Research progress in gold nanoclusters for radiosensitization / 中华放射医学与防护杂志

Radiotherapy still fails to achieve satisfactory efficacy in the treatment of malignant tumors, and applying radiotherapy sensitizers is an effective method to improve the efficacy of radiotherapy. Gold nanomaterials can effectively increase the sensitivity of tumor cells to radiotherapy due to their high atomic numbers. Gold nanoclusters have more excellent radiobiological and radiophysical properties due to their smaller size. This paper reviews the special radiobiological and radiophysical properties of gold nanoclusters and describes in detail their sensitizing effects in external radiation radiotherapy, radionuclide therapy, and X-ray induced photodynamic therapy.

The Results of Hyperfractionated Radiation Therapy Combined with Taxol for Paraaortic Node Recurrence in Cervix Cancer / 대한방사선종양학회지

PURPOSE: The aim of this study was to investigate treatment results, toxicity and efficacy of hyperfractionated radiation therapy combined with paclitaxel for paraaortic node recurrence in cervix cancer. MATERIALS AND METHODS: Between September 1997 to March 1999, 12 patients with paraaortic node recurrence in cervix cancer who previously received radical or postoperative radiotherapy were treated with hyperfractionated radiation therapy combined with paclitaxel. Of these, 2 patients who irradiated less than 30 Gy were excluded, 10 patients were eligible for this study. Median age was 5 1 years. Initial FlGO stage was 1 stage IB1, 2 stage IIA, 7 stage IIB. For initial treatment, 7 patients received radical radiotherapy and 3 received postoperative radiotherapy. The paraaortic field encompassed the gross recur rent disease with superior margin at T 12, and inferior margin was between L5 and S 1 with gap for previously pelvic radiation field. The radiation field was initially anterior and posterior opposed field followed by both lateral field. The daily dose was 1.2 Gy, twice daily fractions, and total radiotherapy dose was between 50.4 and 60 Gy(median, 58.8 Gy). Concurrent chemotherapy was done with paclitaxel as a radiosensitizer. Dose range was from 20 mg/m to 30 mg/m (median, 25 mg/m'), and cycle of chemotherapy was from 3 to 6 (median, 4.5 cycle). Follow-up period ranged from 3 to 21 months. RESULTS: Interval between initial diagnosis and paraaortic node recurrence was range from 2 to 63 months (median, 8 months). The 1 year overall survival rate and median survival were 75% and 9.5 months, respectively. The 1 year disease free survival rate and median disease free survival were 30% and 3 7 months, respectively. At 1 month after treatment, 4 (40%) achieved a complete response and 6 (63%) experienced a partial response and all patients showed response above the partial response. There was distant metastasis in 6 patients and pelvic node recurrence in 2 patients after paraaortic node irradialion. There was 2 patients with grade 3 to 4 leukopenia and 8 patients with grade 1 to 2 nausea/ vom ting which was usually tolerable with antiemetic drug. There was no chronic complication in abdomen and pelvis during follow up period. CONCLUSION: Hyperfractionated radiation therapy combined with paclitaxel as a radiosensitizer showed high response rate and few complication rate in paraaortic node recurrence in cervix cancer. Therefore, present results suggest that hyperfractionated radiation therapy combined with paclitaxel chemotherapy can be used as optimal treatment modality in this patients.

Low Dose Cisplatin as a Radiation Sensitizer in Management of Locally Advanced Squamous Cell Carcinoma of the Uterine Cervix: Evaluation of Acute Toxicity and Early Response / 대한방사선종양학회지

PURPOSE: To evaluate possible acute toxicity and early response of concurrent radiation therapy and low dose daily cisplatin as a radiosensitizer in patients with locally advanced uterine cervical carcinomas. MATERIALS AND METHODS: From December 1996 to January 1999, 38 previously untreated patients with locally advanced squamous cell carcinoma of the uterine cervix (from stage IIB to stage IIIB) were treated at Inha University Hospital. All patients underwent standard pretreatment staging procedures after the initial evaluation by gynecologists and radiation oncologists. Sixteen patients with huge cervical mass (>4 cm) were submitted to the group treated with concurrent radiation therapy and low dose daily cisplatin while the remainder was treated with radiation therapy alone. Radiation therapy consisted of 4500 cGy external beam irradiation to whole pelvis (midline block after 3060 cGy), 900~1000 cGy boost to involved parametrium, and high dose-rate intracavitary brachytherapy (a total dose of 3000~3500 cGy/500 cGy per fraction to point A, twice per week). In the group treated with low dose cisplatin concurrently, 10 mg of daily intravenous cisplatin was given from the 1st day of radiation therapy to the 20th day of radiation therapy. Acute toxicity was measured according to expanded common toxicity criteria of the NCI (C) Clinical Trials. Early response data were analyzed at minimum 4 weeks' follow-up after completion of the treatment protocol. RESULTS: Hematolgic toxicity was more prominent in patients treated with radiation therapy and cisplatin. Six of 16 patients (37.5%) treated with radiation therapy and cisplatin and one of 22 patients (4.5%) treated with radiation therapy alone experienced grade 3 leukopenia. In Fisher's exact test, there was statistically significant difference between two groups regarding leukopenia (P=0.030). There was no apparent difference in the frequency of gastrointestinal and genitourinary toxicity between two groups (P=0.066). Three of 16 patients (18.7%) treated with radiation therapy and cisplatin and two of 22 patients (9.1%) treated with radiation therapy alone experienced more than 5 kg weight loss during the treatment. There was no statistically significant difference on weight loss between two groups (P=0.63). Two patients on each group were not evaluable for the early response because of incomplete treatment. The complete response rate at four weeks' follow-up was 80% (16/20) for the radiation therapy alone group and 78% (11/14) for the radiation therapy and cisplatin group. There was no statistically significant difference in early response between two treatment groups (P=0.126). CONCLUSION: This study led to the conclusion that the hematologic toxicity from the treatment with concurrent radiation therapy and low dose daily cisplatin seems to be more prominent than that from the treatment of radiation therapy alone. There was no grade 4 hematologic toxicity or mortality in both groups. The hematologic toxicity in both treatment groups seems to be well managable medically. Since the risk factors were not balanced between two treatment groups, the direct comparison of early response of both groups was not possible. However, preliminary results regarding early response for patients with bulky cervical tumor mass treated with radiation therapy and low dose daily cisplatin was encouraging. Longer follow-up is necessary to evaluate the survival data. A phase III study is needed to evaluate the efficacy of concurrent daily low dose cisplatin with radiation therapy in bulky cervical cancer.