PEGylated G-CSF(Bolder BioTechnology)

BACKGROUND. Pegfilgrastim administration after chemotherapy increases bone marrow and spleen FDG uptake. Consensus is lacking regarding the optimal interval between pegfilgrastim administration and FDG PET/CT. OBJECTIVE. The purpose of this study was to assess the association between bone marrow and spleen uptake and the interval between pegfilgrastim administration and FDG PET/CT. METHODS. This retrospective study included 70 oncology patients (mean age, 64 ± 12 [SD] years; 48 men, 22 women) receiving chemotherapy who underwent FDG PET/CT (study scan) within 35 days after pegfilgrastim administration and who underwent additional FDG PET/CT at least 4 months before pegfilgrastim initiation or at least 3 months after last pegfilgrastim administration (reference scan). A nuclear medicine physician recorded the SUV_mean for normal osseous structures and spleen and assessed bone marrow uptake using a 4-point visual scale (1, no abnormal uptake; 2, clinically insignificant uptake; 3, clinically significant uptake possibly interfering with interpretation; 4, clinically significant uptake expected to interfere with interpretation). RESULTS. Percentage change in SUV_mean between reference and study scans significantly increased (p < .05) as the interval increased for five sites (i.e., for patients with interval of 7-13 vs 29-35 days, mean percentage change was 32.3% ± 18.2% vs 11.5% ± 17.3% for cervical vertebra, 42.2% ± 18.3% vs 21.3% ± 14.2% for thoracic vertebra, 47.2% ± 19.8% vs 19.1% ± 13.9% for lumbar vertebra, 51.1% ± 25.8% vs 12.7% ± 11.3% for pelvis, and 53.0% ± 25.6% vs 4.4% ± 14.1% for lower extremity); percentage change was not associated with the interval for upper extremity or spleen (p > .05). Visual uptake scores of 4, 3, 2, and 1 were observed in days 7-21, 12-22, 12-28, and 14-35, respectively. Percentage of patients with a score of 3 or 4 was 94.4% for days 7-13, 58.1% for days 14-21, 6.7% for days 22-28, and 0% for days 29-35. A total of 71.4% of patients had a score of 3 or 4 on day 7-21, whereas 4.8% had a score of 3 and 0% had a score of 4 on days 22-35. CONCLUSION. A visual uptake score of 3 or 4 was consistently observed throughout an approximately 3-week interval following pegfilgrastim administration, without any such case beyond 22 days. CLINICAL IMPACT. We recommend a preferred interval of at least 3 weeks after pegfilgrastim administration before PET/CT.

Treatment of accidental radiation-induced myelosuppression is primarily based on supportive care and requires specific treatment based on hematopoietic growth factors injection or hematopoietic cell transplantation for the most severe cases. The cytokines used consisted of pegylated erythropoietin (darbepoetin alfa) 500 IU once per week, pegylated G-CSF (pegfilgrastim) 6 mg × 2 once, stem cell factor 20 µg.kg-1 for five days, and romiplostim (TPO analog) 10 µg.kg -1 once per week, with different combinations depending on the accidents. As the stem cell factor did not have regulatory approval for clinical use in France, the French regulatory authorities (ANSM, formerly, AFSSAPS) approved their compassionate use as an investigational drug "on a case-by-case basis". According to the evolution and clinical characteristics, each patient's treatment was adopted on an individual basis. Daily blood count allows initiating G-CSF and SCF delivery when granulocyte <1,000/mm3, TPO delivery when platelets <50,000/mm3, and EPO when Hb<80 g/L. The length of each treatment was based on blood cell recovery criteria. The concept of "stimulation strategy" is linked to each patient's residual hematopoiesis, which varies among them, depending on the radiation exposure's characteristics and heterogeneity. This paper reports the medical management of 8 overexposed patients to ionizing radiation. The recovery of bone marrow function after myelosuppression was accelerated using growth factors, optimized by multiple-line combinations. Particularly in the event of prolonged exposure to ionizing radiation in dose ranges inducing severe myelosuppression (in the order of 5 to 8 Gy), with no indication of hematopoietic stem cell transplantation.