Local recurrence of squamous cell carcinoma of the head and neck after radio(chemo)therapy: Diagnostic performance of FDG-PET/MRI with diffusion-weighted sequences

Abstract

PurposeTo determine the diagnostic performance of FDG-PET/MRI with diffusion-weighted imaging (FDG-PET/DWIMRI) for detection and local staging of head and neck squamous cell carcinoma (HNSCC) after radio(chemo)therapy.Materials and methodsThis was a prospective study that included 74 consecutive patients with previous radio(chemo)therapy for HNSCC and in whom tumour recurrence or radiation-induced complications were suspected clinically. The patients underwent hybrid PET/MRI examinations with morphological MRI, DWI and FDG-PET. Experienced readers blinded to clinical/histopathological data evaluated images according to established diagnostic criteria taking into account the complementarity of multiparametric information. The standard of reference was histopathology with whole-organ sections and follow-up ≥24 months. Statistical analysis considered data clustering.ResultsThe proof of diagnosis was histology in 46/74 (62.2%) patients and follow-up (mean ± SD = 34 ± 8 months) in 28/74 (37.8%). Thirty-eight patients had 43 HNSCCs and 46 patients (10 with and 36 without tumours) had 62 benign lesions/complications. Sensitivity, specificity, and positive and negative predictive value of PET/DWIMRI were 97.4%, 91.7%, 92.5% and 97.1% per patient, and 93.0%, 93.5%, 90.9%, and 95.1% per lesion, respectively. Agreement between imaging-based and pathological T-stage was excellent (kappa = 0.84, p < 0.001).ConclusionFDG-PET/DWIMRI yields excellent results for detection and T-classification of HNSCC after radio(chemo)therapy.Key points• FDG-PET/DWIMRI yields excellent results for the detection of post-radio(chemo)therapy HNSCC recurrence. • Prospective one-centre study showed excellent agreement between imaging-based and pathological T-stage. • 97.5% of positive concordant MRI, DWI and FDG-PET results correspond to recurrence. • 87% of discordant MRI, DWI and FDG-PET results correspond to benign lesions. • Multiparametric FDG-PET/DWIMRI facilitates planning of salvage surgery in the irradiated neck.

MRI with DWI for the Detection of Posttreatment Head and Neck Squamous Cell Carcinoma: Why Morphologic MRI Criteria Matter

“…On the basis of the experience at our institution and according to published data, 1,14,15 the interpretation of morphologic MRI was performed according to the following criteria: 1) rHNSCC/ sHNSCC was diagnosed in the presence of a masslike lesion with moderately high (intermediate) signal intensity on T2, low signal intensity on T1, and moderate enhancement after IV gadolinium administration; 2) post-RTH inflammatory edema was diagnosed in the presence of a diffuse lesion with high signal intensity on T2, low signal intensity on T1, and strong postcontrast enhancement; and 3) late RTH fibrosis (post-RTH scar) was diagnosed in the presence of a linear or triangular lesion with very low signal intensity on T2 (similar to or lower than that of muscle), low signal intensity on T1, and faint/absent contrast enhancement. 1,14,15 DWI was assessed visually (qualitative DWI) by analyzing the signal intensity on the bϭ1000 image and on the corresponding ADC map. The association of moderately high or very high signal on bϭ1000 and low signal on ADC maps was interpreted as suggesting malignancy.…”

PET/MRI vs PET/CT in Head and Neck Imaging: When, Why, and How?

“…In a study demonstrating the multiparametric capabilities of PET/MRI, Becker et al showed excellent results for detection of recurrent disease and tumor classification of PET/MRI performed with diffusion weighted imaging (DWI) in the post-treatment setting. 42 This study notes the value of concordant imaging results between PET, MRI, and DWI in predicting tumor recurrence, and discordant results corresponding to benign post-treatment changes. 42 These results differ from an earlier study by Queiroz et al, which concluded that DWI was not helpful in the evaluation of head and neck malignancy with PET/MRI.…”

Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton

“…As an alternative to PET-CT, hybrid PET MRI provides robust multiparametric anatomic, functional and metabolic information while significantly reducing radiation exposure [ 12 – 16 ]. It also offers the possibility to accurately detect recurrent disease and to effectively follow patients in a non-invasive fashion by using a combined multiparametric approach once a malignant tumour has been identified [ 17 ].…”