[18F]FDG PET/CT for evaluating early response to neoadjuvant chemotherapy in pediatric patients with sarcoma: a prospective single-center trial
Introduction: This is a prospective, single-center trial in pediatric patients with sarcoma aiming to evaluate [18F]FDG PET/CT as a tool for early response assessment to neoadjuvant chemotherapy (neo-CTX).
Methods: Bone or soft tissue sarcoma patients with i) baseline [18F]FDG PET/CT within four weeks prior to the start of neo-CTX (PET1), ii) early interim [18F]FDG PET/CT (six weeks after the start of neo-CTX (PET2), iii) evaluation of neo-CTX response by histology or MRI, and iv) definitive therapy after neo-CTX (surgery or radiation) were included. Semi-quantitative PET parameters (SUVmax, SUVmean, SUVpeak, MTV and TLG) and their changes from PET1 to PET2 (ΔPET) were obtained. The primary endpoint was to evaluate the predictive value of PET1, PET2 and ΔPET parameters for overall survival (OS) and time to progression (TTP). The secondary outcome was to evaluate if [18F]FDG PET/CT can predict the response to neo-CTX assessed by histopathology or MRI. Primary and secondary outcomes were also evaluated in a sub-population of patients with bone involvement only.
Results: Thirty-four consecutive patients were enrolled (10 females; 24 males; median age 15.1 years). 17/34 patients (50%) had Osteosarcoma, 13/34 (38%) Ewing Sarcoma, 2/34 (6%) synovial sarcoma and 2/34 (6%) embryonal liver sarcoma. Median follow-up was 39 months (range 16-84). Eight of 34 patients (24%) died, 9/34 (27%) were alive with disease and 17/34 (50%) had no evidence of residual/recurrent disease. Fifteen of 34 (44%) and 19/34 (56%) were responders and non-responders, respectively. PET2-parameters were associated with longer TTP (p <0.02). ΔMTV was associated with tissue response to neo-CTX (p=0.047). None of the PET1, PET2 or ΔPET parameters were associated with OS.
Conclusion: [18F]FDG PET/CT performed six weeks after the start of neo-CTX can serve as an early interim biomarker for TTP and pathologic response but not for OS in pediatric patients with sarcoma.
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Posted 23 Sep, 2020
On 15 Oct, 2020
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Received 23 Sep, 2020
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On 22 Sep, 2020
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Received 16 Aug, 2020
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On 27 Jul, 2020
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Invitations sent on 11 Jul, 2020
On 10 Jul, 2020
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On 22 Jun, 2020
[18F]FDG PET/CT for evaluating early response to neoadjuvant chemotherapy in pediatric patients with sarcoma: a prospective single-center trial
Posted 23 Sep, 2020
On 15 Oct, 2020
On 23 Sep, 2020
Received 23 Sep, 2020
Received 23 Sep, 2020
On 23 Sep, 2020
On 22 Sep, 2020
Invitations sent on 22 Sep, 2020
On 22 Sep, 2020
On 21 Sep, 2020
On 21 Sep, 2020
On 17 Aug, 2020
Received 16 Aug, 2020
Received 02 Aug, 2020
On 27 Jul, 2020
On 23 Jul, 2020
Invitations sent on 11 Jul, 2020
On 10 Jul, 2020
On 09 Jul, 2020
On 23 Jun, 2020
On 22 Jun, 2020
Introduction: This is a prospective, single-center trial in pediatric patients with sarcoma aiming to evaluate [18F]FDG PET/CT as a tool for early response assessment to neoadjuvant chemotherapy (neo-CTX).
Methods: Bone or soft tissue sarcoma patients with i) baseline [18F]FDG PET/CT within four weeks prior to the start of neo-CTX (PET1), ii) early interim [18F]FDG PET/CT (six weeks after the start of neo-CTX (PET2), iii) evaluation of neo-CTX response by histology or MRI, and iv) definitive therapy after neo-CTX (surgery or radiation) were included. Semi-quantitative PET parameters (SUVmax, SUVmean, SUVpeak, MTV and TLG) and their changes from PET1 to PET2 (ΔPET) were obtained. The primary endpoint was to evaluate the predictive value of PET1, PET2 and ΔPET parameters for overall survival (OS) and time to progression (TTP). The secondary outcome was to evaluate if [18F]FDG PET/CT can predict the response to neo-CTX assessed by histopathology or MRI. Primary and secondary outcomes were also evaluated in a sub-population of patients with bone involvement only.
Results: Thirty-four consecutive patients were enrolled (10 females; 24 males; median age 15.1 years). 17/34 patients (50%) had Osteosarcoma, 13/34 (38%) Ewing Sarcoma, 2/34 (6%) synovial sarcoma and 2/34 (6%) embryonal liver sarcoma. Median follow-up was 39 months (range 16-84). Eight of 34 patients (24%) died, 9/34 (27%) were alive with disease and 17/34 (50%) had no evidence of residual/recurrent disease. Fifteen of 34 (44%) and 19/34 (56%) were responders and non-responders, respectively. PET2-parameters were associated with longer TTP (p <0.02). ΔMTV was associated with tissue response to neo-CTX (p=0.047). None of the PET1, PET2 or ΔPET parameters were associated with OS.
Conclusion: [18F]FDG PET/CT performed six weeks after the start of neo-CTX can serve as an early interim biomarker for TTP and pathologic response but not for OS in pediatric patients with sarcoma.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6