Salvage Therapy for Prostate Cancer: AUA/ASTRO/SUO Guideline Part III: Salvage Therapy After Radiotherapy or Focal Therapy, Pelvic Nodal Recurrence and Oligometastasis, and Future Directions.

PURPOSE: The summary presented herein covers recommendations on salvage therapy for recurrent prostate cancer intended to facilitate care decisions and aid clinicians in caring for patients who have experienced a recurrence following prior treatment with curative intent. This is Part III of a three-part series focusing on evaluation and management of suspected non-metastatic recurrence after radiotherapy (RT) and focal therapy, evaluation and management of regional recurrence, management for molecular imaging metastatic recurrence, and future directions. Please refer to Part I for discussion of treatment decision-making and Part II for discussion of treatment delivery for non-metastatic biochemical recurrence (BCR) after radical prostatectomy (RP). MATERIALS AND METHODS: The systematic review that informs this Guideline was based on searches in Ovid MEDLINE (1946 to July 21, 2022), Cochrane Central Register of Controlled Trials (through August 2022), and Cochrane Database of Systematic Reviews (through August 2022). Update searches were conducted on July 26, 2023. Searches were supplemented by reviewing electronic database reference lists of relevant articles. RESULTS: In a collaborative effort between AUA, ASTRO, and SUO, the Salvage Therapy for Prostate Cancer Guideline Panel developed evidence- and consensus-based guideline statements to provide guidance for the care of patients who experience BCR after initial definitive local therapy for clinically localized disease. CONCLUSIONS: Continuous and deliberate efforts for multidisciplinary care in prostate cancer will be required to optimize and improve the oncologic and functional outcomes of patients treated with salvage therapies in the future.

Salvage Therapy for Prostate Cancer: AUA/ASTRO/SUO Guideline Part I: Introduction and Treatment Decision-Making at the Time of Suspected Biochemical Recurrence after Radical Prostatectomy.

PURPOSE: The summary presented herein covers recommendations on salvage therapy for recurrent prostate cancer intended to facilitate care decisions and aid clinicians in caring for patients who have experienced a recurrence following prior treatment with curative intent. This is Part I of a three-part series focusing on treatment decision-making at the time of suspected biochemical recurrence (BCR) after radical prostatectomy (RP). Please refer to Part II for discussion of treatment delivery for non-metastatic BCR after RP and Part III for discussion of evaluation and management of recurrence after radiotherapy (RT) and focal therapy, regional recurrence, and oligometastasis. MATERIALS AND METHODS: The systematic review that informs this Guideline was based on searches in Ovid MEDLINE (1946 to July 21, 2022), Cochrane Central Register of Controlled Trials (through August 2022), and Cochrane Database of Systematic Reviews (through August 2022). Update searches were conducted on July 26, 2023. Searches were supplemented by reviewing electronic database reference lists of relevant articles. RESULTS: In a collaborative effort between AUA, ASTRO, and SUO, the Salvage Therapy for Prostate Cancer Panel developed evidence- and consensus-based statements to provide guidance for the care of patients who experience BCR after initial definitive local therapy for clinically localized disease. CONCLUSIONS: Advancing work in the area of diagnostic tools (particularly imaging), biomarkers, radiation delivery, and biological manipulation with the evolving armamentarium of therapeutic agents will undoubtedly present new opportunities for patients to experience long-term control of their cancer while minimizing toxicity.

Salvage Therapy for Prostate Cancer: AUA/ASTRO/SUO Guideline Part II: Treatment Delivery for Non-metastatic Biochemical Recurrence After Primary Radical Prostatectomy.

PURPOSE: The summary presented herein covers recommendations on salvage therapy for recurrent prostate cancer intended to facilitate care decisions and aid clinicians in caring for patients who have experienced a recurrence following prior treatment with curative intent. This is Part II of a three-part series focusing on treatment delivery for non-metastatic biochemical recurrence (BCR) after primary radical prostatectomy (RP). Please refer to Part I for discussion of treatment decision-making and Part III for discussion of evaluation and management of recurrence after radiotherapy (RT) and focal therapy, regional recurrence, and oligometastasis. MATERIALS AND METHODS: The systematic review that informs this Guideline was based on searches in Ovid MEDLINE (1946 to July 21, 2022), Cochrane Central Register of Controlled Trials (through August 2022), and Cochrane Database of Systematic Reviews (through August 2022). Update searches were conducted on July 26, 2023. Searches were supplemented by reviewing electronic database reference lists of relevant articles. RESULTS: In a collaborative effort between AUA, ASTRO, and SUO, the Salvage Therapy for Prostate Cancer Panel developed evidence- and consensus-based guideline statements to provide guidance for the care of patients who experience BCR after initial definitive local therapy for clinically localized disease. CONCLUSIONS: Optimizing and personalizing the approach to salvage therapy remains an ongoing area of work in the field of genitourinary oncology and represents an area of research and clinical care that requires well-coordinated, multi-disciplinary efforts.

Standard Adult Gastric Emptying Scintigraphy Criteria Is Applicable for Partial Meal Ingestion.

BACKGROUND/AIMS: Gastric emptying scintigraphy is commonly performed to assess for dysmotility. A standardized meal with associated threshold criteria was established in 2000 to enable robust interpretation. However, no guidance is available to interpret results when patients do not ingest the entire meal. The purpose of this study is to determine the continued appropriateness of the threshold criteria in contemporary clinical practice and its relevance for partially ingested meals. METHODS: This retrospective study analyzed patients (n = 1365 total) who underwent solid-phase gastric emptying scintigraphy at an academic medical center. Patients were stratified based on their completion of the standard meal. Patients were further stratified into normal and delayed gastric emptying cohorts based on the current criteria. Percent gastric retention values at 1, 2, 3, and 4 h were compared. RESULTS: Median (95% upper reference) normal gastric retention values for the complete standard meal were 64% (87%) at 1 h, 25% (60%) at 2 h, 13% (54%) at 3 h and 4% (9%) at 4 h. Consumption of at least 50% of the standard meal yielded similar retention; 53% (86%) at 1 h, 19% (58%) at 2 h, 6% (29%) at 3 h and 3% (10%) at 4 h. There was no significant age- or gender-specific differences using the current criteria, and no differences were observed based on diabetic status. Retention values matched well with the current criteria and validated with data-driven clustering. CONCLUSION: Adult normative standards for gastric emptying scintigraphy are appropriate for differentiating normal and delayed populations and can be applied to partial meals with at least 50% completion.

Discrepancy between FDG-PET/CT and contrast-enhanced CT in the staging of patients with inflammatory breast cancer: implications for treatment planning.

PURPOSE: Optimizing treatment strategies for patients with inflammatory breast cancer (IBC) relies on accurate initial staging. This study compared contrast-enhanced computed tomography (ce-CT) and FDG-PET/CT for initial staging of IBC to determine the frequency of discordance between the two imaging modalities and potential impact on management. METHODS: 81 patients with IBC underwent FDG-PET/CT and ce-CT prior to starting treatment. FDG-PET/CT and ce-CT scans were independently reviewed for locoregional and distant metastases and findings recorded by anatomic site as negative, equivocal, or positive for breast cancer involvement. Each paired ce-CT and FDG-PET/CT case was classified as concordant or discordant for findings. Discordant findings were subclassified as (a) related to the presence or absence of distant metastases; (b) affecting the locoregional radiation therapy plan; or (c) due to incidental findings not related to IBC. RESULTS: There were 47 discordant findings between ce-CT and FDG-PET/CT in 41 of 81 patients (50.6%). Thirty (63.8%) were related to the presence or absence of distant metastases; most commonly disease detection on FDG-PET/CT but not ce-CT (n = 12). FDG-PET/CT suggested alterations of the locoregional radiation therapy plan designed by CT alone in 15 patients. FDG-PET/CT correctly characterized 5 of 7 findings equivocal for metastatic IBC on ce-CT. CONCLUSIONS: This study demonstrates differences between ce-CT and FDG-PET/CT for initial staging of IBC and how these differences potentially affect patient management. Preliminary data suggest that FDG-PET/CT may be the imaging modality of choice for initial staging of IBC. Prospective trials testing initial staging with FDG-PET/CT versus important clinical end-points in IBC are warranted.

Extraprostatic Uptake of 18F-Fluciclovine: Differentiation of Nonprostatic Neoplasms From Metastatic Prostate Cancer.

OBJECTIVE. Fluciclovine is a synthetic radiolabeled amino acid analog used for imaging of biochemical recurrent prostate cancer. Uptake of fluciclovine is mediated by several amino acid transporters, including alanine-serine-cysteine transporter 2 and large neutral amino acid transporters, which are known to be overexpressed in other malignancies. CONCLUSION. Knowledge of the common patterns of prostate cancer recurrence, in addition to what other neoplasms can show uptake, is critical for accurate study interpretation.

Patterns of breast reconstruction in patients diagnosed with inflammatory breast cancer: The Dana-Farber Cancer Institute's Inflammatory Breast Cancer Program experience.

Inflammatory breast cancer (IBC) exhibits dermal lymphatic involvement at presentation, and thus, the standard surgical approach is a nonskin-sparing modified radical mastectomy (MRM) without breast reconstruction (BR). In this study, we evaluated immediate and delayed BR receipt and its outcomes in IBC. Using an IRB-approved database, we retrospectively evaluated stage III IBC patients who received trimodality therapy (preoperative systemic therapy, followed by MRM and postmastectomy chest wall/regional nodal radiation). Patients with an insufficient response to preoperative systemic therapy and/or who required preoperative radiotherapy were excluded. BR receipt, timing, and morbidity were evaluated. Among 240 stage III IBC patients diagnosed between 1997 and 2016, 40 (17%) underwent BR. Thirteen (33%) had immediate, and 27 (67%) had delayed BR. Four patients had complications (1 [8%] immediate BR and 3 [11%] delayed BR); only 1 BR (delayed) was unsuccessful. From the MRM date, the median time to recurrence was 35 months (<1-212) and median overall survival was 87 months (<1-212). In this cohort of stage III IBC patients, only 11% pursued delayed BR following trimodality therapy, possibly attributable to the observed high recurrence rates hindering BR. Further studies addressing BR outcomes in IBC are needed for better counseling patients regarding their reconstructive options.

Refinement of the Lugano Classification lymphoma response criteria in the era of immunomodulatory therapy.

Uniformly adopted response criteria are essential for assessment of therapies incorporating conventional chemotherapy and chemoimmunotherapy regimens. Recently, immunomodulatory agents, such as immune checkpoint inhibitors, have demonstrated impressive activity in a broad range of lymphoma histologies. However, these agents may be associated with clinical and imaging findings during treatment suggestive of progressive disease (PD) despite evidence of clinical benefit (eg, tumor flare or pseudo-progression). Considering this finding as PD could lead to patients being prematurely removed from a treatment from which they actually stand to benefit. This phenomenon has been well described with checkpoint blockade therapy in solid tumors and anecdotally seen in lymphoma as well. To address this issue in the context of lymphoma immunomodulatory therapy, a workshop was convened to provide provisional recommendations to modify current response criteria in patients receiving these and future agents in clinical trials. The term "indeterminate response" was introduced to identify such lesions until confirmed as flare/pseudo-progression or true PD by either biopsy or subsequent imaging.

The Impact of Residual Disease After Preoperative Systemic Therapy on Clinical Outcomes in Patients with Inflammatory Breast Cancer.

BACKGROUND: Inflammatory breast cancer (IBC) is a rare and aggressive disease treated with multimodality therapy: preoperative systemic therapy (PST) followed by modified radical mastectomy (MRM), chest wall and regional nodal radiotherapy, and adjuvant biologic therapy and/or endocrine therapy when appropriate. In non-IBC, the degree of pathologic response to PST has been shown to correlate with time to recurrence (TTR) and overall survival (OS). We sought to determine if pathologic response correlates with oncologic outcomes of IBC patients. METHODS: Following review of IBC patients' records (1997-2014), we identified 258 stage III IBC patients; 181 received PST followed by MRM and radiotherapy and were subsequently analyzed. Pathologic complete response (pCR) to PST, hormone receptor and human epidermal growth factor receptor 2 (HER2) status, grade, and histology were evaluated as predictors of TTR and OS by Cox model. RESULTS: Overall, 95/181 (52%) patients experienced recurrence; 93/95 (98%) were distant metastases (median TTR 3.2 years). Seventy-three patients (40%) died (median OS 6.9 years). pCR was associated with improved TTR (hazard ratio [HR] 0.20, 95% confidence interval [CI] 0.09-0.46, p < 0.01, univariate; HR 0.17, 95% CI 0.07-0.41, p < 0.0001, multivariate) and improved OS (HR 0.26, 95% CI 0.11-0.65, p < 0.01, univariate). In patients with pCR, grade III (HR 1.91, 95% CI 1.16-3.13, p = 0.01), and triple-negative phenotype (HR 3.54, 95% CI 1.79-6.98, p = 0.0003) were associated with shorter TTR, while residual ductal carcinoma in situ was not (HR 0.85, 95% CI 0.53-1.35, p = 0.48, multivariate). CONCLUSIONS: In stage III IBC, pCR was associated with prognosis, further influenced by grade, hormone receptor, and HER2 status. Investigating mechanisms that contribute to better response to PST could help improve oncologic outcomes in IBC.

Inflammatory breast cancer and development of brain metastases: risk factors and outcomes.

Brain metastases are associated with significant morbidity. Minimal research has been conducted on the risk factors for and incidence of brain metastases in women with inflammatory breast cancer (IBC). 210 women with Stage III or IV IBC diagnosed from 1997-2011 were identified. Competing risk analysis and competing risks regression were used to calculate the incidence of brain metastases and identify significant risk factors. After a median follow-up in surviving patients of 2.8 years (range 0.6-7.6) and 3.3 years (range 0.2-14.5) in the 47 and 163 patients with (MET) and without (non-MET) metastatic disease at diagnosis, 17 (36 %) and 30 (18 %) developed brain metastases, respectively. The cumulative incidence at 1, 2, and 3 years was 17 % [95 % confidence interval (CI), 8-30], 34 % (95 % CI, 20-48), and 37 % (95 % CI, 22-51) for the MET cohort. The corresponding non-MET values were 4 % (95 % CI, 2-8), 8 % (95 % CI 5-13), and 15 % (95 % CI, 10-22). Once non-MET patients developed extracranial distant metastases, the subsequent 1, 2, and 3 years cumulative incidence of brain metastases was 18 % (95 % CI, 10-28), 25 % (95 % CI, 15-36), and 31 % (95 % CI, 20-43). On multivariate analysis, brain metastases were associated with younger age [hazard ratio (HR), 0.73; 95 % CI, 0.53-1.00; P = 0.05] and distant metastases at diagnosis (HR, 2.33; 95 % CI, 1.11-4.89; P = 0.03). The incidence of brain metastases is high in women with IBC. Particularly for patients with extracranial distant metastases, routine screening with magnetic resonance imaging should be considered.

Inflammatory Breast Cancer: Patterns of Failure and the Case for Aggressive Locoregional Management.

BACKGROUND: Inflammatory breast cancer (IBC) is a rare and aggressive subtype. This study analyzes the patterns of failure in patients with IBC treated at our institution. METHODS: We retrospectively analyzed the records of 227 women with IBC presenting between 1997 and 2011. Survival analysis was used to calculate overall survival (OS) and disease-free survival. Competing risk analysis was used to calculate locoregional recurrence (LRR). RESULTS: A total of 173 patients had locoregional-only disease at presentation (non-MET). Median follow-up in the surviving patients was 3.3 years. Overall, 132 (76.3 %) patients received trimodality therapy with chemotherapy, surgery, and radiotherapy. Three-year OS was 73.1 % [95 % confidence interval (CI) 64.9-82.4]. Cumulative LRR was 10.1, 16.9, and 21.3 % at 1, 2, and 3 years, respectively. No variable was significantly associated with LRR. Fifty-four patients had metastatic disease at presentation (MET). Median follow-up in the surviving patients was 2.6 years. Three-year OS was 44.3 % (95 % CI 31.4-62.5). Twenty-four (44.4 %) patients received non-palliative local therapy (radiotherapy and/or surgery). For these patients, median OS after local therapy was 2 years. Excluding six patients who received local therapy for symptom palliation, the crude incidence of locoregional progression or recurrence (LRPR) was 17 % (4/24) for those who received local therapy compared with 57 % (13/23) for those who did not. CONCLUSIONS: For non-MET patients, LRR remains a problem despite trimodality therapy. More aggressive treatment is warranted. For MET patients, nearly 60 % have LRPR with systemic therapy alone. Local therapy should be considered in the setting of metastatic disease to prevent potential morbidity of progressive local disease.

Cancer immunotherapy: imaging assessment of novel treatment response patterns and immune-related adverse events.

Cancer immunotherapy is changing the imaging evaluation of cancer treatment response and treatment-related toxic effects. New emerging patterns of treatment response and treatment-related toxic effects after treatment with immunomodulating agents have been observed. Treatment response after immunomodulatory therapy can be associated with significantly delayed decrease in tumor size, and new or enlarging tumors observed soon after completion of treatment may not reflect disease progression. In addition, activation of the immune system to fight cancer may lead to unwanted autoimmune-mediated toxic effects that could be mistaken for metastatic disease or misdiagnosed as a non-treatment-related process and delay appropriate clinical management. Radiologists must recognize the novel treatment response patterns and the wide range of autoimmune toxic effects, which should not be mistaken for treatment failure or metastatic disease progression.

Phase 2 study of rituximab-ABVD in classical Hodgkin lymphoma.

In classical Hodgkin lymphoma, circulating clonotypic malignant cells express CD20, which potentially explains the observed activity of rituximab. This multicenter phase 2 study investigated the combination of rituximab-ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) for stage II-IV untreated classical Hodgkin lymphoma. A goal was to assess the behavior of circulating clonotypic B cells clinically. Of 49 evaluable patients, 69% had stage IIB-IV disease; 8% had CD20(+) Hodgkin and Reed-Sternberg cells. Rituximab-ABVD was generally well tolerated. Delivered relative dose intensity was 94% for AVD and 79% for bleomycin. After 6 cycles, 81% of patients were in complete remission. Only 8% received radiation therapy. The actuarial 3-year event-free and overall survival rates were 83% and 98%, respectively. EBV copy number in plasma fell dramatically during cycle 1 in patients with EBV(+) tumors. Persistence of detectable circulating clonotypic B cells was associated with a greater relapse frequency (P < .05). Rituximab-ABVD and clonotypic B cells warrant additional study in classical Hodgkin lymphoma.

Neuroendocrine Tumors: Diagnostics.

Neuroendocrine neoplasms (NEN) are rare tumors arising from neuroendocrine cells. NEN are ideally suited for a theragnostic approach due to their specific expression of somatostatin receptors (SSTR). SSTR imaging of NEN dates back to the 1980s, but has evolved recently due to the introduction of more sensitive SSTR PET radiotracers. SSTR PET is a primary imaging modality for identifying NEN and characterizing SSTR expression. SSTR PET is complementary to anatomic imaging for assessing tumor response to treatment. SSTR PET is mandated to determine eligibility for peptide receptor radionuclide therapy. Here, the role of imaging to aid management of NEN is reviewed.

Alpha-emitter Peptide Receptor Radionuclide Therapy in Neuroendocrine Tumors.

Peptide receptor radionuclide therapy (PRRT) has become mainstream therapy of metastatic neuroendocrine tumors not controlled by somatostatin analog therapy. Currently, beta particle-emitting radiopharmaceuticals are the mainstay of PRRT. Alpha particle-emitting radiopharmaceuticals have a theoretic advantage over beta emitters in terms of improved therapeutic efficacy due to higher cancer cell death and lower nontarget tissue radiation-induced adverse events due to shorter path length of alpha particles. We discuss the available evidence for and the role of alpha particle PRRT.

Late Subacute Cerebral Hematoma Mimicking a Metastasis on PSMA PET/CT.

ABSTRACT: A 64-year-old man with history of prostate cancer was found to have rising prostate-specific antigen after radical prostatectomy. 18 F-DCFPyL PET/CT demonstrated a prostate-specific membrane antigen-avid brain lesion in the left frontal lobe and no other findings to account for rising prostate-specific antigen. Brain MRI demonstrated a small intraparenchymal hematoma with late subacute features in this location. The patient reported a seizure 3 weeks before but was otherwise asymptomatic, and neurologic examination was normal. Follow-up MRI demonstrated gradual decrease in size of the hematoma without treatment.

Evaluating the added value of concurrent contrast-enhanced diagnostic CT for PSMA-PET/CT Interpretation.

RATIONALE AND OBJECTIVES: To determine whether concurrent contrast-enhanced diagnostic CT (DxCT) confers added diagnostic certainty compared to PSMA-PET/CT alone. MATERIALS AND METHODS: This retrospective multi-reader study analyzed imaging comprising combined F-18-piflufolastat PSMA-PET/CT with diagnostic chest/abdominopelvic CT from prostate cancer patients within the first 6 months of FDA-approval of the PET agent. Six nuclear radiology readers were randomly presented with PSMA-PET/CT studies with or without DxCT and asked to report their diagnostic certainty for PSMA-avid lesions found on PET. Subsequently, readers re-reviewed the same study after an interlude (with the CT if not previously presented and vice-versa) to determine if DxCT altered their diagnostic assessment. Inter-rater concordance was assessed on a subset of images read by all readers. Diagnostic certainties for PSMA-PET/CT with and without DxCT were compared, and the variables for which DxCT may add value were examined. RESULTS: Good inter-rater concordance across readers was noted for both PET/CT (Finn's coefficient of reliability for overall scan certainty: 0.85,p < 0.01) and combined DxCT-PET/CT (0.59,p < 0.01). Overall certainty and concordance between PET/CT and combined DxCT-PET/CT datasets were similar (overall scan certainty: 92% ± 16 vs. 92% ± 17,p = 0.43), with no significant advantage for adding DxCT across different anatomic locations or clinical parameters. A slight predilection for combined DxCT-PET/CT was noted when interpreting images acquired for the initial staging of prostate cancer (89% ± 16 vs. 93% ± 17,p = 0.08). CONCLUSION: Good inter-reader concordance can be achieved across different training levels with PSMA-PET/CT. Furthermore, using DxCT concurrent with PSMA-PET/CT does not significantly improve diagnostic certainty for most indications but may be useful for initial staging.

Randomized Phase II Study Evaluating the Addition of Pembrolizumab to Radium-223 in Metastatic Castration-resistant Prostate Cancer.

The checkpoint immunotherapeutic pembrolizumab induces responses in a small minority of patients with metastatic castration-resistant prostate cancer (mCRPC). Radium-223 (R223) may increase immunogenicity of bone metastases and increase pembrolizumab (P) activity. In a randomized phase II study, we assessed the effect of R223+P compared with R223 on tumor immune infiltration, safety, and clinical outcomes in patients with mCRPC. The primary endpoint was differences in CD4+ and CD8+ T-cell infiltrate in 8-week versus baseline bone metastasis biopsies; secondary endpoints were safety, radiographic progression-free survival (rPFS), and overall survival (OS). Of the 42 treated patients (29 R223+P, 13 R223), 18 R223+P and 8 R223 patients had evaluable paired tumor biopsies. Median fold-change of CD4+ T cells was -0.7 (range: -9.3 to 4.7) with R223+P and 0.1 (-11.1 to 3.7) with R223 (P = 0.66); for CD8+ T cells, median fold-change was -0.6 (-7.4 to 5.3) with R223+P and -1.3 (-3.1 to 4.8) with R223 (P = 0.66). Median rPFS and OS was 6.1 (95% confidence interval: 2.7-11.0) and 16.9 months [12.7-not reached (NR)], respectively, with R223+P and 5.7 (2.6-NR) and 16.0 (9.0-NR), respectively, with R223. Although R223+P was well tolerated with no unexpected toxicity, the combination did not improve efficacy. High-dimensional flow cytometry demonstrated minimal immune modulation with R223, whereas R223+P induced CTLA-4 expression on circulating CD4+ T cells. Clinical responders possessed lower circulating frequencies of Ki67+ T and myeloid cells at baseline and higher circulating frequencies of TIM-3+ T and myeloid cells by week 9. Although R223+P did not induce T-cell infiltration into the tumor microenvironment, exhaustion of induced peripheral T-cell immune responses may dampen the combination's clinical activity.

Positron emission tomography/computed tomography imaging in Merkel cell carcinoma: a study of 270 scans in 97 patients at the Dana-Farber/Brigham and Women's Cancer Center.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and lethal cutaneous neuroendocrine carcinoma. Imaging is crucial for accurate staging, which remains a strong predictor of survival, as well as earlier detection of recurrence and progression, which are common despite aggressive management. There is no consensus on the role of initial and subsequent imaging for MCC. OBJECTIVE: We sought to evaluate the use of 2-fluoro-[(18)F]-deoxy-2-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the management of MCC. METHODS: In all, 270 FDG-PET/CT studies were performed in 97 patients with pathology-proven MCC at the Dana-Farber/Brigham and Women's Cancer Center, Boston, Mass, from August 2003 to December 2010. RESULTS: FDG-PET/CT scans were obtained as part of the initial (61 scans in 61 patients) and subsequent (209 scans in 79 patients) treatment strategies. MCCs were FDG-avid with a mean maximum standardized uptake value of primary lesions of 6.5 (range 1.3-12.9) and a mean maximum standardized uptake value of regional and distant metastases of 7.2 (range 1.5-9.9). FDG-PET/CT upstaged 16% of patients who underwent baseline scans. FDG-PET/CT studies showed that bone and bone-marrow metastases were more common than previously reported, and were often undetected by CT. LIMITATIONS: Our study is limited by its retrospective design, and potential referral bias associated with a tertiary care center. CONCLUSIONS: FDG-PET/CT performed as part of the initial management strategy tended to upstage patients with more advanced disease. FDG-PET/CT performed as part of the subsequent treatment strategy identified metastatic disease, particularly in bone/bone marrow, which was not seen on CT. FDG-PET/CT imaging is a valuable staging and restaging tool in MCC management.