The results of this pilot study suggested that (62)Cu-ATSM uptake may be a predictive indicator of tumor response to chemoradiotherapy in patients with locally advanced head and neck cancer.
Cell-free plasma DNA is elevated in cancer patients and decreases in response to effective treatments. Consequently, these nucleic acids have potential as new tumor markers. In our current study, we investigated whether the plasma DNA concentrations in patients with cancer are altered during the course of radiation therapy. To first determine the origin of cell-free plasma DNA, plasma samples from mice bearing transplanted human tumors were analyzed for human-specific and mouse-specific cell-free DNA. Human-specific DNA was detectable only in plasma from tumor-bearing mice. However, mouse-specific plasma DNA was significantly higher in tumorbearing mice than in normal mice, suggesting that cell-free plasma DNA originated from both tumor and normal cells. We measured the total cell-free plasma DNA levels by quantitative polymerase chain reaction in 15 cancer patients undergoing radiation therapy and compared these values with healthy control subjects. The cancer patients showed higher pretreatment plasma DNA concentrations than the healthy controls. Eleven of these patients showed a transient increase of up to eightfold in their cell-free plasma DNA concentrations during the first or second week of radiation therapy, followed by decreasing concentrations toward the end of treatment. In two other cancer patients, the cell-free plasma DNA concentrations only decreased over the course of the treatment. The total cell-free plasma DNA levels in cancer patients thus show dynamic changes associated with the progression of radiation therapy. Additional prospective studies will be required to elucidate the potential clinical utility and biological implications of dynamic changes in cell-free plasma DNA during radiation therapy. (Cancer Sci 2009; 100: 303-309) T he response of malignant tumors to radiation therapy varies, even if they show similar histopathological origins and clinical staging. An accurate assessment of the radiation sensitivity of individual tumors during the early phase of radiation therapy could provide valuable guidance for selecting the most appropriate treatment plan for individual patients, such as patientspecific modifications of the dose and field of radiation therapy, or additional or alternative therapeutic modalities earlier in the course of treatment. This in turn might contribute to better patient outcomes. However, conventional methods, including imaging diagnoses using computed tomography and magnetic resonance imaging or histopathological examination of biopsy samples, are limited in their ability to evaluate the radiation sensitivity of individual tumors during or immediately following radiation therapy. Hence, alternative assessment methods are required.Previous studies have shown that cell-free DNA is present in the bloodstream of cancer patients at higher concentrations than in healthy controls.(1-4) Although the cell origins and the mechanisms underlying cell-free DNA generation in cancer patients are not yet fully understood, it has been suggested that tumor cells might actively secr...
Background: Extramammary Paget's disease (EMPD) is a relatively rare malignancy, and there are few reports related to radiation therapy. In the present study, we investigated the outcome of radiation therapy for EMPD.Patients and methods: Forty-one patients with EMPD in the genitalia underwent radiation therapy with curative intent.Fifteen patients had regional lymph node metastases before radiation therapy, but none had distant metastasis. Total doses of 45-80.2 Gy (median, 60 Gy) were delivered to tumor sites in 23-43 fractions (median, 33 fractions).Results: At a median follow-up period of 41 months, 16 patients had developed recurrences, including 5 with local progression within the radiation field and 12 with lymph node or/and distant metastases outside the radiation field. The local progression-free and disease-free rates were 88% and 55% at 3 years, and 82% and 46% at 5 years, respectively. Nine patients died at 6-73 months after irradiation; the causes of death were tumor progression in five patients, infectious pneumonia in two, renal failure in one and old age in one. The overall and cause-specific survival rates were 93% and 96% at 3 years, and 68% and 84% at 5 years, respectively. Tumor invasion into the dermis and regional lymph node metastasis were significant prognostic factors for both distant metastasis and survival. No therapy-related toxicities of grade ≥3 were observed.Conclusions: Radiation therapy is safe and effective for patients with EMPD. It appeared to contribute to prolonged survival owing to good tumor control, and to be a promising curative treatment option.
The accuracy of the CyberKnife Synchrony Respiratory Tracking System (SRTS) is considered to be patient‐dependent because the SRTS relies on an individual correlation between the internal tumor position (ITP) and the external marker position (EMP), as well as a prediction method to compensate for the delay incurred to adjust the position of the linear accelerator (linac). We aimed to develop a system for obtaining pretreatment statistical measurements of the SRTS tracking error by using beam's eye view (BEV) images, to enable the prediction of the patient‐specific accuracy. The respiratory motion data for the ITP and the EMP were derived from cine MR images obtained from 23 patients. The dynamic motion phantom was used to reproduce both the ITP and EMP motions. The CyberKnife was subsequently operated with the SRTS, with a CCD camera mounted on the head of the linac. BEV images from the CCD camera were recorded during the tracking of a ball target by the linac. The tracking error was measured at 15 Hz using in‐house software. To assess the precision of the position detection using an MR image, the positions of test tubes (determined from MR images) were compared with their actual positions. To assess the precision of the position detection of the ball, ball positions measured from BEV images were compared with values measured using a Vernier caliper. The SRTS accuracy was evaluated by determining the tracking error that could be identified with a probability of more than 95% (Ep95). The detection precision of the tumor position (determined from cine MR images) was <0.2 mm. The detection precision of the tracking error when using the BEV images was <0.2 mm. These two detection precisions were derived from our measurement system and were not obtained from the SRTS. The median of Ep95 was found to be 1.5 (range, 1.0–3.5) mm. The difference between the minimum and maximum Ep95 was 2.5 mm, indicating that this provides a better means of evaluating patient‐specific SRTS accuracy. A suitable margin, based on the predicted patient‐specific SRTS accuracy, can be added to the clinical target volume.PACS number: 87.53.Ly
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