COMPUTERIZED INTERACTIVE MORPHOMETRY IN THE DIFFERENTIAL-DIAGNOSIS OFIRRADIATED PROSTATES

Radiation therapy is becoming a treatment of choice for many patients with prostatic carcinoma. Distinguishing radiation change in prostate glands from carcinoma may be difficult. In this study we objectively a ssessed, by morphometric methods, the nuclear characteristics of benig n and malignant prostates with a history of radiation treatment (125I implant with or without prior external beam radiation). This is part o f our continuing efforts to achieve difficult differential diagnoses b y analyzing perimeter, diameter and nuclear profile area of cells or i nterest and applying methods of statistical classification. Biopsies w ere performed 18-36 months following implant therapy. Eleven cases wit h residual prostate tumor constituted the malignant group. These were compared to 20 bengin cases (benign glands in the 11 carcinoma cases p lus 9 other cases with no residual carcinoma). Immunohistochemical sta ining with keratin 903 was performed on all cases. Differences in the nuclear parameters were most evident in the average nuclear profile ar eas (32.5 mu m2 for the malignant groups vs. 39.6 for the benign) and in the mean maximal cord length (diameter) (7.4 mu m for the malignant group vs. 9.0 for the benign). Classification, however, is based on t he size distribution plots of nuclear profile areas, which, in the mal ignant cases, had a sharper peak at lower value, while the benign case s had higher value and a broader- peak with a trailing off into the la rger values. This study emphasized the marked nuclear alterations that occur in irradiated prostates. These changes, which affect the benign glands to a greater degree than the residual carcinoma, most likely a re a reflection of tuner radioresistance and can be used for a differe ntial diagnosis based on statistical classification.