ACR Appropriateness Criteria®
Clinical Condition: Invasive Cancer of the Cervix
Variant 1: FIGO stage Ib.
Radiologic Exam Procedure |
Appropriateness Rating |
Comments |
MRI |
8 |
|
X-ray, chest |
5 |
|
CT |
5 |
As spiral techniques evolve, the role of CT will be reassessed. |
PET |
4 |
|
US, pelvis |
1 |
|
US, abdomen |
2 |
|
US, endovaginal |
2 |
|
NUC, bone scan |
1 |
|
Intravenous urogram (IVU) |
1 |
|
X-ray, colon, barium enema (BE) |
1 |
|
Appropriateness Criteria Scale
1 2 3 4 5 6 7 8 9
1 = Least appropriate 9 = Most appropriate
|
Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.
Variant 2: FIGO stage Ib, tumor size >2 cm.
Radiologic Exam Procedure |
Appropriateness Rating |
Comments |
MRI |
8 |
|
X-ray, chest |
5 |
|
CT |
5 |
|
PET |
4 |
|
US, pelvis |
2 |
|
US, abdomen |
2 |
|
US, endovaginal |
2 |
|
NUC, bone scan |
1 |
|
Intravenous urogram (IVU) |
1 |
|
X-ray, colon, barium enema (BE) |
1 |
|
Appropriateness Criteria Scale
1 2 3 4 5 6 7 8 9
1 = Least appropriate 9 = Most appropriate
|
Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.
Variant 3: FIGO stage Ib, tumor size >3 cm.
Radiologic Exam Procedure |
Appropriateness Rating |
Comments |
MRI |
8 |
|
X-ray, chest |
5 |
|
CT |
5 |
|
PET |
5 |
|
US, pelvis |
2 |
|
US, abdomen |
2 |
|
US, endovaginal |
2 |
|
NUC, bone scan |
1 |
|
Intravenous urogram (IVU) |
1 |
|
X-ray, colon, barium enema (BE) |
1 |
|
Appropriateness Criteria Scale
1 2 3 4 5 6 7 8 9
1 = Least appropriate 9 = Most appropriate
|
Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.
Variant 4: FIGO stage greater than Ib.
Radiologic Exam Procedure |
Appropriateness Rating |
Comments |
MRI |
8 |
|
X-ray, chest |
8 |
|
CT |
7 |
|
PET |
7 |
|
US, pelvis |
2 |
|
US, abdomen |
2 |
|
US, endovaginal |
2 |
|
NUC, bone scan |
2 |
|
Intravenous urogram (IVU) |
1 |
|
X-ray, colon, barium enema (BE) |
1 |
|
Appropriateness Criteria Scale
1 2 3 4 5 6 7 8 9
1 = Least appropriate 9 = Most appropriate
|
Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.
Cervical cancer is the third most common gynecological malignancy. It is estimated that during 2004 there will be approximately 10,520 new cases of cervical cancer and 3,900 deaths from this disease in the United States. Between 1959-61 and 1989-91, there has been a 63% decrease in the mortality of cervical cancer. This improvement in mortality has been attributed to the development of the Papanicolaou smear, and only minor improvement has been achieved in the survival rate for invasive cervical cancer. Established risk factors for cervical cancer include early sexual activity, especially with multiple partners, cigarette smoking, immunosuppression, and infection with human papilloma viruses 16 and 18.
The prognosis of cervical carcinoma is primarily determined by the stage of disease, the volume of the primary tumor, and the histologic grade. The current staging system for cervical cancer is based on the FIGO classification. It defines the clinical staging system for cervical carcinoma based on clinical assessment including physical examination under anesthesia, colposcopy, endocervical curettage, hysteroscopy, cystoscopy, proctoscopy, IVU, BE, and X-rays of lungs and skeleton. Errors in clinical FIGO staging have been reported. When compared with surgical findings, FIGO staging errors are 28% in stage Ib disease and 50%-64% in stage IIa-IIb disease. Clinical evaluation underestimates the surgical stage in 15%-36% of patients. In clinically staged Ib disease, underestimation of tumor extent occurs in 21% and overestimation in 6% of patients. Inaccuracy in clinical staging is predominantly due to difficulties in evaluating parametrial and pelvic sidewall invasion, bladder or rectal wall invasion, metastatic spread, and in evaluating primary endocervical (endophytic) tumors. Aside from the inaccuracies of clinical staging, evaluation of lymph node metastasis, which is an important prognostic factor and a determinant in treatment planning, is not included in the clinical staging system. In surgically treated stages Ib and IIa cervical cancer, survival rates decline from 85%-90% to 50%-55%, respectively, in the presence of metastatic lymph nodes. In spite of these limitations of clinical FIGO staging, modern cross-sectional imaging modalities such as US, CT, and MRI have not been incorporated into clinical staging. Among the most common arguments against the use of CT or MRI as staging tools are their high cost and unavailability universally.
Current Role of Imaging
The most important issue in staging cervical cancer is to distinguish early disease (stages IA and IB) that can be treated with surgery from advanced disease that must be treated with radiation alone or combined with chemotherapy. Imaging modalities must be directed to solve this clinically important question. Conventional radiological studies such as excretory urography, BE, and lymphangiography are less commonly used today. However, there has been an increase in the use of cross-sectional imaging, particularly CT and MRI.
Plain chest radiographs are obtained as a staging procedure to identify pleural effusion or pulmonary metastasis, which occur in the late stages of cervical cancer. However, chest CT is superior to plain film in both occasions.
Excretory urography is a sensitive test in the detection of urinary obstruction. However, a low incidence (2.4%) of urinary obstruction in stage Ib disease argues against the routine use of this test. Discontinuation of the routine use of BE, cystoscopy, and sigmoidoscopy has been suggested previously.
Transabdominal US can show the presence of hydronephrosis but has a limited role in the evaluation of local extent of the cervical cancer. Transrectal and transvaginal US have been used in the assessment of local disease but are limited in the detection of parametrial disease and pelvic side wall involvement due to poor soft-tissue contrast, small field of view, and operator dependence.
CT has staging accuracy ranging from 32% to 80% in cervical cancer. The sensitivity for parametrial invasion ranges from 17% to 100% with an average of 64%. Specificity ranges from 50% to 100% with an average of 81%. There is a consensus in the literature that the value of CT increases with higher stages of disease, and that CT has limited value (a positive predictive value of 58%) in evaluating early parametrial invasion. However, CT has an accuracy of 92% in depicting advanced disease. The major limitation of CT in local staging is its inadequate differentiation between tumor and normal cervical stroma or parametrial structures. Therefore, CT is mainly used in advanced disease and in the assessment of lymph nodes. The positive predictive value of CT for nodal involvement is 65% with a negative predictive value of 86%. CT is also performed to detect distant metastases, for radiotherapy planning, and for guiding interventional procedures.
MRI is very accurate in determining tumor size and location (exophytic or endocervical), the depth of stromal invasion, and the local extension of the tumor. MRI is superior to clinical evaluation in assessing tumor size, and MRI measurements are within 0.5 cm of the surgical size in 70% to 90% of cases. The staging accuracy of MRI ranges from 75% to 96%. The sensitivity of MRI in evaluating parametrial invasion is 69%, and the specificity is 93%. In studies that compare MRI and CT for the evaluation of parametrial invasion, MRI was superior to CT. In evaluating nodal disease, the sensitivity and specificity of MRI, 50% and 95% respectively, are similar to those of CT. In assessing local tumor invasion, T2-weighted images are superior to contrast-enhanced T1-weighted images. MRI can be a cost-effective staging technique. In a study of patients with cervical cancer, those who underwent MRI as the initial imaging procedure for staging required fewer tests and procedures compared with those who underwent standard clinical imaging.
Lymphangiography
Although lymphangiography has been routinely used in the past for the pretreatment evaluation of lymph node metastases, it has been mostly replaced in this role by CT and MRI. Single studies that have compared lymphangiography and CT have shown similar accuracy (72%-91% and 71%-88%, respectively) for both modalities. CT may have a slightly higher specificity than lymphangiography (88%-95% versus 59%-93%), but lymphangiography is more sensitive than CT (63%-88% versus 53%-72%), especially in early stages (I-II) of disease. A meta-analysis compared the utility of lymphangiography, CT and MRI in patients with cervical cancer. Although summary-receiver-operator characteristics revealed no significant differences in the overall performance, there was a trend toward better performance for MRI than for lymphangiography or CT.
Although the current use of PET in the initial evaluation of cervical cancer is still under investigation, PET can be used to assess nodal disease and tumor recurrence. In the detection of metastatic lymph nodes in patients with cervical cancer, PET has been reported to have a sensitivity of 91% and a specificity of 100%, which are higher than those for MRI (73% and 83% respectively). Another study showed that when abdominal CT is negative, PET has a sensitivity of 85.7%, a specificity of 94.4%, and an accuracy of 92% for detecting para-aortic lymph node metastasis in patients with advanced cervical cancer. For detecting recurrence, PET has been reported to have a sensitivity and specificity of 85.7% to 90.3% and 76.1% to 86.7%, respectively. PET has added value in patients with recurrent cervical cancer who undergo salvage therapy as it can provide precise restaging information. A recent study suggests that abnormal PET findings were the most significant prognostic factor for developing metastasis and death from cervical cancer.
Abbreviations
- BE, barium enema
- CT, computed tomography
- FIGO, International Federation of Gynecology and Obstetrics
- IVU, intravenous urogram
- MRI, magnetic resonance imaging
- NUC, nuclear medicine
- PET, positron emission tomography
- US, ultrasound