Biomedical subjects

J Damilakis

Publications and source records attributed to J Damilakis.

49 records · Page 3Linked to original sources

PubMed1997

Effect of the menstrual cycle on gallbladder fasting volume and postprandial emptying in nulliparous young females.

RATIONALE AND OBJECTIVES: Reports on the effect of the ovulatory cycle on gallbladder motility are inconsistent. The authors investigated the gallbladder motor function at both phases of the menstrual cycle in humans. METHODS: Seventeen young, healthy, nulliparous women participated in the study. Gallbladder fasting volume and postprandial emptying were measured twice in each subject using real-time ultrasonography: one at the follicular (12th-13th day) and another at the luteal (21st-22nd day) phases. From the emptying curves, the duration of the lag phase and the ejection fraction of emptying were calculated. RESULTS: Fasting volume was significantly greater (P = 0.025) at the luteal (14.8 +/- 8 mL standard deviation [SD]) than at the follicular (11.2 +/- 4.7 mL SD) phase. Although the lag phase duration was longer (P = 0.009) at the follicular (5.2 +/- 6.4 SD minutes) than the luteal (1.6 +/- 3.6 minutes SD) phase, the ejection fraction was significantly greater at the latter one (follicular phase: 62 +/- 13.2% SD; luteal phase: 73.4 +/- 14% SD; P = 0.0085). CONCLUSIONS: Female sex hormones seem to biologically affect the gallbladder motor function.

Adult↗

PubMed1996

The impact of overall treatment time on the results of radiotherapy for nonsmall cell lung carcinoma.

PURPOSE: We evaluated the impact of overall treatment time on the disease-free survival (DFS) and local control after radiotherapy for nonsmall cell lung carcinoma. METHODS AND MATERIALS: One hundred fifty-three cases considered as responders to radiotherapy were retrospectively analyzed. Patients with Karnofsky status < 70, pretreated with chemotherapy and with pleural or pericardial effusion, were excluded from the analysis. Radiation dose homogenization was done with calculation of the normalized total dose without (NTD) and with time correction (NTD-T) for alpha/beta = 10 Gy. RESULTS: Kaplan-Meier curves for 2-year DFS showed that any analysis based on radiation dose can prove to be erroneous when the time factor is neglected. Although there was no difference between the 47-55 Gy and 56-64 Gy NTD groups, a log rank test revealed a strong difference (p < 0.0002) between NTD-T groups. No difference was observed for patients with mediastinal involvement. Logistic regression analysis showed a statistical association of dose on 2-year local progression-free probability for different time compartments. For those cases without mediastinal involvement, the daily dose lost because of treatment protraction beyond 20 days after the beginning of radiotherapy was estimated to 0.2 Gy/day. When all cases were considered together this was calculated to 0.45 Gy/day. CONCLUSION: Time factor should not be underestimated when evaluating the results of radiotherapy for nonsmall cell lung cancer. There is strong evidence that prolonged overall treatment time could be a major cause of the failure of radiotherapy to control the local disease.

Carcinoma, Non-Small-Cell Lung↗

PubMed1996

Accidental embryo irradiation during barium enema examinations. An estimation of absorbed dose.

RATIONALE AND OBJECTIVES: To investigate the possibility of an embryo to receive a dose of more than 10 cGy, the threshold of malformations induction in embryos reported by the International Commission on Radiological Protection, during barium enema examinations. METHODS: Thermoluminescent dosimeters were placed in a phantom to calculate the depth-to-skin conversion coefficient needed for dose estimation at the average embryo depth in patients. Barium enema examinations were performed in 20 women of childbearing age with diagnostic problems demanding longer fluoroscopy times. Doses at 6 cm, the average embryo depth, were determined by measurements at the patients' skin followed by dose calculation at the site of interest. RESULTS: The range of doses estimated at embryo depth for patients was 1.9 to 8.1 cGy. The dose always exceeded 5 cGy when fluoroscopy time was longer than 7 minutes. CONCLUSION: The dose at the embryo depth never exceeded 10 cGy. This study indicates that fluoroscopy time should not exceed 7 minutes in childbearing-age female patients undergoing barium enema examinations.

Abnormalities, Radiation-Induced↗

PubMed1996

Functional imaging of tumours with 99Tcm-sestamibi pinhole scintigraphy.

This study presents the advantages of pinhole over parallel-hole scintigraphy in the assessment of 99Tcm-sestamibi-related tumour biology. Twenty-five patients with malignancies underwent 99Tcm-sestamibi scintigraphy (Cardiolite, Dupont) before radiotherapy, 10 of whom had repeat scintigrams after the delivery of 25 Gy and at the end of radiotherapy. A total of 45 scintigrams with parallel-hole and pinhole collimation were evaluated for tumour avidity and ability to provide images for differential biological analysis within the tumour (areas of different uptake) or beyond the main mass (multifocality, satellite tumoral foci). The pinhole collimator was located with precision over the tumour area using a radiotherapy simulator. In 19 of 45 (42%) parallel-hole scintigrams the tumours were non-avid, whereas in 13 of 45 (29%) the tumours could be identified but the image quality was very poor. In contrast, tumour avidity was assessed in all 25 cases (100%) using pinhole scintigraphy and all pinhole images were evaluable for assessment of 99Tcm-sestamibi biology. The tumour-to-normal tissue (T/N) count ratio for the tumoral centre ranged from 1.71 to 4.36 (median 3.07) vs 1.54 to 3.20 (median 2.18) at the periphery, as assessed by pinhole imaging. Of 10 cases followed up with repeated scintigrams during radiotherapy, 2 showed an increasing T/N ratio during radiotherapy, both of whom did not respond to treatment. In the other eight cases, the T/N ratio decreased progressively during radiation treatment and all eight cases showed a varying degree of response on computed tomography or magnetic resonance imaging carried out 2 months after radiotherapy. It is concluded that 99Tcm-sestamibi tumour avidity can be successfully assessed with pinhole scintigraphy. Pinhole scintigraphy provides tumour images suitable for the evaluation of biological features related to radiolabelled pharmaceuticals. The premature observation that tumours showing increased 99Tcm-sestamibi uptake during radiotherapy correlated with poor therapeutic outcome requires further investigation.

Adenocarcinoma↗

PubMed1995

Radiation exposure to the hands of operators during angiographic procedures.

The hands of those undertaking angiographic studies are close to the X-ray beam and may receive high doses. However, during recent years little information is available on these doses. The exposure to the left and right hand was measured with thermoluminescent dose meters during several conventional angiographic procedures. Mean doses to the left hand ranged from 0.24 to 0.96 mSv and to the right hand from 0.12 to 0.71 mSv, related to the type of procedure performed. The protection provided by new flexible lead gloves was estimated. The dose reduction with the glove was 19.5%. Operators can approach the dose limit to hands set by the International Commission on Radiological Protection (ICRP) during high workload. The data presented emphasize the importance of wearing lead gloves.

Angiography↗

PubMed1994

LQ-based model for biological radiotherapy planning.

Despite the increasing accumulation of radiobiological data, radiotherapy planning does not take into account the alpha/beta values of normal irradiated tissues. The importance of the fact that the dose per fraction outside the 100% isodose area is not at all identical to the one inside the tumor area is also underestimated. Altered fractionation regimens further complicate the reliability of the conventional radiotherapy plans. In this study we report a theoretical application of the Macejewski's concept of "normalised total dose" that could make feasible the integration of alpha/beta and dose per fraction values in everyday radiotherapy practice. The concept of cumulative normalised total dose permits the preparing of radiotherapy plans with normalised isodose areas (the cumulative isodose area maps) for chosen ranges of radiation normalised doses. The effect of overall treatment time and interfraction interval is also taken into account. The present study suggests some guidelines that could be of value for the elaboration of a computer program for biological radiotherapy planning.

Animals↗

PubMed1994

Variation between os calces as measured by broadband ultrasound attenuation.

We compared broadband ultrasonic attenuation (BUA) values of right with left os calcis in 65 women. All subjects were right handed, and they were divided into two groups: Group 1 consisted of 32 normal volunteers and Group 2 of 33 osteoporotic subjects. Both groups had mean absolute differences in BUA between the two os calces greater than the coefficient of variation (p < 0.001). This difference is not related to stated handedness of the individuals. Osteoporosis affects both os calces similarly. BUA measurements should always be performed in the same site in longitudinal studies, otherwise false comparisons will result.

Adult↗

PubMedDate not supplied

Bladder and rectum volume estimations using CT and stereology.

Twelve prostate cancer patients underwent a treatment planning CT prior to radiotherapy. Stereologic method based on Cavalieri principle was applied to CT images. Systematic and random sampling of CT slices were performed with alternative ways for assessing the volumes of bladder and rectum. The contribution of point counting to the precision of the obtained volume estimations was analysed. It was found that 100-150 test points counted on only 5-7 systematically sampled slices through bladder or rectum suffice for reliable volume estimations of the above organs. Also, the superiority of systematic vs random sampling was confirmed. The suggested volumetric method gives the possibility of generating unbiased and efficient bladder and rectum volume assessments directly from CT data with great saving in labour.

Algorithms↗

PubMedDate not supplied

Tailored low dose three-dimensional CT of paranasal sinuses.

A technique for three-dimensional (3D) computed tomography (CT) of the paranasal sinuses was evaluated. The influence of milliamperage and reconstruction algorithms on image quality was studied in a phantom. Eleven patients with bony abnormalities of the paranasal sinuses underwent CT to assess the clinical impact of 3D CT protocol. Contiguous 1.5-mm sections obtained at 120 kVp/175 mA/1.9 sec can provide 3D images with high diagnostic image quality. This technique offers the advantage of a much lower dose than that of the conventional CT (CCT) examination of paranasal sinuses. Three-dimensional CT protocol of paranasal sinuses is suggested for use for the evaluation of bony abnormalities and for preoperative planning of the above region.

Humans↗

PubMedDate not supplied

The bicipital groove as a landmark for orientation of the humeral prosthesis in cases of fracture.

We studied 45 dry cadaveric humeri to determine whether the bicipital groove of the humerus can be used as a landmark for a proper, individualized orientation of a humeral prosthesis, especially in the case of a fracture. We performed 3 computed tomography sections (at a level just below the lower portion of the head, at the middle of the humeral head, and at a distance 5 cm below the first section), and we used special software for 3-dimensional image processing. To reproduce the individual posterior version of the head, when a humeral prosthesis is implanted for fracture, the lateral fin of the prosthesis should be a mean distance 5.2 +/- 2.6 mm (-1.5 to 10.7 mm) from the posterior edge of the bicipital groove. If the lateral fin of the humeral prosthesis seats just behind the posterior edge of the bicipital groove, a difference of -6.3 degrees to 41.7 degrees from the normal posterior version occurs. A new, simple methodology for an individualized posterior version of a humeral prosthesis in cases of fracture is proposed. We applied this in 6 consecutive patients with fracture of the humeral head that required hemiarthroplasty.

Cadaver↗

PubMedDate not supplied

Serum evaluation of angiogenic cytokine basic fibroblast growth factor, hepatocyte growth factor and TNF-alpha in patients with myelodysplastic syndromes: correlation with bone marrow microvascular density.

Recent studies have documented that angiogenesis plays a significant role in haematological malignancies, including mylodysplastic syndromes (MDS). Basic fibroblast growth factor (b-FGF), Hepatocyte growth factor (HGF) and Tumor necrosis factor-alpha (TNF-alpha) are multifunctional cytokines that potently stimulate angiogenesis. The aim of the present study was to evaluate the microvascular density (MVD) and the serum levels of these angiogenic factors in patients with myelodysplastic syndromes (MDS). In 61 patients with MDS, MVD was measured in bone marrow biopsies and b-FGF, HGF and TNF-alpha were determined in the serum of the same patients by enzyme-linked immunosorbent assay (ELISA). Serum levels of b-FGF, HGF and TNF-alpha as well as MVD in the bone marrow were increased in MDS patients compared to healthy controls (p<0.0001). Levels of b-FGF, HGF and TNF-alpha were also significantly higher in high-risk for leukemic transformation MDS than in low-risk (p<0.0001). Significant differences were also found regarding MVD in high and low risk patients (p<0.001). Both b-FGF and HGF levels were significant predictors of survival (p<0.0005, log-rank test). The present study showed that serum levels of b-FGF, HGF and TNF-alpha are significantly increased and dependent on the severity of MDS suggesting that the determination of these parameters may offer considerable information regarding disease progression and prognosis.

Aged↗

PubMedDate not supplied

A phase I trial of weekly docetaxel and cisplatinum combined to concurrent hyperfractionated radiotherapy for non-small cell lung cancer and squamous cell carcinoma of head and neck.

We conducted a phase I study to evaluate the activity and tolerability of concurrent docetaxel and cisplatinum radiosensitization with hyperfractionated irradiation, in patients with advanced non-small cell lung cancer (NSCLC) and squamous cell carcinoma of the head and neck (SCCHN). Nine patients (5 stage III(A) and 4 III(B)) with NSCLC, and 15 with SCCHN (10 stage III and 5 IV) were treated with a b.i.d. hyperfractionated (HF) radiotherapy schedule. The normalized total dose for alpha/beta ratio = 10 Gy was 69.6 Gy for NSCLC and 80.5 Gy for SCCHN patients. The standard dose of cisplatin (10 mg/m(2)) was given combined to docetaxel on a weekly basis. The docetaxel starting dose level was 10 mg/m(2)/week and was escalated by 3 mg/m(2) increments in cohorts of 8 patients (5 SCCHN and 3 NSCLC). DLT (grade 3 malaise) was observed in 4 out of 8 patients treated at the 16 mg/m(2)/week docetaxel dose level. The 13 mg/m(2)/week docetaxel dose level was defined as the MTD causing grade 3 mucositis in 4 out of 8 patients. In total 4 (17%) patients developed grade 3 neutropenia. G-CSF support was given in 1/8, 4/8, and 5/8 patients treated at the 10, 13 and 16 mg/m(2) docetaxel dose levels respectively. Fatigue was the most common adverse event (5/24: 21%) and was responsible for more than 1 week treatment delay in 4 out of 8 patients treated at the 16 mg/m(2)/week docetaxel dose level. Nine (3 NSCLC and 6 SCCHN patients: 37.5%) had treatment delay of 1 week, while 7 (3 NSCLC and 4 SCCHN: 29%) had delays of 2 weeks for combined chemoradiation sequelae. Acute hypersensitivity reactions occurred in 3 (12.5%) patients, and grade 3 mucositis in 2/8, 5/8 and 6/8 patients, treated at 10, 13 and 16 mg/m(2)/week docetaxel dose levels respectively. The overall response rate was 79% (CI = 63-96%) with 33% and 53% CRs for NSCLC and SCCHN patients respectively. There were 3 deaths among 9 NSCLC and 4 among 15 SCCHN patients. Local and/or distant disease recurrences were shown in 4 NSCLC and in 6 SCCHN patients; 5 NSCLC and 9 SCCHN patients are alive with no evidence of tumor progression at 8.5 months mean follow-up time. Radiosensitization with docetaxel and cisplatin given concurrently with HF (b.i.d.) radiotherapy on a weekly basis is a promising approach and the recommended dose for further phase II studies is 10 mg/m(2)/week for both drugs. The antitumor activity shown was significant in both types of tumors. The incorporation of docetaxel in chemoradiotherapy regimens for future treatment of squamous cell carcinoma of the lung and head and neck, merits evaluation in phase II and III trials.

Aged↗

PubMedDate not supplied

Concurrent platinum and docetaxel chemotherapy and external radical radiotherapy in patients with invasive transitional cell bladder carcinoma. A preliminary report of tolerance and local control.

PURPOSE: The present study aims to evaluate the feasibility, toxicity, and efficacy of concurrent chemotherapy with cisplatinum and docetaxel, and external radical radiotherapy for transitional cell carcinoma of urinary bladder. MATERIALS AND METHODS: 42 patients (34 men, 8 females) with invasive bladder carcinoma (clinical stages T1-4) were treated after transurethral biopsy with chemotherapy and concomitant external radiotherapy. Chemotherapy consisting of cisplatin infusion (30 mg/m2) and Docetaxel (40 mg/m2) was given twice a week simultaneously with-irradiation during the whole treatment period (6-8 weeks) as follows: Cisplatin (D1,D8,D15,D22, D25,D36,D43,D50) and Docetaxel (D4, D11, D18, D25, D32, D39, D46, D53). An external irradiation scheme 1.8 to 2.0 Gy per fraction, 5 days a week was used up to 68-74 Gy (6MeV photons) total tumor dose. RESULTS: All but S patients completed the planned chemoradiation protocol. The complete response rate (CR-rate) assessed at 3 months after completion of combined treatment was 100%, 63.6%, 46.15% and 95% for clinical stage (c) cT1 (9/9), cT2 (7/11), cT3 (6/13) and cT4 (1/4) cases respectively. None of 9 patients with T1 tumors had any local failure at 36.1 months mean follow-up time. In total, 9 of 37 patients (24.32%) relapsed locally and/or distantly and were followed for 25.04 months (mean time), 50% of the relapses occurred at a mean time of 7.25 months. The mortality rate was 10.81% (4/37). All these patients died with a mean time of 11 months. 32 cases remain alive 19-46 months after treatment; 27 of those are with no evidence of disease with a mean follow-up time of 32.24 months. In total, there was a 78.50% (30/37) and a 75.67%, (28/37) rate of overall survival and pelvic control respectively at 25.04 months mean follow-up time. Chemotherapy was discontinued in 2 cases due to acute gastrointestinal toxicity and in 3 more, due to patient compliance. There was 1 toxic death 2 months after treatment completion due to ureteral obstruction and impaired renal function. The acute toxicity was estimated as moderate to severe and caused the interruption of treatment for 5 to 10 days in 8 of 37 patients (21.62%). Myelotoxicity appeared in 22/37 patients but febrile grade III and IV neutropenia was observed in 3 patients (8.10%) and thrombocytopenia (Grade I-III) in 8 (21.62%). Concerning late effects a sigmoid stricture, a transient small bowel obstruction, 4 patients with contracted bladder and 1 case with renal failure were found. Grade I to III hypersensitivity reactions appeared in 8/37 patients (21.62%) while stomatitis (grade I-II) and grade II skin toxicity appeared in 3 and 4 patients respectively. These and other symptoms (Grade I to II peripheral edema, transient myalgias and arthralgias in 7/37 cases), paresthesias or numbness (3/37) and peripheral motor dysfunction (1/37) were responsible for early reduction of docetaxel dose from 40 mg/m2 to 20 mg/m2. CONCLUSION: This preliminary analysis suggest that the radiosensitizing effect of cisplatin and docetaxel to megavoltage irradiation yielded a high CR-rate in transitional cell bladder carcinoma patients with medium to severe early and late side effects. The value of such a combined treatment as far as the tumor eradication is concerned requires further evaluation, because of the small number of patients, the short follow-up, and the absence of other studies using docetaxel as a radiosensitizer in urothelial cell cancer.

Aged↗