18F-FDG PET/CT in solitary plasmacytoma: metabolic behavior and progression to multiple myeloma

Construction and validation of an 18F-FDG-PET/CT-based prognostic model to predict progression-free survival in newly diagnosed multiple myeloma patients

OBJECTIVE

To investigate the relationship between 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) related parameters and the prognosis of multiple myeloma and to establish and validate a prediction model regarding the progression-free survival (PFS) of multiple myeloma.

METHODS

A retrospective analysis of 126 newly diagnosed multiple myeloma patients who attended Nanjing Drum Tower Hospital from 2014-2021. All patients underwent PET/CT before treatment and were divided into a training cohort (n = 75) and a validation cohort (n = 51). Multivariate Cox proportional hazard regression analysis incorporated PET/CT-related parameters and clinical indicators. A nomogram was established to individually predict PFS in MM patients. The model was evaluated by calculating the C-index and calibration curve.

RESULTS

Here, 4.2 was used as the cut-off value of SUVmax to divide patients into high and low groups. PFS significantly differed between patients in the high-SUVmax group and low-SUVmax group, and SUVmax was an independent predictor of PFS in newly diagnosed multiple myeloma (NDMM) patients. Univariate and multivariate cox regression analysis suggested that lactate dehydrogenase (LDH), bone marrow plasma cell (BMPC), and SUVmax affected PFS. These factors were incorporated to construct a nomogram model for predicting PFS at 1 and 2 years in NDMM patients. The C-index and calibration curves of the nomogram exhibited good accuracy and consistency, and the DCA curves suggested that the model had good clinical utility.

CONCLUSION

The PET/CT parameter SUVmax is closely related to the prognosis of myeloma patients. The nomogram constructed in this study based on PET/CT-related parameters and clinical indicators individually predicts the PFS rate of NDMM patients and enables further risk stratification of NDMM patients.

EANM guidelines on the use of [18F]FDG PET/CT in diagnosis, staging, prognostication, therapy assessment, and restaging of plasma cell disorders

We provide updated guidance and standards for the indication, acquisition, and interpretation of [18F]FDG PET/CT for plasma cell disorders. Procedures and characteristics are reported and different scenarios for the clinical use of [18F]FDG PET/CT are discussed. This document provides clinicians and technicians with the best available evidence to support the implementation of [18F]FDG PET/CT imaging in routine practice and future research.

Solitary bone plasmacytoma of spine with involvement of intervertebral disk: a case report and literature review

Primary malignant bone tumors of the spine are exceedingly rare, with solitary bone plasmacytoma (SBP) representing approximately 30% of all cases. Radiological assessments are crucial for localizing SBP and for ruling out a diagnosis of multiple myeloma (MM). Imaging features resembling a "mini-brain" appear to be distinctive for SBP. Vertebral lesions accompanied by adjacent disc space involvement typically suggest spinal infections, while the potential for SBP involvement is often overlooked. We present a case of a 61-year-old female with SBP who exhibited thoraco-lumbar spine destruction and adjacent disc space involvement. The patient sought treatment at our medical center due to lumbodorsal pain radiating bilaterally to the inguinal regions. Radiological findings revealed an osteolytic lesion involving the intervertebral disc, making it challenging to distinguish between tumor and inflammation. A biopsy of the vertebral lesion confirmed the diagnosis of SBP, which was further supported by laboratory results. Post-diagnosis, the patient underwent radiotherapy, receiving a total dose of 4000 Gy, which alleviated her symptoms. We also provide a comprehensive literature review on SBP with disc involvement to aid both clinical and radiological diagnoses.

18 F-FDG PET/CT in Solitary Extramedullary Plasmacytoma of the Penis

ABSTRACT

A 72-year-old man presented with a painless penile mass for 3 months. Contrast-enhanced CT revealed heterogeneous enhancement, whereas 18 F-FDG PET/CT displayed inhomogeneous 18 F-FDG accumulation in the lesion without other abnormal activity. The histopathological examination from biopsied specimen confirmed the diagnosis of a plasmacytoma. However, the subsequent tests, including serum/urine immunofixation electrophoresis, serum/urine free light chain assay, and bone marrow smear/biopsy, did not show any abnormalities. The conclusive diagnosis was a solitary extramedullary plasmacytoma of the penis.

Plasmacytoma and Amyloid Lymphadenopathy, FDG, and Fluorocholine

ABSTRACT

A 56-year-old man with thoracal mass suspected of solitary plasmacytoma was referred for 18 F-FDG PET-CT scan. His PET-CT revealed FDG-avid rib mass and cervical lesion at level 2. He also underwent 18 F-fluorocholine (FCH) PET-CT to evaluate possible metastatic spread of the disease. FCH PET-CT showed increased uptake at the rib mass, while the cervical lesion was not FCH-avid. Biopsies confirmed rib lesion was a solitary plasmacytoma; however, the cervical lesion was an amyloid deposited lymph node. This case showed FCH PET-CT is a valuable companion of FDG scan for the evaluation of plasma cell dyscrasias with a better specificity.

Diagnostic value of FDG-PET/CT in fever of unknown origin

Background

Fever of unknown origin (FUO) is a challenging clinical problem in medicine that needs collaboration of various diagnostic techniques to establish the accurate diagnosis. We evaluated the diagnostic performance of 18F-FDG PET/CT in patients who presented themselves with FUO. Our study included 40 patients with FUO who underwent PET/CT examination and their results were compared to the results of laboratory, histopathological, microbiological investigations and/or response to therapy.

Results

The final diagnosis included malignancy in 20 patients (50%), infectious causes in 7 patients (17.5%) and non-infectious inflammatory causes in 6 patients (15%). Fever resolved without diagnosis in 4 patients (10%), while no definite diagnosis was reached in 3 patients (7%). PET/CT successfully contributed to diagnosis of 35 out of 40 patients with diagnostic accuracy of 87.5%. The sensitivity, specificity, positive predictive value and negative predictive value of PET/CT in our study were 93.5%, 66.7%, 90.6% and 75%, respectively.

Conclusion

PET/CT is a useful tool to investigate and diagnose the cause of FUO. It provides information that can guide the treatment strategy of the patients.

18F-FDG Versus Non-FDG PET Tracers in Multiple Myeloma

Multiple myeloma (MM) accounts for 0.9% of cancer diagnoses, and incidence and mortality rate have increased in previous years. 18F-fluorodeoxyglucose (FDG) PET-computed tomography (CT) is an established modality for MM evaluation. MR imaging is helpful where 18F-FDG PET-CT is lacking. To standardize PET reporting, methods like Italian Myeloma Criteria for PET Use and Deauville criteria have been studied. Tracers like 11C-acetate and 11C-choline/18F-fluoromethylcholine (FCH) have shown higher sensitivity and detected more focal lesions and diffuse involvement than 18F-FDG PET-CT. 18F-FCH showed higher maximum standardized uptake value than 18FDG. 11C-methionine appears to be the best radiopharmaceutical, apart from 18F-FDG, for evaluating MM.

A Review of Posteromedial Lesions of the Chest Wall: What Should a Chest Radiologist Know?

A heterogeneous group of tumors can affect the posteromedial chest wall. They form diverse groups of benign and malignant (primary or secondary) pathologies that can arise from different chest wall structures, i.e., fat, muscular, vascular, osseous, or neurogenic tissues. Chest radiography is very nonspecific for the characterization of chest wall lesions. The modality of choice for the initial assessment of the chest wall lesions is computed tomography (CT). More advanced cross-sectional modalities such as magnetic resonance imaging (MRI) and positron emission tomography (PET) with fluorodeoxyglucose are usually used for further characterization, staging, treatment response, and assessment of recurrence. A systematic approach based on age, clinical history, and radiologic findings is required for correct diagnosis. It is essential for radiologists to be familiar with the spectrum of lesions that might affect the posteromedial chest wall and their characteristic imaging features. Although the imaging findings of these tumors can be nonspecific, cross-sectional imaging helps to limit the differential diagnosis and determine the further diagnostic investigation (e.g., image-guided biopsy). Specific imaging findings, e.g., location, mineralization, enhancement pattern, and local invasion, occasionally allow a particular diagnosis. This article reviews the posteromedial chest wall anatomy and different pathologies. We provide a combination of location and imaging features of each pathology. We will also explore the role of imaging and its strengths and limitations for diagnosing posteromedial chest wall lesions.

Prognostic Nomogram for Predicting Overall Survival of Solitary Bone Plasmacytoma Patients: A Large Population-Based Study

Background

The aim of the study was to develop a nomogram to predict the overall survival (OS) of patients with solitary plasmacytoma of bone (SBP).

Materials and Methods

Patients diagnosed with SBP between 1993 and 2012 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. All eligible patients were randomly allocated to the training sets and the validation sets. The nomogram was developed with the training set and validated with the validation set using the concordance index (C-index), calibration plots, and decision curve analyses (DCA).

Results

Age, marital status, tumor grade, treatment were independent prognostic indicators for OS (P<0.05) and were integrated to construct the nomogram. C-indexes for OS prediction in the training and validation sets were 0.78 and 0.73, respectively. The calibration plots demonstrated good consistency between the predicted and actual survival. DCA demonstrated that the new model has great benefits. In the total cohort, the median OS of patients in the low- and high-risk groups were 12.17 (95% CI 11.92–12.42) and 3.92 (95% CI 2.83–5.01) years, respectively.

Conclusion

The nomogram showed excellent applicability and accuracy, which could be a reliable tool for predicting OS in SBP patients.

18F-FDG-PET/CT in laryngeal cancer: Comparison with conventional imaging and prognostic role

OBJECTIVE

The aim of this study was to investigate the diagnostic accuracy of staging ¹⁸F-FDG-PET/CT in laryngeal cancer, compare these results with conventional imaging (CI) and assess the value of ¹⁸F-FDG-PET/CT features to predict survival.

METHODS

Fifty-four patients with laryngeal squamous cell cancer and baseline ¹⁸F-FDG-PET/CT were retrospectively enrolled. The PET images were analyzed visually and semi-quantitatively by measuring several metabolic parameters. A combination of clinical follow-up/imaging follow-up and/or histopathology was taken as reference standard. Progression free survival (PFS) and disease specific survival (DSS) were computed using Kaplan-Meier curves.

RESULTS

All primary tumors were clearly identified by CI, and 52/54 by ¹⁸F-FDG-PET/CT with a sensitivity of 96.3%. Cervical nodal metastases were detected in 40/54 patients at ¹⁸F-FDG-PET/CT and in 34/49 patients at CI. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy on a patient-based analysis for nodal disease were 100%, 85.7%, 94.6%, 100% and 95.9% at ¹⁸F-FDG-PET/CT, and 91.4%, 85.7%, 94.1%, 80%, 89.8% at CI. Diagnostic performances of PET/CT and CI were not significantly different on a patient-based, side-by-side and level-by-level analysis. ¹⁸F-FDG-PET/CT recognized distant metastases in 7 patients allowing to an upstaging. At a median follow-up of 27 months, relapse/progression of disease occurred in 31 patients and death occurred in 32. Metabolic tumor volume (MTV T), MTV total and total lesion glycolysis (TLG) showed to be independent prognostic factors for PFS.

CONCLUSIONS

Both CI and PET/CT had good diagnostic performances for the staging of laryngeal cancer; baseline metabolic features (MTV and TLG) showed an important prognostic value in assessing the rate of PFS.

18F-FDG-PET/CT in laryngeal cancer: comparison with conventional imaging and prognostic role

OBJECTIVE

The aim of this study was to investigate the diagnostic accuracy of staging 18 F-FDG-PET/CT in laryngeal cancer, compare these results with conventional imaging (CI) and assess the value of 18 F-FDG-PET/CT features to predict survival.

METHODS

Fifty-four patients with laryngeal squamous cell cancer and baseline 18 F-FDG-PET/CT were retrospectively enrolled. The PET images were analyzed visually and semi-quantitatively by measuring several metabolic parameters. A combination of clinical follow-up/imaging follow-up and/or histopathology was taken as reference standard. Progression free survival (PFS) and disease specific survival (DSS) were computed using Kaplan-Meier curves.

RESULTS

All primary tumors were clearly identified by CI, and 52/54 by 18 F-FDG-PET/CT with a sensitivity of 96.3%. Cervical nodal metastases were detected in 40/54 patients at 18 F-FDG-PET/CT and in 34/49 patients at CI. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy on a patient-based analysis for nodal disease were 100%, 85.7%, 94.6%, 100% and 95.9% at 18 F-FDG-PET/CT, and 91.4%, 85.7%, 94.1%, 80%, 89.8% at CI. Diagnostic performances of PET/CT and CI were not significantly different on a patient-based, side-by-side and level-by-level analysis. 18 F-FDG-PET/CT recognized distant metastases in 7 patients allowing to an upstaging. At a median follow-up of 27 months, relapse/progression of disease occurred in 31 patients and death occurred in 32. Metabolic tumor volume (MTV T), MTV total and total lesion glycolysis (TLG) showed to be independent prognostic factors for PFS.

CONCLUSIONS

Both CI and PET/CT had good diagnostic performances for the staging of laryngeal cancer; baseline metabolic features (MTV and TLG) showed an important prognostic value in assessing the rate of PFS.

18F-FDG PET or PET/CT role in plasmacytoma: A systematic review

BACKGROUND

The metabolic behavior of plasmacytoma at ¹⁸F-FDG PET/CT is not yet clear.

OBJECTIVE

The aim of this systematic review was to analyze published data about the role of ¹⁸F-FDG PET or PET/CT in patients affected by plasmacytoma.

METHODS

Acomprehensive computer literature search of the Scopus, PubMed/MEDLINE, Embase and Cochrane Library databases was conducted including articles up to July 2019 to find relevant published papers about the performance of ¹⁸F-FDG PET and PET/CT in plasmacytoma.

RESULTS

The comprehensive computer literature search revealed 371 articles. On reviewing the titles and abstracts, 363 articles were excluded because the reported data were not within the field of interest of this review. Eight articles were selected and retrieved in full-text version. From the analyses of the selected studies, the following main findings have been founded: 1) plasmacytoma generally is a ¹⁸F-FDG-avid tumor and PET/CT had good diagnostic performance with high sensitivity; 2) ¹⁸F-FDG PET/CT influenced patient management in most cases avoiding useless therapies and choosing the best therapeutic approach; 3) prognostic value of PET/CT qualitative and semiquantitative parameters is only suggested with controversial reports.

CONCLUSION

Despite several limitations affect this analysis, especially related to the low number of articles and patients studied, plasmacytoma looks to be an ¹⁸F-FDG-avid tumor in most of the cases; ¹⁸F-FDG PET or PET/CT had good diagnostic performance and had a significant clinical impact in change of therapeutic approach. Moreover, a possible prognostic role of PET/CT features is described.

Primary tumor standardized uptake value (SUVmax) measured on 18F-FDG PET/CT and mixed NSCLC components predict survival in surgical-resected combined small-cell lung cancer

Purpose

The combined small-cell lung cancer (c-SCLC) is rare and has unique clinicopathological futures. The aim of this study is to investigate ¹⁸F-FDG PET/CT parameters and clinicopathological factors that influence the prognosis of c-SCLC.

Methods

Between November 2005 and October 2014, surgical-resected tumor samples from c-SCLC patients who received preoperative ¹⁸F-FDG PET/CT examination were retrospectively reviewed. The maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to evaluate metabolic parameters in primary tumors. The survivals were evaluated with the Kaplan–Meier method. Univariate and multivariate analyses were used to evaluate potential prognostic factors.

Results

Thirty-one patients were enrolled, with a median age of 62 (range: 35 − 79) years. The most common mixed component was squamous cell carcinoma (SCC, n = 12), followed by large-cell carcinoma (LCC, n = 7), adenocarcinoma (AC, n = 6), spindle cell carcinoma (n = 4), adenosquamous carcinoma (n = 1) and atypical carcinoid (n = 1). The median follow-up period was 53.0 (11.0–142.0) months; the 5-year overall survival (OS) and progression-free survival(PFS) rate were 48.4% and 35.5%, respectively. Univariate survival analysis showed that gender, smoking history, tumor location were associated with PFS (P = 0.036, P = 0.043, P = 0.048), SUVmax and TNM stage were closely related to PFS in both Mixed SCC and non-SCC component groups (P = 0.007, P = 0.048). SUV_max, smoking history, tumor size and mixed SCC component were influencing factors of OS in patients (P = 0.040, P = 0.041, P = 0.046, P = 0.029). Multivariate survival analysis confirmed that TNM stage (HR = 2.885, 95%CI: 1.323–6.289, P = 0.008) was the most significantly influential factor for PFS. High SUV_max value (HR = 9.338, 95%CI: 2.426–35.938, P = 0.001) and mixed SCC component (HR = 0.155, 95%CI: 0.045–0.530, P = 0.003) were poor predictors for OS.

Conclusion

Surgical-resected c-SCLCs have a relatively good prognosis. TNM stage is the most significant factor influencing disease progression in surgical-resected c-SCLCs. SUVmax and mixed NSCLC components within c-SCLCs had a considerable influence on the survival. Both high SUVmax and mixed SCC component are poor predictors for patients with c-SCLCs.

Untreated plasmacytoma of bone containing macroscopic intralesional fat and mimicking intraosseous lipoma: A case report and review of the literature

Solitary plasmacytoma is a rare form of plasma cell neoplasm defined by local neoplastic accumulation of monoclonal plasma cells in the absence of systemic proliferative plasma cell disease. In this case report, a 65-year-old female with remote past medical history of papillary thyroid cancer presented with shoulder pain and radiographs showing an aggressive osteolytic lesion presumed to represent an osseous metastasis. The subsequent MRI and CT examinations demonstrated diffuse intralesional macroscopic fat without a nonlipogenic soft tissue component or focal, nodular mass-like enhancement. The presence of macroscopic fat in an untreated osseous lesion suggested a benign lesion with the favored diagnosis an intraosseous lipoma with non-displaced pathological fracture. Therefore, the decision was made to forego image-guided percutaneous biopsy and instead proceed directly to open surgical biopsy and partial distal claviculectomy. Pathology of the resected specimen showed focally dense infiltration of plasma cells within the marrow space and scant hematopoiesis compatible with a plasma cell neoplasm. To the best of our knowledge, this is first case report of solitary plasmacytoma of bone, or any untreated plasma cell neoplasm, containing macroscopic fat upon imaging. The decision to forego image-guided percutaneous biopsy had significant treatment implications as the primary therapy for patients with SPB is not surgical, but localized radiation therapy. Based on this case, solitary plasmacytoma of bone may be included as one of the rare fat containing malignant bone lesions and imaging guided percutaneous biopsy should be considered in symptomatic fat-containing bone lesions.

Maximizing the Clinical Benefit of Radiotherapy in Solitary Plasmacytoma: An International Multicenter Analysis

Objective: Although local definitive radiotherapy (RT) is considered the standard of care for solitary plasmacytoma (SP), the optimal RT parameters for SP patients have not been defined. The aim of this retrospective study is to analyze the effectiveness of various RT doses, volumes, and techniques, as well as to define the relevant prognostic factors in SP. Methods: Between 2000 and 2019, 84 patients, including 54 with solitary bone plasmacytoma (SBP) and 30 with extramedullary plasmacytoma (EMP), underwent RT at six institutions. Results: The overall RT median dose was 42 Gy (range, 36.0–59.4). The median follow-up period was 46 months. Overall, the local control (LC) rate was 96%, while the complete remission (CR) rate was 46%. The 5-year local relapse-free survival (LRFS), multiple myeloma-free survival (MMFS), progression-free survival (PFS), and overall survival (OS) rates were 89%, 71%, 55%, and 93%, respectively. Using an RT dose above 40 Gy was associated with a higher complete remission (CR) rate and a lower rate of local relapse. Modern irradiation techniques were associated with a trend toward a higher LC rate (98% vs. 87% for conventional, p = 0.09) and a significantly lower local relapse rate (6% vs. 25% for conventional, p = 0.04). However, RT dose escalation and technique did not lead to a significant effect on MMFS, PFS, and OS. Univariate analyses identified several patient characteristics as potentially relevant prognostic factors. In SBP patients, systemic therapy administration was associated significantly with MMFS and PFS rates. Conclusion: Using an RT dose >40 Gy and modern RT techniques may improve the local control and reduce the rate of relapse, without a significant impact on survival rates. The addition of systemic therapies may improve the MMFS and PFS rates of SBP patients.

Does Radiotherapy with Surgery Improve Survival and Decrease Progression to Multiple Myeloma in Patients with Solitary Plasmacytoma of Bone of the Spine?

OBJECTIVE

To investigate the outcomes of radiotherapy with or without surgery during treatment of patients with solitary plasmacytoma of bone (SBP) of the spine.

METHODS

Patients diagnosed with SBP of the spine treated with radiotherapy with or without surgery were identified and extracted from the SEER database. Propensity score matched (PSM) analysis was performed to balance patient characteristics between radiotherapy alone and radiotherapy with surgery groups. Patients in different age-groups were stratified and analyzed.

RESULTS

A total of 1275 patients with SBP of the spine treated with radiotherapy with or without surgery were extracted from the SEER database. Before PSM, the unadjusted Kaplan-Meier curve showed that the radiotherapy with surgery group had worse overall survival than did the radiotherapy without surgery group (both P < 0.05), whereas the difference of overall survival was attenuated after PSM. Stratified analysis found that the radiotherapy with surgery group had less progression to multiple myeloma for young patients (age <45 years) with SBP of the spine than did the radiotherapy without surgery group.

CONCLUSIONS

The results of our study suggest that radiotherapy with surgery may show less progression to multiple myeloma for younger patients with SBP of the spine.

Solitary plasmacytoma of maxillofacial bones: correlation of CT features with pathological findings

OBJECTIVE

To explore the CT features of solitary plasmacytoma (SP) of maxillofacial bones and correlation with pathological findings.

METHODS AND MATERIALS

We retrospectively reviewed the clinical, CT and pathological features of SP in the maxillofacial bones. 16 patients with clinically and histologically proven SP of maxillofacial bones were involved. They were aged from 27 to 79 years old (median 55.5 years old), and included 12 males and 4 females (males vs females: 3:1). All patients performed CT examination, in whom 13 patients underwent enhanced scanning and 3 plain scanning. The CT images were assessed for lesion location, size (maximum diameter), shape (round, oval and irregular), boundary (defined and illdefined), bone changes (bone destruction, residual bone, sclerotic margin and periosteal reaction), density of soft tissue mass and enhancement manifestations, and invasion of adjacent structures.

RESULTS

13 patients suffered from SP in the mandible, 2 in the zygoma, and 1 in the maxilla and hard palate. The maximum diameter of lesions ranged from 2.4 to 8.2 cm (mean 3.93 ± 1.435 cm). Most lesions were founded as a solitary osteolytic lesions (15/16, 93.75%) with round or ovoid shape (13/16, 81.25%), smooth margin (16/16, 100%) and defined boundary (16/16, 100%) in bone marrow. They destroyed bone cortex (15/16, 93.75%) and had residual bone (10/16, 62.5%), without sclerosis margin (15/16, 93.75%) and periosteal reaction (14/16, 87.5%). They easily formed soft tissue masses (16/16, 100%) and invade adjacent anatomical structures (15/16, 93.75%). The density of lesions was usually uniform (12/16, 75%) with strong enhancement. There was a significant difference in CT values between plain and enhanced scanning [50.75 ± 9.140 Hounfield unit (HU) vs 101.0 ± 28.830 HU; p < 0.001), with the mean difference of CT values 50.25 HU.

CONCLUSIONS

SP is predominant in the mandible of elderly male patients. A solitary, round or ovoid, well-defined, osteolytic, invasive mass in bone marrow, which destroys bone cortex, has residual bone, no sclerosis margin and periosteal reaction, and shows strong enhancement, is suggestive of this diagnosis.

Long-term clinical outcomes in a cohort of patients with solitary plasmacytoma treated in the modern era

BACKGROUND

The risk of recurrence of solitary plasmacytoma (SP)/progression to MM is well established, but patient, imaging and treatment factors influencing risk of progression require further evaluation.

METHODS

This is a retrospective analysis of 66 SP patients (23 UK, 43 Brazil) diagnosed 1989-2016. Patient baseline characteristics were recorded. The incidence of progression to MM was calculated, including biochemical and imaging findings and the treatment modality received. Survival estimates were determined by Kaplan-Meier analyses.

RESULTS

With a median follow-up of 53.6 months the 5 year overall survival (OS) was 90.7% (95%CI 79-96%). The median progression free survival (PFS) from diagnosis was 61 months. Cumulative incidence of progression to MM was 49.9% at 5 years (95% CI 35.6-62.6%) and was significantly higher with bone plasmacytoma (47.2%, 95%CI 31.9-61.1%), than an extramedullary location (8.3%, 95%CI 0.4-32.3%, Gray test p = 0.0095)). The majority of patients with solitary bony plasmacytoma (SBP) received radiotherapy (RT) (51/53, 96.2%) whereas most extramedullary cases were treated with surgical resection (7/13, 53.8%). A small proportion of SBP patients received additional upfront chemotherapy, with 5/6 in remission after a median follow-up (FU) of 10 years. The diagnostic yield of surveillance functional FU imaging without other indications of relapse/progression was low. The positive predictive value of functional FU imaging was high but with a low negative predictive value, especially in cases of suspected relapse/progression.

CONCLUSION

Our data suggests functional imaging should be used if clinical suspicion of relapse/progression, rather than a routine surveillance tool, and upfront adjuvant chemotherapy is worthy of prospective evaluation.

The Finding of the "Mini Brain" May Not Be a Unique Anatomic Appearance of Spinal Plasmacytoma

MRI and F-FDG PET/CT were performed on a 37-year-old man who was suspected with malignant spinal tumor on x-ray examination. An FDG-avid expansile lytic lesion was found in his T12 vertebra. The lesion showed a characteristic "mini-brain" appearance on MRI and CT. This extremely high specificity sign and consistent manifestation on PET image indicated plasmacytoma as the most optimal diagnosis. But finally, a giant cell tumor was confirmed after surgery. The case cautions that the specificity of the diagnostic characteristics of "mini-brain" sign for plasmacytoma or multiple myeloma may not be as high as previously reported.

Solitary Plasmacytoma of Bone of the Spine: Results From Surveillance, Epidemiology, and End Results (SEER) Registry

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To determine the prognostic indicators in patients with solitary plasmacytoma of bone (SPB) of the spine.

SUMMARY OF BACKGROUND DATA

Population-level estimates for prognosis among patients with SPB of the spine are still lacking. Sociodemographic and clinical predictors of outcome have not been well characterized.

METHODS

The Surveillance, Epidemiology, and End Results Registry was used to identify all patients with SPB of the spine from 1995 through 2014. Associated population data were used to determine annual incidence and limited-duration prevalence. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across groups using log-rank test. A Cox regression model was used for multivariate analysis of survival. Logistic regression was performed to identify predictors of the progression to multiple myeloma (MM).

RESULTS

The incidence and prevalence of the disease increased during the study period. Spinal SPB most commonly affected older people (>50) with a male preponderance. The median OS were 74.0 months. The 5 and 10-year survival rates for these patients were 56.1% and 36.7%, respectively. On multivariable analyses, older age, and surgery without radiotherapy were correlated with poor survival of patients with spinal SPB. The 3-year probability of progression to MM was 10.1%. Patients aged >70 years were associated with progression to MM. There was no significant association between the methods of surgical resection (radical or local/partial) and OS or progression to MM.

CONCLUSION

The findings of this study provide population-based estimates of the incidence, prevalence and prognosis for patients with SPB of the spine. This analysis indicated that the only identifiable prognostic indicators were older age and surgery without radiotherapy. Moreover, the methods of surgical resection did not influence the OS or progression to MM.

LEVEL OF EVIDENCE

4.

Recurrence of Extramedullary Plasmacytomas Involving Lymph Nodes and Pancreas Revealed by 68Ga-DOTATATE and 18F-FDG PET/CT

A 40-year-old man with history of extramedullary plasmacytoma in nasal cavity presented with right submandibular mass for 3 months. F-FDG PET/CT demonstrated mild radioactivity in the right submandibular mass, pancreatic mass, and lymph nodes in the abdomen and left hilum of the lung. To differentiate from pancreatic neuroendocrine tumor, Ga-DOTATATE PET/CT was performed. The above lesions were TATE avid, and additional lesions with intense radioactivity were also detected in the right internal mammary node and intrapericardial node. Finally, biopsy of the right submandibular mass confirmed recurrence of extramedullary plasmacytoma.

Prognostic significance of normalized FDG-PET parameters in patients with multiple myeloma undergoing induction chemotherapy and autologous hematopoietic stem cell transplantation: a retrospective single-center evaluation

PURPOSE

The purpose of this study was to determine retrospectively, through a single-center evaluation, whether FDG PET-CT normalized semi-quantitative parameters may predict response to induction chemotherapy (iChT) and hematopoietic stem cell transplantation (HSCT), as well as disease progression and progression-free survival in multiple myeloma (MM) patients, thus becoming a tool of personalized medicine.

METHODS

Patients undergoing iChT and HSCT with baseline and post-treatment FDG PET-CTs from January 2008 to July 2015 were included. The following baseline and post-treatment parameters were obtained: SUVmax, SUVmean, SUVpeak, MTVsum, TLGsum, rPET (lesion SUVmax/liver SUVmax) and qPET (lesion SUVpeak/liver SUVmean). Baseline-to-post-treatment changes (Δ) were also calculated. Metabolic and clinical laboratory progression or response at follow-up were noted; time-to-metabolic-progression (TMP) was defined as the interval from post-treatment scan to eventual progression at follow-up FDG PET-CTs. Possible association between each functional parameter and metabolic/clinical-laboratory progression or response was determined. Kaplan-Meier curves allowed to depict the TMP trend according to FDG PET-CT parameters.

RESULTS

Twenty-eight patients were included. Significantly higher ΔrPET and ΔqPET values were observed in ten patients with "metabolic response", with respect to 18 patients having "metabolic progression" (median 0.62 [IQR 0.32 - 1.34] vs median 0.00 [IQR -0.25 - 0.49] for ΔrPET; P = 0.045; median 0.51 [IQR 0.32 - 1.13] vs median 0.00 [IQR -0.31 - 0.67] for ΔqPET; P = 0.035). Neither normalized nor non normalized parameters differed significantly between the 20 patients with "clinical-laboratory response" and the eight patients with "clinical-laboratory progression". ΔrPET value lower than 0.38 and ΔqPET value lower than 0.27 predicted a significantly shorter TMP (P = 0.003 and P = 0.005, respectively).

CONCLUSIONS

Normalized semi-quantitative parameters are effective in predicting persistent response to treatment and shorter TMP in patients with MM undergoing iChT and HSCT.

The role of initial 18F-FDG PET/CT in the management of patients with suspected extramedullary plasmocytoma

Background

Extramedullary plasmacytoma (EMP) is a plasma cell malignancy that originates in soft tissues without evidence of systemic spread, and its management differs from other plasma cell neoplasms. The purpose of the present study was to evaluate the role of initial ¹⁸F-FDG PET/CT in the management of patients with clinical suspected EMP.

Methods

¹⁸F-FDG PET/CT scans performed in 21 patients (M/F = 12/9, mean age 51.1 ± 15.3 years) with clear suspicion of EMP from 2006 to 2015 were analysed retrospectively. The detection of new lesions and the change in treatment were evaluated.

Results

PET/CT detected new lesions in 38.1% (8/21) of patients with 17 lesions, and lymph nodes were the most common site, accounting for 70.6% (12/17) of all lesions, followed by bone (n = 2), and less frequently, breast (n = 1), lung (n = 1), and stomach (n = 1). These findings resulted in treatment changes in 7 patients with EMP. Among these, 4 patients had major treatment changes and 3 patients had minor changes. Of the 21 patients, progression to MM was observed in 8 patients (8/21, 38.1%). In univariate analysis, tumour size > 4 cm and partial response (PR) after treatment were significant prognostic factors for Progression-free survival (PFS).

Conclusions

Our data indicated that ¹⁸F-FDG PET/CT is helpful in the detection of additional lesions throughout the body, including lymph node involvement and distant additional lesion, which may have resulted in treatment change.

Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel

Solitary plasmacytoma is an infrequent form of plasma cell dyscrasia that presents as a single mass of monoclonal plasma cells, located either extramedullary or intraosseous. In some patients, a bone marrow aspiration can detect a low monoclonal plasma cell infiltration which indicates a high risk of early progression to an overt myeloma disease. Before treatment initiation, whole body positron emission tomography-computed tomography or magnetic resonance imaging should be performed to exclude the presence of additional malignant lesions. For decades, treatment has been based on high-dose radiation, but studies exploring the potential benefit of systemic therapies for high-risk patients are urgently needed. In this review, a panel of expert European hematologists updates the recommendations on the diagnosis and management of patients with solitary plasmacytoma.