Biomedical subjects

G Paganelli

Publications and source records attributed to G Paganelli.

At least 55 records · Page 3Linked to original sources

PubMed2000

Adoptive immunotherapy by avidin-driven cytotoxic T lymphocyte-tumor bridging.

We have shown previously that T cells, tagged with biotinylated anti-CD3 antibody fragments, can exert avidin-dependent cytolytic activity on suitably biotinylated tumor cells in vitro. In this study, we demonstrate that avidin-driven CTL-tumor bridging in vivo leads to growth inhibition of murine tumors WEHI-164 fibrosarcoma and RMA lymphoma. The biodistribution of biotin-tagged 111In-labeled T cells demonstrated a selective avidin-dependent and time-dependent accumulation of radioactivity at tumor sites. The specificity of lymphocyte tumor localization was demonstrated by the concurrent time-dependent decrease of radioactivity in the blood and in all other organs. Furthermore, we documented a therapeutic effect of the adoptively transferred T cells, i.e., a significant delay of tumor growth at early stages. All of the experiments included a control group of mice, which received all of the reagents, except avidin. These avidin-minus mice showed no specific localization and no delay in tumor growth, indicating that avidin bridging was essential for T-cell activity at tumor sites.

Animals↗

PubMed2000

Sentinel node localization by lymphoscintigraphy: a reliable technique with widespread applications.

The concept of the sentinel lymph node (SN) represents an important contribution to guide appropriate surgery of cancer. Diagnostic non-invasive or minimally invasive procedures that provide accurate preoperative staging of the lymph node status are badly needed. The technique of SN biopsy, first developed with the purpose to select melanoma patients for regional node dissection, has been extended to other malignancies. Initial studies in breast carcinoma, conducted with vital blue dye, showed that the SN concept was biologically valid, although SN was missed in up to 30%-40% of cases. If a radioactive tracer is injected close to the tumor, then the SN can be identified by lymphoscintigraphy (LS), and a gamma ray detecting probe (GDP) can be used to locate the skin projection of SN and assist biopsy. These techniques are already used successfully in melanoma and breast carcinoma where the various parameters involved, such as the size of the radioactive particles, the injection site and injection volume, have recently been optimized. In a large series of breast cancer patients, the overall predictive value of the SNs biopsy guided by LS and GDP was 96.8%; in patients with small carcinomas (< 1.2 cm diameter), the concordance between SN and axillary status was 98.6%. In patients with melanoma, LS combined with GDP showed itself to be superior to the blue dye mapping. LS associated with GDP allowed the detection of SN in 98% of cases and 72 SNs in 54 basins were localized. Using blue dye instead, SN was stained only in 80% of patients (50 SNs in 40 basins). Lymphoscintigraphic techniques have shown promising results also in tumors such as vulva and tongue. In conclusion, LS is a simple nuclear medicine technique, relatively inexpensive and well accepted by patients. SN biopsy guided by a GDP is becoming widely adopted for a variety of neoplasms, contributing significantly to the search for less aggressive treatments in patients with early stages of cancer.

Axilla↗

PubMed2000

Use of technetium-99m-labeled colloid albumin for preoperative and intraoperative localization of nonpalpable breast lesions.

BACKGROUND: Management of clinically occult breast lesions is still a major point of debate. Several techniques (eg, skin projection, guidewire localization) have been proposed, but all of them have technical limitations. STUDY DESIGN: The aim of this study was to assess the efficacy of a new method to locate occult breast lesions using technetium-99m (99mTc)-labeled colloid particles of human serum albumin (radioguided occult lesion localization). We studied 647 consecutive patients (mean age 51.3 years; range 25 to 77 years) with nonpalpable breast lesions detected mammographically or by ultrasonography. Within 24 hours before operation, 3.7 MBq (0.1 mCi) of 99mTc-labeled colloid was injected directly into the center of the lesion using stereotactic mammographic guidance (when only microcalcifications were present) or ultrasonographic guidance (for opacities). Excision biopsy was performed with a gamma-detecting probe. After excision, the area was checked for residual radioactivity and the specimen was radiographed to verify complete removal of the lesion. The material was then sent for pathologic examination. The absorbed dose to the inoculated area and the external irradiation to staff were also determined. RESULTS: In all 647 patients, the "hot spot" was located easily and quickly. X-ray and scintigraphy of the specimen verified the presence and centricity of the lesion in all patients but three (99.5%). Pathologic examination revealed 340 cancer lesions (52.6%). Of these patients, 339 (99.7%) were treated by breast-conserving operations and one (0.3%) received a modified radical mastectomy. No major surgical or postoperative complications were encountered. No recurrences were documented during follow-up. The absorbed dose to the breast and other tissue was negligible (0.03 +/- 0.02 mGy/MBq), as was the dose to the surgeon's hands (7.5 +/- 5.0 microSv/h). The latter dose represents 0.015% and 0.002% of the recommended limits of the European Community for the general population and for exposed workers, respectively. CONCLUSIONS: Radioguided occult lesion localization seems to offer a simple and reliable method to locate occult breast lesions with a gamma-detecting probe, allowing complete removal of the lesion in 99.5% of patients. Because of the small quantity of radioactivity, the procedure is safe for both patients and medical staff.

Adult↗

PubMed2000

Sentinel node biopsy in early vulvar cancer.

Lymph node pathologic status is the most important prognostic factor in vulvar cancer; however, complete inguinofemoral node dissection is associated with significant morbidity. Lymphoscintigraphy associated with gamma-probe guided surgery reliably detects sentinel nodes in melanoma and breast cancer patients. This study evaluates the feasibility of the surgical identification of sentinel groin nodes using lymphoscintigraphy and a gamma-detecting probe in patients with early vulvar cancer. Technetium-99m-labelled colloid human albumin was administered perilesionally in 37 patients with invasive epidermoid vulvar cancer (T1-T2) and lymphoscintigraphy performed the day before surgery. An intraoperative gamma-detecting probe was used to identify sentinel nodes during surgery. A complete inguinofemoral node dissection was then performed. Sentinel nodes were submitted separately to pathologic evaluation. A total of 55 groins were dissected in 37 patients. Localization of the SN was successful in all cases. Eight cases had positive nodes: in all the sentinel node was positive; the sentinel node was the only positive node in five cases. Twenty-nine patients showed negative sentinel nodes: all of them were negative for lymph node metastases. Lymphoscintigraphy and sentinel-node biopsy under gamma-detecting probe guidance proved to be an easy and reliable method for the detection of sentinel node in early vulvar cancer. This technique may represent a true advance in the direction of less aggressive treatments in patients with vulvar cancer.

Adult↗

PubMed2000

Diagnosis of persistent ovarian carcinoma with three-step immunoscintigraphy.

The diagnosis of recurrent ovarian carcinoma is usually determined at surgical re-exploration since the main non-invasive diagnostic tests have low accuracy. It would be desirable to have a high accuracy non-invasive diagnostic procedure. With this aim, we have assessed the utility of three-step immunoscintigraphy. Thirty patients were intravenously injected with biotinylated monoclonal antibodies MOv18 and B72.3, followed by avidin-streptavidin injection and finally by 111In-biotin. Tumour recurrences were imaged 2 h post radioactivity injection. All patients underwent surgical re-exploration 3-4 days after immunoscintigraphy; the presence of tumour in the area of immunoscintigraphic uptake was evaluated in the biopsied material. Twenty-one patients studied were true-positive, five were true-negative, four were false-positive and none was false-negative. The diagnostic accuracy, positive predictive value and negative predictive value were 87%, 84% and 100% respectively. If these findings are confirmed in a larger number of patients, we expect immunoscintigraphy to be introduced as a cost-effective procedure in the follow-up of patients who have received surgery for ovarian carcinoma, since it promises to reliably identify patients who do not require surgical re-exploration, and guide biopsies when they are indicated.

Adult↗

PubMed2000

Sentinel node localization in primary melanoma: preoperative dynamic lymphoscintigraphy, intraoperative gamma probe, and vital dye guidance.

BACKGROUND: Sentinel node (SN) biopsy can be used to select patients with primary melanoma for therapeutic lymphadenectomy. The aim of the study was to assess the efficacy of 3 methods to locate the SN: preoperative dynamic lymphoscintigraphy, intraoperative patent blue dye (PBD), and gamma-detecting probe (GDP). METHODS: We studied 133 patients with cutaneous melanoma and clinically negative lymph nodes. Within 24 hours before surgery, colloid labeled with technetium 99m was injected intradermally around the site of the primary melanoma. The patients were studied before their operations by using dynamic lymphoscintigraphy. A total of 208 SNs were found in 164 lymph node basins. In addition, all the patients had PBD injected immediately before the surgical procedure. When the blue-stained node was identified intraoperatively, its radioactivity level was measured with the GDP. In the absence of blue coloration, the GDP was used to trace the SN. RESULTS: Of 208 SNs, 168 (80.8%) were identified in the regional draining basin during intraoperative lymphatic mapping by using PBD. By using the GDP method, 202 (97.1%) of 208 were identified (GDP vs PBD; P < .01). By combining the 2 methods, 206 (99%) of 208 SNs were detected. Of the 133 patients, 29 (21.8%) had pathologically positive SNs, and were subsequently subjected to regional lymphadenectomy. In 26 (89.7%) of 29 patients, the SN was the only node with metastasis. Three cases (10.3%) of recurrence in patients with microscopic SN metastasis and 7 cases (6.7%) of recurrence in patients without SN metastasis were found during a median follow-up of 566 days. CONCLUSIONS: Preoperative dynamic lymphoscintigraphy and intraoperative mapping with PBD and GDP offer simple and reliable methods of staging regional lymph nodes without subjecting every patient to a regional lymphadenectomy.

Adolescent↗

PubMed2000

Is there a role for sentinel node biopsy in early N0 tongue tumors?

BACKGROUND: Detecting metastases to the cervical lymph nodes is the main problem in the management of squamous cell carcinoma of the tongue. We investigated the ability of sentinel node (SN) biopsy to predict neck status in 11 patients with lateral T1-T2, N0, and M0 squamous cell carcinoma of the tongue who underwent ipsilateral neck dissection 30 to 40 days after primary surgery. METHODS: In 5 patients, technetium 99m-labeled particles were injected close to the operation scar on the day before neck dissection, and the labeled neck nodes were revealed by lymphoscintigraphy. The next 6 patients underwent lymphoscintigraphy both before surgery and before neck dissection. During neck dissection, the ipsilateral SNs were identified by using a hand-held probe and removed separately. RESULTS: Three patients (27%) had metastatic neck nodes. In all cases, labeled nodes were revealed by scintigraphy. Ipsilateral SNs were removed from 8 patients and correctly predicted the state of the neck (6 negatives and 2 positives). Lymphoscintigraphy before and after surgery revealed that drainage was modified after surgery in 5 of 6 patients; the pre-surgery drainage pattern varied markedly among the 5 pN0 patients. CONCLUSIONS: The technique allows easy and safe identification of SNs and shows promise in guiding selective neck dissection. Surgery on the primary tumor often modifies lymphatic drainage, so that SN biopsy may only be useful if the primary operation and neck dissection are performed at the same time.

Adult↗

PubMed2000

Dosimetry in radionuclide therapies with 90Y-conjugates: the IEO experience.

The basis for a successful radionuclide therapy is a high and stable uptake of the radiopharmaceutical in the target tissue along with low activity concentration in other normal organs. The contribution of dosimetry in radionuclide therapy is to predict before the treatment the absorbed doses in tumor and normal organs, to identify the critical organs, to minimize any possible toxicity and to evaluate the maximum tolerated dose. We report our experience concerning pharmacokinetics and dosimetry of two 90Y-therapeutic protocols: 3-step pretargeting radioimmunotherapy (RIT) according to the biotin-avidin system and receptor mediated radionuclide therapy with the somatostatin analogue [DOTA-D-Phe1-Tyr3] octreotide named DOTATOC. For the dosimetric analysis, analogous approaches for the two radiolabeled compounds due to the similar pharmacokinetic characteristics were adopted; the MIRD formalism was applied, taking into account both the physical and the biological characteristics of the radioconjugate and patients' metabolism. In order to determine biological clearance, serial blood samples and complete urine collection were obtained up to 48 hours after injection; to evaluate biodistribution, several whole body scans were acquired. Both therapies showed the advantageous characteristics of a fast blood clearance and a predominantly renal excretion of the radiopharmaceuticals thus lowering the irradiation of the total body. Although pharmacokinetic characteristis were similar, different critical organs were found for the two therapies; in particular, some considerations regarding red marrow, spleen and kidneys were required. The results of our studies indicate that high activities of 90Y-biotin (3-step RIT) and 90Y-DOTATOC can be administered with acceptable radiation doses to normal organs.

Humans↗

PubMed1999

Intraoperative examination of axillary sentinel lymph nodes in breast carcinoma patients.

BACKGROUND: Routine histologic examination of axillary sentinel lymph nodes predicts axillary lymph node status and may spare patients with breast carcinoma axillary lymph node dissection. To avoid the need for two separate surgical sessions, the results of sentinel lymph node examination should be available intraoperatively. However, routine frozen-section examination of sentinel lymph nodes is liable to yield false-negative results. This study was conducted to ascertain whether extensive intraoperative examination of sentinel lymph nodes by frozen section examination would attain a sensitivity comparable to that obtained by routine histologic examination without intraoperative frozen section examination. METHODS: In a consecutive series of 155 clinically lymph node negative breast carcinoma patients, the axillary sentinel lymph nodes were examined intraoperatively, before complete axillary lymph node dissection. The frozen sentinel lymph nodes were sectioned subserially at 50-microm intervals. For each level, one section was stained with hematoxylin and eosin and the other section immunostained for cytokeratins using a rapid immunocytochemical assay. RESULTS: Sentinel lymph node metastases were detected in 70 of the 155 patients (45%). In 37 cases the sentinel lymph nodes were the only axillary lymph nodes with metastases. Immunocytochemistry did not increase the sensitivity of the examination. Five patients had metastases in the nonsentinel axillary lymph nodes despite having negative sentinel lymph nodes. The general concordance between sentinel and axillary lymph node status was 96.7%; the negative predictive value of intraoperative sentinel lymph node examination was 94.1%. CONCLUSIONS: The intraoperative examination of axillary sentinel lymph nodes is effective in predicting the axillary lymph node status of breast carcinoma patients and may be instrumental in deciding whether to spare patients axillary lymph node dissection.

Axilla↗

PubMed1999

Sentinel lymph node biopsy and axillary dissection in breast cancer: results in a large series.

BACKGROUND: Axillary lymph node dissection is an established component of the surgical treatment of breast cancer, and is an important procedure in cancer staging; however, it is associated with unpleasant side effects. We have investigated a radioactive tracer-guided procedure that facilitates identification, removal, and pathologic examination of the sentinel lymph node (i.e., the lymph node first receiving lymphatic fluid from the area of the breast containing the tumor) to predict the status of the axilla and to assess the safety of foregoing axillary dissection if the sentinel lymph node shows no involvement. METHODS: We injected 5-10 MBq of 99mTc-labeled colloidal particles of human albumin peritumorally in 376 consecutive patients with breast cancer who were enrolled at the European Institute of Oncology during the period from March 1996 through March 1998. The sentinel lymph node in each case was visualized by lymphoscintigraphy, and its general location was marked on the overlying skin. During breast surgery, the sentinel lymph node was identified for removal by monitoring the acoustic signal from a hand-held gamma ray-detecting probe. Total axillary dissection was then carried out. The pathologic status of the sentinel lymph node was compared with that of the whole axilla. RESULTS: The sentinel lymph node was identified in 371 (98.7%) of the 376 patients and accurately predicted the state of the axilla in 359 (95.5%) of the patients, with 12 false-negative findings (6.7%; 95% confidence interval = 3.5%-11.4%) among a total of 180 patients with positive axillary lymph nodes. CONCLUSIONS: Sentinel lymph node biopsy using a gamma ray-detecting probe allows staging of the axilla with high accuracy in patients with primary breast cancer. A randomized trial is necessary to determine whether axillary dissection may be avoided in those patients with an uninvolved sentinel lymph node.

Albumins↗

PubMed1999

Three-step radioimmunotherapy with yttrium-90 biotin: dosimetry and pharmacokinetics in cancer patients.

A three-step avidin-biotin approach has been applied as a pretargeting system in radioimmunotherapy (RIT) as an alternative to conventional RIT with directly labelled monoclonal antibodies (MoAbs). Although dosimetric and toxicity studies following conventional RIT have been reported, these aspects have not previously been evaluated in a three-step RIT protocol. This report presents the results of pharmacokinetic and dosimetric studies performed in 24 patients with different tumours. Special consideration was given to the dose delivered to the red marrow and to the haematological toxicity. The possible additive dose to red marrow due to the release of unbound yttrium-90 was investigated. The protocol consisted in the injection of biotinylated MoAbs (first step) followed 1 day later by the combined administration of avidin and streptavidin (second step). After 24 h, biotin radiolabelled with 1.85-2.97 GBq/m2 of 90Y was injected (third step). Two different chelating agents, DTPA and DOTA, coupled to biotin, were used in these studies. Indium-111 biotin was used as a tracer of 90Y to follow the biodistribution during therapy. Serial blood samples and complete urine collection were obtained over 3 days. Whole-body and single-photon emission tomography images were acquired at 1, 16, 24 and 40 h after injection. The sequence of images was used to extrapolate 90Y-biotin time-activity curves. Numerical fitting and compartmental modelling were used to calculate the residence time values (tau) for critical organs and tumour, and results were compared; the absorbed doses were estimated using the MIRDOSE3.1 software. The residence times obtained by the numerical and compartmental models showed no relevant differences (<10%); the compartmental model seemed to be more appropriate, giving a more accurate representation of the exchange between organs. The mean value for the tau in blood was 2.0+/-1.1 h; the mean urinary excretion in the first 24 h was 82.5%+/-10.8%. Without considering any contribution of free 90Y, kidneys, liver, bladder and red marrow mean absorbed doses were 1.62+/-1.14, 0.27+/-0.23, 3.61+/-0.70 and 0. 11+/-0.05 mGy/MBq, respectively; the effective dose was 0.32+/-0.06 mSv/MBq, while the dose to the tumour ranged from 0.62 to 15.05 mGy/MBq. The amount of free 90Y released after the injection proved to be negligible in the case of 90Y-DOTA-biotin, but noteworthy in the case of 90Y-DTPA-biotin (mean value: 5.6%+/-2.5% of injected dose), giving an additive dose to red marrow of 0.18+/-0.08 mGy per MBq of injected 90Y-DTPA-biotin. Small fractions of free 90Y originating from incomplete radiolabelling can contribute significantly to the red marrow dose (3.26 mGy per MBq of free 90Y) and may explain some of the high levels of haematological toxicity observed. These results indicate that pretargeted three-step RIT allows the administraton of high 90Y activities capable of delivering a high dose to the tumour and sparing red marrow and other normal organs. Although 90Y-biotin clears rapidly from circulation, the use of DOTA-biotin conjugate for a stable chelation of 90Y is strongly recommended, considering that small amounts of free 90Y contribute significantly in increasing the red marrow dose.

Antibodies, Monoclonal↗

PubMed1999

Antibody-guided three-step therapy for high grade glioma with yttrium-90 biotin.

While the incidence of brain tumours seems to be increasing, median survival in patients with glioblastoma remains less than 1 year, despite improved diagnostic imaging and neurosurgical techniques, and innovations in treatment. We have developed an avidin-biotin pre-targeting approach for delivering therapeutic radionuclides to gliomas, using anti-tenascin monoclonal antibodies, which seems potentially effective for treating these tumours. We treated 48 eligible patients with histologically confirmed grade III or IV glioma and documented residual disease or recurrence after conventional treatment. Three-step radionuclide therapy was performed by intravenous administration of 35 mg/m2 of biotinylated anti-tenascin monoclonal antibody (1st step), followed 36 h later by 30 mg of avidin and 50 mg of streptavidin (2nd step), and 18-24 h later by 1-2 mg of yttrium-90-labelled biotin (3rd step). 90Y doses of 2.22-2.96 GBq/m2 were administered; maximum tolerated dose (MTD) was determined at 2.96 GBq/m2. Tumour mass reduction (>25%-100%), documented by computed tomography or magnetic resonance imaging, occurred in 12/48 patients (25%), with 8/48 having a duration of response of at least 12 months. At present, 12 patients are still in remission, comprising four with a complete response, two with a parital response, two with a minor response and four with stable disease. Median survival from 90Y treatment is 11 months for grade IV glioblastoma and 19 months for grade III anaplastic gliomas. Avidin-biotin based three-step radionuclide therapy is well tolerated at the dose of 2.2 GBq/m2, allowing the injection of 90Y-biotin without bone marrow transplantation. This new approach interferes with the progression of high-grade glioma and may produce tumour regression in patients no longer responsive to other therapies.

Adolescent↗

PubMed1999

Clinical validation of the avidin/indium-111 biotin approach for imaging infection/inflammation in orthopaedic patients.

We report here the results of a validation study of the avidin/indium-111 biotin approach in patients with skeletal lesions. This study involved 54 patients with orthopaedic conditions: 20 patients with intermediate suspected osteomyelitis of the trunk, 19 patients with infection/inflammation of prosthetic joint replacements, and 15 patients with suspected osteomyelitis of appendicular bones. Avidin (3 mg) was injected as an i.v. bolus, followed 4 h later by 111In-biotin; imaging was acquired 30 min and 16-18 h after administration of 111In-biotin. Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocyte scintigraphy was performed in 39/54 patients. The overall sensitivity of the avidin/111In-biotin scan was 97.7% (versus 88.9% for 99mTc-HMPAO leucocyte scintigraphy). While the diagnostic performance of avidin/111In-biotin scintigraphy was similar to that of 99mTc-HMPAO leucocyte scintigraphy in patients with prosthetic joint replacements or osteomyelitis of appendicular bones, the avidin/111In-biotin approach clearly performed better than 99mTc-HMPAO leucocyte scintigraphy in patients with suspected osteomyelitis of the trunk (100% sensitivity, specificity and accuracy versus 50% sensitivity, 100% specificity and 66.7% accuracy for 99mTc-HMPAO-leucocyte scintigraphy). These results demonstrate the feasibility of the avidin/111In-biotin approach for imaging sites of infection/inflammation in the clinical setting. Although no systematic advantages of avidin/111In-biotin scintigraphy were found versus 99mTc-HMPAO leucocyte scintigraphy, the newer scintigraphic method is more practicable and involves lower biological risk for the operators.

Avidin↗

PubMed1999

Biokinetics and dosimetry in patients administered with (111)In-DOTA-Tyr(3)-octreotide: implications for internal radiotherapy with (90)Y-DOTATOC.

Recent advances in receptor-mediated tumour imaging have resulted in the development of a new somatostatin analogue, DOTA-dPhe(1)-Tyr(3)-octreotide. This new compound, named DOTATOC, has shown high affinity for somatostatin receptors, ease of labelling and stability with yttrium-90 and favourable biodistribution in animal models. The aim of this work was to evaluate the biodistribution and dosimetry of DOTATOC radiolabelled with indium-111, in anticipation of therapy trials with (90)Y-DOTATOC in patients. Eighteen patients were injected with DOTATOC (10 microg), labelled with 150-185 MBq of (111)In. Blood and urine samples were collected throughout the duration of the study (0-2 days). Planar and single-photon emission tomography images were acquired at 0.5, 3-4, 24 and 48 h and time-activity curves were obtained for organs and tumours. A compartmental model was used to determine the kinetic parameters for each organ. Dose calculations were performed according to the MIRD formalism. Specific activities of >37 GBq/ micromol were routinely achieved. Patients showed no acute or delayed adverse reactions. The residence time for (111)In-DOTATOC in blood was 0.9+/-0.4 h. The injected activity excreted in the urine in the first 24 h was 73%+/-11%. The agent localized primarily in spleen, kidneys and liver. The residence times in source organs were: 2.2+/-1.8 h in spleen, 1.7+/-1.2 h in kidneys, 2.4+/-1.9 h in liver, 1.5+/-0.3 h in urinary bladder and 9. 4+/-5.5 h in the remainder of the body; the mean residence time in tumour was 0.47 h (range: 0.03-6.50 h). Based on our findings, the predicted absorbed doses for (90)Y-DOTATOC would be 7.6+/-6.3 (spleen), 3.3+/-2.2 (kidneys), 0.7+/-0.6 (liver), 2.2+/-0.3 (bladder), 0.03+/-0.01 (red marrow) and 10.1 (range: 1.4-31.0) (tumour) mGy/MBq. These results indicate that high activities of (90)Y-DOTATOC can be administered with low risk of myelotoxicity, although with potentially high radiation doses to the spleen and kidneys. Tumour doses were high enough in most cases to make it likely that the desired therapeutic response desired would be obtained.

Adult↗

PubMed1999

Effect of complex polyphenols and tannins from red wine (WCPT) on chemically induced oxidative DNA damage in the rat.

BACKGROUND: Flavonoids are polyphenolic antioxidants occurring in vegetables and fruits as well as beverages such as tea and wine which have been thought to influence oxidative damage. AIM OF THE STUDY: We wanted to verify whether a complex mixture of wine tannins (wine complex polyphenols and tannins, WCPT) prevent chemically-induced oxidative DNA damage in vivo. METHODS: Oxidative DNA damage was evaluated by measuring the ratio of 8-hydroxy-2'-deoxyguanosine (80HdG)/ 2-deoxyguanosine (2dG) x 10(-6) in hydrolyzed DNA using HPLC coupled with electrochemical and UV detectors. RESULTS: We treated rats with WCPT (57 mg/kg p.o.) for 14 d, a dose 10-fold higher than what a moderate wine drinker would be exposed to. WCPT administration significantly reduced the ratio of 80HdG/2dG x 10(-6) in liver DNA obtained from rats treated with 2-nitropropane (2NP) relative to controls administered 2NP only (33. 3 +/- 2.5 vs. 44.9 +/- 3.2 x 10(-6) 2dG; micro +/- SE; p<0.05). On the contrary, pretreatment with WCPT for 10 d did not protect the colon mucosa from oxidative DNA damage induced by 1, 2-dimethylhydrazine (DMH). 2NP and DMH are hepatic and colon carcinogens, respectively, capable of inducing oxidative DNA damage. CONCLUSIONS: WCPT have protective action against some types of chemically-induced oxidative DNA damage in vivo.

1,2-Dimethylhydrazine↗

PubMed1999

Comparison of radioguided excision with wire localization of occult breast lesions.

BACKGROUND: Clinically occult breast lesions are found with increasing frequency as a result of the widespread use of mammographic screening. METHODS: This study reports a new localization technique in which a small quantity of 99mTc-labelled colloidal albumin is inoculated directly into the lesion under stereotactic-radiographic or ultrasonographic guidance. Correct positioning of the inoculum is checked by scintigraphy. A gamma ray detection probe is then used to locate the lesion and guide its surgical removal. The results of this method in 30 patients were compared with those obtained using the established hook wire method in another 30 patients. RESULTS: In the wire localization group, the mean(s.d.) distance from the lesion centre to the specimen margin was 24.5(0.4) (range 15-45) mm. For the radioguided group the figures were 13.8(0.3) (range 5-25) mm. The mean(s.d.) lesion concentricity (difference between the maximum and minimum distance from the lesion border to specimen margin) was 6.2(0.4) (range 2-15) mm in the wire localization group and 3.8(0.2) (range 1-10) mm in the radioguided group. CONCLUSION: Use of a gamma probe allowed rapid, easy and accurate removal of occult breast lesions. In comparison to the hook wire method, radioguided removal allows reduced excision volume and better lesion centring within the specimen.

Biopsy↗

PubMed1999

Receptor-mediated radionuclide therapy with 90Y-DOTA-D-Phe1-Tyr3-Octreotide: preliminary report in cancer patients.

Recent advances in receptor mediated tumor imaging led to the development of a new somatostatin analogue DOTA-D-Phe1-Tyr3-Octreotide. This new compound, named DOTATOC, has shown high affinity for somatostatin receptors, stable labeling with yttrium-90 (90Y) and favourable biodistribution in patients. The aim of this work was to evaluate acute and late toxicity and the response rate in cancer patients administered 90Y-DOTATOC. Twenty patients received three equal i.v. injections of 90Y-DOTATOC. Cohorts of 5 patients were treated starting with 1.1 GBq per cycle in escalating dosage (0.4 GBq increments) in subsequent groups. No patients showed acute or delayed major adverse reactions up to the dose of 2.2 GBq of 90Y-DOTATOC per cycle (6.6 GBq total). Maximum tolerated dose has not been determined yet. One patient, after 4.4 GBq total dose, developed delayed kidney grade II toxicity. Complete and partial tumor mass reduction (CR and PR) was measured in 25% of patients along with 55% showing stable disease (SD) and 20% progressive disease (PD). These results indicate that high activities of 90Y-DOTATOC can be administered with low risk of myelotoxicity, although the radiation doses to the kidneys require careful consideration. Tumor doses were high enough in most cases to obtain objective therapeutic responses.

Adult↗

PubMed1999

Radiation protection in radioguided surgery of breast cancer.

The protocols for sentinel lymph node biopsy and radioguided occult lesion localization could potentially be of great value in the management of breast cancer patients. Both involve the injection of a 99Tcm-labelled radiopharmaceutical close to or into the lesion, localization of the sentinel lymph node or occult lesion by scintigraphy, and surgical removal with the aid of a hand-held gamma-ray detector. We present dosimetric data on patients and hospital personnel involved in these procedures. For evaluation of radiation protection, we measured the absorbed dose and air kerma rate. Activity levels in excised tissues and surgical instruments were also determined. For patients, the mean absorbed dose to the abdomen was 0.45 mGy, which is low compared to doses received from other diagnostic examinations. For surgeons after 100 operations, the mean absorbed dose to the hands was 0.45 mGy and the mean effective dose 0.09 mSv. Absorbed doses to all hospital personnel involved in the procedures were very low compared to recommended annual limits stipulated by the International Commission on Radiological Protection. We conclude that these procedures, performed according to protocols laid down by the European Institute of Oncology, Milan, are safe from the point of view of radiological protection and that only routine precautions are necessary.

Breast Neoplasms↗