Computed tomography 21 days after chemotherapy, three‐dimensional estimates of metastatic volume and the need for surgery in patients with germ cell cancer

Abstract

Objective To assess whether the response visible on computed tomography (CT) 21 days after the ®rst course of chemotherapy in patients with nonseminomatous germ cell tumour predicts the need for surgery and whether three-dimensional (3D) reconstruction adds to the diagnostic accuracy. Patients and methods CT scans from 52 patients treated with cisplatin-based chemotherapy were assessed for tumour shrinkage by measuring the changes of a onedimensional (1D) measurement of the maximum transverse diameter, and comparing CT scans before, 21 days after the ®rst course and at the end of chemotherapy (1D method). In a subset of patients, using a special formula, the 1D-derived 2D and 3D shrinkage (2D der and 3D der ) were compared with four other computed or calculated methods (1D, 2D, 3D calc , 3D comp ).Results At day 21, in 32 of 52 patients (62%) there was <50% tumour shrinkage using the 1D assessment; 21 of them (66%) needed surgery, compared with none of the 20 patients with >50% tumour shrinkage by day 21 (x 2 =22.83, P<0.001). The 1D method showed signi®cantly less shrinkage than all the other methods but when this was used to derive a 3D shrinkage, assuming the mass to be spherical (3D der ), it was not statistically different from that of 3D comp . Conclusions The assessment of the response from 1D CT scan estimates 21 days after initiating chemotherapy identi®es a subgroup of patients who have a high probability of needing surgery. Although expected to be more accurate, the 3D comp estimate of tumour shrinkage was no better than the 3D der estimate.

Tumor response to chemotherapy: The validity and reproducibility of RECIST guidelines in NSCLC patients1

“…Simple tridimensional volume measurements can be as accurate as area volume measurements. 9,10) This was reflected in our study, in which tridimensional volume measurements and area volume measurements were highly correlated (all cases 0.98/measurable cases 0.97).…”

Stage migration and pilot studies of reduced chemotherapy supported by positron‐emission tomography findings suggest new combined strategies for stage 2 nonseminoma germ cell tumour

“…The five patients who had surgery after two courses show that there might be a substantial proportion in whom the need for surgery can be identified early enough to avoid having to give the third or fourth cycle of chemotherapy. Reports from our group have shown that CT at 21 days can predict the need for retroperitoneal surgery after one cycle [8]. Truncating chemotherapy to two instead of three cycles might be safe in such patients when combined with surgery after treatment.…”

“…Limited CT was used at 21 days in patients treated by one of the authors (R.T.D.O.). since 1990, according to protocols published elsewhere [8]. PET was used either on a full‐ring bismuth germanate PET‐only scanner or a full‐ring bismuth germanate, four‐slice PET/CT scanner, when capacity was available for selected patients during the last 12 months.…”

“…The justification for three courses of chemotherapy in IGCCCG good‐risk patients is based on two trials [6,7] involving 188 and 812 patients, with overall 91% vs 90% relapse‐free survival for three vs four courses, with only 19% having surgery after chemotherapy. Recent reports from the Anglian Germ Cell Cancer Group (AGCCG) showed that most of the 62% failing to show a response on CT at 21 days after the first course of chemotherapy needed retroperitoneal surgery after three cycles [8].…”

Volumetry of hepatic metastases in computed tomography using the watershed and active contour algorithms

“…A more ambiguous result was obtained for a study involving nonseminomatous germ cell tumors where no significant difference was found between a volumetric of tumor shrinkage and tumor shrinkage calculated from a uni-dimensional measurement using a spherical model [7]. A similar result was obtained in a study involving germ cell cancer and lymphoma [8].…”