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Charles W Scarantino

Publications and source records attributed to Charles W Scarantino.

6 recordsLinked to original sources
PubMed2005

An analysis of an implantable dosimeter system for external beam therapy.

BACKGROUND AND PURPOSE: To review the data from an implantable radiation dosimetry system used in a clinical setting and to examine correlations between dosimeter readings and potential causative error sources. MATERIALS AND METHODS: MOSFET (metal oxide semiconductor field effect transistor) based encapsulated dosimeters were evaluated in a phantom (in vitro) and in a study with 18 patients. The dosimeters were placed in the gross tumor volume or in collateral normal tissue. Predicted dose values were established by imaging the dosimeters in the planning CTs. RESULTS: The in vitro study confirmed that bounding cumulative errors due to setup, planning, and machine output within a +/-5% level is achievable. In patients, it was found that deviations from the targeted dose often exceeded the 5% level. CONCLUSIONS: The use of an implantable dosimeter system could provide an effective empiric check on the dose delivered at depth. Such a tool may have value for institutional quality assurance, as well as for therapy delivered to individual patients.

Dose-Response Relationship, Radiation↗
PubMed2005

Initial clinical results of an in vivo dosimeter during external beam radiation therapy.

PURPOSE: An implantable radiation dosimeter has been developed to monitor dose delivered at depth in patients undergoing external beam therapy. A clinical pilot study was conducted to test the safety, efficacy, and utility of the device. METHODS AND MATERIALS: Ten patients, all with unresectable malignant disease, were enrolled to assess implantation risk and movement of the device in the body and to compare the in vivo measured dose to the value predicted by the treatment planning system software. RESULTS: Migration of the sensor away from the point of original placement was noted in only 1 patient (due to unconsolidated host tissue) and no adverse events were recorded during the implantation procedure or thereafter. Daily dose measurements were recorded successfully for all sensors in all patients. Variance between measured and predicted dose values was reported as a frequency of error at the > or =5% and > or =8% levels. The error frequency at the > or =8% level was as high as 47%, 29%, and 21% for lung, prostate, and rectal tumors, respectively. CONCLUSIONS: The implantable dosimeter was found to be safe and effective in measuring dose at depth. There are many factors that can influence delivered dose, and the implantable dosimeter measures the net effect of these factors. The daily sensor readings provide a new tool for rigorous treatment quality assurance.

Humans↗
PubMed2005

Randomized trial of short- versus long-course radiotherapy for palliation of painful bone metastases.

BACKGROUND: Radiation therapy is effective in palliating pain from bone metastases. We investigated whether 8 Gy delivered in a single treatment fraction provides pain and narcotic relief that is equivalent to that of the standard treatment course of 30 Gy delivered in 10 treatment fractions over 2 weeks. METHODS: A prospective, phase III randomized study of palliative radiation therapy was conducted for patients with breast or prostate cancer who had one to three sites of painful bone metastases and moderate to severe pain. Patients were randomly assigned to 8 Gy in one treatment fraction (8-Gy arm) or to 30 Gy in 10 treatment fractions (30-Gy arm). Pain relief at 3 months after randomization was evaluated with the Brief Pain Inventory. The Wilcoxon-Mann-Whitney test was used to compare response to treatment in terms of pain and narcotic relief between the two arms and for each stratification variable. All statistical comparisons were two-sided. RESULTS: There were 455 patients in the 8-Gy arm and 443 in the 30-Gy arm; pretreatment characteristics were equally balanced between arms. Grade 2-4 acute toxicity was more frequent in the 30-Gy arm (17%) than in the 8-Gy arm (10%) (difference = 7%, 95% CI = 3% to 12%; P = .002). Late toxicity was rare (4%) in both arms. The overall response rate was 66%. Complete and partial response rates were 15% and 50%, respectively, in the 8-Gy arm compared with 18% and 48% in the 30-Gy arm (P = .6). At 3 months, 33% of all patients no longer required narcotic medications. The incidence of subsequent pathologic fracture was 5% for the 8-Gy arm and 4% for the 30-Gy arm. The retreatment rate was statistically significantly higher in the 8-Gy arm (18%) than in the 30-Gy arm (9%) (P < .001). CONCLUSIONS: Both regimens were equivalent in terms of pain and narcotic relief at 3 months and were well tolerated with few adverse effects. The 8-Gy arm had a higher rate of re-treatment but had less acute toxicity than the 30-Gy arm.

Adult↗
PubMed2004

An implantable radiation dosimeter for use in external beam radiation therapy.

An implantable radiation dosimeter for use with external beam therapy has been developed and tested both in vitro and in canines. The device uses a MOSFET dosimeter and is polled telemetrically every day during the course of therapy. The device is designed for permanent implantation and also acts as a radiographic fiducial marker. Ten dogs (companion animals) that presented with spontaneous, malignant tumors were enrolled in the study and received an implant in the tumor CTV. Three dogs received an additional implant in collateral normal tissue. Radiation therapy plans were created for the animals and they were treated with roughly 300 cGy daily fractions until completion of the prescribed cumulative dose. The primary endpoints of the study were to record any adverse events due to sensor placement and to monitor any movement away from the point of placement. No adverse events were recorded. Unacceptable device migration was experienced in two subjects and a retention mechanism was developed to prevent movement in the future. Daily dose readings were successfully acquired in all subjects. A rigorous in vitro calibration methodology has been developed to ensure that the implanted devices maintain an accuracy of +/-3.5% relative to an ionization chamber standard. The authors believe that an implantable radiation dosimeter is a practical and powerful tool that fosters individualized patient QA on a daily basis.

Animals↗
PubMed2003

Phase III quality-of-life study results: impact on patients' quality of life to reducing xerostomia after radiotherapy for head-and-neck cancer--RTOG 97-09.

PURPOSE: To determine whether prevention of hyposalivation after curative radiotherapy (RT) to the head and neck improves patients' quality of life (QOL). METHODS AND MATERIALS: Patients were to receive at least 50 Gy to 50% of the volume of the major salivary glands, provide unstimulated and stimulated saliva samples, and complete the University of Washington head-and-neck QOL tool before RT and 3 and 6 months after RT. Patients were randomized to receive pilocarpine 5 mg or placebo q.i.d. RESULTS: A total of 249 patients was randomized between March 1998 and January 2000. Of these, 214 were eligible for QOL analysis. Patients were evenly distributed between arms by race, gender, tobacco use, tumor site, T stage (50% T2-T3), and salivary function. A Karnofsky performance status of 90% was more common in the pilocarpine arm. Twenty percent of the patients on the pilocarpine arm and 29% of the patients on the placebo arm were taking nutritional supplements. The placebo arm patients had greater mouth pain and chewing difficulties. Compliance for the QOL tool at 3 and 6 months was 65% and 50%, respectively. Despite statistically significant (p = 0.047 and p = 0.049, respectively) preservation of salivary function in the pilocarpine arm, patients on the pilocarpine arm reported difficulties with swallowing (75%), activity (80%), hyposalivation (64%), and taste (81%). No difference was noted between arms at 3 months in mucositis scores, with both arms demonstrating increased requirement for oral nutrients. CONCLUSION: Objective prevention of hyposalivation did not affect patients' assessment of salivary function or QOL because of the greater impact mucositis plays in QOL after RT.

Female↗