{'fraction_non_alphanumeric': 0.03425076452599388, 'fraction_numerical': 0.02996941896024465, 'mean_word_length': 5.788381742738589, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Use of 18F‐FDG positron emission tomography following allogeneic transplantation to guide adoptive immunotherapy with donor lymphocyte infusions

Fluorine‐18 fluorodeoxyglucose positron emission tomography (18F‐FDG PET) provides valuable prognostic information in the management of lymphoma patients. However, the utility of 18F‐FDG PET following allografting is unclear. We analysed the use of 18F‐FDG PET after allogeneic reduced‐intensity transplantation (RIT) performed in our institution. Between June 1998 and January 2002, 55 patients underwent RIT for either Hodgkin or non‐Hodgkin lymphoma. At least one 18F‐FDG PET scan was performed during the post‐transplant period (median five studies) in 15 (27·2%) of these 55 patients. PET scans were performed after re‐staging computed tomography (CT) and were categorised depending on 18F‐FDG uptake. The first PET scan was informative in 11 of 15 patients (73%) and influenced the administration of donor lymphocyte infusions (DLI) in nine: leading to earlier DLI administration in two patients, earlier dose escalation in one, withholding of DLI administration in five and dose reduction in one. In addition, subsequent monitoring with 18F‐FDG PET scans documented a graft‐versus‐lymphoma effect in five patients (median post‐DLI follow‐up 33 months, range 13–36 months). These preliminary data suggest that 18F‐FDG PET has a role in guiding DLI administration and monitoring the immunotherapeutic effect in patients after allogeneic transplantation. This retrospective pilot study forms the basis for a prospective study to clarify the utility of 18F‐FDG PET/CT in these patients.