ABSTRACT
We investigated the role of the selective avoidance of haematopoietically 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. We designed a one-armed two-stage Simon's design study 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% (α = 0.05; ß = 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. 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. Hence, 18FDG-PET-guided BM-sparing IMRT was able to reduce acute HT in this clinical setting.
ABSTRACT
OBJECTIVES: The primary objective is to assess the efficacy of 68Ga-PSMA-11-PET/CT to detect recurrent location(s) in hormone-sensitive prostate cancer (PCa). Secondary objectives are (1) to evaluate changes in clinical management; (2) to determine which covariates independently predict positive scan; (3) to assess 68Ga-PSMA-11-PET/CT performance in different settings of PSA relapse. MATERIALS AND METHODS: Inclusion criteria include (1) histologically diagnosed PCa; (2) previous radical therapy; (3) proven biochemical recurrence (BCR) or biochemical persistence (BCP); (4) hormone-sensitive PCa (HSPC); (5) androgen deprivation therapy (ADT)-free for at least 6 months; (6) PSA < 1.5 ng/mL or any PSA in case of negative choline-PET/CT (n = 38). Changes in clinical management were defined by multidisciplinary tumour-board. Clinical settings were BCP (group-1, n = 25); first-time BCR (group-2, n = 121); BCR after salvage therapy (group-3, n = 77). RESULTS: Two hundred twenty-three (223) consecutive patients were enrolled: median PSA = 0.65 ng/mL (0.2-8.9) and median PSAdt = 9.3 months (0.4-144.6). 96.9% received RP as primary therapy. 68Ga-PSMA-11-PET/CT positivity rate was 39.9% (CI95% 33.5-46.7%). Disease confined to pelvis was detected in 23.3% of cases. At least one distant lesion was observed in 16.6% of cases. Secondary objectives are as follows: (1) changes in clinical management were observed in 34.5% of patients; (2) PSA, PSAdt and T stage > 3a were independent predictors (all p < 0.03); (3) 68Ga-PSMA-11-PET/CT positivity rate was 56% (in group 1, 36.3% in group 2, 40.3% in group 3. CONCLUSION: This study attested the overall good performance of 68Ga-PSMA-11-PET/CT to detect PCa locations in HSPC patients eligible for salvage therapy, influencing the therapy management in 35.4% of cases. Furthermore, patient characteristics are influencing factors of 68Ga-PSMA-11-PET/CT positivity rate and should be considered to reduce false negative scan.
