In:
European Journal of Nuclear Medicine and Molecular Imaging, Springer Science and Business Media LLC, Vol. 50, No. 2 ( 2023-01), p. 572-580
Abstract:
To evaluate the pathological complete response (pCR) rate of locally advanced rectal cancer (LARC) after adaptive high-dose neoadjuvant chemoradiation (CRT) based on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG-PET/CT). Methods The primary endpoint was the pCR rate. Secondary endpoints were the predictive value of 18 F-FDG-PET/CT on pathological response and acute and late toxicity. All patients performed 18 F-FDG-PET/CT at baseline (PET 0 ) and after 2 weeks during CRT (PET 1 ). The metabolic PET parameters were calculated both at the PET 0 and PET 1 . The total CRT dose was 45 Gy to the pelvic lymph nodes and 50 Gy to the primary tumor, corresponding mesorectum, and to metastatic lymph nodes. Furthermore, a sequential boost was delivered to a biological target volume defined by PET 1 with an additional dose of 5 Gy in 2 fractions. Capecitabine (825 mg/m 2 twice daily orally) was prescribed for the entire treatment duration. Results Eighteen patients (13 males, 5 females; median age 55 years [range, 41–77 years]) were enrolled in the trial. Patients underwent surgical resection at 8–9 weeks after the end of neoadjuvant CRT. No patient showed grade 〉 1 acute radiation-induced toxicity. Seven patients (38.8%) had TRG = 0 (complete regression), 5 (27.0%) showed TRG = 2, and 6 (33.0%) had TRG = 3. Based on the TRG results, patients were classified in two groups: TRG = 0 (pCR) and TRG = 1, 2, 3 (non pCR). Accepting p 〈 0.05 as the level of significance, at the Kruskal–Wallis test, the medians of baseline-MTV, interim -SUVmax, interim -SUVmean, interim -MTV, interim -TLG, and the MTV reduction were significantly different between the two groups. 18 F-FDG-PET/CT was able to predict the pCR in 77.8% of cases through compared evaluation of both baseline PET/CT and interim PET/CT. Conclusions Our results showed that a dose escalation on a reduced target in the final phase of CRT is well tolerated and able to provide a high pCR rate.
Type of Medium:
Online Resource
ISSN:
1619-7070
,
1619-7089
DOI:
10.1007/s00259-022-05944-0
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2023
detail.hit.zdb_id:
2098375-X
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