Five-point Likert scaling on MRI predicts clinically significant prostate carcinoma.
BACKGROUND
To clarify the relationship between the probability of prostate cancer scaled using a 5-point Likert system and the biological characteristics of corresponding tumor foci.


METHODS
The present study involved 44 patients undergoing 3.0-Tesla multiparametric MRI before laparoscopic radical prostatectomy. Tracing based on pathological and MRI findings was performed. The relationship between the probability of cancer scaled using the 5-point Likert system and the biological characteristics of corresponding tumor foci was evaluated.


RESULTS
A total of 102 tumor foci were identified histologically from the 44 specimens. Of the 102 tumors, 55 were assigned a score based on MRI findings (score 1: n = 3; score 2: n = 3; score 3: n = 16; score 4: n = 11 score 5: n = 22), while 47 were not pointed out on MRI. The tracing study revealed that the proportion of >0.5 cm(3) tumors increased according to the upgrade of Likert scores (score 1 or 2: 33%; score 3: 68.8%; score 4 or 5: 90.9%, χ(2) test, p < 0.0001). The proportion with a Gleason score >7 also increased from scale 2 to scale 5 (scale 2: 0%; scale 3: 56.3%; scale 4: 72.7%; 5: 90.9%, χ(2) test, p = 0.0001). On using score 3 or higher as the threshold of cancer detection on MRI, the detection rate markedly improved if the tumor volume exceeded 0.5 cm(3) (<0.2 cm(3): 10.3%; 0.2-0.5 cm(3): 25%; 0.5-1.0 cm(3): 66.7%; 1.0 < cm(3): 92.1%).


CONCLUSIONS
Each Likert scale favobably reflected the corresponding tumor's volume and Gleason score. Our observations show that "score 3 or higher" could be a useful threshold to predict clinically significant carcinoma when considering treatment options.
Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan. bjtai0614@gmail.com.
Taisuke
T
Harada
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. takataka@rf6.so-net.ne.jp.
Takashige
T
Abe
Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan. fumi-k@zg7.so-net.ne.jp.
Fumi
F
Kato
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. ryu-matsumoto@amber.plala.or.jp.
Ryuji
R
Matsumoto
Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan. hiris@wb4.so-net.ne.jp.
Hiromi
H
Fujita
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. sa0034@med.hokudai.ac.jp.
Sachiyo
S
Murai
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. naoto_mi@yb3.so-net.ne.jp.
Naoto
N
Miyajima
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. kunihiko.tsuchiya@gmail.com.
Kunihiko
K
Tsuchiya
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. maruyama_satoru@ybb.ne.jp.
Satoru
S
Maruyama
Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan. kkudo@huhp.hokudai.ac.jp.
Kohsuke
K
Kudo
Department of Urology, Hokkaido University Graduate School of Medicine, North-15, West-7, North Ward, Sapporo, 060-8638, Japan. nozomis@mbj.nifty.com.
Nobuo
N
Shinohara
D000368:Aged; D000465:Algorithms; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000145:classification / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D064232:Visual Analog Scale