Measurement of radiation exposure in relatives of thyroid cancer patients treated with (131)I

This work evaluates the radiological risk that patients treated with I for differentiated thyroid cancer could present to relatives and occupationally exposed workers. Recently, the International Atomic Energy Agency issued document K9010241, which recommends that patient discharge from the hospital must be based on the particular status of each patient. This work measures effective dose received by caregivers of patients treated with I at the Instituto Nacional de Cancerología, Mexico City. Thermoluminescent dosimeters were carried during a 15-d period by 40 family caregivers after patient release from hospital. Relatives were classified into two groups, ambulatory and hospitalized, according to the release mode of the patient, and three categories according to the individual patient home and transport facilities. Categories A, B, and C were defined going from most to least adequate concerning public exposure risk. Measurements were performed for 20 family caregivers in each group. The effective dose received by all caregivers participating in this study was found to be less than 5 mSv, the recommended limit per event for caregivers suggested by ICRP 103. In addition, 70 and 90% of ambulatory and hospitalized groups, respectively, received doses lower than 1 mSv. Caregivers belonging to category C, with home situations that are not appropriate for immediate release, received the highest average doses; i.e., 2.2 ± 1.3 and 3.1 ± 1.0 mSv for hospitalized and ambulatory patients, respectively. Results of this work have shown that the proper implementation of radiation protection instructions for relatives and patients can reduce significantly the risk that differentiated thyroid cancer patients treated with I can represent for surrounding individuals. The results also stress the relevance of the patient's particular lifestyle and transport conditions as the prevailing factors related to the dose received by the caregiver. Therefore, the patient's status should be the criterion used to decide his/her release modality. This work provides support to recommend the implementation of the "patient specific release criteria" in accordance with ICRP 94, IAEA Safety Report No. 63, and IAE document K9010241 A for patients treated with radiopharmaceuticals.

Radiosensitization of cervical cancer cells with epigenetic drugs hydralazine and valproate

PURPOSE

To evaluate the radiosensitizing effects of the DNA methylation inhibitor hydralazine in combination with valproic acid, a histone deacetylase inhibitor in cervical cancer cells.

MATERIALS AND METHODS

Cell viability assays were performed in the SiHa cervical cancer cell line treated with hydralazine and valproic acid for five days with and without cisplatin. Cell irradiation was performed using teletherapy (1.25 MV).

RESULTS

Neither hydralazine, valproic acid or cisplatin as single agents increased the cytotoxicity from radiation, however, the combination of hydralazine with valproic acid at ten microM and one mM, respectively, did induce radiosensitization (p = 0.046). Interestingly, this effect was further increased with the triple combination of hydralazine, valproic acid, and cisplatin (p = 0.041), where cell viability decreased more than 50% as compared to radiation alone.

CONCLUSIONS

The present results demonstrate that epigenetic drugs increase the efficacy of cisplatin chemoradiation in cervical cancer cells.

First-line chemotherapy with liposomal doxorubicin plus cisplatin for patients with advanced malignant pleural mesothelioma: phase II trial

Background:

Chemotherapy based on platinum is the standard treatment for unresectable malignant pleural mesothelioma (MPM). Liposomal doxorubicin (LD) consists of pegylated phospholipid vesicles that encapsulate doxorubicin-enhancing liposome deposition in the tumour. We evaluated the toxicity profile and anti-tumour activity of cisplatin plus LD in untreated patients with MPM, as well as ^99mTc-LD distribution in MPM lesions after chemotherapy administration.

Methods:

A total of 38 patients with non-resectable MPM received LD 40 mg m⁻² and cisplatin 60 mg m⁻² every 21 days. Gamma camera images of ^99mTc-LD were acquired to evaluate LD accumulation in measurable tumour tissue. The study was registered in Clinical Trials (NCT00886028).

Results:

In all, 72% of patients were stage III and 28% were stage IV. Eighty four percent and 16% have high and low risk acording EORTC respectively. The median time to progression was 4.6 months (95% confidence interval (95% CI: 3.4–5.9 months), and median overall survival (OS) was 19.6 months (15.2–37.2 months). Patients that responded to chemotherapy treatment had better survival than patients who did not. Functional physical scales, dysnea, cough, and chest/arm pain demonstrated improvement. The accumulation ratio of LD in tumour and soft tissues vs liver was 0.78±0.16 and 0.29±0.09, respectively. After 1 h of administration, LD uptake in tumour tissue was higher than in soft tissue (P< 0.001).

Conclusion:

The combination of LD and cisplatin results in an active therapeutic regimen for unresectable MPM, with an acceptable toxicity profile and improvement in quality of life. ^99mTc-LD showed higher levels of tumour uptake as compared with surrounding tissues.

Liposomal doxorubicin and cisplatin as first-line chemotherapy in unresectable malignant pleural mesothelioma: A phase II study

e13507

Background: Malignant pleural mesothelioma (MPM) is a poor prognosis neoplasm. Its worldwide incidence is rising but until recently chemotherapy has not been shown to be effective in its treatment. The combination of cisplatin and pemetrexed is the approved “standard” treatment in unresectable MPM. Liposomal doxorubicin (LD) consists of pegylated phospholipid- vesicles that encapsulate doxorubicin conferring minimal capture from the reticulo-endothelial system resulting in a greater serum half- life, an enhanced liposome deposition in the tumor and a lower degree of toxicity. We evaluated the combination of LD and Cisplatin (Cis) in chemonaive patients with unresectable MPM. Methods: From September 2006 to October 2008, consecutive patients with stage III / IV MPM were included to receive LD 40 mg/m2 and Cis 60 mg/m2 every 21 days for a maximum of 4 cycles. Imaging studies were performed prior and after 2 cycles to assess response. Gamma camera images (GCI) of Tc-99m-labeled LD were acquired to evaluate LD accumulation in measurable tumor tissue. Patients gave written informed consent. Results: Twenty seven patients were included, 81.5% were stage III and 18.5% were IV. According to EORTC prognostic factors, 33.3% and 66.7% had poor and good prognosis, respectively. Median age was 59.2 years (33–80). Median follow-up was of 5.2 ± 0.8 months. Median survival has not been reached. The 2-year overall survival was 52.5% ± 14.2. Median time to progression was 5.0 ± 1.1 months (CI 95%, 2.7–7.3). Overall response was 45.5%, stable disease 36.4% and progression of 18.2%. GCI showed good accumulation and retention (60%) of the labeled LD in tumor tissue at 4 h after the initial injection. There were no toxic deaths. Conclusions: Cis+LD is a highly active regimen in MPM with comparable results to the most active regimens so far reported. A phase III trial is warranted to confirm these findings.

No significant financial relationships to disclose.