Ki-67 assessment of pancreatic neuroendocrine neoplasms: Systematic review and meta-analysis of manual vs. digital pathology scoring

Ki-67 assessment is a key step in the diagnosis of neuroendocrine neoplasms (NENs) from all anatomic locations. Several challenges exist related to quantifying the Ki-67 proliferation index due to lack of method standardization and inter-reader variability. The application of digital pathology coupled with machine learning has been shown to be highly accurate and reproducible for the evaluation of Ki-67 in NENs. We systematically reviewed all published studies on the subject of Ki-67 assessment in pancreatic NENs (PanNENs) employing digital image analysis (DIA). The most common advantages of DIA were improvement in the standardization and reliability of Ki-67 evaluation, as well as its speed and practicality, compared to the current gold standard approach of manual counts from captured images, which is cumbersome and time consuming. The main limitations were attributed to higher costs, lack of widespread availability (as of yet), operator qualification and training issues (if it is not done by pathologists), and most importantly, the drawback of image algorithms counting contaminating non-neoplastic cells and other signals like hemosiderin. However, solutions are rapidly developing for all of these challenging issues. A comparative meta-analysis for DIA versus manual counting shows very high concordance (global coefficient of concordance: 0.94, 95% CI: 0.83-0.98) between these two modalities. These findings support the widespread adoption of validated DIA methods for Ki-67 assessment in PanNENs, provided that measures are in place to ensure counting of only tumor cells either by software modifications or education of non-pathologist operators, as well as selection of standard regions of interest for analysis. NENs, being cellular and monotonous neoplasms, are naturally more amenable to Ki-67 assessment. However, lessons of this review may be applicable to other neoplasms where proliferation activity has become an integral part of theranostic evaluation including breast, brain, and hematolymphoid neoplasms.

Effects of depth of incision on final outcome in radial keratotomy

OBJECTIVE

To assess the effect of depth of incision on the final outcome of radial keratotomy for correction of myopia.

METHODS

Sixty-five eyes with preoperative uncorrected myopia between 2.5-6.0D in subjects with a mean age of 29.2 (+/-7) years underwent radial keratotomy between Sept 1999-July 2002 in department of Ophthalmology, Military Hospital, Rawalpindi. Based on their preoperative depth of incision the eyes were divided into group-A (twenty-five eyes), with an incision depth of 500-530 microm, and Group-B (forty eyes), with an incision depth of 531-560 microm. The comparison between the postoperative visual acuity of two groups was made at the end of study after one years' follow up.

RESULTS

A total of Sixteen eyes in Group-A (64%) that were within one diopter of emmetropia at first follow-up reverted back to their preoperative myopic state after one year of surgery as compared to only two eyes (5%) in Group-B (p<0.05). Hyperopic shift occurred in two eyes (8%) in Group-A, as compared to four eyes (10%) of Group-B (p>0.05). After one year, refraction showed that only 24% cases of Group-A were within 1 diopter of emmetropia as compared to 85% cases in Group-B. Similarly, 40% cases of Group-A were within 2 diopters of emmetropia as compared to 90% cases of Group-B. Glare and variation of vision in the initial four weeks were the most frequently reported complications in both groups.

CONCLUSION

Depth of corneal incision significantly affects the outcome of surgery, if central optical zone is kept the same in cases of low to moderate degrees of myopia.