Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study
Abstract Background Neoadjuvant (preoperative) radiochemotherapy (nRCT) is a standard of care in locally advanced rectal cancer (LARC). Several studies have shown that the decline in 18FDG uptake after 2 weeks of nRCT compared with the baseline, i.e. the tumor’s metabolic response, may correlate wit...
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BMC
2025-08-01
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| Series: | Radiation Oncology |
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| Online Access: | https://doi.org/10.1186/s13014-025-02703-x |
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| author | Yulia Kundel Zoya Cohen Noa Gordon Aaron Sulkes Sara Morgenstern Gali Perl Nir Wasserberg David Groshar Hanna Bernstine Baruch Brenner |
| author_facet | Yulia Kundel Zoya Cohen Noa Gordon Aaron Sulkes Sara Morgenstern Gali Perl Nir Wasserberg David Groshar Hanna Bernstine Baruch Brenner |
| author_sort | Yulia Kundel |
| collection | DOAJ |
| description | Abstract Background Neoadjuvant (preoperative) radiochemotherapy (nRCT) is a standard of care in locally advanced rectal cancer (LARC). Several studies have shown that the decline in 18FDG uptake after 2 weeks of nRCT compared with the baseline, i.e. the tumor’s metabolic response, may correlate with histopathological response. However, our previous prospective study suggested that the tumor’s histopathological response could be predicted by the metabolic response already observed after 1 week of nRCT. The current study was undertaken to validate these findings. Methods Thirty-eight patients with LARC who received standard nRCT followed by radical surgery were enrolled. Metabolic response, evaluated by the percent of change in maximum standardized uptake value (ΔSUVmax%), measured by PET-CT imaging at baseline and on day 8 of nRCT, was compared with the histopathological response at surgery. Histopathological response was assessed by pathological complete response (pCR) and, when possible, by tumor regression grade (TRG). We also examined the association of baseline and second PET-CT parameters with pCR and TRG at surgery. Trial registration: 0239–07-RMC, registration date: 21/08/2007. Results Neither pCR nor TRG were associated with any change in PET-CT parameters after 1 week of treatment. Baseline metabolic tumor volume (MTV) was the only PET-CT parameter with a statistically significant association with pCR (p = 0.002), but not with TRG (p = 0.08). Conclusions A decrease in SUVmax after 1 week of nRCT for LARC failed to predict the achievement of pCR or TRG in the post-nRCT surgical specimen, underlining the importance of validation clinical trials. Nonetheless, our findings on the correlation between baseline MTV and histopathological response can, if confirmed, be a useful tool for treatment selection. Validation in a larger independent cohort is planned. |
| format | Article |
| id | doaj-art-35f93001e7724ef7ab6556fcc27b8642 |
| institution | Kabale University |
| issn | 1748-717X |
| language | English |
| publishDate | 2025-08-01 |
| publisher | BMC |
| record_format | Article |
| series | Radiation Oncology |
| spelling | doaj-art-35f93001e7724ef7ab6556fcc27b86422025-08-20T04:03:06ZengBMCRadiation Oncology1748-717X2025-08-0120111110.1186/s13014-025-02703-xEarly prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation studyYulia Kundel0Zoya Cohen1Noa Gordon2Aaron Sulkes3Sara Morgenstern4Gali Perl5Nir Wasserberg6David Groshar7Hanna Bernstine8Baruch Brenner9Institute of Oncology, Rabin Medical Center, Beilinson HospitalFelsenstein Medical Research Center, Rabin Medical Center, Beilinson HospitalInstitute of Oncology, Rabin Medical Center, Beilinson HospitalInstitute of Oncology, Rabin Medical Center, Beilinson HospitalInstitute of Pathology, Rabin Medical Center, Beilinson HospitalInstitute of Oncology, Rabin Medical Center, Beilinson HospitalDepartment of Surgery B, Rabin Medical Center, Beilinson HospitalDepartment of Nuclear Medicine, Rabin Medical Center, Beilinson HospitalDepartment of Nuclear Medicine, Rabin Medical Center, Beilinson HospitalInstitute of Oncology, Rabin Medical Center, Beilinson HospitalAbstract Background Neoadjuvant (preoperative) radiochemotherapy (nRCT) is a standard of care in locally advanced rectal cancer (LARC). Several studies have shown that the decline in 18FDG uptake after 2 weeks of nRCT compared with the baseline, i.e. the tumor’s metabolic response, may correlate with histopathological response. However, our previous prospective study suggested that the tumor’s histopathological response could be predicted by the metabolic response already observed after 1 week of nRCT. The current study was undertaken to validate these findings. Methods Thirty-eight patients with LARC who received standard nRCT followed by radical surgery were enrolled. Metabolic response, evaluated by the percent of change in maximum standardized uptake value (ΔSUVmax%), measured by PET-CT imaging at baseline and on day 8 of nRCT, was compared with the histopathological response at surgery. Histopathological response was assessed by pathological complete response (pCR) and, when possible, by tumor regression grade (TRG). We also examined the association of baseline and second PET-CT parameters with pCR and TRG at surgery. Trial registration: 0239–07-RMC, registration date: 21/08/2007. Results Neither pCR nor TRG were associated with any change in PET-CT parameters after 1 week of treatment. Baseline metabolic tumor volume (MTV) was the only PET-CT parameter with a statistically significant association with pCR (p = 0.002), but not with TRG (p = 0.08). Conclusions A decrease in SUVmax after 1 week of nRCT for LARC failed to predict the achievement of pCR or TRG in the post-nRCT surgical specimen, underlining the importance of validation clinical trials. Nonetheless, our findings on the correlation between baseline MTV and histopathological response can, if confirmed, be a useful tool for treatment selection. Validation in a larger independent cohort is planned.https://doi.org/10.1186/s13014-025-02703-xRadiochemotherapyLocally advanced rectal cancerPET-CTResponse predictionValidation |
| spellingShingle | Yulia Kundel Zoya Cohen Noa Gordon Aaron Sulkes Sara Morgenstern Gali Perl Nir Wasserberg David Groshar Hanna Bernstine Baruch Brenner Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study Radiation Oncology Radiochemotherapy Locally advanced rectal cancer PET-CT Response prediction Validation |
| title | Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study |
| title_full | Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study |
| title_fullStr | Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study |
| title_full_unstemmed | Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study |
| title_short | Early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18FDG PET-CT imaging: a prospective clinical validation study |
| title_sort | early prediction of histopathological response of locally advanced rectal cancer after 1 week of preoperative radiochemotherapy using 18fdg pet ct imaging a prospective clinical validation study |
| topic | Radiochemotherapy Locally advanced rectal cancer PET-CT Response prediction Validation |
| url | https://doi.org/10.1186/s13014-025-02703-x |
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