Gating provides improved accuracy for differentiating artifacts from true lesions in equivocal fixed defects on technetium 99m tetrofosmin perfusion SPECT

BACKGROUND

Because equivocal fixed perfusion defects on single photon emission computed tomography (SPECT) often cause a diagnostic dilemma in patients with suspected coronary artery disease (CAD), we used receiver-operating characteristic (ROC) curve analysis to evaluate the degree of increased accuracy provided by adding gated images for interpretation of such cases.

METHODS AND RESULTS

One hundred five (29%) of 365 consecutive patients undergoing technetium 99m tetrofosmin gated SPECT for evaluation of CAD demonstrated an equivocal fixed defect. Two independent observers graded the probability for true lesion with a 5-point system over 3 steps of interpretation: reviewing tomographic images alone (step 1), adding projection images (step 2), and adding gated cine images (step 3). Based on clinical criteria, 66 patients were categorized as disease negative and 25 as disease positive, while the final diagnosis was undetermined in 14 cases. Diagnostic performance was significantly higher at step 3 than at step 1 for both observers (p < 0.05 and < 0.0001) and at step 2 for observer B (p < 0.005). The maximum accuracy increased from 78.0% to 80.2% at step 2 to 84.6% to 86.8% at step 3. Moreover, the agreement of interpretation between the 2 observers was higher at step 3 (kappa = 0.53) than at step 1 (kappa = 0.29) or step 2 (kappa = 0.25).

CONCLUSION

In patients showing an equivocal fixed defect on 99mTc tetrofosmin SPECT, gated cine images provide improved differential accuracy and enhanced objectivity of interpretation by reducing interobserver variance.

Pheochromocytoma complicated with cardiomyopathy after delivery--a case report and literature review

Pheochromocytoma in pregnancy is very rare but it is associated with very high maternal and fetal mortality. Therefore, it is important to include pheochromocytoma in the differential diagnosis of hypertension associated with pregnancy. It is difficult to make a diagnosis of pheochromocytoma in pregnancy before delivery. The characteristic symptoms of pheochromocytoma could be initiated during delivery because the process of delivery, general anesthesia, fetal movement, induce acute surge of catecholamine release, which could also induce cardiomyopathy. Early diagnosis and intensive care can affect the prognosis of cardiomyopathy induced by pheochromocytoma. Proper management with alpha-blockade, beta-blockade and angiotension converting enzyme inhibitor could acutely reverse the course of cardiomyopathy.

Left main coronary artery dissection after blunt chest trauma presented as acute anterior myocardial infarction: assessment by intravascular ultrasound: a case report

Coronary artery injury after blunt chest trauma is very rare, but this can result in a serious acute myocardial infarction. Coronary artery dissection is an uncommon complication of thoracic injuries. We report a case of a 17-year-old male who was presented with an anterior myocardial infarction following blunt chest trauma after a bicycle accident. His coronary angiography revealed aneurysmal dilatation with dissection of the distal left main stem coronary artery. Intravascular ultrasound showed a dissecting flap at the left main stem coronary artery. The patient was treated conservatively and discharged without serious sequelae. When symptoms and electrocardiographic findings are compatible with acute myocardial infarction, careful evaluation is important in patients with thoracic injuries for proper management. If the patient is stable, medical therapy may be appropriate. But early intervention should be considered in the presence of ongoing myocardial ischemia.

Pleomorphic fibroma of the eyelid

BACKGROUND

This report describes the pathology of an unusual variant of fibroma of the eyelid. The soft ovoid tumour was excised from the centre of the left lower lid in an 84-year-old patient had been growing slowly for several years.

METHODS

The tumour was studied by conventional histology, immunohistochemistry and electron microscopy.

RESULTS

The tumor was formed by fibroblasts of spindle and multinucleate type, and the collagenous stroma contained mast cells and blood vessels which exhibited minor inflammatory changes. With the immunohistochemical methods the only positive marker was for vimentin.

CONCLUSION

On morphological grounds it was possible to distinguish this extremely rare tumour from other mesenchymal tumours. The presence of distinctive multinucleate giant cells makes the term pleomorphic fibroma an appropriate name for this type of lesion.

Distribution of antioxidant enzymes in the normal aged human conjunctiva: an immunocytochemical study

BACKGROUND

The purpose of the study was to map the precise location of four antioxidant enzymes in the normal human conjunctiva.

METHODS

Conjunctival tissue (seventeen specimens) from seven patients was processed for light microscopy and immunogold electron microscopy. Antibodies were used to label glutathione peroxidase, glutathione S-transferase (acidic and neutral forms) and copper/zinc superoxide dismutase.

RESULTS

All layers of the epithelium exhibited labelling for all four enzymes, although there were differences in labelling intensities and distribution between the enzymes. Wing cells showed more intense labelling for glutathione peroxidase, glutathione S-transferase (neutral form) and copper/zinc superoxide dismutase than did basal and superficial cells. The strongest immunoreactivity was detected for glutathione S-transferase (acidic) and was equally strong in the superficial and wing cells. Wing cells demonstrated more immunoreactivity in the cell nuclei with antibodies against all four enzymes. A high degree of labelling was also observed in the microplicae and actin cortex of the superficial cells. Leukocytes, fibroblasts, endothelial cells and erythrocytes within the stroma exhibited minimal labelling.

CONCLUSION

The subtle changes in distribution of antioxidant enzymes in the normal human conjunctival epithelium most probably reflect exposure to free radicals in the tear film and are based on the different proliferative and functional activities of each of the anatomical layers.

Anti-GAD antibodies in Chinese patients with youth and adult-onset IDDM and NIDDM

An autoimmune basis for the pathogenesis of insulin-dependent diabetes mellitus (IDDM) is supported by the frequent presence of autoantibodies - islet cell antibodies (ICAs) and GAD antibodies (GADab). However, in Chinese patients with clinical IDDM, a low prevalence of ICAs was observed. In non-insulin-dependent diabetic (NIDDM) patients, it has been suggested that the presence of GADab may identify a subset of latent autoimmune diabetes in adults (LADA). We determined the frequency of GADab in a large group of 134 IDDM and 168 NIDDM Chinese patients, and assessed the relation with ICAs status. Results showed that 39.6% IDDM and 16.1% NIDDM patients had GADab, and 20.1% and 4.8%, respectively had detectable ICAs. Frequency of GADab positivity was not influenced by whether the patients had youth or adult-onset IDDM or NIDDM, or by duration of diabetes. NIDDM patients seropositive for GADab shared similar clinical characteristics and fasting C-peptide levels with those who were GADab negative. Presence of GADab therefore did not serve to identify a subgroup of patients with latent or slow-onset IDDM. Half (53%) of our IDDM patients had neither GADab nor ICAs. The reason for this observation is unclear. One theory is that other autoantigens yet to be identified may be contributory. Alternatively, in the Chinese, autoimmunity may not be the major factor in the pathogenesis of IDDM.

Changing indications for penetrating keratoplasty in the west of Scotland from 1970 to 1995

In an attempt to predict the trends which might occur in the changing patterns of corneal surgery in the next decade and hence the financial implications, a retrospective study of the treatment of corneal disease was carried out using the pathological reports issued during the last 25 years in the West of Scotland Ophthalmic Pathology Service. This is a supra-regional specialist service which covers the major population areas in Scotland, although most of the specimens were submitted by consultants in the teaching hospitals in Glasgow. The major indications for surgery in the 1486 specimens received were post-inflammatory scarring (387 cases), repeat penetrating keratoplasty (309), keratoconus (257), Fuchs' dystrophy (120) and secondary endothelial failure after cataract surgery (158). In the past 6 years the indications changed and the commonest indications were secondary endothelial failure and post-inflammatory scarring. The study demonstrates a regional difference when compared with other reports and highlights the increasing demand for penetrating keratoplasty and the consequent resource implications.

Polymorphism of angiotensin converting enzyme gene is associated with circulating levels of plasminogen activator inhibitor-1

The deletion (D) allele of the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene is strongly associated with an increased level of circulating ACE. The ACE gene polymorphism may influence the production of angiotensin II (Ang II). It has been shown that Ang II modulates fibrinolysis, that is, Ang II increases plasminogen activator inhibitor-1 (PAI-1) mRNA and plasma PAI-1 levels in vitro and in vivo. Considered together, we tested the hypothesis that the deletion allele of the ACE gene might be associated with increased levels of PAI-1. We related the ACE genotype to PAI-1 antigen levels in 603 men and 221 women attending a routine health screening. As a whole, the plasma PAI-1 level was not strongly associated with ACE genotype. Since the PAI-1 level was significantly influenced by well-known risk factors for coronary artery disease (CAD), we further analyzed the data after excluding subjects with major cardiovascular risk factors. In low-risk male subjects, the DD genotype had significantly higher levels of plasma PAI-1 (DD: 20.3 +/- 2.2; DI: 13.9 +/- 1.1; II: 13.6 +/- 1.3 ng/mL, P = .010 by ANOVA). In low-risk female subjects, the DD genotype showed a tendency to a high level of plasma PAI-1 without statistical significance. When analysis was restricted to postmenopausal women (age > or = 55 or FSH > or = 35 ng/mL), the DD genotype showed a significantly higher level of PAI-1 than subjects with the DI and II genotypes (27.7 +/- 6.2 versus 15.6 +/- 1.8 ng/mL, P = .028). The DD polymorphism of the ACE gene is associated with high PAI-1 levels in male and possibly in postmenopausal female subjects who have lower conventional cardiovascular risk factors. These results suggest that the increased ACE activity caused by DD polymorphism may play an important role in elevating the level of plasma PAI-1. Our data support the notion that the genetic variation of ACE contributes to the balance of the fibrinolytic pathway.

Microvilli elongate in response to hydrogen peroxide and to perturbations of intracellular calcium

Using scanning electron microscopy and fluorescence microscopy, we have found that apical microvilli of diverse cell types, including nonepithelial cells, elongate in culture in response to the oxidative stress of hydrogen peroxide. The microvilli induced in culture on retinal pigment epithelial cells display a 30-nm axial periodicity similar to that described for stable microvilli of intestinal brush border. Microvilli can also be induced to elongate by chelating intracellular Ca2+ and by the Ca(2+)-uptake inhibitor thapsigargin. Thus a response of microvillar protrusion occurs widely and may be related to depletion of intracellular calcium stores.

A histologic study (including DNA quantification and Ki-67 labeling index) in uveal melanomas after brachytherapy with ruthenium plaques

PURPOSE

To investigate the proliferative potential and DNA damage in uveal melanomas treated by brachytherapy.

METHODS

Forty-two enucleated eyes that had been treated with 106Ru/106Rh radioactive plaques for uveal melanoma were subgrouped according to the extent of irradiation damage. Cell proliferation was determined by immunoreactivity for the proliferation marker Ki-67 (Mib-1) and ploidy by quantitative DNA image analysis. Thirty globes containing uveal melanomas without prior brachytherapy served as a control group.

RESULTS

The values for Ki-67 reactivity and ploidy could be correlated with radiation-induced changes within the tumors. In regions of the tumor where complete exposure to the prescribed radiation dose was assumed from the histologic findings, the Ki-67 index was close to or equal to zero. Hypoploidy was exclusive to irradiated tumors and was most often detected in effectively irradiated regions. Tumor regions classified as partially irradiated or recurrent showed an increase of Ki-67 indices and DNA content. Values obtained in recurrent tumors did not significantly differ from the control group.

CONCLUSIONS

Tumor cell proliferation and variations in ploidy status could be detected after brachytherapy, but the response varied markedly both within individual tumors and within the irradiated group. Evidence of persisting proliferative potential could be obtained in ostensibly sterilized tumor tissue, but a negligible Ki-67 index and the presence of hypoploidy were considered to be reliable indicators for radiation-induced loss of proliferative potential.

A novel pattern of oculocerebral malformation

AIMS/BACKGROUND

To report a novel pattern of oculocerebral malformation related to the group of diseases characterised by cobblestone lissencephaly.

METHODS

By means of a case report with specialist descriptions of the novel neuropathological and ophthalmic pathology features.

RESULTS

The patient, born to healthy consanguineous parents, presented in the neonatal period with jaundice, convulsions, and macrocephaly. Computed tomography demonstrated hydrocephalus and abnormal cerebral gyration. Ophthalmic examination revealed severe myopia and segments of retinal atrophy. Cytogenetic investigation revealed a balanced reciprocal translocation (46,XX,t(5p11;19q13.1)) that was inherited from the mother and was present in several normal relatives. Mild short stature and profound mental handicap were evident. The child died aged 7 years. At necropsy the brain showed 'cobblestone' (type II) lissencephaly. Cerebellar cortical architecture was abnormal and the brain stem lacked cerebral peduncles, basis pontis, and pyramids. Biopsies of skeletal muscles were normal. The ocular abnormalities included discrete sectors of retina of varying thickness with disordered neuronal lamination and gliosis. The optic nerve was gliotic and contained few nerve fibres. The anterior iris surface was studded with cellular stromal nodules which appear to be melanocytic in nature.

CONCLUSION

Retinal dysgenesis occurs in the group of syndromes with 'cobblestone lissencephaly', the best known being Walker-Warburg syndrome. In this case, relatively long survival, lack of muscular dystrophy, and novel ocular pathology distinguish it from the other diagnoses in this group of syndromes. We suggest this child was affected by a distinct and novel oculocerebral syndrome.

Initial clinical assessment of CT-MRI image fusion software in localization of the prostate for 3D conformal radiation therapy

PURPOSE

To assess the utility of image fusion software and compare MRI prostate localization with CT localization in patients undergoing 3D conformal radiation therapy of prostate cancer.

MATERIALS AND METHODS

After a phantom study was performed to ensure the accuracy of image fusion procedure, 22 prostate cancer patients had CT and MRI studies before the start of radiotherapy. Immobilization casts used during radiation treatment were also used for both imaging studies. After the clinical target volume (CTV) (prostate or prostate + seminal vesicles) was defined on CT, slices from the MRI study were reconstructed to precisely match the CT slices by identifying three common bony landmarks on each study. The CTV was separately defined on the matched MRI slices. Data related to the size and location of the prostate were compared between CT and MRI. The spatial relationship between the tip of urethrogram cone on CT and prostate apex seen on MRI was also estimated.

RESULTS

The phantom study showed the registration discrepancies between CT and MRI smaller than 1.0 mm in any pair in comparison. The patient study showed a mean image registration error of 0.9 (+/- 0.6) mm. The average prostate volume was 63.0 (+/- 25.8) cm3 and 50.9 (+/- 22.9) cm3 determined by CT and MRI, respectively. The difference in prostate location with the two studies usually differed at the base and at the apex of the prostate. On the transverse MRI, the prostate apex was situated 7.1 (+/- 4.5) mm dorsal and 15.1 (+/- 4.0) mm cephalad to the tip of urethrogram cone.

CONCLUSIONS

CT-MRI image fusion study made it possible to compare the two modalities directly. MRI localization of the prostate is more accurate than CT, and indicates the distance from cone to apex is 15 mm. CT-MRI image fusion technique provides valuable supplements to CT technology for more precise targeting of the prostate cancer.

Neck failure in T2N0 squamous cell carcinoma of the true vocal cords: the Fox Chase experience and review of the literature

There is a need for additional data in the literature regarding elective nodal irradiation in the treatment of T2N0 squamous cell carcinoma of the glottic larynx. We examined the experience at the Fox Chase Cancer Center and performed a literature review in order to define a treatment policy. Sixteen patients with T2 squamous cell carcinoma of the glottic larynx were treated with radiation therapy. Ten patients were irradiated to the larynx alone and six to the larynx and regional nodes. None of the patients in our series experienced a nodal recurrence regardless of whether the neck was electively irradiated. A literature review of 413 patients revealed that 2.6% of patients who did not have their nodes electively irradiated and had their primary tumor controlled experienced a nodal failure compared to 3.7% if the primary and regional nodes were irradiated (P = 0.88). Similarly, there was no significant difference in the rate of nodal failure for patients who experienced a recurrence at the primary site regardless of whether they received elective nodal irradiation (P = 0.36). We recommend treatment to the larynx alone since our policy is to treat the regional nodes only when the incidence of occult lymphadenopathy in the neck exceeds 15%.

Cardiac tamponade due to a rupture of the coronary arteriovenous aneurysm--a case report

We experienced an unusual case of cardiac tamponde caused by a rupture of the coronary arteriovenous aneurysm in a 54-year-old woman. The patient was suffered from sudden chest pain and syncope, and was initially managed by pericardiocentesis following an echocardiogram which revealed a massive pericardial effusion with signs of cardiac tamponade. She was referred to our hospital under the impression of aortic dissection with cardiac tamponade. She underwent an emergency operation and was found to have a 2 x 2 cm sized bleeding cystic mass protruding from the proximal anterior descending coronary artery. The aneurysm was excised and the openings connected with the coronary artery and right ventricular outflow tract were closed with sutures from the inside of aneurysm. Subsequent coronary arteriography supported the diagnosis.

Optimization of conformal radiation treatment of prostate cancer: report of a dose escalation study

PURPOSE

The development of conformal radiation technique including improved patient immobilization has allowed us to test the value of dose escalation in optimizing the radiation treatment of prostate cancer.

METHODS AND MATERIALS

Outcome is reported for 233 consecutive patients treated with conformal technique between March 1989 and October 1992. Dose was escalated from 68 Gy to 79 Gy. Patient status is reported at 3 years follow-up, which is available in all alive patients. Pretreatment and serial posttreatment prostate specific antigen (PSA) values are available for all patients. Biochemical freedom of disease (bNED) defines failure as PSA > 1.5 ngm/ml and rising on two consecutive measures. Dose response for bNED control of cancer and late morbidity are represented by logit response models fitted to the data. Kaplan-Meier methods, the log rank test, and Cox Regression models are also used.

RESULTS

No dose response is observed for bNED survival for patients with pretreatment PSA <10 ngm/ml comparing patients treated above or below 71.5 Gy or on multivariate analysis. Dose response is observed for bNED survival for pretreatment PSA groups of 10-19.9 ngm/ml and 20+ ngm/ml. The dose associated with 50% bNED survival at 3 years is 64 Gy and 76 Gy, respectively. The slope of the dose responses are 13 and 9%, respectively. Dose response is demonstrated for Grade 2 gastrointestinal (GI), Grade 2 genitourinary (GU), and Grade 3,4 combined GI and GU late morbidity. The slopes of the morbidity responses are steeper than for cancer control (19 to 21%).

CONCLUSIONS

Patients with pretreatment PSA < 10 ngm/ml do not benefit from dose escalation, and the serious late morbidity of conformal radiation at 70 Gy is < 3%. Patients with PSA values 10-19.9 ngm/ml and 20+ ngm/ml benefit from dose escalation beyond 70 Gy. Treatment beyond 75 Gy results in > 10% serious morbidity unless special precautions are taken to protect the rectal mucosa. All levels of severity of radiation morbidity show a dose response and combined with the dose response for bNED survival these data allow the optimization of treatment.

Late GI and GU complications in the treatment of prostate cancer

PURPOSE

To assess the factors that predict late GI and GU morbidity in radiation treatment of the prostate.

METHODS AND MATERIALS

Seven hundred twelve consecutive prostate cancer patients treated at this institution between 1986 and 1994 (inclusive) with conformal or conventional techniques were included in the analysis. Patients had at least 3 months follow-up and received at least 65 Gy. Late GI Grade 3 morbidity was rectal bleeding (requiring three or more procedures) or proctitis. Late Grade 3 GU morbidity was cystitis or stricture. Multivariate analysis (MVA) was used to assess factors related to the complication-free survival. The factors assessed were age, occurrence of side effects > or = Grade 2 during treatment, irradiated volume parameters (use of pelvic fields, treatment of seminal vesicles to full dose or 57 Gy, and use of additional rectal shielding), dose, comorbidities, and other treatments (hormonal manipulation, TURP).

RESULTS

Acute GI and GU side effects (Grade 2 or higher) were noted in 246 and 201 patients, respectively; 67 of these patients exhibited both. GI side effects were not correlated with GU side effects acutely. Late and acute morbidities were correlated (both GI and GU). Fifteen of the 712 patients expressed Grade 3 or 4 GI injuries 3 to 32 months after the end of treatment, with a mean of 14.3 months. One hundred fifteen patients expressed Grade 2 or higher GI morbidity (mean: 13.7 months). The 43 Grade 2 or higher GU morbidities occurred significantly later (mean: 22.7 months). Central axis dose was the only independent variable significantly related to the incidence of late GI morbidity on MVA. No treatment volume parameters were significant for Grade 3. The following parameters were significantly related (by MVA) to Grade 2 GI morbidity: central axis dose, use of the increased rectal shielding, androgen deprivation therapy starting before RT. Acute and late GI morbidities were highly correlated. History of diabetes, treatment of pelvic nodes, and age less than 60 years were significantly related to acute GI side effects. The parameters significantly related to late Grade 2 or higher GU morbidity were central axis dose, androgen deprivation therapy (Zoladex or Lupron) prior to radiation therapy (RT), history of obstructive symptoms, and acute GU side effects. There were too few late Grade 3 GU morbidities to perform multivariate analysis. Acute GU side effects were highly correlated with late GU injury. The following were correlated with acute GU side effects: history of diabetes (+), treatment with conformal fields (-), TURP before RT (-), presentation with urinary obstructive symptoms.

CONCLUSION

Both late GI and GU morbidity demonstrate a dose dependence, but only the volume dependence observed is a reduction in late Grade 2-4 GI morbidity by increasing the rectal shielding in the lateral fields for the final 10 Gy. Moreover, both late GI and GU morbidity was increased in patients treated with hormone manipulation prior to RT. GI and GU injuries were correlated with their corresponding acute side effects. GI and GU complications must not be combined for analysis to determine the factors related to their occurrence.

Evidence of increased failure in the treatment of prostate carcinoma patients who have perineural invasion treated with three-dimensional conformal radiation therapy

BACKGROUND

The detection of perineural invasion (PNI) in the diagnostic transrectal biopsy of the prostate is associated with a 93% frequency of extracapsular disease extension in patients treated by prostatectomy for adenocarcinoma of the prostate. Extracapsular extension is associated with an inferior outcome compared with that of patients who have organ-confined disease. This study examined the association of PNI and treatment failure in a consecutive series of patients treated with three-dimensional conformal radiation therapy (3DCRT) alone.

METHODS

The authors report actuarial biochemical no evidence of disease (bNED) survival rates for 484 consecutive patients with clinically localized prostate carcinoma diagnosed by transrectal needle biopsy who completed 3DCRT alone between May 1989 and December 1994. The median follow-up time was 28 months (range, 2-75 months), and the median dose to the center of the prostate was 7368 centigray (cGy) (range, 6316-8074 cGy). Patients were subdivided into 2 groups according to pretreatment prostate specific antigen (PSA) levels (< 20 ng/mL vs. > or = 20 ng/mL). Pathology records were reviewed for the presence or absence of PNI. bNED failure was defined as a PSA level > or = 1.5 ng/mL and rising on 2 consecutive occasions. bNED survival rates were calculated using Kaplan-Meier methodology and comparisons of survival curves were accomplished using the log rank test.

RESULTS

The 3-year bNED survival for all 484 patients was 77%. The presence of PNI predicted decreased bNED survival in all patients. This detrimental effect, however, was confined to patients with pretreatment PSA values < 20 ng/mL. The bNED survival rates for patients with pretreatment PSA < 20 ng/mL demonstrated a highly significant decrease if PNI was present versus when it was absent (65% vs. 88% at 3 years, 39% vs. 65% at 5 years; P = 0.0009 for overall curve comparison). For patients with pretreatment PSA < 20 ng/mL, multivariate analysis of prognostic variables demonstrated a significant association between bNED survival and PNI (P = 0.002), palpation stage (P = 0.02), and pretreatment PSA (P = 0.006). Gleason score, age, and dose were not independent predictors of bNED survival in this group of patients.

CONCLUSIONS

To the authors' knowledge, this is the first report demonstrating that PNI detected on diagnostic transrectal biopsy is a significant predictor of decreased bNED survival in patients treated with radiotherapy. The subgroup of patients affected are those with pretreatment PSA < 20 ng/mL. This result suggests that such patients may benefit from more aggressive treatment, particularly the use of larger planning target volumes or adjuvant therapies.

Increasing prostate-specific antigen profile following definitive radiation therapy for localized prostate cancer: clinical observations

PURPOSE

To examine the natural history of patients who have received definitive radiation therapy alone for clinically localized prostate cancer and have an increasing prostate-specific antigen (PSA) profile.

PATIENTS AND METHODS

One hundred fifty-one men with an increasing PSA profile after definitive radiotherapy were identified. The subsequent natural history of these men, including local recurrence, distant metastasis, and survival, was examined. In 119 men, posttreatment PSA doubling times (PSADT) were calculated using linear regression. Cox regression models were used to examine the effect of clinical and treatment variables on clinical failure and survival.

RESULTS

Patients with high pretreatment PSA values, high Gleason scores, and T3 tumors were more likely to develop a PSA elevation. The median calculated post-treatment PSADT was 13 months, and 95% of patients had posttreatment PSADT of less than 3 years. PSADT was correlated with tumor stage and Gleason score. Five years after PSA elevation, the estimated rate of clinical local recurrence is 26% and the estimated rate of distant metastases is 47%. Rapid PSADT (< 12 months) and a short interval from the end of treatment to PSA elevation (< 12 months) were significant independent predictors of distant metastases. The estimated rates of overall and cause-specific survival 5 years after PSA elevation are 65% and 76%, respectively. Gleason grade is the only significant independent predictor of overall and cause-specific survival after PSA elevation.

CONCLUSION

The natural history of men who have an increasing PSA profile following definitive radiotherapy is heterogeneous. In the absence of salvage therapy, at least three quarters of men will have clinical evidence of recurrent disease 5 years after a PSA elevation is detected. Men with a rapid posttreatment PSADT and a short interval from the end of treatment to an increasing PSA profile are at a very high risk of developing distant metastasis within 5 years of PSA elevation.

Short communication: CT-MRI image fusion for 3D conformal prostate radiotherapy: use in patients with altered pelvic anatomy

We describe the application of CT-MRI fusion software for 3D conformal radiotherapy in two patients with localized prostate cancer who had significantly altered pelvic anatomy due to prior surgery. Patient A had a hemipelvectomy for fibrosarcoma and Patient B had an abdominoperineal resection (APR) for rectal carcinoma. Using the Picker AcQSIM 3D treatment planning software equipped with CT-MRI fusion capabilities, we were able to construct 3D conformal treatment plans for the two patients. The CT-MRI fusion was invaluable in the 3D conformal treatment planning of these cases with distorted pelvic anatomy. It allowed for accurate identification of the clinical target volume (CTV) and was also able to better visualize normal structures so that the radiation beams could be placed to minimize toxicity to the normal tissues.

Keratokyphosis in rabbits: a functional and morphologic study

Keratokyphosis, a "nonfreeze keratomileusis" procedure, was applied in rabbits. The refractive changes were -6.5 +/- 0.7 (SD), -9.5 +/- 2.6, and -13.0 +/- 3.2 D for convex applanation surfaces with a vertex of +100 microns, +125 microns, and +150 microns in the microkeratome and +1.5 +/- 2.0 and +2.5 +/- 2.6 D for concave applanation surfaces with a vertex of -100 microns and -125 microns. The pachymetric corneal changes were +43 +/- 24 microns, +39 +/- 32 microns, and +71 +/- 24 microns for the convex applanation surfaces and -21 +/- 40 microns and -17 +/- 24 microns for the concave. Wound healing was uncomplicated. The scar at the interface was 0-5 microns wide. The mean central density of nerve endings was 1,255 +/- 532/mm2. The endothelial cell size was 25.1% (p < 0.01) greater as measured by specular microscopy than by vital preparation technique; this difference was greater with higher (33.4%) than with lower (18.02%) corneal refraction (p = 0.02). In addition, there was a method-independent correlation (correlation coefficient, -0.63) between endothelial cell count and corneal thickness. This may indicate an increased demand on corneal endothelium in thickened corneas.