Soft tissue necrosis after radiotherapy for head and neck cancer

A 60-year-old man with cT2N0M0 hypopharyngeal squamous cell carcinoma received definitive chemoradiotherapy. FDG PETCT at 4 weeks showed complete metabolic response at primary site (Figure 1). At 6 months, contrasted CT showed no evidence of disease with soft tissue air indicating radiation necrosis and ulceration (Figure 2). The patient had symptom of dysphagia. Laryngoscopy and esophagogastroduodenoscopy showed inflammation without other severe findings. He had conservative care as a treatment option. At 12 months, contrasted CT showed improved nonenhancing ulceration without disease progression (Figure 3).

Diagnostic Value of PET/MR with DWI for Burkitt Lymphoma

18F-FDG-PET/MR images, including DWI, of a 46-year-old male admitted to the Emergency Room of our tertiary center, who was suffering from diplopia, left orbital pain, and a headache for two weeks, demonstrated multiple hepatic nodules, a pancreatic mass, and skeletal metastases, in addition to thrombosis of the left cavernous sinus, thickening of the small intestine, and a large hepatic lesion identified at head and neck MR and whole-body CT, respectively. Hepatic and bone marrow biopsies revealed the diagnosis of Burkitt lymphoma. After four cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, methotrexate/ifosfamide, etoposide, and high dose cytarabine (R- CODOX-M/IVAC), a complete metabolic response occurred.

Case Report: Two Rare Cases of Complete Metabolic Response to Crizotinib in Patients With Rearranged ROS1 and ALK Metastatic Non-small Lung Cancer

Crizotinib is a tyrosine kinase inhibitor (TKI) indicated in first-line treatment of rearranged c-ros oncogene 1 (ROS1) and anaplastic lymphoma kinase (ALK) metastatic non-small-cell lung cancer (NSCLC). However, the common response reported after treatment is partial and few complete responses have been reported in PROFILE studies with computed tomography (CT) evaluation. To date, only one case report of complete metabolic response on 2-deoxy-2-[18F] fluoro-D-glucose positron emission tomography-computed tomography (18F-FDG-PET/CT) was published, reporting on a patient with ROS1 rearranged NSCLC. We highlighted the 18F-FDG-PET/CT useful approach for therapeutic assessment of TKI in metastatic mutated NSCLC reporting two complete metabolic responses in patients treated with crizotinib for a rearranged ROS1 and a metastatic ALK NSCLC.

Combination Brentuximab Vedotin and Bendamustine for Pediatric Patients with Relapsed/Refractory Hodgkin Lymphoma

In patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL), achieving a complete metabolic response (CMR) following salvage therapy is associated with superior outcomes, and optimal treatments need to be identified. The combination of brentuximab vedotin and bendamustine (BVB), while highly active in adult patients, has not been extensively evaluated in pediatric patients with R/R HL. We performed a multi-institution retrospective review of pediatric patients <21 years of age with R/R HL treated with BVB from January 2016 to July 2019. Response was assessed by local radiologists according to Lugano classification criteria. Twenty-nine patients (17 relapsed, 12 refractory) with a median age of 15 years (range 10-20) were treated with BVB and received a median of three cycles of therapy (range 2-7). Patients received an infusion of 1.8mg/kg of brentuximab vedotin on day 1 with bendamustine 90mg/m2 on Days 1 and 2 of 3-week cycles. Nineteen patients (66%) achieved a CMR (CI: 46 to 82%). An objective response was observed in 23 patients (ORR 79%) (CI: 60 to 92%). The most common grade 3/4 toxicities were hematologic and 3 patients (10%) experienced grade 3 infusion reactions. Seventeen of 18 patients underwent successful mobilization and collection of stem cells. Sixteen patients (13 autologous, 3 allogeneic) received a consolidative transplant following BVB. The 3-year post-BVB event-free and overall survival was 65% (95%CI: 46 to 85%) and 89% (95%CI: 74 to 100), respectively. For pediatric patients with R/R HL, BVB was well tolerated and compares favorably with currently accepted salvage regimens.

Necrosis, as Identified on Pre-Radiotherapy 18F-FDG PET/CT, is a Predictor for Complete Metabolic Response in Patients with Non-Small Cell Lung Cancer.

Purpose: To investigate necrosis on pre-radiotherapy (RT) 18F-FDG PET/CT (PETNECROSİS) is a predictor for complete metabolic response (CMR) in patients with non-small cell lung cancer (NSCLC).Methods: We studied patients with inoperable stage I-III NSCLC who underwent pre- and post-radiotherapy 18F-FDG PET/CT. The relationship between CMR and PETNECROSIS, SUVmax, gross tumor volume calculated with 18F-FDG PET/CT (GTVPET-CT), tumor size, histology, metabolic tumor volume (MTV), and RT dose was assessed using logistic regression analysis. To evaluate necrosis on 18F FDG PET/CT, we drew a region of interest (ROI) in the area showing visually very low/or no fluorodeoxyglucose (FDG) uptake on PET images. If the SUVmax was lower than the blood pool SUVmax and showed significantly lower attenuation [10 to 30 Hounsfield Units (HU)] from the surrounding tissue on non-intravenous contrast-enhanced low dose correlative CT, we defined it as necrotic (PETNECROSİS).Results: Fifty-three patients were included in the study. The mean age was 68.1±9.8 years. Twenty-one patients had adenocarcinoma, 32 had squamous cell carcinoma. All parameters were independent of histologic status. Multivariate logistic regression analysis showed that, SUVmax ≤11.6vs>11.6 (p=0.003, OR:7.670, 95CI%:2.013-29.231) and PETNECROSİS absence/presence were independent predictors for CMR (p=0.028, OR:6.704, 95CI%1.214-30.394).Conclusion: The necrosis on 18F FDG PET/CT and SUVmax>11.6 could be an imaging marker for the complete metabolic response after chemoradiotherapy or RT alone in patients with NSCLC.

Intracranial response after extracranial radiation in a patient with rapidly progressing metastatic melanoma

Growing literature supports the synergistic effect of radiation as a primer for renewed enhanced systemic immunological responses in patients receiving immunotherapy for metastatic melanoma. Radiographic regression of extracranial tumours after treatment of intracranial metastatic lesions has been reported and these observations point to an abscopal effect that traverses the blood–brain barrier. We describe a patient with rapidly progressing metastatic melanoma despite combined immune checkpoint blockade, who achieved a complete metabolic response of both his extracranial and intracranial disease after the commencement of palliative radiation to his axilla. This is the first published case, to our knowledge, of a sustained, complete intracranial abscopal response from extracranial radiation. We discuss potential mechanistic relations between radiation, the blood–brain barrier and the abscopal effect.

Complete Metabolic Response in FDG-PET-CT Scan before Discontinuation of Immune Checkpoint Inhibitors Correlates with Long Progression-Free Survival

Checkpoint inhibitors have revolutionized the treatment of patients with metastasized melanoma. However, it remains unclear when to stop treatment. We retrospectively analyzed 45 patients (median age 64 years; 58% male) with metastasized melanoma from 3 cancer centers that received checkpoint inhibitors and discontinued therapy due to either immune-related adverse events or patient decision after an (18F)2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) combined with a low-dose CT scan (FDG-PET-CT) scan without signs for disease progression. After a median of 21 (range 1–42) months of immunotherapy an FDG-PET-CT scan was performed to evaluate disease activity. In these, 32 patients (71%) showed a complete metabolic response (CMR) and 13 were classified as non-CMR. After a median follow-up of 34 (range 1–70) months, 3/32 (9%) of CMR patients and 6/13 (46%) of non-CMR patients had progressed (p = 0.007). Progression-free survival (PFS), as estimated from the date of last drug administration, was significantly longer among CMR patients than non-CMR (log-rank: p = 0.001; hazard ratio: 0.127; 95% CI: 0.032–0.511). Two-year PFS was 94% among CMR patients and 62% among non-CMR patients. Univariable Cox regression showed that metabolic response was the only parameter which predicted PFS (p = 0.004). Multivariate analysis revealed that metabolic response predicted disease progression (p = 0.008). In conclusion, our findings suggest that patients with CMR in an FDG-PET-CT scan may have a favorable outcome even if checkpoint inhibition is discontinued.