CT findings of chemotherapy-induced toxicity: what radiologists need to know about the clinical and radiologic manifestations of chemotherapy toxicity

Cancer chemotherapy has evolved from cytotoxic agents and now includes several new agents that target specific molecules responsible for the regulation of cell growth, nutrient supply, and differentiation. These molecularly targeted therapies have a different mechanism of action than do classic cytotoxic agents, which predominantly attack rapidly proliferating cells. Not surprisingly, therefore, the toxicity of targeted and cytotoxic agents may differ in both clinical and radiologic presentation. Many of the toxicities of targeted therapies are not cumulative or dose dependent, some are asymptomatic, and others may first manifest radiologically. It is imperative that radiologists be aware of these toxicities and that they learn to recognize the relevant findings so that they can provide a complete differential diagnosis and thus play an important role in patient care.     

Globalization of P4 medicine: predictive, personalized, preemptive, and participatory--summary of the proceedings of the Eighth International Symposium of the International Society for Strategic Studies in Radiology, August 27-29, 2009

In August 2009, the International Society for Strategic Studies in Radiology held its eighth biennial meeting. The program focused on the globalization of predictive medicine--or P4 medicine--as it relates to the practice of radiology and radiology research. P4 medicine refers to predictive, personalized, preemptive, and participatory medicine and was the inspiration of Elias Zerhouni, MD, former director of the National Institutes of Health. This article is a summary of some of the key concepts presented at the meeting by an international group of radiologists, imaging scientists, and leaders of industry. In predictive medicine, imaging and imaging-related technologies will likely play an increasing role in the early detection of disease and, thus, the preemption of the development of advanced, hard-to-treat disease. Research into systems biology and molecular imaging promises to personalize medicine, facilitating the provision of the right care to the right patient at the right time. In participatory medicine, increasing interactions with referring physicians and patients will be helpful in raising awareness and recognition of the role of radiologists and will have a positive effect on professionalism. There is also a need to increase awareness of the vital role of radiologists as imaging and radiation safety experts who evaluate the necessity and appropriateness of examinations, monitor performance quality, and are available for postexamination consultations.     

Selective inhibition of cyclooxygenase-2 attenuates nitroglycerin-induced calmodulin-dependent protein kinase II alpha in rat trigeminal nucleus caudalis

The nitric oxide donor, nitroglycerin (NTG) can trigger a migraine attack, after a delay of several hours in migraineurs, but not in healthy people. This long delay does not favor a pure vasodilatatory action. In rats, subcutaneous administration of NTG (10 mg/kg) significantly and selectively increases the number of calmodulin-dependent protein kinase II alpha (CamKIIα)-immunoreactive neurons in the trigeminal caudal nucleus (TNC) after 4 h. The aim of our study was to determine if any isoforms of the cyclooxygenase (COX) enzyme might have a role in the NTG-induced increase of CamKIIα expression. In our experiments, we demonstrated that pretreatment with NS398, the selective COX-2 inhibitor attenuated the NTG-induced CamKIIα expression in the TNC at doses of 3 and 5 mg/kg. In contrast, SC560, a selective COX-1 inhibitor failed to modulate this phenomenon in any of the dosages used (1, 5 and 10 mg/kg). These findings suggest that COX-2, but not COX-1 derived metabolites are important factors in the NTG-induced CamKIIα expression. Thus this isoform may play a significant role in the induction of migraine. These data could help in the better understanding of the pathogenesis of headaches and the action of antimigraine drugs.     

Magnetic resonance imaging in the prediction of biochemical recurrence of prostate cancer after radical prostatectomy

OBJECTIVE

To investigate whether magnetic resonance imaging (MRI) findings, when converted into a scoring system, can predict the biochemical recurrence of prostate cancer after radical prostatectomy (RP).

PATIENTS AND METHODS

Between January 2000 and October 2004, 610 patients with biopsy‐confirmed prostate cancer had MRI before RP, with whole‐mount step‐sectioning of the pathology sample. MRI findings were retrospectively scored on a seven‐point scale based on Tumour‐Node‐Mestastasis staging (1, no tumour seen, to 7, lymph node metastasis). MRI scores were added to published 5‐ and 10‐year clinical preoperative nomograms for predicting recurrence. The predictive accuracy of MRI was quantified as the differences in bootstrap‐corrected concordance indices of the models with and without MRI.

RESULTS

As of August 2007, 64 (10.5%) patients had a biochemical recurrence. MRI scores were associated with recurrence (P < 0.001) with hazard ratios of 1.76 and 1.81 in the 5‐ and 10‐year models, respectively. Actual recurrence rates by MRI score were: 1, 0%; 2, 4.5%; 3, 9%; 4, 24.1%; 5, 33.3%; 6, 69.2%; 7, 100%. When MRI was added, the concordance indices of the 5‐ and 10‐year models increased, from 0.762 to 0.776 (P = 0.081) and 0.773 to 0.788 (P = 0.107), respectively; the improvement was not significant.

CONCLUSION

The MRI scoring system devised was a strong predictor of biochemical recurrence after RP. Although MRI did not provide added prognostic value to standard clinical nomograms, in centres where MRI is used routinely, it might increase the confidence of the clinician in assessing the risk of recurrence by contributing supporting data.     

Structural whole‐brain covariance of the anterior and posterior hippocampus: Associations with age and memory

The hippocampus (HC) interacts with distributed brain regions to support memory and shows significant volume reductions in aging, but little is known about age effects on hippocampal whole‐brain structural covariance. It is also unclear whether the anterior and posterior HC show similar or distinct patterns of whole‐brain covariance and to what extent these are related to memory functions organized along the hippocampal longitudinal axis. Using the multivariate approach partial least squares, we assessed structural whole‐brain covariance of the HC in addition to regional volume, in young, middle‐aged and older adults (n = 221), and assessed associations with episodic and spatial memory. Based on findings of sex differences in both memory and brain aging, we further considered sex as a potential modulating factor of age effects. There were two main covariance patterns: one capturing common anterior and posterior covariance, and one differentiating the two regions by capturing anterior‐specific covariance only. These patterns were differentially related to associative memory while unrelated to measures of single‐item memory and spatial memory. Although patterns were qualitatively comparable across age groups, participants' expression of both patterns decreased with age, independently of sex. The results suggest that the organization of hippocampal structural whole‐brain covariance remains stable across age, but that the integrity of these networks decreases as the brain undergoes age‐related alterations.