Phase I Trial of SPECT-Guided Liver-Directed Radiotherapy for Patients with Low Functional Liver Volume.

BACKGROUND: Traditional constraints specify that 700 cc of liver should be spared a hepatotoxic dose when delivering liver-directed radiotherapy to reduce the risk of inducing liver failure. We investigated the role of single photon emission computed tomography (SPECT) to identify and preferentially avoid functional liver during liver-directed radiation treatment planning in patients with preserved liver function but limited functional liver volume after receiving prior hepatotoxic chemotherapy or surgical resection. METHODS: This phase I trial with a 3 + 3 design evaluated the safety of liver-directed radiotherapy using escalating functional liver radiation dose constraints in patients with liver metastases. Dose limiting toxicities (DLTs) were assessed 6-8 weeks and 6 months after completing radiotherapy. RESULTS: All twelve patients had colorectal liver metastases and received prior hepatotoxic chemotherapy. Eight patients underwent prior liver resection. Median computed tomography (CT) anatomical non-tumor liver volume was 1,584 cc (range 764-2,699 cc). Median SPECT functional liver volume was 1,117 cc (range 570-1,928cc). Median non-target CT and SPECT liver volumes below the volumetric dose constraint were 997 cc (range 544-1,576 cc) and 684 cc (range 429-1,244 cc), respectively. The prescription dose was 67.5-75 Gy in 15 fractions or 75-100 Gy in 25 fractions. No DLTs were observed during follow-up. One-year in-field control was 57%. One-year overall survival was 73%. CONCLUSION: Liver-directed radiotherapy can be safely delivered to high doses when incorporating functional SPECT into the radiation treatment planning process which may enable sparing of lower volumes of liver than traditionally accepted in patients with preserved liver function. TRIAL REGISTRATION: NCT02626312.

Temporary Reversal of Hepatoenteric Collaterals during 90Y Radioembolization Planning and Administration.

PURPOSE: This paper aims to evaluate the safety and efficacy of the temporary redirection of blood flow of hepatoenteric collaterals using a balloon catheter in the common hepatic artery (CHA) to prevent the nontarget deposition of 90Y microspheres. MATERIALS AND METHODS: In this retrospective single-center study of patients who received 90Y radioembolization (RE) from September 2010 to September 2015, diagnostic (67 patients) or treatment (72 patients) angiograms with the attempted use of a balloon catheter in the CHA to temporarily direct blood flow away from the hepatoenteric arteries were analyzed. SPECT/CT nuclear scintigraphy was performed after both diagnosis and treatment. RESULTS: Overall, only 12 hepatoenteric arteries in 11 patients required embolization due to persistent hepatoenteric flow despite the use of the balloon occlusion technique in a total of 86 patients. Physicians performed the 90Y RE using balloon occlusion with glass (n = 22) or resin (n = 50) microspheres. Over 80% administration of the prescribed 90Y dose was accomplished in 34 (67%) resin and 20 (95%) glass microsphere patients. Post-treatment 90Y RE scintigraphy confirmed the absence of extrahepatic activity in all patients. One grade 2 gastrointestinal ulcer was present after 90 days of follow-up. CONCLUSION: Temporary CHA occlusion with a balloon catheter is a reliable and reproducible alternative to the conventional coil embolization of hepatoenteric arteries during diagnostic Tc-99m macroaggregated albumin and therapeutic 90Y RE delivery.

Incidental 18F-Fluciclovine Uptake in a Desmoid Tumor Detected in a Patient Undergoing PET/CT Imaging for Prostate Cancer.

ABSTRACT: A 74-year-old man with biochemical recurrent prostate cancer underwent 18F-fluciclovine PET/CT for restaging to determine subsequent treatment strategy. 18F-fluciclovine PET/CT imaging demonstrated incidental focal heterogeneous increased 18F-fluciclovine uptake corresponding to a soft tissue nodule within the musculature of the left anterior abdominal wall. Subsequent ultrasound-guided biopsy of the lesion revealed histopathology compatible with a desmoid tumor. Consequently, the patient underwent surgical resection with wide local excision of the lesion.

Phase II study of Radium-223 dichloride combined with hormonal therapy for hormone receptor-positive, bone-dominant metastatic breast cancer.

BACKGROUND: Radium-223 dichloride (Ra-223) is a targeted alpha therapy that induces localized cytotoxicity in bone metastases. We evaluated the efficacy and safety of Ra-223 plus hormonal therapy in hormone receptor-positive (HR+), bone-dominant metastatic breast cancer. METHODS: In this single-center phase II study, 36 patients received Ra-223 (55 kBq/kg intravenously every 4 weeks) up to 6 cycles with endocrine therapy. The primary objective was to determine the clinical disease control rate at 9 months. Secondary objectives were to determine (a) tumor response rate at 6 months, (b) progression-free survival (PFS) durations, and (c) safety. RESULTS: The median number of prior systemic treatments for metastatic disease was 1 (range, 0-4). The disease control rate at 9 months was 49%. The tumor response rate at 6 months was 54% (complete response, 21%; partial, 32%). The median PFS was 7.4 months (95% CI, 4.8-not reached [NR]). The median bone-PFS was 16 months (95% CI, 7.3-NR). There were no grade 3/4 adverse events. CONCLUSIONS: Ra-223 with hormonal therapy showed possible efficacy in HR+ bone-dominant breast cancer metastasis, and adverse events were tolerable. We plan to further investigate the clinical application of Ra-223 in these patients. (NCT02366130).

Granulomatous/sarcoid-like lesions associated with checkpoint inhibitors: a marker of therapy response in a subset of melanoma patients.

BACKGROUND: Immune checkpoint therapy has dramatically changed the landscape of cancer therapy, providing an efficacious and durable therapeutic option for patients with advanced-stage disease. However, dermatologic toxicities are a well-recognized side effect in patients receiving this therapy. A spectrum of immune related adverse events (irAEs) involving the skin can occur and include immunobullous disorders, lichenoid dermatitis, and vitiligo. Granulomatous/sarcoid-like lesions are now being recognized with the current class of checkpoint inhibitors (CPIs) that involve the dermis, the subcutaneous tissue (panniculitis), and lymph nodes. CASE PRESENTATION: We report 3 patients who developed granulomatous/sarcoid-like lesions while being treated with immune checkpoint therapy for advanced-stage melanoma, and we provide a comprehensive review of the literature in which similar cases are described. To date, 26 patients (including the 3 from this report) have been described with a median age of 57 years who developed granulomatous/sarcoid-like lesions associated with CPIs (median onset 6 months), of which 77% of patients had melanoma as primary tumor. To manage this adverse side effect, therapy was withheld in 38% of patients and 44% of the patients were treated with systemic steroids and 8% patients with localized therapy (one patient with intralesional triamcinolone). 96% of patients demonstrated either resolution or improvement of granulomatous/sarcoid-like lesions associated with CPIs irrespective of medical intervention. Therapeutic response, stable disease, or remission of primary malignancy was observed in 71% of reported patients who developed granulomatous/sarcoid-like lesions associated with CPIs over a median follow-up of 11.5 months since initiation of treatment. CONCLUSIONS: The development of granulomatous/sarcoid-like lesions associated with CPIs is a recognized manifestation with the current class of immune checkpoint therapy that may clinically and radiographically mimic disease recurrence. Awareness of this type of toxicity is important for appropriate management and possible measurement of therapeutic response in a subset of patients who manifest this type of immune-mediated reaction.

Imaging Characteristics of Chemotherapy Related Adult-Onset Still Disease.

A 60-year-old man with lymphoma completed chemotherapy on October 21, 2016, with complete remission. He then received rituximab maintenance therapy. Since March 2017, he has had progressive fatigue, myalgias, rash, weight loss, diarrhea, and recurrent low-grade fever. Subsequent bone marrow biopsy and FDG PET/CT demonstrated no active lymphoma. An In-white blood cell scan showed abnormal tracer uptake on 20-hour postinjection, but not on 3-hour postinjection images, including innumerable skeleton muscle foci, multiple cutaneous foci, and persistent diffuse increased uptake in the lungs. Diagnosis of adult-onset Still disease was made accordingly. The patient's cytopenia was deemed a chemotherapy-related adverse effect.

Increased 18F-FDG Uptake Associated With Gastric Banding Surgical Mesh on PET/CT.

Surgical mesh was used in the 1980s and early 1990s for vertical banded gastroplasty as treatment for morbid obesity. This procedure was replaced by the more popular laparoscopic gastric banding in the mid-1990s. Surgical mesh, commonly used in hernioplasty, has been associated with increased F-FDG uptake related to an inflammatory foreign body reaction and is a known cause of false-positive PET scans. We present a case of increased F-FDG uptake related to surgical mesh in a patient who had undergone vertical banded gastroplasty.

Bone Windows for Distinguishing Malignant from Benign Primary Bone Tumors on FDG PET/CT.

Objective. The default window setting on PET/CT workstations is soft tissue. This study investigates whether bone windowing and hybrid FDG PET/CT can help differentiate between malignant and benign primary bone tumors. Materials and methods. A database review included 98 patients with malignant (n=64) or benign primary bone (n=34) tumors. The reference standard was biopsy for malignancies and biopsy or >1 year imaging follow-up of benign tumors. Three radiologists and/or nuclear medicine physicians blinded to diagnosis and other imaging viewed the lesions on CT with bone windows (CT-BW) without and then with PET (PET/CT-BW), and separate PET-only images for malignancy or benignity. Three weeks later the tumors were viewed on CT with soft tissue windows (CT-STW) without and then with PET (PET/CT-STW). Results. Mean sensitivity and specificity for identifying malignancies included: CT-BW: 96%, 90%; CT-STW: 90%, 90%; PET/CT-BW: 95%, 85%, PET/CT-STW: 95%, 86% and PET-only: 96%, 75%, respectively. CT-BW demonstrated higher specificity than PET-only and PET/CT-BW (p=0.0005 and p=0.0103, respectively) and trended toward higher sensitivity than CT-STW (p=0.0759). Malignant primary bone tumors were more avid than benign lesions overall (p<0.0001) but the avidity of benign aggressive lesions (giant cell tumors and Langerhans Cell Histiocytosis) trended higher than the malignancies (p=0.08). Conclusion. Bone windows provided high specificity for distinguishing between malignant and benign primary bone tumors and are recommended when viewing FDG PET/CT.

Fast Dixon whole-body MRI for detecting distant cancer metastasis: a preliminary clinical study.

PURPOSE: To evaluate the feasibility of fast Dixon whole-body (WB) magnetic resonance imaging (MRI) for detecting bone and liver metastasis in clinical patients and to compare its performance with skeletal scintigraphy (SS) for detecting bone metastases using reference imaging with >1 year follow-up as the gold standard. MATERIALS AND METHODS: Twenty-nine patients with bone metastases prospectively underwent WB MRI and SS. WB MRI included coronal T2, axial T1 with and without intravenous gadolinium (including triphasic liver sequences), and axial diffusion-weighted imaging, plus spinal sagittal postcontrast T1-weighted images. The skeleton was divided into 16 segments. Reviewers blinded to other images identified up to five lesions per segment and rated them using a five-point confidence scale for metastatic disease. Sensitivities and specificities were compared using the McNemar test. RESULTS: The sensitivity of WB MRI and SS in detecting bone metastases was 70.8% and 59.6% (P = 0.003), respectively; specificity was 89.1% and 98.7% (P < 0.0001). WB MRI detected all livers with metastases (n = 8). One focal nodular hyperplasia was classified as a metastasis on WB MRI. CONCLUSION: Fast Dixon WB MRI is feasible in clinical patients, highly specific, and more sensitive than SS in detecting bone metastases, and can detect metastases of the liver.

Musculoskeletal pitfalls in 18F-FDG PET/CT: self-assessment module.

Identification of pitfalls is essential to the correct interpretation of (18)F-FDG PET/CT. The educational objectives of this self-assessment module are for the participant to exercise, self-assess, and improve his or her knowledge of FDG PET/CT of the musculoskeletal system.

Musculoskeletal pitfalls in 18F-FDG PET/CT: pictorial review.

OBJECTIVE: Thorough evaluation of the musculoskeletal system on PET/CT requires a fund of specialized knowledge and the use of musculoskeletal-oriented viewing techniques. The study of musculoskeletal pitfalls introduces many subspecialty-specific topics and provides instruction in the methods necessary for optimal evaluation of the musculoskeletal system when interpreting PET/CT. CONCLUSION: This article reviews musculoskeletal pitfalls in PET/CT. On completion, reviewers should have an improved ability to evaluate the musculoskeletal system on PET/CT.