FLT-PET-CT for the Detection of Disease Recurrence After Stereotactic Ablative Radiotherapy or Hyperfractionation for Thoracic Malignancy: A Prospective Pilot Study

Differentiating local recurrence from post-treatment changes on PET scans following stereotactic ablative radiotherapy (SABR) or hyperfractionation for lung tumors is challenging. We performed a prospective pilot study of 3-deoxy-3-[18F]-fluorothymidine (FLT)-PET-CT in patients with equivocal post-radiation FDG-PET-CT to assess disease recurrence.Methods: We prospectively enrolled 10 patients, 9 treated with SABR and 1 with hyperfractionated external beam radiotherapy for thoracic malignancy with subsequent equivocal follow-up FDG-PET-CT, to undergo FLT-PET-CT prior to biopsy or serial imaging. FLT-PET scans were interpreted by a radiologist with experience in reading FLT-PET-CT and blinded to the results of any subsequent biopsy or imaging.Results: Of the 10 patients enrolled, 8 were evaluable after FLT-PET-CT. Based on the FLT-PET-CT, a blinded radiologist accurately predicted disease recurrence vs. inflammatory changes in 7 patients (87.5%). The combination of higher lesion SUVmax and higher ratio of lesion SUVmax to SUVmax of mediastinal blood pool was indicative of recurrence. Qualitative assessment of increased degree of focality of the lesion also appears to be indicative of disease recurrence.Conclusion: Adjunctive FLT-PET-CT imaging can complement FDG-PET-CT scan in distinguishing post-treatment radiation changes from disease recurrence in thoracic malignancies. These findings support the investigation of FLT-PET-CT in a larger prospective study

Impact of Audiovisual-Assisted Therapeutic Ambience in Radiation Therapy (AVATAR) on Anesthesia Use, Payer Charges, and Treatment Time in Pediatric Patients

Purpose Pediatric radiation therapy (RT) requires optimal immobilization that often necessitates daily anesthesia. To decrease anesthesia use, we implemented a novel audiovisual-assisted therapeutic ambience in RT (AVATAR) system that projects video onto a radiolucent screen within the child’s line of vision to provide attentional diversion. We investigated its reduction on anesthesia use, payer charges, and treatment time, in addition to its impact on radiation delivery. Methods and Materials A 6-year retrospective analysis was performed among children undergoing RT (n = 224) 3 years before and 3 years after the introduction of AVATAR. The frequency of anesthesia use before and after AVATAR implementation, in addition to RT treatment times, were compared. The number of spared anesthesia treatments allowed for a charge to payer analysis. To document the lack of surface dose perturbation by AVATAR, a phantom craniospinal treatment course was delivered both with and without AVATAR. Additionally, an ion chamber course was delivered to document changes to the dose at depth. Results More children were able to avoid anesthesia use entirely in the post-AVATAR cohort compared with the pre-AVATAR cohort (73.2% vs 63.4%; P = .03), and fewer required anesthesia for each treatment (18.8% vs 33%; P = .03). AVATAR introduction reduced anesthesia use for all ages studied. Treatment time per session was reduced by 38% using AVATAR compared with anesthesia. There were 326 fewer anesthesia sessions delivered over 3 years after AVATAR was introduced, with an estimated savings of >$500,000. Optically stimulated luminescent dosimeters revealed a small increase in dose of 0.8 Conclusions AVATAR introduction decreased anesthesia use in children undergoing RT. More children avoided anesthesia entirely, and fewer needed anesthesia for every treatment, resulting in a reduction in treatment time and savings of nearly$550,000 in approximately 3 years, with minimal perturbation of RT dose delivery

Rhabdomyosarcoma

Rhabdomyosarcoma is a heterogeneous disease both in presentation and histology. Improvements in a multimodality therapy resulted in the improved overall survival for patients with a low‐risk and intermediate‐risk disease but not for patients with a metastatic disease. We reviewed and contrasted the North American and European practice patterns, though ultimately the principles of staging, surgery, radiation therapy, and chemotherapy are similar in both Children's Oncology Group and International Society of Paediatric Oncology treatment approaches. Efforts are underway to investigate improved local control rates in higher risk patients using radiation dose escalation strategies, and delayed primary excision in select cases. The prognostic significance of imaging‐based chemotherapy response, proton therapy, novel biomarkers, and targeted drugs will be determined in upcoming clinical trials

Low-Dose Total Skin Electron Beam Therapy Combined With Mogamulizumab for Refractory Mycosis Fungoides and Sézary Syndrome

Purpose: Management of patients with refractory mycosis fungoides and Sézary syndrome (SS) is often challenging, as available therapies lack durable response and consistent activity across disease compartments. Combining low-dose total skin electron beam therapy (LD-TSEBT) upfront with mogamulizumab could optimize the clinical outcome of these patients. LD-TSEBT is effective in clearing skin disease, and mogamulizumab is an antitumor immunotherapy with long-term tolerability, suggesting its potential as a maintenance therapy after maximal response. We examine the combination regimen in patients with SS who were previously treated. Methods and Materials: Two patients with SS were treated with combination LD-TSEBT and mogamulizumab. Both patients received mogamulizumab 1 mg/kg weekly × 4 and then bi-weekly; LD-TSEBT (12 Gy) was initiated within 2 days of starting mogamulizumab and given over 2-3 weeks. Safety and clinical response were evaluated. Results: Total skin electron beam therapy plus mogamulizumab (TSE-Moga) was well-tolerated without any unanticipated adverse events. Patient 1 (T4N2bM0B2) was a 63-year-old woman with 4 prior systemic therapies; time to global response with TSE-Moga was 9 weeks. Patient 2 (T4NxM0B2) was a 75-year-old man with 5 prior systemic therapies; time to global response was 4 weeks. Both patients lacked global response to their prior therapies but achieved global complete response (blood and skin) with TSE-Moga. After a follow-up of 72 weeks and 43 weeks, respectively, global complete response continued. Conclusions: TSE-Moga demonstrated excellent tolerability and promising clinical activity with ongoing global complete responses in 2 patients with refractory SS. This encouraging experience supports our ongoing clinical trial evaluating the efficacy and safety of TSE-Moga in mycosis fungoides and SS