropin (TSH)-stimulated serum thyroglobulin (Tg) level can be used to predict the likelihood of finding radioactive iodine (RAI) avid metastatic foci on postablation scanning. However, there is little data regarding the predictive value of a nonstimulated postoperative Tg obtained on levothyroxine therapy in patients being considered for recombinant human TSH (rhTSH)-assisted remnant ablation. The study included 290 intermediate-risk differentiated thyroid cancer (DTC) patients with a postsurgical nonstimulated Tg<10 ng/mL prior to rhTSH-assisted remnant ablation. Patients were stratified into four groups based on the postsurgical nonstimulated Tg value: Tg<0.6 ng/mL (n=146), Tg 0.6-0.9 ng/mL (n=76), Tg 1-5 ng/mL (n=51), and Tg>5-10 ng/mL (n=17). RAI avid metastatic foci were identified using post-therapy scanning with SPECT/CT (single photon emission computed tomography). RAI avid metastases were identified in 16% (46/290) of patients, including 12% (17/146) with Tg<0.6 ng/mL, 14% (11/76) with Tg 0.6-0.9 ng/mL, 25% (13/51) with Tg 1-5 ng/mL, and 29% (5/17) with Tg>5-10 ng/mL (p=0.02). While 99% of the RAI avid foci were located in the neck, lung uptake was seen in one patient with Tg<0.6 ng/mL (0.7%, 1/146), one patient with Tg 0.6-0.9 ng/mL (1.3%, 1/76), and 2 patients with Tg>5-10 ng/mL (11%, 2/17 patients). A postoperative nonstimulated Tg<0.6 ng/mL does not exclude identification of RAI avid metastatic foci on postablation SPECT/CT scanning in intermediate-risk DTC patients. Therefore, patient selection for RAI ablation in the intermediate-risk group must be based on an integration of multiple risk factors rather than any single clinicopathologic risk factor.

Therapeutic Implications of Diffuse Hepatic Uptake Following I-131 Therapy for Differentiated Thyroid Cancer

To determine if diffuse hepatic uptake (DHU) of radioactive iodine (I-131) following radioactive iodine treatment has prognostic implications in otherwise scan-negative patients. This is a retrospective review of patients treated for differentiated thyroid cancer (DTC) at Beth Israel Deaconess Medical Center between January 1990 and June 2006. This group included patients receiving therapy to ablate presumed remnant tissue, as well as treatment for persistent disease as measured by thyroglobulin or imaging. All patients included in the study had no remnant uptake and otherwise negative posttherapy scans. A total of 57 patients with 63 scans met these criteria. The scans were then scored for DHU on a scale of 0 to 5, with 0 being no uptake and 5 being intense uptake relative to background. Sixteen of 63 treatments were remnant ablations. Ten of 57 patients had positive thyroglobulin antibodies. Average DHU was similar in the ablation and therapeutic groups (1.9 vs. 2.3, P = .3). There was no correlation with either I-131 dose or the presence of thyroglobulin antibodies. There was a difference for DHU in the rate of disease-free survival, (undetectable thyroglobulin and no clinical or radiographic evidence of metastasis); 50% of patients with hepatic uptake scores of 0-2 were disease-free compared to 15% with scores of 3-5 (P<.01). The average length of follow-up for disease-free patients was 4.6 years. In patients with DHU with otherwise negative whole-body scans following I-131 treatment, more intense hepatic uptake is associated with lower likelihood of complete response to I-131 treatment.

Increased Iodine Uptake in the Nabothian Cyst

A 31-year-old female patient with papillary thyroid cancer, status post-total thyroidectomy and radioablation with (131)I underwent posttherapy whole-body scan with SPECT, which revealed increased iodine activity in the cervix. The subsequent ultrasound examination demonstrated that the site of elevated iodine activity was caused by cervical Nabothian cyst.

Discordance in 68Ga-DOTANOC and 177Lu-DOTATATE uptake in diagnostic and post-therapy scans in patients with medullary thyroid cancer-likely reasons

Discordance in 68Ga-DOTANOC and 177Lu-DOTATATE uptake in diagnostic and post-therapy scans in patients with medullary thyroid cancer-likely reasons

I-131 MIBG post-therapy scan is more sensitive than I-123 MIBG pretherapy scan in the evaluation of metastatic neuroblastoma

Iodine-123 metaiodobenzylguanidine (I-123 MIBG) scintigraphy is gradually replacing I-131 MIBG scans in the diagnostic workup of neuroblastoma. High-dose I-131 MIBG, however, is commonly used for subsequent therapy in patients with proven MIBG-avid lesions. The objective of this study was to compare the sensitivities of pretherapy I-123 MIBG and post-therapy I-131 MIBG scans for detecting metastatic lesions of neuroblastoma and determine the suitability of post-therapy scans for detecting new metastases. Pretherapy I-123 MIBG scans and post-therapy I-131 MIBG scans of 126 patients with neuroblastoma were analyzed retrospectively and the number of detected lesions was compared. In 70 patients (55.6% cases), the pretherapy and post-therapy scans were concordant, showing similar MIBG-avid foci. In the remaining 56 patients (44.4% cases), the post-therapy I-131 MIBG scans revealed additional lesions (i.e. a total of 716 lesions) compared with pretherapy I-123 MIBG scans (only 532 lesions). All lesions detected on pretherapy I-123 MIBG scans were revisualized on the post-therapy I-131 MIBG scans, the latter also revealing 184 new MIBG-avid lesions. Post-therapy I-131 MIBG scans demonstrate new lesions in almost half of the patients when compared with pretherapy I-123 MIBG scans and therefore are essential to delineate the disease extent.

Quantitative SPECT/CT reconstruction for 177Lu and 177Lu/90Y targeted radionuclide therapies

We investigated the quantitative accuracy of SPECT/CT imaging studies as would be performed before and after targeted radionuclide therapy (TRT) using phantom experiments with (i) 99mTc, (ii) 177Lu and (iii) 90Y/177Lu. While the experiment with 99mTc imitated a diagnostic scan, the experiments with 177Lu and 90Y/177Lu modeled post-therapy acquisitions. At the next stage, we reconstructed images from pre- and post-therapy patient studies. The data were first reconstructed using two methods with limited corrections for the physics effects. Then, to generate quantitatively accurate absolute activity distributions, we applied a hybrid (model-based and window-based) reconstruction strategy where some of the physics effects were accurately modeled while corrections for other effects were empirical and based on information obtained from the projection data. The accuracies of absolute activity recovered by the hybrid method from the six phantom experiments were very similar to each other and acceptable for potential use in TRT. When measured in identical regions of interest, the 99mTc activity was reconstructed with errors ranging between −3.3% and 2.9%, while the 177Lu activity was reconstructed from experiments with 177Lu and 90Y/177Lu with errors ranging between −1.6% and 1.6%. The reconstruction algorithms with limited corrections led to larger and case-specific errors as might have been expected. From a clinical prospective, our results showed that physics-based reconstructions improved resolution of images corresponding to both diagnostic scans with 99mTc and post-therapy scans with 177Lu. Our analysis of patient study demonstrated that lack of corrections led to overestimation of activities in organs and tumor by 29–39% for the diagnostic scan with 99mTc and by 105–218% for post-therapy scan with 177Lu.

Is Detection of Additional Lesions in Post–Peptide Receptor Radionuclide Therapy Scans With Respect to Diagnostic Imaging Only Due to Different Affinity of Ligands?

It is known that different affinity profiles for somatostatin receptor subtypes among different radiopharmaceuticals result in different organ and tumor uptakes and even in different sensitivities in the detection of lesions. Such differences are considered main factors explaining cases of detecting additional lesions in posttherapy scans with respect to diagnostic imaging. We show a posttherapy scan revealing more lesions--namely, a diffuse bone involvement with many small focal bony uptake areas--than the diagnostic scan using the same radiopharmaceutical (111In-pentetreotide) in a 71-year-old man with metastases from a well-differentiated ileal neuroendocrine tumor.