Biomedical subjects

Phillip M Devlin

Publications and source records attributed to Phillip M Devlin.

8 recordsLinked to original sources

PubMed2006

Magnetic resonance-guided interstitial therapy for vaginal recurrence of endometrial cancer.

PURPOSE: To evaluate the feasibility and to describe the acute toxicity of a real-time intraoperative magnetic resonance (MR)-image guided interstitial approach to treating vaginal recurrence of endometrial cancer. METHODS AND MATERIALS: From February 2004 to April 2005, 10 patients with recurrent endometrial cancer underwent MR-guided interstitial brachytherapy. Parameters evaluated included needle placement, dose-volume histograms (DVH), and complications. RESULTS: Magnetic resonance-image guidance resulted in accurate needle placement. Tumor DVH values included median volume, 47 cc; V100, 89%; V150, 61%; V200, 38%; D90, 71 Gy; and D100, 60 Gy. DVH of organs at risk resulted in a median D2cc of external beam and brachytherapy dose (% of brachytherapy prescription): bladder, 75Gy(3) (88%); rectum, 70Gy(3) (87%); and sigmoid, 56Gy(3) (41%). All patients experienced either a Grade 1 or 2 acute toxicity related to the radiation; only 1 patient had Grade 3 toxicity. No toxicities were attributable to the use of MR guidance. CONCLUSIONS: Real-time MR guidance during the insertion of interstitial needles reduces the likelihood of an inadvertent insertion of the needles into the bladder and the rectum. Three-dimensional dosimetry allows estimation of the dose to organs at risk. Toxicities are limited.

Aged↗

PubMed2005

The history of the smallpox vaccine.

Smallpox was a highly virulent, contagious disease. Initial attempts to control the disease by variolation were controversial and dangerous. Variolation was the subject of some of the earliest published clinical trials. Vaccination was discovered by Edward Jenner in 1796. From initial skepticism by the medical community the uptake became so widespread that smallpox vaccination was made compulsory in England and Wales in 1853. Eventually, this led to the eradication of smallpox in 1980. Parallels can be drawn with modern vaccination and the smallpox vaccine especially with the current intense media scrutiny of modern vaccinations.

History, 18th Century↗

PubMed2005

CT computer-optimized high-dose-rate brachytherapy with surface applicator technique for scar boost radiation after breast reconstruction surgery.

PURPOSE: Immediate breast reconstruction has become increasingly prevalent after mastectomy for breast cancer. Postoperative scar boost radiation for the reconstructed breast presents many planning challenges due to the shape, size, and curvature of the scar. High-dose-rate (HDR) surface applicator brachytherapy is a novel and effective method of delivering scar boost radiation. Two cases, one with a saline implant and one with a transverse rectus abdominis musculocutaneous flap reconstruction, illustrate the method and advantages of HDR optimization of surface applicators. METHODS AND MATERIALS: For 2 patients a mold of the breast was made with Aquaplast sheets. A reproducible system was used for arm positioning. Skin fiducials, including tattoos from external beam planning, were matched to fiducials on the mold. HDR catheters were sited on the mold at 1cm intervals, with the central catheter situated along the scar. Topographically, both scars demonstrated extreme curvature in both craniocaudal and mediolateral directions. A CT computer-optimized HDR plan was developed, with the reference dose prescribed at the skin surface. The dosimetry was compared to single-field and matched-field electron plans. RESULTS: This surface applicator technique provided a uniform skin dose of 100% to the entire clinical target volume (CTV) without hot spots in both patients. The patient position and surface applicator setup were consistently reproducible. The patients tolerated the treatment well with minimal skin erythema. In the single-field electron plan, skin dose was decreased to 50% at the periphery of the scar. Matching fields addressed this depth dose decrement, but resulted in large localized hot spots of more than 200% centrally in each field. CONCLUSION: CT computer-optimized HDR surface applicator brachytherapy provided a reproducible homogeneous method of treating highly curved scars on the reconstructed breast. Electron beam treatment would result in longer and more complex treatments yet still provide a less homogeneous dose than this surface applicator technique.

Brachytherapy↗

PubMed2004

Dosimetric consequences of manual pullback procedure for coronary artery radiotherapy with 90Sr/90Y beta-source.

PURPOSE: This work presents a quantitative dosimetric analysis of the Novoste (90)Sr/(90)Y beta-source cardiovascular brachytherapy treatments using a manual pullback technique for patients with in-stent restenosis. METHODS AND MATERIALS: Based on our previous measurements, a model was developed to estimate the dose in the middle of the junction region for tandem irradiation expressed as fraction of prescription dose (FPD) and dosimetric overlap length (DOL) receiving more/less than a threshold dose. The overlap/gap size was measured using the digital cine images recorded during treatment and then FPD and DOL were quantified. RESULTS: Statistical analysis of 55 patients showed that the overlap size and the FPD at 2 mm radial distance were in range of 0 to 23 mm and 13-200% of prescription dose (Rx), respectively. Four gaps out of 76 pullback cases were found, but their size was at most 5 mm. CONCLUSION: Use of a 5 mm overlap avoided underdosed regions in the vast majority of the cases. These results are the first step towards an analysis of the clinical outcome of these patients.

Brachytherapy↗

PubMed2004

Prospective phase II trial of PFL-induction chemotherapy followed by definitive local treatment for advanced squamous cell carcinoma of the head and neck: 10-year follow-up.

Reported is an analysis of overall survival at 10 years of 102 patients with advanced squamous cell carcinoma of the head and neck (SCCHN) who were enrolled in a prospective phase II trial of high-dose cisplatin, 5-fluorouracil (5-FU), and high-dose leucovorin (PFL) induction chemotherapy followed by surgery and/or definitive radiation therapy (RT) between 1987 and 1991. Initially, 14 patients underwent primary site (PS) and neck surgery irrespective of the clinical response to PFL. The high rate of clinical and pathologic complete response (CR) to PFL prompted a switch from PS surgery to definitive RT. Of 102 patients, 18 (17.6%) who completed PFL and local-regional treatment for SCCHN between 1988 to 1991 were alive in December 2000. Among these, 1 of 14 patients (7%) who had undergone PS resection and 17 of 85 (20%) who were treated after PFL with definitive RT but without PS surgery were alive at 10 years. Median survival time was higher in the nonsurgical group (98.9 vs. 51.9 months). Subset analysis suggested that patients with oropharyngeal PS had the longest median survival (108.6 months). The oropharyngeal patients represented the 61% (11/18) of the long-term survivors with organ preservation. An organ preservation approach for patients with advanced SCCHN who demonstrated PS CR to chemotherapy demonstrated a trend to improved overall survival.

Adolescent↗

PubMed2003

GAF film dosimetry of a tandem positioned beta-emitting intravascular brachytherapy source train.

Coronary artery brachytherapy may require treatment of lesions longer than a single source length. A treatment option is tandem positioning of the single source. This study presents relative dosimetric measurements of a cardiovascular brachytherapy source and the dosimetric characteristics in the junction region of tandem treatments. Measurements were carried out using a Novoste Beta Cath 90Sr/90Y 40 mm beta source in a plastic water phantom. Radiochromic MD-55-2 film, calibrated using both 6 MV photon and 6 MeV electron beams from a linear accelerator, was used as the dosimeter. Dose distributions around a single source and in the junction region of tandem irradiation were measured. Measurements of the near field dose as close as 1.2 mm from the source are presented. Significant over- or underdoses in the junction region of tandem irradiation were quantified. At a radial distance of 2 mm from the longitudinal axis of the source, the dose value in the middle of the junction region, normalized to the dose at 2 mm midline single source, was about 182% for a 2-seed overlap and 16% for a 2-seed gap, respectively. Dose distributions in the junction region as a function of source overlap and radial distance have fairly high gradients and exhibit characteristic patterns. The fraction of prescription dose was found to have a sigmoidal dependence on overlap size, for radial distances ranging between 1.2 and 3 mm. The parameters of these sigmoids, quantified as functions of radial distance, could be used to provide quick and reasonable over/underdose estimates, given any potential overlap or gap in the junction area, with an uncertainty within 10%.

Beta Particles↗

PubMed2002

Gemcitabine-induced radiation recall.

PURPOSE: To study and report 6 patients with radiation recall in unique sites, secondary to gemcitabine chemotherapy. METHODS AND MATERIALS: The clinical presentations and outcomes of 6 patients with radiation recall secondary to gemcitabine chemotherapy were retrospectively analyzed over the course of a 1-year period. RESULTS: Radiation recall reactions were seen in the central nervous system, skin, gastrointestinal tract, and in the lymphatic and musculoskeletal systems. The time between initiation of radiation and recall of the radiation phenomenon ranged from 3 weeks to 8 months from the time gemcitabine was initiated. The usual dosage of gemcitabine in these cases was 1000 mg/m(2) given on a weekly basis. No radiation therapy was given concomitantly with gemcitabine. Treatment of the recall reaction consisted of discontinuing gemcitabine and initiating steroid therapy, supportive therapy, and/or nonsteroidal anti-inflammatory agents. Minimal improvement was seen in 3 out of 6 patients, and resolution of the radiation recall was seen in 3 out of 6 patients. A comprehensive review of the literature revealed that radiation recall with gemcitabine has been related to skin reactions only; no previous cases of radiation recall occurring in the central nervous system have been reported with any chemotherapy agent. CONCLUSION: Radiation recall from gemcitabine chemotherapy is rare, but can potentially arise in any site that has been previously irradiated. Treating physicians must be aware of this potential toxicity from gemcitabine and radiation and discontinue the gemcitabine if radiation recall is observed.

Adult↗

PubMed2002

An Internet-ready database for prospective randomized clinical trials of high-dose-rate brachytherapy for adenocarcinoma of the prostate.

PURPOSE: To demonstrate a new interactive Internet-ready database for prospective clinical trials in high-dose-rate (HDR) brachytherapy for prostate cancer. METHODS AND MATERIALS: An Internet-ready database was created that allows common data acquisition and statistical analysis. Patient anonymity and confidentiality are preserved. These data forms include all common elements found from a survey of the databases. The forms allow the user to view patient data in a view-only or edit mode. Eight linked forms document patient data before and after receiving HDR therapy. The pretreatment forms are divided into four categories: staging, comorbid diseases, external beam radiotherapy data, and signs and symptoms. The posttreatment forms separate data by HDR implant information, HDR medications, posttreatment signs and symptoms, and follow-up data. The forms were tested for clinical usefulness. CONCLUSION: This Internet-based database enables the user to record and later analyze all relevant medical data and may become a reliable instrument for the follow-up of patients and evaluation of treatment results.

Adenocarcinoma↗