Patients
According to the revised FIGO criteria (1), T stage was classified as pT1 in 30 patients, pT2a in 3, pT2b in 1, pT3b in 1 and pT3c in 21. The histopathologic types of primary tumors with malignancy or borderline malignancy were high-grade serous carcinoma (n = 16), low-grade serous carcinoma (n = 1), serous borderline tumor (n = 2), adenocarcinoma proven from ascites or pleural effusion (n = 2), mucinous carcinoma (n = 1), mucinous borderline tumor (n = 5), seromucinous carcinoma (n = 1), seromucinous borderline tumor (n = 2), endometrioid carcinoma (n = 6), carcinosarcoma (n = 2), clear cell carcinoma (n = 7), undifferentiated carcinoma (n = 2), Sertoli-Leydig cell tumor (poorly differentiated (n = 1), moderately differentiated (n = 1)), immature teratoma grade 1 (n = 4), squamous cell carcinoma (n = 2) and large cell neuroendocrine carcinoma (n = 1). N stage was classified as N0 in 50 patients, and N1 in 6 including pelvic and/or para-aorta lymph nodes. M stage was classified as M0 in 44 patients and M1 in 12 including the sternum, supraclavicular, subclavicular, axillary, and longitudinal lymph nodes. Demographic data for the 56 patients are listed in Table 1. Histopathologic types of primary benign tumors with suspected malignancy were endometrial cyst (n = 7), mucinous cystadenoma n = 7), mature cystic teratoma (n = 5), serous cystadenoma (n = 4), struma ovalii (n = 1), fibroma (n = 1), thecoma (n = 1), lymphangioma (n = 1), and abscess (n = 1) (Table 2). The histopathologic types of ovarian cancer after NAC were high-grade serous carcinoma (n = 6), and carcinosarcoma (n = 1) (Table 3). The histopathologic types of recurrent ovarian cancer were high-grade serous carcinoma (n = 5), clear cell carcinoma (n = 2), large cell neuroendocrine carcinoma (n = 2), seromucinous carcinoma (n = 1). and adenocarcinoma (n = 1) (Table 4).
Table 1
Characteristics of patients with primary ovarian cancer
Case | Age (years) | Histology | Pathological staging | PET/MRI staging | ceMRI and/or ceCT staging |
1 | 40 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
2 | 52 | LGSC | T1N0M0 | T1N0M0 | T1N0M0 |
3 | 41 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
4 | 47 | endometrioid | T3cN0M1 | T3cN0M1 | T3cN0M0 |
5 | 58 | seromucinous | T1N0M0 | T1N0M0 | T1N0M0 |
6 | 52 | clear | T2aN0M0 | T1N0M0 | T1N0M0 |
7 | 65 | mucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
8 | 19 | immature teratoma, G1 | T1N0M0 | benign | benign |
9 | 69 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
10 | 42 | mucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
11 | 45 | HGSC | T2bN0M0 | T1N0M0 | T1N0M0 |
12 | 76 | mucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
13 | 73 | Sertoli-Leydig moderate | T1N0M0 | T1N0M0 | T1N0M0 |
14 | 31 | seromucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
15 | 67 | CS | T2aN1M1 | T2aN1M1 | T2aN1M0 |
16 | 77 | HGSC | T3cN1M1 | T3cN1M1 | T3cN1M0 |
17 | 78 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
18 | 65 | endometrioid | T3cN0M0 | T3cN0M0 | T3cN0M0 |
19 | 56 | endometrioid | T2aN1M0 | T2aN1M0 | T2aN1M0 |
20 | 78 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
21 | 66 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
22 | 43 | Sertoli-Leydig poor | T1N0M0 | T1N0M0 | T1N0M0 |
23 | 20 | immature teratoma, G1 | T1N0M0 | T1N0M0 | T1N0M0 |
24 | 62 | CS | T3cN0M1 | T3cN0M1 | T3cN0M1 |
25 | 50 | mucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
26 | 41 | serous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
27 | 67 | SCC | T1N1M1 | T1N1M1 | T1N0M0 |
28 | 63 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
29 | 54 | endometrioid | T1N0M0 | T1N0M0 | T1N0M0 |
30 | 71 | HGSC | T3cN0M1 | T3cN0M1 | T3cN0M0 |
31 | 73 | serous borderline | T1N0M0 | benign | benign |
32 | 73 | undifferentiated carcinoma | T3cN0M1 | T3cN0M1 | T3cN0M1 |
33 | 23 | immature teratoma, G1 | T1N0M0 | T1N0M0 | T1N0M0 |
34 | 31 | neuroendocrine carcinoma | T3cN0M0 | T3cN0M0 | T3cN0M0 |
35 | 38 | mucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
36 | 53 | seromucinous borderline | T1N0M0 | T1N0M0 | T1N0M0 |
37 | 43 | endometrioid | T1N0M0 | T1N0M0 | T1N0M0 |
38 | 61 | mucinous | T1N0M0 | T1N0M0 | T1N0M0 |
39 | 51 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
40 | 62 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
41 | 56 | HGSC | T3bN0M0 | T1N0M0 | T1N0M0 |
42 | 68 | SCC | T1N1M1 | T1N1M1 | T1N0M1 |
43 | 80 | undifferentiated carcinoma | T3cN1M1 | T3cN1M1 | T3cN1M0 |
44 | 56 | endometrioid | T1N0M0 | T1N0M0 | T1N0M0 |
45 | 51 | clear | T1N0M0 | T1N0M0 | T1N0M0 |
46 | 72 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
47 | 75 | adenocarcinoma | T3cN0M0 | T3cN0M0 | T3cN0M0 |
48 | 45 | HGSC | T1N0M0 | T1N0M0 | T1N0M0 |
49 | 11 | immature teratoma G1 | T1N0M0 | T1N0M0 | T1N0M0 |
50 | 76 | adenocarcinoma | T3cN0M1 | T3cN0M1 | T3cN0M0 |
51 | 48 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
52 | 65 | HGSC | T3cN0M1 | T3cN0M1 | T3cN0M0 |
53 | 59 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
54 | 66 | HGSC | T3cN0M1 | T3cN0M1 | T3cN0M0 |
55 | 64 | HGSC | T3cN0M0 | T3cN0M0 | T3cN0M0 |
56 | 80 | HGSC | T3cN0M1 | T3cN0M1 | T3cN0M0 |
Underline indicates over- or under-diagnosis. |
G, grade; HGSC, high-grade serous carcinoma; LGSC, low-grade serous carcinoma; |
CS, carcinosarcoma; SCC, squamous cell carcinoma |
Table 2
Characteristics of patients with pathologically benign ovarian tumor
Characteristics | n | % |
Total number of patients | 29 | |
Mean age (range), years | 50.7 (16–75) | |
Histology | | |
endometrial cyst | 7 | 24.1 |
mucinous cystadenoma | 7 | 24.1 |
mature cystic teratoma | 5 | 17.2 |
serous cystadenoma | 4 | 13.8 |
struma ovarii | 2 | 6.9 |
fibroma | 1 | 3.4 |
thecoma | 1 | 3.4 |
lymphangioma | 1 | 3.4 |
abscess | 1 | 3.4 |
Table 3
Characteristics of patients after neoadjuvant chemotherapy
Characteristics | n | % |
Total number of patients | 7 | |
Mean age (range), years | 67.7 (50–78) | |
Histology | | |
HGSC | 6 | 85.7 |
CS | 1 | 14.3 |
HGSC, high-grade serous carcinoma; CS, carcinosarcoma |
Table 4
Characteristics of patients with recurrence
Characteristics | n | % |
Total number of patients | 11 | |
Mean age (range), years | 56.9 (34–73) | |
Histology | | |
HGSC | 5 | 45.5 |
clear | 2 | 18.2 |
neuroendocrine carcinoma | 2 | 18.2 |
seromucinous | 1 | 9.1 |
adenocarcinoma | 1 | 9.1 |
HGSC, high-grade serous carcinoma |
Characterization
Sensitivity, specificity and accuracy for characterization were 97.4%, 86.2% and 92.5% for 18F-FDG PET/MRI and 97.4%, 58.6% and 80.6% for ceMRI, respectively (p = 0.0133, significant difference) (Table 5). Figure 1 shows representative images for characterizations.
Table 5
Comparison of 18F-FDG PET/MRI with ceMRI and/or ceCT for patient-based T, N and M staging, detection of residual disease after neoadjuvant chemotherapy, and detection of recurrence
| 18F-FDG PET/MRI | ceMRI and ceCT | |
Primary tumor |
Sensitivity | 97.4% (37/38) | 97.4% (37/38) | |
Specificity | 86.2% (25/29) | 58.6% (17/29) | |
Accuracy | 92.5% (62/67) | 80.6% (54/67) | P = 0.0133 < 0.05 |
T staging | | | |
Accuracy | 96.4% (54/56) | 92.9% (52/56) | P = 0.4795 |
T2a (growth into uterus, fallopian tubes, or ovaries) |
Sensitivity | 100% (2/2) | 50% (1/2) | |
Specificity | 100% (30/30) | 100% (30/30) | |
Accuracy | 100% (32/32) | 96.9% (31/32) | P = 1.0000 |
T2b (growth into other nearby pelvic organs such as bladder, sigmoid colon, or rectum) |
Sensitivity | 0% (0/1) | 0% (0/1) | |
Specificity | 100% (31/31) | 100% (31/31) | |
Accuracy | 96.9% (31/32) | 96.9% (31/32) | P = 1.0000 |
T3b (growth into organs outside the pelvis, but ≤2 cm across) |
Sensitivity | 95.5% (21/22) | 90.9% (20/22) | |
Specificity | 100% (33/33) | 100% (33/33) | |
Accuracy | 98.2% (54/55) | 96.4% (53/55) | P = 1.0000 |
T3c (growth into organs outside the pelvis, > 2 cm across) |
Sensitivity | 100% (21/21) | 100% (21/21) | |
Specificity | 100% (34/34) | 100% (34/34) | |
Accuracy | 100% (55/55) | 100% (55/55) | P = 0 |
N staging |
Accuracy | 100% (6/6) | 33.3% (2/6) | |
Specificity | 100% (21/21) | 100% (21/21) | |
Accuracy | 100% (27/27) | 85.2% (23/27) | P = 0.1336 |
M staging |
Sensitivity | 100% (12/12) | 25.0% (3/12) | |
Specificity | 100% (1/1) | 100% (1/1) | |
Accuracy | 100% (13/13) | 30.8% (4/13) | P = 0.0077 < 0.01 |
Evaluation of residual disease for interval debulking surgery after neoadjuvant chemotherapy |
Sensitivity | 71.4% (5/7) | 57.1% (4/7) | |
Specificity | 0% (0/0) | 0% (0/0) | |
Accuracy | 71.4% (5/7) | 57.1% (4/7) | P = 1.0000 |
Evaluation of recurrence |
Sensitivity | 100% (9/9) | 88.9% (8/9) | |
Specificity | 100% (2/2) | 100% (2/2) | |
Accuracy | 100% (11/11) | 90.9% (10/11) | P = 1.0000 |
T staging
Overall accuracies of T staging for 18F-FDG PET/MRI and ceMRI/ceCT were 96.4% (54/56) and 92.9% (52/56), respectively (no significant difference, p = 0.4795). Use of 18F-FDG PET/MRI understaged the actual T stage in 2 patients (3.6%), whereas ceMRI/ceCT resulted in understaging in 4 patients (7.1%). Use of 18F-FDG PET/MRI incorrectly classified 1 T2b and 1 T3b tumors as T1, whereas ceMRI/ceCT incorrectly classified 1 T2a, 1 T2b, and 2 T3b tumors as T1. Sensitivity, specificity and accuracy for detecting growth into the uterus, fallopian tubes, or ovaries were 100%, 100% and 100% for 18F-FDG PET/MRI, and 50%, 100% and 96.9% for ceMRI, respectively (no significant difference, p = 1). Sensitivity, specificity and accuracy for growth into other nearby pelvic organs such as the bladder, sigmoid colon, or rectum were 0%, 100% and 96.9% for 18F-FDG PET/MRI and 0%, 100% and 96.9% for ceMRI, respectively (no significant difference, p = 1). Sensitivity, specificity and accuracy for growth into organs outside the pelvis and no bigger than 2 cm in extent were 95.5%, 100% and 98.2% for 18F-FDG PET/MRI and 90.9%, 100% and 96.4% for ceCT, respectively (no significant difference, p = 1). Sensitivity, specificity and accuracy for growth into organs outside the pelvis and larger than 2 cm in extent were 100%, 100% and 100% for 18F-FDG PET/MRI and 100%, 100% and 100% for ceCT, respectively (no significant difference, p = 0) (Table 5). Figure 2 shows representative images for T2 and T3 staging.
N staging
Patient-based sensitivity, specificity and accuracy for N staging including retroperitoneal lymph nodes metastasis were 100%, 100% and 100% for 18F-FDG PET/MRI and 33.3%, 100% and 85.2% for ceCT, respectively (no significant difference, p = 0.1336). Use of ceCT incorrectly classified 4 N1 lymph nodes as N0 (Table 5). Lesion-based sensitivity, specificity and accuracy for N staging including retroperitoneal lymph nodes metastasis were 78.6%, 95.7% and 93.9% for 18F-FDG PET/MRI, and 42.9%, 96.6% and 90.8% for ceCT, respectively. Sensitivity showed a tendency toward a difference (p = 0.0736), and specificity and accuracy were not significant (p = 1 and p = 0.2888, respectively) (Table 6). Figure 3 shows representative images for N staging.
Table 6
Comparison of 18F-FDGPET/MRI and ceCT for lesion-based nodal metastasis
| 18F-FDG PET/MRI | ceCT | |
Sensitivity | 78.6% (11/14) | 42.9% (6/14) | P = 0.0736 |
Specificity | 95.7% (112/117) | 96.6% (113/117) | P = 1 |
Accuracy | 93.9% (123/131) | 90.8% (119/131) | P = 0.2888 |
M staging
Sensitivity, specificity and accuracy for M staging were 100%, 100% and 100% for 18F-FDG PET/MRI, and 25.0%, 100% and 30.8% for ceCT, respectively (p = 0.0077, significant difference). Use of ceCT incorrectly classified 9 M1 tumors as M0 (Table 5). Figure 4 shows representative images for M staging.
Residual disease for IDS after NAC
Sensitivity, specificity and accuracy for detecting residual disease for IDS after NAC were 71.4%, 0% and 71.4% for 18F-FDG PET/MRI, and 57.1%, 0% and 57.1% for ceCT, respectively (no significant difference, p = 1) (Table 5). Figure 5 shows representative images for detecting residual disease for IDS after NAC.
Recurrence
Sensitivity, specificity and accuracy for detecting recurrence were 100%, 100% and 100% for 18F-FDG PET/MRI, and 88.9%, 100% and 90.9% for ceCT, respectively (no significant difference, p = 1) (Table 5). Figure 6 shows representative images for recurrence.