Nasopharyngeal carcinoma other imaging findings: Difference between revisions
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==Overview== | ==Overview== | ||
[[Positron emission tomography]] scan may be helpful in the diagnosis of [[nasopharyngeal carcinoma]]. | [[Positron emission tomography]] ([[Positron emission tomography|PET]]) scan may be helpful in the diagnosis of [[nasopharyngeal carcinoma]]. It is useful in detection of residual or recurrent tumor after treatment and distant metastasis, predictional of clinical cancer outcome and PET/CT scan is used for NPC staging. | ||
==Other Imaging Studies== | ==Other Imaging Studies== | ||
[[Positron emission tomography]] | [[Positron emission tomography|PET scan]] may be helpful in the diagnosis of [[nasopharyngeal carcinoma]]. PET scan is used for: | ||
* Detection of residual or recurrent nasopharyngeal tumor after treatment | |||
* Detection of distant metastasis | |||
* Prediction of clinical cancer outcomes evaluation of tumor metabolic activity | |||
* NPC staging in combination with CT | |||
PET has been reported to be more sensitive than CT and MRI at detecting residual and recurrent tumours in the nasopharynx. | |||
The role of positron emission tomography (PET) in the detection of distant metastases in other malignancies has been established,38 but its application in the staging of nasopharyngeal carcinoma has not been ascertained | |||
PET provides metabolic parameters (maximum standardised uptake value and total lesion glycolysis) that could be interpreted to represent tumour biology and predict clinical outcomes | |||
PET/CT has been shown to be of value in NPC staging,where the main advantage is for the detection of distant metastasis [8]. It is also used for monitoring patients after therapy and detecting NPC recurrence. | |||
PET imaging has emerged in recent years and is a sensitive technique in detecting clinically occult metastatic disease.The technique works on the premise that cancer cells are more metabolically active, have a higher rate of glucose metabolism, with concomitant increased glucose uptake. The most commonly used radiopharmaceutical, fl uorine-18-labeled 2-deoxyglucose (18FFDG) is a glucose analogue that is accumulated by metabolically active cells, including cancer cells, seen as areas of increased tracer uptake. The role of PET is evolving. Liu et al showed PET as being more sensitive in detecting skeletal metastases compared to skeletal scintigraphy (70% compared with 37%) in 30 of 202 patients; in this study, nodal staging was the only signifi cant factor for bone metastasis.34 In another study by Chang et al, 81 of 95 patients without evidence of metastatic disease with conventional workup (including fi breoptic nasopharyngoscopy, chest X-ray, bone scan, abdominal ultrasound and MRI of the head and neck) were imaged with PET at staging and 3 to 4 months after treatment. While conventional studies identifi ed 4 patients with distant metastases, PET identifi ed another 10. Again, nodal stage was found to be a signifi cant factor for metastasis.35 However, PET alone suffered from a low specifi city, as indicated by Chang. Also, the poor spatial resolution in conventional PET makes it diffi cult to localise anatomically the areas of increased FDG uptake. Integrated PET-CT offers a higher specifi city; Lardinois showed that integrated PET-CT was able to show additional information in 20 out of 49 patients as compared to visual correlation between unfused PET-CT images.36 Another study of 33 patients by Gordin showed that while PET-CT, PET and conventional CT had sensitivity rates of 92%, the specifi city was 90%, 65% and 15%, respectively, with 5 of 7 false positive conventional PET scans being diagnosed as areas of physiological uptake by PET-CT.37 The role of PET-CT remains to be resolved, although it may have a role in patients with lesions that are diffi cult to identify on conventional imaging; in patients with bulky nodal disease and in patients with suspected bone metastases. | |||
==References== | ==References== | ||
Revision as of 16:19, 8 March 2019
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Nasopharyngeal carcinoma Microchapters |
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Differentiating Nasopharyngeal carcinoma from other Diseases |
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Nasopharyngeal carcinoma other imaging findings On the Web |
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American Roentgen Ray Society Images of Nasopharyngeal carcinoma other imaging findings |
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Risk calculators and risk factors for Nasopharyngeal carcinoma other imaging findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Faizan Sheraz, M.D. [2]
Overview
Positron emission tomography (PET) scan may be helpful in the diagnosis of nasopharyngeal carcinoma. It is useful in detection of residual or recurrent tumor after treatment and distant metastasis, predictional of clinical cancer outcome and PET/CT scan is used for NPC staging.
Other Imaging Studies
PET scan may be helpful in the diagnosis of nasopharyngeal carcinoma. PET scan is used for:
- Detection of residual or recurrent nasopharyngeal tumor after treatment
- Detection of distant metastasis
- Prediction of clinical cancer outcomes evaluation of tumor metabolic activity
- NPC staging in combination with CT
PET has been reported to be more sensitive than CT and MRI at detecting residual and recurrent tumours in the nasopharynx.
The role of positron emission tomography (PET) in the detection of distant metastases in other malignancies has been established,38 but its application in the staging of nasopharyngeal carcinoma has not been ascertained
PET provides metabolic parameters (maximum standardised uptake value and total lesion glycolysis) that could be interpreted to represent tumour biology and predict clinical outcomes
PET/CT has been shown to be of value in NPC staging,where the main advantage is for the detection of distant metastasis [8]. It is also used for monitoring patients after therapy and detecting NPC recurrence.
PET imaging has emerged in recent years and is a sensitive technique in detecting clinically occult metastatic disease.The technique works on the premise that cancer cells are more metabolically active, have a higher rate of glucose metabolism, with concomitant increased glucose uptake. The most commonly used radiopharmaceutical, fl uorine-18-labeled 2-deoxyglucose (18FFDG) is a glucose analogue that is accumulated by metabolically active cells, including cancer cells, seen as areas of increased tracer uptake. The role of PET is evolving. Liu et al showed PET as being more sensitive in detecting skeletal metastases compared to skeletal scintigraphy (70% compared with 37%) in 30 of 202 patients; in this study, nodal staging was the only signifi cant factor for bone metastasis.34 In another study by Chang et al, 81 of 95 patients without evidence of metastatic disease with conventional workup (including fi breoptic nasopharyngoscopy, chest X-ray, bone scan, abdominal ultrasound and MRI of the head and neck) were imaged with PET at staging and 3 to 4 months after treatment. While conventional studies identifi ed 4 patients with distant metastases, PET identifi ed another 10. Again, nodal stage was found to be a signifi cant factor for metastasis.35 However, PET alone suffered from a low specifi city, as indicated by Chang. Also, the poor spatial resolution in conventional PET makes it diffi cult to localise anatomically the areas of increased FDG uptake. Integrated PET-CT offers a higher specifi city; Lardinois showed that integrated PET-CT was able to show additional information in 20 out of 49 patients as compared to visual correlation between unfused PET-CT images.36 Another study of 33 patients by Gordin showed that while PET-CT, PET and conventional CT had sensitivity rates of 92%, the specifi city was 90%, 65% and 15%, respectively, with 5 of 7 false positive conventional PET scans being diagnosed as areas of physiological uptake by PET-CT.37 The role of PET-CT remains to be resolved, although it may have a role in patients with lesions that are diffi cult to identify on conventional imaging; in patients with bulky nodal disease and in patients with suspected bone metastases.