Imaging Guidelines
a) Screening: Routine screening for EC is not recommended.
b) Diagnosis: Upper GI endoscopy-guided biopsy is used for the diagnosis of primary tumor.[23 ] There are two types of echoendoscopes available: radial and linear array. EUS using
linear array echoendoscopes have a limited field but have the important ability to
visualize a needle in real time and hence are used for tissue sampling. Endoscopy
also helps in guiding nasogastric tube insertion for feeding when needed. In patients
having clinically palpable and significant appearing supraclavicular node or liver
metastasis, tissue diagnosis can be obtained from node or liver metastasis, when planned
for palliative therapy.
c) Staging
Role of EUS
On EUS, five layers of the esophageal wall described are layer 1 (hyperechoic) superficial
mucosa, layer 2 (hypoechoic) deep mucosa, layer 3 (hyperechoic) submucosa, layer 4
(hypoechoic) muscularis propria, and layer 5 (hyperechoic) adventitia. Tumors appear
as hypoechoic lesions involving the wall layers, and malignant lymph nodes are typically
seen in the vicinity of the tumor, appearing hypoechoic and round with smooth borders,
and may be more than 10 mm in size.[27 ] The standard 7.5 to 12 MHz frequency transducers do not have adequate resolution
to accurately “T” stage very early stage disease with mucosal involvement or superficial
submucosal involvement, and a 20 MHz radial mini-probe may be needed for scanning
in such cases. The accuracy of EUS increases with increasing T stage. EUS can be performed
in patients with early-stage EC prior to endoscopic resection (ER) or in patients
planned for upfront surgery, mainly to rule out lymph-node metastases in selected
high-risk cases. Although EUS is the only modality for distinguishing different layers
of esophageal wall, ER is more accurate than EUS for the staging of T1a/T1b EC and
may also be therapeutic in some cases.[16 ] When high-definition white-light or image-enhanced endoscopy is suggestive of a
small nodular lesion with high grade dysplasia or early-stage EC, a staging ER is
encouraged.[16 ]
[28 ] An EUS-guided fine-needle aspiration can be performed for suspicious lymph nodes
if they can be sampled without traversing the tumor or major blood vessels and if
the result will change management.[16 ] Most patients with stenotic tumors are likely to have locally advanced disease where
an EUS may be unnecessary.[29 ] If at all an EUS is indicated in stenotic tumors, a smaller caliber wire-guided
probe or mini-probe can be used; however, availability and cost may be an issue. [Fig. 2(A–C) ] shows EC staging on EUS with malignant regional node.
Fig. 2 Staging of esophageal cancer on endoscopic ultrasonography. (A ) T1 tumor invading the submucosa (arrowhead). (B ) T2 tumor invading the muscularis propria (arrowhead). (C ) T4 tumor involving the aorta (arrowhead). A malignant regional lymph node is also
seen (arrow).
Role of CT
CECT thorax and abdomen with oral contrast is recommended for EC staging. CT of the
pelvic region should be included for esophagogastric junction tumors or if clinically
indicated. Upper third EC including cervical EC requires additional evaluation with
CECT neck. CT thorax protocol for EC is shown in [Table 2 ].[19 ]
Table 2
CT thorax protocol for EC
Modality
Typical protocol
CT thorax
-Noncontrast and CECT are performed
-On table positive oral contrast (500 mL water + 30 mL nonionic contrast), or plain
water, to distend the esophagus.
-For CECT, 100 cc of intravenous nonionic contrast (300 mg iodine per mL) at 2.5–3 mL/sec
Abbreviations: CECT, contrast-enhanced computed tomography; EC, esophageal cancer.
On CECT, differentiation of T1 and T2 is not possible.[21 ]
[22 ] T3 stage on CT presents as mural thickening (> 3mm) and periesophageal fat infiltration
without any loss of fat plane/invasion of adjacent structures.[2 ] CT most accurately provides the craniocaudal length of the tumor (along with the
corresponding vertebral level) that is essential for deciding upon the surgical resection
margins.[2 ]
[3 ] CT plays a significant role in T4 staging of tumor. Involvement of pleura, pericardium,
azygous vein, diaphragm, or peritoneum (for esophagogastric junction EC) is considered
as T4a stage, whereas, aorta, vertebral body, or tracheal involvement upgrades the
lesion to T4b stage.[2 ]
[4 ] Specific signs of tracheobronchial involvement by EC on CT are fistula formation
with the airway, intraluminal extension of tumor within the airway, and tracheobronchial
mural thickening.[3 ]
[22 ] Focal loss of fat plane of the EC with the airway with preserved fat planes proximal
and distal to it also likely suggests tracheobronchial involvement.[22 ] More than 90-degree contact of EC with aorta, loss of triangular fat between esophagus,
aorta, and spine, suggests aortic involvement on CECT.[2 ]
[3 ]
[22 ] Pericardial involvement may be suggested by pericardial thickening/effusion.[3 ]
[22 ] CECT helps in assigning Siewert category to esophagogastric junction AC tumors that
have management and prognostic implications.[16 ] Besides, CECT is important for the detection of metastasis to liver and lungs.[22 ]
[Fig. 3 (A–E) ] shows EC staging on CECT.
Fig. 3 Esophageal carcinoma staging on axial contrast-enhanced computed tomography. (A ) Mild asymmetric mid-esophageal wall thickening (arrowhead), with no peri-adventitial
infiltration and maintained fat planes with the adjacent structures (T2). (B ) Mid-esophageal growth with periadventitial fat infiltration (T3) without any tracheobronchial
or aortic invasion. The mass is seen to indent upon posterior wall of left mainstem
bronchus (arrowhead); however, invasion was ruled out by bronchoscopy. (C ) More than 90-degree arc of contact between the esophageal mass and aorta with involvement
of aortic wall (arrowhead), along with soft tissue extension into the triangular fat
pad indicating aortic invasion (T4b). (D ) Irregular circumferential thickening involving the upper thoracic esophagus with
frank fistulous communication with the tracheal lumen (arrowhead), and passage of
oral positive contrast into the trachea (T4b). (E ) Well defined left lower lobe nodule (arrowhead) on lung window, in a case of esophageal
cancer, suggestive of lung metastasis (M1).
Role of FDG-PET/CT
Following intravenous injection of 18F-FDG-PET-CT images are acquired from skull base
to mid-thigh. Both oral and intravenous contrast is used for the acquisition of CT
images. The predominant role of FDG-PET/CT is to detect distant metastases including
metastasis to bones and distant nodal metastasis when no metastasis is detected on
CECT scan.[16 ] PET-CT is the modality of choice to diagnose occult metastasis to various organs
that thus help in avoiding futile surgeries.[30 ]
[31 ]
[32 ] Besides, PET-CT is also useful to detect second primary tumor and studies have indicated
that FDG-PET/CT is superior to conventional anatomical imaging to evaluate synchronous
tumors (especially head and neck cancers and colon neoplasm) during primary staging
of esophageal SCC.[33 ] PET/CT also plays an important role in radiation therapy treatment planning of EC.[34 ]
[35 ] PET-CT-based intensity-modulated radiation therapy offers several advantages that
includes (1) dose escalation to target (tumor), (2) minimizes dose delivery to normal
tissue, (3) decrease acute toxicity, (4) lessens long-term toxicity by optimizing
treatment delivery to target tissue, thereby achieving better therapy outcome. [Fig. 4 (A ] and [B) ] shows EC staging on FDG-PET/CT.
Fig. 4 (A and B ) Staging of esophageal cancer on fluorodeoxyglucose-positron emission tomography/computed
tomography (FDG-PET/CT) images reveals moderately FDG-avid primary esophageal mass
lesion (arrowhead) with extensive FDG-avid metastatic abdominal nodes (curved arrow)
and multifocal hypermetabolic hepatic (metastatic) lesions (arrow) implying M1 stage.
Role of Other Modalities
Magnetic resonance imaging (MRI) plays a pertinent role in detecting the status of
spinal cord, when there is intraspinal extension of the tumor with involvement of
vertebrae. Also, when there is doubt on CT regarding pericardial and aortic wall involvement,
MRI can come to the rescue. One of the studies has shown that PET-MR has comparable
sensitivity with EUS in staging primary esophageal involvement, and offers higher
diagnostic accuracy compared with EUS and PET/CT.[36 ] However, due to limited availability and cost factor, PET-MR is not routinely used.
[Table 3 ] enlists the role of each modality in staging of EC.[2 ]
[3 ]
[4 ]
[16 ]
[22 ]
[30 ]
[31 ]
[32 ]
Table 3
Role of various modalities in staging of EC[2 ]
[3 ]
[4 ]
[16 ]
[22 ]
[30 ]
[31 ]
[32 ]
Modality
Role in staging
Endoscopic resection
-DifferentiatingT1a from T1b
-Biopsy from lesion
EUS
-T staging
-N staging
-EUS-guided FNA of regional nodes
CECT thorax and abdomen with oral contrast
-Additional CECT neck if upper third (including cervical) EC
-Additional CECT pelvis (if pelvic symptoms or EGJ tumors)
-T3 stage
-T4a and T4b stages
-Craniocaudal dimension of the tumor
-Helps to assign Siewert category for adenocarcinoma of EGJ as follows:
a. Siewert type I: tumor epicenter within 1 to 5 cm above EGJ
b. Siewert type II: tumor epicenter within 1 cm above and 2 cm below EGJ
c. Siewert type III: tumor epicenter between 2 and 5 cm below EGJ (included under
gastric carcinoma)
-Metastasis to liver and lungs
FDG-PET/CT
-Distant metastasis (including bone and distant nodal metastasis) when CECT is negative
for metastasis
-Occult metastasis to various organs
-Synchronous tumors
MRI
-Status of spinal cord in case of intraspinal extension of the tumor with involvement
of vertebrae.
-Pericardial involvement when doubtful on CT
-Aortic involvement when doubtful on CT
Abbreviations: CECT, contrast-enhanced computed tomography; EC, esophageal cancer;
EGJ, esophagogastric junction; EUS, endoscopic ultrasound; FDG-PET/CT, fluorodeoxyglucose-positron
emission tomography/computed tomography; MRI, magnetic resonance imaging.
A retrospective multicenter study demonstrated that use of short axis diameter (instead
of the usual longest diameter) in the Response Evaluation Criteria in Solid Tumors
(RECIST) for EC after neoadjuvant chemotherapy correlates well with pathological response
and is significantly associated with survival.[37 ] On comparison with pre-therapy CECT, new onset enhancing mural thickening anywhere
in esophagus, significant increase in lymph nodal size as per RECIST or new onset
metastatic lesions, all are suggestive of disease progression on CECT. FDG-PET/CT
parameters like maximum standard uptake value (SUVmax) or metabolic tumor volume (MTV),
aid in predicting prognosis and response assessment of patients treated after concurrent
chemoradiation therapy.[38 ] Immune-modified Response Evaluation Criteria in Solid Tumors (iRECIST) is used for
assessing response in advanced EC receiving immunotherapy to take into account the
phenomenon of pseudoprogression.[39 ]
[40 ]
[Fig. 5 (A ] and [B) ] shows pre-treatment and post-radiotherapy response on PET/CT. [Table 4 ] shows post-therapy response evaluation for EC.[37 ]
[38 ]
Fig. 5 (A and B ) Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT)
images of a 50-year-old patient diagnosed as metastatic carcinoma esophagus treated
with radiotherapy (RT). (A ) Sagittal pretreatment PET/CT image depicts the metabolically active primary neoplastic
mass lesion (arrowhead). (B ) Sagittal post therapy PET/CT image after 3 months of RT reveals significant reduction
in metabolic activity of primary lesion, suggestive of significant metabolic remission.
Table 4
Post-therapy response assessment for EC
Modality
Response assessment after therapy
CECT
≥ 30% decrease in esophageal mural thickening (short axis) or the lymph node (short
axis), post-therapy suggests partial response
≥ 20% increase in esophageal mural thickening (short axis) or the lymph node (short
axis), post-therapy suggests disease progression
FDG-PET/CT
SUVmax and MTV after concurrent chemoradiation therapy help in assessing response
as well as prognosis. No definite cutoff value has been mentioned
Abbreviations: CECT, contrast-enhanced computed tomography; EC, esophageal cancer;
FDG-PET/CT, fluorodeoxyglucose-positron emission tomography/computed tomography; MTV,
metabolic tumor volume; SUVmax, maximum standard uptake value.
In the post-treatment setting, most of the recurrences (95%) are known to occur within
the first 2 years after bimodality therapy (definitive chemoradiotherapy) and first
3 years after trimodality therapy (chemoradiotherapy and surgery).[41 ] There are no well-established guidelines for follow-up; however, CT scan of chest
and abdomen with contrast is recommended every 6 months for first 2 years at least.[16 ] Along with this, 3 monthly follow-up with history and physical examination, upper
GI tract endoscopy at 3 months, followed by at 1 year, and then every 3 yearly are
recommended. From 2 to 5 years, follow-up can be 6 monthly (clinical) with annual
imaging, and after 5 years annual clinical follow-up with imaging only if indicated
clinically.[17 ]
[Table 5 ] shows the follow-up guidelines for EC.[16 ]
[17 ]
Table 5
Guidelines on follow-up of EC patients
Follow-up method
Frequency
CECT thorax and abdomen
• First 2 years: Every 6 months
• 2–5 years: Annual
• After 5 years: Only if indicated
Upper GI endoscopy
• At 3 months
• 1 year
• Then 3 yearly
Clinical (history and physical examination)
• First 2 years: 3 monthly
• 2–5 years: 6 monthly
• After 5 years: Annual
Abbreviations: CECT, contrast-enhanced computed tomography; EC, esophageal cancer;
GI, gastrointestinal.
Principles of Management
For mucosal tumors, treatment options include ER and/or ablation (high-grade dysplasia,
AC limited to mucosa, small tumor [<2cm] that are asymptomatic and non-circumferential).[42 ] Upper third EC are best treated with definitive chemoradiation (CTRT). In middle
and lower third, patients with T2N0 or less may be operated upfront without any neoadjuvant
therapy.[16 ] Any localized disease greater than T3N0 mandates neoadjuvant therapy despite being
upfront resectable. As of today, the best evidence is for neoadjuvant chemoradiotherapy(NACTRT)
with CROSS protocol for SCC and perioperative chemotherapy with Fluorouracil, Leucovorin,
Oxaliplatin, Docetaxel (FLOT) FLOT regimen for AC.[43 ]
For early-stage resectable tumors, either transhiatal or transthoracic (Ivor-Lewis)
total esophagectomy or extended-3 field lymphadenectomy is performed depending upon
the location or extent of tumor.[44 ] CTRT is given for T4b stage, except when trachea, great vessels, vertebra or heart,
are involved, in which case, palliative chemotherapy is the only option. Depending
on HER 2 overexpression and PD-L1 expression, targeted therapy or immunotherapy respectively,
are given.[16 ]
Overall EC is very aggressive disease with poor prognosis. Five-year overall survival
for localized disease is 39 and 4% for metastatic disease. SCC histology has poor
outcome as opposed to AC histology.[45 ] Nutritional rehabilitation and cardiopulmonary evaluation are vital components in
the overall management of EC patients.
[Fig. 6 ] depicts an algorithm for the management of EC. Location/stage-wise treatment of
EC is presented in [Table 6 ].[16 ]
[43 ]
Fig. 6 Algorithm for the management of esophageal carcinoma. NACTRT, neoadjuvant chemoradiotherapy;
Periop, perioperative; SCC: Squamous cell carcinoma.
Table 6
Location/stage-wise treatment of esophageal cancer
Location/stage of EC
Treatment
Upper third EC (including cervical)
Definitive chemoradiation
Tis, T1a
Endoscopic mucosal resection
Middle and lower third T1b, T2N0 or less
Upfront surgery
Middle and lower third localized disease greater than T3N0
NACTRT with CROSS protocol for SCC and perioperative chemotherapy with FLOT regimen
for AC
T4b stage
Definitive chemoradiation
Involvement of trachea, great vessels, vertebra or heart
Palliative chemotherapy
Metastatic disease
Systemic therapy (chemotherapy and/or immunotherapy)
Abbreviations: EC: Esophageal cancer, NACTRT: neoadjuvant chemoradiotherapy, SCC:
Squamous cell carcinoma, FLOT: Fluorouracil, Leucovorin, Oxaliplatin, Docetaxel, AC:
Adenocarcinoma
Abbreviations: CECT, contrast enhanced computed tomography; COPD, chronic obstructive
pulmonary disease; DICOM, digital imaging and communications in medicine; EUS, endoscopic
ultrasonography; FDG-PET/CT, fluorodeoxyglucose positron emission tomography computed
tomography; FNAC, fine-needle aspiration cytology; MRI, magnetic resonance imaging;
RIS, radiology information system; SUVmax, maximum standardized uptake value.
Synoptic reporting format 1
Staging (pre-treatment) Esophageal and esophagogastric junction Cancer Imaging - Reporting
and Data System (ECI-RADS) based on CECT or FDG-PET/CT
Demographics (Information provided by RIS and DICOM headers)
Name of the facility where examination was provided
a. Name of the patient
b. Patient's gender
c. Patient's date of birth and age
d. Name(s) of referring physician(s) or other health care provider(s)
e. Name of type of examination
f. Date and time of the examination
g. Date and time of dictation and final transcription
Relevant clinical information
a. Clinical symptoms
b. Addictions – Smoking/Alcohol/ Chewing tobacco
c. Co-existing health morbidities – Gastroesophageal reflux disease (GERD)/achalasia/
H. pylori status/COPD/ Diabetes Mellitus/ Immunocompromised status
d. Occupational history for any relevant occupational exposures
e. Previous cancer
f. Previous surgery
g. Previous chemotherapy or radiation
h. Endoscopy findings (if done): distance of tumor from incisors, proximal and distal
tumor extent, luminal obstruction, Barrett's esophagus
i Endoscopic ultrasound findings (if done): T staging, regional nodal status
h. Current working diagnoses (if any)
i. Recent most relevant laboratory tests including biomarkers (if available):
Body of the report:
a. Type of study and the technical protocol
b. Quality of examination
T Category
Esophagus
Location/epicenter: Cervical/upper third thoracic/middle third thoracic/lower third
thoracic including esophagogastric junction
Size: Thickness* and craniocaudal dimension (including vertebral levels)
SUVmax (FDG-PET/CT):
Luminal obstruction: Present/Absent
Local invasion: Present/absent
Local invasion (for cervical esophageal cancer): Larynx, hypopharynx, thyroid gland, vertebrae
Local invasion (T4a) (for thoracic esophagus and esophagogastric junction cancer)
Pleura: Involved/indeterminate/uninvolved
Pericardium$ : Involved/indeterminate/uninvolved
Azygous vein: Involved/indeterminate/uninvolved
Peritoneum (for esophagogastric junction): Involved/indeterminate/uninvolved
Diaphragm: Involved/indeterminate/uninvolved
Local invasion (T4b)
Aorta$ :
Loss of fat plane: Yes/no
Angle of contact: ≤ 90/> 90 degree
Involved/indeterminate/uninvolved
Vertebra$ :
Involved/indeterminate/uninvolved
Trachea/bronchus:
Abutment/mass within airway lumen/fistula formation with airway
Involved/indeterminate/uninvolved
Siewert type (for esophagogastric junction tumors): I/II/III
N Category
Nodes:
Number of regional nodes (if involved): 1–2/ 3–6/ 7 or more
Size and station of node (if involved):
SUVmax (FDG-PET/CT):
Involved/indeterminate/uninvolved #
M Category
Distant metastasis:
Site:
SUVmax (FDG-PET/CT):
Other findings
Synchronous tumor: Yes/ No
Any other finding:
*Needs additional imaging: EUS
$ Needs additional imaging: MRI
# Needs FNAC correlation
Synoptic reporting format 2
Post-therapy Esophageal and esophagogastric junction Cancer Imaging - Reporting and
Data System (pECI-RADS) based on CECT or FDG-PET/CT
Demographics (information provided by RIS and DICOM headers)
Name of the facility where examination was provided
a. Name of the patient
b. Patient's gender
c. Patient's date of birth and age
d. Name(s) of referring physician(s) or other health care provider(s)
e. Name of type of examination
f. Date and time of the examination
g. Date and time of dictation and final transcription
Relevant clinical information
a. Clinical symptoms
d. Recent most relevant laboratory tests and/or imaging findings
Indication: [Post surgery/ post neoadjuvant chemotherapy/chemoradiotherapy/post definitive radiotherapy]
Body of the report:
a. Type of study and the technical protocol
b. Quality of examination
c. Comparison to previous study and date
Findings:
1. No evidence of residual disease/recurrence
2. No evidence of residual pathological lymph nodes/no new pathological lymph nodes.
3. Post-treatment changes are noted including:
[a] Post-surgery anastomotic stricture/leak: Yes/no
[b] Post-RT mucosal edema/stricture/pneumonitis: Yes/no
4. There are no findings to suggest a second primary in the oropharynx/head and neck/lungs
5. Evaluation of the visualized portions of liver, adrenals, lungs and bones show
no aggressive lesions suspicious for metastatic involvement.
IMPRESSION:
1. Expected post treatment changes
2. Category of disease*.
*CECT or FDG-PET/CT Surveillance Legend:
Category 1: No evidence of residual disease/recurrence.
Category 2: Low volume residual disease/low suspicion of recurrence.
SUVmax on FDG-PET/CT:
Category 3: High volume residual disease/ high suspicion of recurrence
SUVmax on FDG-PET/CT:
Category 4: No change in tumor volume/definitive recurrence
SUVmax on FDG-PET/CT:
Synoptic reporting format 3
Endoscopic ultrasound reporting format for esophageal cancer
• Tumor—T stage, maximal tumor thickness (mm)
• Nodes—Size, echogenicity, shape, borders, location, N stage, whether FNAC done
• Metastases (if seen)
• Incomplete staging due to stenotic tumors (when present)
Follow-Up Imaging and Management of Recurrent Disease
Anastomotic leak is suspected in presence of fever, tachycardia, tachypnea, or arrhythmia
in immediate postoperative period. Also, a close watch needs to be kept on the neck
wound (for erythema /swelling) and nature of drain output (bilious/ purulent) in the
postoperative period. CECT detects immediate post-surgical complications like fistulization
of neoesophagus with airway and anastomotic leaks, and is also useful for the detection
of esophageal edema after definitive concurrent chemoradiotherapy.[2 ]
[46 ] CECT thorax assists in diagnosis by showing oral contrast extravasation and or air
fluid level in pleural/mediastinum. CECT thorax also helps in draining out the collection
by guiding pigtail.
Esophagogram on fluoroscopy can also be used in the immediate postoperative period
to detect fistula or leaks, and a negative test warrants CECT, if clinical suspicion
is high.[20 ] Delayed post-therapy imaging includes detection of recurrence and post-surgery/RT
stricture. [Fig. 7 (A ] and [B) ] CECT images show post-NACTRT stricture formation in midesophagus (in supplement).
Mantziari et al found FDG-PET/CT parameters (SUVmax, total lesion glycolysis and MTV)
to be quite useful in predicting tumor recurrence and disease-free survival in patients
with EC.[47 ] CECT may show new onset enhancing esophageal mural thickening suggestive of recurrence.
Post-RT esophageal stricture occurs 3 to 8 months later and can be seen as esophageal
luminal narrowing with proximal dilatation and air-fluid levels.[2 ]
[48 ]
Fig. 7 (A and B ) Case of squamous cell carcinoma of the middle third of the esophagus, postneoadjuvant
chemoradiotherapy, presented with increasing dysphagia. Brush cytology was negative
for malignancy. Axial (A ) and sagittal (B ) computed tomographic images show a short segment smooth circumferential wall thickening
(arrowhead), with proximal esophageal dilatation.
Localized recurrences after surgery are best treated with CTRT. Residual or recurrent
disease after CTRT is considered for salvage surgery. Various systemic therapy options
exist for both histologies. For palliation of dysphagia, local radiation (external
beam or brachytherapy), feeding procedures (nasojejunal/gastric tube), or esophageal
or airway stenting (for tracheobronchial infiltration) are feasible options.