Bone marrow-sparing IMRT in anal cancer patients: final results of a prospective phase II trial in Radiotherapy and Oncology
2021
AOU Città della Salute di Torino
Tipo pubblicazione
Conference Abstract
Autori/Collaboratori (11)Vedi tutti...
Franco P
IRCCS Ospedale Policlinico San Martino, Genoa, Italy
Arcadipane F
IRCCS Ospedale Policlinico San Martino, Genoa, Italy
Olivero F
IRCCS Ospedale Policlinico San Martino, Genoa, Italy
et alii...
Abstract
Purpose or Objective We investigated the role of the selective avoidance of hematopoietically active pelvic bone marrow (BM), with a targeted intensity-modulated radiotherapy (IMRT) approach, to reduce acute hematologic toxicity (HT) in anal cancer patients undergoing concurrent chemo-radiation Materials and Methods We designed a one-armed two-stage Simon's design to test the hypothesis that BM-sparing IMRT would improve by 20% the rate of G0-G2 (vs G3-G4) HT, from 42% of RTOG 0529 historical data to 62% (a=0.05;B=0.20). A minimum of 21/39 (54%) with G0-G2 toxicity represented the threshold for the fulfilment of the criteria to define this approach as ‘promising'. We employed 18FDG-PET to identify active BM within the pelvis. Acute HT was assessed via weekly blood counts and scored as per the Common Toxicity Criteria for Adverse Effects version 4.0 Results From December 2017 to October 2020, we enrolled 39 patients. Maximum observed acute HT comprised 20% rate of >G3 leukopenia and 11% rate of >G3 thrombocytopenia. Overall 11 out of 39 treated patients (28%) experienced >G3 acute HT. Conversely, in 28 patients (72%) G0-G2 HT events were observed, above the threshold set (Figure). No significant differences were found between patients experiencing G3-G4 acute HT and those who did not in terms of age, gender, tumor and nodal stage and most of the dosimetric parameters employed during the optimization process (ACTPBM V10, ACTPBM V20 and ACTLSBM mean dose). A borderline statistical significant difference (p=0.055) was observed in terms of ACTLSBM V40. Specifically mean ACTLSBM V40 was found to be 24.8 Gy (SD: 7.8) for patients not experiencing major acute HT and 30.4 Gy (SD: 9.8) for those in which G3-G4 acute HT was observed. Conclusion Hence, 18FDG-PET-guided BM-sparing IMRT was able to reduce acute HT in anal cancer patients undergoing concurrent chemoradiation with definitive intent.
DOI : 10.1016/S0167-8140(21)07249-2
Keywords
unclassified drug; adult; anus cancer; avoidance behavior; blood cell count; blood toxicity; bone marrow; cancer patient; cancer staging; cell cycle G0 phase; chemoradiotherapy; clinical article; clinical trial; conference abstract; controlled study; female; gender; human; intensity modulated radiation therapy; leukopenia; male; pelvic girdle; phase 2 clinical trial; prospective study; radiotherapy; thrombocytopenia;