Peak Width of Skeletonized Mean Diffusivity as Neuroimaging Biomarker in Cerebral Amyloid Angiopathy

BACKGROUND AND PURPOSE

Whole-brain network connectivity has been shown to be a useful biomarker of cerebral amyloid angiopathy and related cognitive impairment. We evaluated an automated DTI-based method, peak width of skeletonized mean diffusivity, in cerebral amyloid angiopathy, together with its association with conventional MRI markers and cognitive functions.

MATERIALS AND METHODS

We included 24 subjects (mean age, 74.7 [SD, 6.0] years) with probable cerebral amyloid angiopathy and mild cognitive impairment and 62 patients with MCI not attributable to cerebral amyloid angiopathy (non-cerebral amyloid angiopathy-mild cognitive impairment). We compared peak width of skeletonized mean diffusivity between subjects with cerebral amyloid angiopathy-mild cognitive impairment and non-cerebral amyloid angiopathy-mild cognitive impairment and explored its associations with cognitive functions and conventional markers of cerebral small-vessel disease, using linear regression models.

RESULTS

Subjects with Cerebral amyloid angiopathy-mild cognitive impairment showed increased peak width of skeletonized mean diffusivity in comparison to those with non-cerebral amyloid angiopathy-mild cognitive impairment (P < .001). Peak width of skeletonized mean diffusivity values were correlated with the volume of white matter hyperintensities in both groups. Higher peak width of skeletonized mean diffusivity was associated with worse performance in processing speed among patients with cerebral amyloid angiopathy, after adjusting for other MRI markers of cerebral small vessel disease. The peak width of skeletonized mean diffusivity did not correlate with cognitive functions among those with non-cerebral amyloid angiopathy-mild cognitive impairment.

CONCLUSIONS

Peak width of skeletonized mean diffusivity is altered in cerebral amyloid angiopathy and is associated with performance in processing speed. This DTI-based method may reflect the degree of white matter structural disruption in cerebral amyloid angiopathy and could be a useful biomarker for cognition in this population.

cgDNA: a software package for the prediction of sequence-dependent coarse-grain free energies of B-form DNA

cgDNA is a package for the prediction of sequence-dependent configuration-space free energies for B-form DNA at the coarse-grain level of rigid bases. For a fragment of any given length and sequence, cgDNA calculates the configuration of the associated free energy minimizer, i.e. the relative positions and orientations of each base, along with a stiffness matrix, which together govern differences in free energies. The model predicts non-local (i.e. beyond base-pair step) sequence dependence of the free energy minimizer. Configurations can be input or output in either the Curves+ definition of the usual helical DNA structural variables, or as a PDB file of coordinates of base atoms. We illustrate the cgDNA package by comparing predictions of free energy minimizers from (a) the cgDNA model, (b) time-averaged atomistic molecular dynamics (or MD) simulations, and (c) NMR or X-ray experimental observation, for (i) the Dickerson–Drew dodecamer and (ii) three oligomers containing A-tracts. The cgDNA predictions are rather close to those of the MD simulations, but many orders of magnitude faster to compute. Both the cgDNA and MD predictions are in reasonable agreement with the available experimental data. Our conclusion is that cgDNA can serve as a highly efficient tool for studying structural variations in B-form DNA over a wide range of sequences.

[A case of odontoma. Importance of an objective examination]

A case of odontoma which escaped attention at first objective examination and panoramic radiography makes it possible to stress the primary importance of inspection in dental practice.

Cisplatin and etoposide salvage therapy and resection of the residual tumor in pretreated germ cell testicular cancer

Thirty-two consecutive patients with pretreated germinal testis cancer received three to four inductions of cisplatin and etoposide therapy (PE). Patients not pretreated, or only partially pretreated with bleomycin (B), also received this drug for a maximum of 12 doses. Sixteen patients underwent secondary surgery for the removal of residual masses. Twelve (37.5%) entered complete remission (CR) with chemotherapy alone, and an additional 9 cases (28%) were rendered tumor-free by surgery. The 21 disease-free patients (65.5%) received two further inductions and no maintenance. Toxicity was moderate, and 1 of the 16 patients who underwent surgery died postoperatively of pulmonary embolism. After a median follow-up period of 26 months (range, 9-60), 2 patients have died in CR and 15 (47%) are currently alive and have been continuously disease-free. The major determinant of tumor response was prior therapy. Eleven of 14 (78%) patients who were not pretreated with cisplatin achieved a continuous disease-free status versus only 4 of the 18 pretreated patients (22%, P less than 0.01). In this set of cases, complete responders to prior PVB therapy did better than incomplete responders treated for tumor progression. It can be concluded that normal-dose PE +/- B therapy, followed by surgical resection of the residual tumor, is a satisfactory salvage therapy in patients not pretreated with cisplatin and is also active in complete responders to prior PVB therapy.

Early resection of residual tumor during cisplatin, vinblastine, bleomycin combination chemotherapy in stage III and bulky stage II nonseminomatous testicular cancer

Sixty consecutive patients with Stage III or bulky Stage II nonseminomatous germinal testis tumors were treated with cisplatin, vinblastine, bleomycin combination chemotherapy (PVB). One patient died of acute toxicity after the first course of therapy, 16 entered complete remission (CR) after two or three inductions, and 36 underwent surgery for removal of residual masses after the third cycle. No residual tumor was found in 16 cases, 10 had mature teratoma, and residual malignant tumor was completely resected in 8 of 10 patients. On the whole, 52 of 59 cases (88%) who completed the therapy entered CR, 34 (58%) with PVB and 18 (30%) with PVB and resection of the residual disease. The major beneficiaries of surgery were patients with bulky metastases (17 of 45, 38%) and those with primary teratocarcinoma (13 of 24, 54%). All of the patients who entered CR received two additional inductions and no maintenance. After a median follow-up period of greater than 3 years, 40 patients (68%) remain continuously disease-free, 1 died in CR, and 3 of the 11 who had relapse were salvaged. All of the 32 patients with lung deposits less than 5 cm and/or lymph node metastases less than 10 cm entered CR after the combined treatment modality, and 29 (91%) are alive disease-free. Also, 20 of 27 patients (74%) with far-advanced disease (lung and lymph node metastases larger than 5 and 10 cm, respectively, extrapulmonary disease) entered CR after PVB and surgery, but only 11 (41%) are continuously disease-free. Early resection of the residual tumor during PVB combination chemotherapy greatly increased the CR rate, but relapses were very frequent in patients with far-advanced disease.

Relapse pattern of pathologic stage I nonseminomatous germ cell tumors of the testis following orchidectomy and lymphadenectomy

A retrospective analysis of patients with pathologic stage I nonseminomatous germinal testis tumors treated with orchidectomy and retroperitoneal lymphadenectomy was done in an attempt to define the relapse pattern and to eventually identify risk factors predisposing to tumor recurrence. Of 102 patients, 91 (89.2%) remain disease free with a median follow-up of greater than 5 years (range 3-10 years), and 11 (10.8%) suffered relapse 3-35 months after lymphadenectomy (median free interval 6 months). 9 of 11 patients developed primarily intrathoracic recurrences. The tumor was so rapidly progressing at relapse, that it was diagnosed when clinically advanced in 7 of 11 cases. Nevertheless, 8 of 11 patients were salvaged with effective available chemotherapy and resection of residual disease. Only scrotal violation showed a significant increased risk of tumor recurrence (5 of 24 cases, versus 6 of 78 who had inguinal orchidectomy, p less than 0.05). We recommend a very close follow-up for all patients with pathologically assessed stage I nonseminomatous germinal testis tumors during the first 3 years following orchidectomy and retroperitoneal lymphadenectomy. With early recognition of relapse, an approximately 100% cure rate will be achieved with effective available chemotherapy.

The antiemetic effect of methylprednisolone in patients treated with cis-platinum (CDDP) for advanced testicular germ cell tumors

In cis-platinum treatment, nausea and vomiting are very serious side-effects and patients may be reluctant to accept or continue therapy. The purpose of this study is to verify the antiemetic effect of methylprednisolone in patients treated with cis-platinum in combination with other chemotherapeutic agents. Methylprednisolone in doses of 100 mg/m2 i.v. per 5 consecutive days was given to 33 patients receiving cis-platinum combination chemotherapies (134 cycles) at the Istituto Nazionale Tumori of Milan for advanced germ cell tumors of the testis. Seventy percent of cycles were partially or completely protected from vomiting. Only minor side-effects caused by methylprednisolone were observed. From this study it appears that methylprednisolone is an effective antiemetic drug in patients receiving cis-platinum combination chemotherapy.

Retroperitoneal lymphadenectomy and aggressive chemotherapy in nonbulky clinical Stage II nonseminomatous germinal testis tumors

In a former series of 60 resected Stage II nonseminomatous germinal testis tumors the authors succeeded in demonstrating that adjuvant cisplatin, vinblastine, and bleomycin (PVB) was able to significantly improve survival (100% in 11 treated versus 28.5% in 7 historical controls, P less than 0.01) only in patients with retroperitoneal metastases greater than 5 cm, macroscopic extranodal spread, tumor invasion into retroperitoneal veins (pathologic Stage II-C). Forty-eight evaluable patients with clinical nonbulky Stage II nonseminomatous testis cancer underwent retroperitoneal lymphadenectomy as primary treatment. Four courses of postoperative PVB were administered only to 18 clinically understaged patients (14 pathologic Stage II-C, and 4 postoperatively reclassified as Stage III). The remaining 30 patients were followed at monthly intervals. After a median follow-up of 25 months, relapses were: 1 (10%) in 10 pathologic Stage I patients; 8 (40%) in 20 pathologic Stage II-A and II-B; null in the 18 treated. Eight of the nine patients (89%) who had relapse entered continuous complete remission following salvage therapy. The overall 2-year disease-free survival in this case series is 98%. Retroperitoneal lymphadenectomy followed by compulsive follow-up and selective use of aggressive chemotherapy is an alternative to remission induction chemotherapy as primary treatment in clinical nonbulky Stage II nonseminomatous testis cancer, and to immediate adjuvant chemotherapy in all patients with resected Stage II disease.

Adjuvant chemotherapy in resected stage-II nonseminomatous germ cell tumors of testis. In which cases is it necessary?

In an attempt to reduce the recurrence rate and to improve survival in resected stage-II nonseminomatous testicular cancer, two consecutive series of patients were treated with adjuvant vinblastine-bleomycin (VB) continuous infusion, or cisplatin, vinblastine, bleomycin (PVB). 11 former patients who received no adjuvant chemotherapy and 5 who refused the adjuvant treatment were considered historical controls. After a median follow-up of 5 years, relapses were 4 in 15 patients treated with VB (27%), 1 in 29 treated with PVB (3%) and 8 in the untreated (50%). Adjuvant PVB significantly reduced the recurrence rate (p less than 0.001), while VB did not (p = 0.4). However, the advantage of adjuvant PVB was evident only in patients with retroperitoneal metastases larger than 5 cm, macroscopic extranodal spread, and tumor invasion into retroperitoneal veins, who were classified as pathologic stage II-C: no relapse and 100% survival following adjuvant PVB in 11 cases, versus 86% relapses and 28.5% survival in 7 untreated patients (p less than 0.01); 2 relapses and 2 survivors in 3 treated with VB. On the other hand, only 1 of the 39 patients with less extensive retroperitoneal disease died of testicular cancer, and he was in the VB adjuvant treatment group. We conclude that only aggressive adjuvant chemotherapy significantly reduces the recurrence rate and improves survival in resected stage-II nonseminomatous testis cancer. However, it is mandatory only in the very high risk subset II-C of patients, while the others could be carefully followed at monthly intervals and safely treated with aggressive chemotherapy only in the event of relapse.