Denervation atrophy of the masticatory muscles in a patient with nasopharyngeal cancer: MR examinations before and after radiotherapy

Ariji, Y; Fuwa, N; Tachibana, H; Ariji, Eiichiro

doi:10.1038/sj.dmfr.4600691

Cited by 17 publications

(20 citation statements)

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“…Cell necrosis and vascular and mitochondrial damage have been observed early after RT in rodent and dog muscles [16-17]. These effects explain the slight muscle parenchymal edema detected by prolonged T1 and modestly increased T2 sequences observed in our study, and the reduced muscle thickness and volume, which have been reported by others following muscle irradiation [24-26]. One of the processes which may explain some of these changes is muscle denervation, characterized by initial high T2 signal intensity and normal intensity on T1-weighted images in the acute phase, followed with muscle atrophy and fatty infiltration causing high signal on T1 and muscle volume loss (27).…”

Section: Discussionsupporting

confidence: 79%

Anatomical changes in the pharyngeal constrictors after chemo-irradiation of head and neck cancer and their dose–effect relationships: MRI-based study

Popovtzer

Cao

Feng

et al. 2009

Radiotherapy and Oncology

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Purpose-Dysfunction of pharyngeal constrictors (PCs) after chemo-irradiation of head and neck (HN) cancer has been proposed as major cause of dysphagia. We conducted prospective MRI study to evaluate anatomical changes in the PCs after chemoirradiation, to gain insight of the mechanism of their dysfunction and their dose-effect relationships. The PCs were compared to the sternocleidomastoid muscles (SCMs), which receive high doses but do not relate to swallowing.Patients and Methods-Twelve patients with stage III-IV HN cancer underwent MRI before and 3 months after the completing chemo-irradiation. T1-and T2-weighted signals and muscle thickness were evaluated for PCs (superior, middle, and inferior), and SCMs. Mean muscle doses were determined after registration with the planning CT.Results-T1-weighted signals decreased in both PCs and SCMs receiving >50 Gy (p<0.03), but not in muscles receiving lower doses. T2-weighted signals in the PCs increased significantly as the dose increased (R 2 =0.34, p=0.01). The T2 signal changes in the PCs were significantly higher than the T2 changes in the SCMs (p<0.001). Increased thickness was noted in all PCs, with muscles receiving >50 Gy gaining significantly more thickness than PCs receiving lesser doses (p=0.02). In contrast, the SCM thickness decreased post-therapy (p=0.002).Conclusions-These MRI-based findings, notably the differences between PCs and SCMs, suggest that underlying causes of PC dysfunction are inflammation and edema, likely consequential to acute mucositis affecting the submucosa -lying PCs. These results support reducing mean PC doses to ≤50 Gy, as well as reducing acute mucositis, to improve long-term dysphagia.

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Section: Discussionsupporting

confidence: 79%

Anatomical changes in the pharyngeal constrictors after chemo-irradiation of head and neck cancer and their dose–effect relationships: MRI-based study

Popovtzer

Cao

Feng

et al. 2009

Radiotherapy and Oncology

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“…Involvement of these branches usually occurs with neoplasms arising from the masticator space, nasopharynx, or oropharynx, or through retrograde spread along the inferior alveolar nerve. 30 The posterior trunk of V3 divides into three nerves: the ATN, lingual nerve, and inferior alveolar nerve.…”

Section: Trigeminal Nervementioning

confidence: 99%

Perineural Tumor Spread

Maroldi¹,

Farina²,

Borghesi³

et al. 2008

Neuroimaging Clinics of North America

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“…Primary review of titles and abstracts narrowed this to 11 potentially relevant studies. Based on full-text review, only four of these papers met all inclusion criteria (Figure 1) [14-17]. …”

Section: Resultsmentioning

confidence: 99%

“…The four included papers focused on the MRI appearance of the masticatory muscles following different radiotherapy protocol [14-17]. Tumors varied, with histological types reported in three papers [14,16,17].…”

Section: Resultsmentioning

confidence: 99%

“…Tumors varied, with histological types reported in three papers [14,16,17]. Two papers reported outcome based on retrospective clinical and imaging assessment records [15,16], whereas the remaining two papers were case reports [14,17]. In the first included study, Chong et al retrospectively screened medical records of five patients who reported facial pain, mandibular osteoradionecrosis and reduced range of motion (trismus) at different follow-up times after radiotherapy [16].…”

Section: Resultsmentioning

confidence: 99%

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MRI findings of radiation-induced changes of masticatory muscles: A systematic review

Al-Saleh

Jaremko

Saltaji

et al. 2013

Journal of Otolaryngology - Head & Neck Surgery

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BackgroundRadiotherapy to the head and neck regions can result in serious consequences to the temporomandibular joint (TMJ) and chewing muscles. Magnetic resonance imaging (MRI) demonstrates soft-tissue alterations after radiotherapy, such as morphology and signal intensity.ObjectiveThe purpose of this review is to critically and systematically analyse the available evidence regarding the masticatory muscles alterations, as demonstrated on MRI, after radiotherapy for head and neck cancer.Data sourcesElectronic search of MEDLINE, EMBASE, EBM reviews and Scopus.Inclusion criteriaReports of any study design investigating radiation-induced changes in masticatory muscles after radiotherapy in patients with head and neck cancer were included.Results and synthesis methodsAn electronic database search resulted in 162 papers. Sixteen papers were initially selected as potentially relevant studies; however, only four papers satisfied all inclusion criteria. The included papers focused on the MRI appearance of masticatory muscles following radiotherapy protocol. Two papers reported outcome based on retrospective clinical and imaging records, whereas the remaining two papers were case reports. Irradiated muscles frequently show diffuse increase in T2 signal and post-gadolinium enhancement post-irradiation. Also, muscle size changes were reported based on subjective comparison with the contralateral side. The quality of all included papers was considered poor with high risk of bias.ConclusionThere is no evidence that MRI interpretations indicate specific radiation-induced changes in masticatory muscles. There is a clear need for a cohort study comparing patients with pre- and post-radiotherapy MRI.

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Denervation atrophy of the masticatory muscles in a patient with nasopharyngeal cancer: MR examinations before and after radiotherapy

Cited by 17 publications

References 0 publications

Anatomical changes in the pharyngeal constrictors after chemo-irradiation of head and neck cancer and their dose–effect relationships: MRI-based study

Anatomical changes in the pharyngeal constrictors after chemo-irradiation of head and neck cancer and their dose–effect relationships: MRI-based study

Perineural Tumor Spread

MRI findings of radiation-induced changes of masticatory muscles: A systematic review

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