Magnetic Resonance Imaging Grading of Pituitary Macroadenoma- SIPAP Classification Revisited.

BACKGROUNDMagnetic resonance imaging (MRI) is regarded as the modality of choice in diagnosis of pituitary adenomas. Since surgery is the first line therapy for all pituitary adenomas with exception of prolactinoma, simple and reproducible MRI classification based on major directions of tumour growth is an essential tool providing the exact road map for right surgical approach and maximum safe resection.SIPAP MRI classification for pituitary adenomas is derived from KNOSP-STEINER classification of parasellar growth, to which has been added grading for superior, inferior, anterior and posterior tumour extension.We, therefore, propose to incorporate SIPAP classification in routine reporting template of pituitary adenomas, for ideal radiological description of tumour delineation, relationship to juxtasellar structures, and tumour size, hence facilitating greater success rate in surgical and subsequent clinical management.METHODSTwo radiologists retrospectively reviewed imaging of 49 patients with biopsy-proven pituitary macroadenoma and graded according to SIPAP classification. Study was conducted at Aga Khan University Hospital from 1st July 2019 to 30th June 2020. Data was analyzed using Stata version 15. Interobserver variability was calculated using Cohen’s Kappa. Comparison between grading before and after treatment was performed by Chi-square test. P values <0.05 were considered statistically significant.RESULTSSixty three percent patients were male and 37% female. Overall, maximum preoperative and postoperative volume was 71.82 cm3 and 49.50 cm3 respectively, with significant difference in pre and post-operative volumes (14.1±17.7 vs. 4.5±10.4, p-value <0.001). Length showed most significant difference pre and post-operatively (2.4±1.1 vs. 1.3±1.1, p-value <0.001). Individual tumour extensions according to SIPAP for pre- and post-operative grading showed significant difference (p-value <0.001), except for anterior extension. For suprasellar extension, 67.3% patients had pre-operative grade 3 and 63.3% had post-operative grade 0. For infrasellar extension, 51.0% had pre-operative grade 2 and 71.4% had post-operative grade 0. Anterior, posterior and parasellar extensions showed increased frequency in grade 0 in post-operative stage compared to pre-operative. Substantial inter-observer agreement was achieved for Superior, Inferior, Anterior and Posterior extent with all Kappa statistics values above 0.7 (p-value <0.001).CONCLUSIONWe propose incorporating simple and objective SIPAP classification in routine MR reporting for ideal pituitary tumour delineation, relationship to juxtasellar structures and tumour size.

Fluorescence-guided surgery using indocyanine green in dogs with superficial solid tumours

BackgroundNear-infrared fluorescence (NIRF) imaging is a relatively novel technique that can aid surgeons during intraoperative tumour identification.MethodsNine canine oncology patients (five mammary gland tumours, three mast cell tumours and one melanoma) received intravenous indocyanine green (ICG). After 24 hours, tumours were resected and fluorescence intensities of tumours and surroundings were evaluated. Additional wound bed tissue was resected if residual fluorescence was present after tumour resection. Ex vivo, fluorescence-guided dissection was performed to separate tumour from surrounding tissue.ResultsIntraoperative NIRF-guided tumour delineation was feasible in four out of nine dogs. Wound bed imaging after tumour removal identified nine additional fluorescent lesions, of which four contained tumour tissue. One of these four true positive in vivo lesions was missed by standard-of-care inspection. Ex vivo fluorescence-guided tumour dissection showed a sensitivity of 72 per cent and a specificity of 80 per cent in discriminating between tumour and surrounding tissue.ConclusionThe value of ICG for intraoperative tumour delineation seems more limited than originally thought. Although NIRF imaging using ICG did identify remaining tumour tissue in the wound bed, a high false positive rate was also observed.