Biomedical subjects

N A Janjan

Publications and source records attributed to N A Janjan.

87 records · Page 5Linked to original sources

PubMed1990

Comparison of dose distribution by means of bolus versus water bath phantom techniques in treatment of cutaneous sarcoma of an extremity.

Cutaneous involvement by Kaposi's sarcoma (KS) is frequently diffuse, requiring large field irradiation. Selective tissue compensation techniques, accomplished with either a 1.5 cm bolus cast or water bath phantom, are compared. Dosimetric determinations were performed using 6 MVX with bone heterogeneity corrections. Application of 1.5 cm bolus effectively eliminated dose buildup and provided tissue compensation equivalent to water bath phantom technique. Treatment of other cutaneous malignancies, such as angiosarcoma, requiring higher total doses, should be accompanied by dosimetric evaluation, because cutaneous and midline dose inhomogeneity may result in a significant total dose differential over the target volume. Application of 1.5 cm bolus improved accuracy in treatment positioning, eliminated concerns regarding infection control in AIDS-related KS, and provided dose homogeneity comparable to the more standard water bath phantom technique.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Angiosarcoma of the forearm definitively treated by hyperfractionated irradiation.

A case report of an angiosarcoma treated definitively with hyperfractionated irradiation is presented. Radial and ulnar aspects of the proximal forearm, wrist, and digits were diffusely involved on angiography. Hyperfractionated irradiation totaling 7,440 cGy was delivered to the entire circumference of the hand, forearm, and distal 5 cm of the arm; a confluent dry erythema without moist desquamation was observed at completion of therapy. No significant local or systemic toxicity was noted with the administration of an Adriamycin-containing adjuvant chemotherapy regimen following irradiation. Local regional control at 2 years is documented both clinically and by angiographic examination and the patient otherwise is free of disease. Function remains excellent with no lymphedema or joint fibrosis observed and grip strength of treated and untreated hands is comparable at 35 pounds. For patients refusing amputation or who are otherwise inoperable, hyperfractionated irradiation provides a therapeutic option.

Adult↗

PubMed1990

Treatment-related toxicities with Fluosol-DA 20% infusion during radiation in advanced head and neck malignancies.

Fluosol-DA 20%, a synthetic perfluorocarbon emulsion first developed as a blood substitute, is currently being investigated as a radiation sensitizer. Theoretically, an oxygen-carrying perfluorocarbon emulsion combined with oxygen inhalation might be able to increase tumor response by decreasing the relative proportion of hypoxic tumor cells. Twenty-one patients with advanced head and neck malignancies receiving primary radiation therapy were evaluated for treatment-related toxicity. Mucosal reactions and weight loss during treatment in the group of patients who received the perfluorocarbon emulsion and the group who did not were comparable. Late sequelae appeared comparable. No patient in either group who completed radiation therapy required an interruption of the treatment course. We conclude that Fluosol-DA 20% is a tolerated adjunct to primary radiation therapy. Further study is needed to determine whether the agent will improve local/regional tumor control.

Blood Substitutes↗

PubMed1989

Mediastinal involvement by myxoid liposarcoma.

Metastatic involvement of the mediastinum by liposarcoma is uncommon, and clinical experience in its management is limited. A patient with liposarcoma of the lower extremity having a concomitant anterior mediastinal mass as the only manifestation of distant metastatic involvement is described.

Adult↗

PubMed1989

Small cell undifferentiated carcinoma of the maxillary sinus: technical considerations for radiation therapy.

Treatment principles for extrapulmonary small cell undifferentiated carcinoma follow those established for primary lung presentations including systemic chemotherapy and prophylactic cranial irradiation. Radiation of carcinoma involving the maxillary sinus includes lateral and anterior portals which exit through the brain. Presented is a treatment strategy used for postoperative radiation of small cell undifferentiated carcinoma of the maxillary sinus in conjunction with prophylactic cranial irradiation. Specifics of dosimetry include achievement of 55 to 60 Gy within the tumor volume of the maxillary sinus, while achieving homogeneity of dose (30 Gy) within the cranial contents. Application of the described technique to analogous clinical presentations is also discussed.

Aged↗

PubMed1989

Dose to the cardiac vascular and conduction systems in primary breast irradiation.

Using computerized tomography (CT) in which cardiac anatomy was defined, doses delivered to the cardiac compartments, vascular and conduction systems were assessed for various standard techniques of primary breast irradiation. Included in the analysis were 6 MV photon tangents (T) alone, or in conjunction with a separate internal mammary field (IMF). Beams evaluated in the IMF were 6 MV photons, 12 MeV electron beam, and mixed photon/electron beam; Cobalt 60 was also analyzed as an alternate photon beam. Treatment of the IMF with photons, either alone or in combination with electron beam, delivered doses ranging between 30 Gy to 50 Gy to all chambers of the heart, coronary arteries and branches of the conduction system. Complete sparing of the posterior cardiac structures and volume is accomplished with treatment plans using tangents alone or in combination with 12 MeV electron beam irradiation to the IMF. Sparing of the anterior wall of the left ventricle, Bundle of His and left anterior descending coronary artery is also achieved in treatment with tangents and 12 MeV electron beam IMF. Doses to this region with tangents alone ranged from 20 Gy to 45 Gy compared to 0 to 30 Gy with tangents and 12 MeV electron beam IMF. Clinical significance of these findings will be discussed.

Breast Neoplasms↗

PubMed1989

Educational role of cancer pain rounds.

Lack of appropriate physician education is one of several reasons for the recognized deficits in cancer pain management. This article describes the educational role of a weekly meeting, "Cancer Pain Rounds," attended by a multidisciplinary team of health professionals skilled in cancer pain management and student physicians caring for inpatients with cancer. Educational benefits occur in three spheres including factual information concerning assessment, treatment, and attitude issues, legitimization of the cancer pain problem, and role modeling. This type of educational experience will hopefully improve cancer pain management.

Analgesia↗

PubMed1988

Mammary carcinoma developing after radiotherapy and chemotherapy for Hodgkin's disease.

Two patients developed breast cancer after treatment of Hodgkin's disease. Both had received mediastinal irradiation 13 to 15 years, respectively, before the diagnosis of breast carcinoma. One patient had synchronous bilateral breast cancer when the diagnosis was made. Discussed is the risk of mammary carcinoma as a second malignant neoplasm in patients treated for Hodgkin's disease.

Adult↗

PubMed1988

Occult carcinoma of the breast masquerading as primary adenocarcinoma of the small intestine. A case report.

A fifty-year-old woman with abdominal pain, diarrhea, and weight loss ultimately required exploratory laparotomy. The entire small intestine was extensively infiltrated by poorly differentiated adenocarcinoma; mesenteric lymph nodes and surrounding omentum were involved, but no extragastrointestinal tumor was found. A presumptive diagnosis of unresectable primary carcinoma of the small bowel was made. Chemotherapy was initiated with 5-fluorouracil 300 mg/m2/day by continuous intravenous infusion. Nine months later a left breast mass with multiple ipsilateral axillary and supraclavicular lymph nodes developed; biopsy revealed a poorly differentiated adenocarcinoma morphologically identical to the tumor involving her small bowel. In spite of breast irradiation and systemic hormonal therapy, the patient deteriorated rapidly and died from progressive metastatic disease.

Breast Neoplasms↗

PubMed1988

Head and neck tumors: dosimetric considerations of mixed-energy photon beam therapy.

The goal of sophisticated treatment planning in radiation therapy is to maximize dose to the tumor or target volume, while the integral dose is minimized, to reduce normal tissue morbidity. In the head and neck regions, the anatomic irregularities of individual patients and the critical structures that limit the administration of dose within the irradiated volumes often complicate the optimization of dosimetry. The availability of dual-energy accelerators that deliver beams of low- and high-energy photons allows the convenient administration of mixed-energy photon irradiation and facilitates the development of optimal treatment strategies for selected lesions. Highly lateralized carcinomas of the upper aerodigestive tract, in which sparing of contralateral cervicofascial tissue is desirable, are particularly well suited for this technique. Treatment plans that make use of irradiation with conventional single-energy beams and mixed-energy photon therapy are compared for representative lesions of the head and neck.

Carcinoma, Squamous Cell↗

PubMed1987

Technique for verifying treatment fields using portal images with diagnostic quality.

The image quality of portal films for megavoltage photon beams, when using the double-exposure technique, is poor compared to diagnostic quality, X ray images. A technique is described to record on a single film a megavoltage portal image superimposed upon a diagnostic X ray image, which provides the radiotherapist with "diagnostic quality" portal images. The technique uses a commercially available X ray tube mounted on the head of a 60Co unit. The alignment procedure, which uses a leveling device to ensure that the X ray focal spot and 60Co source are at the same location for each exposure, is confirmed by registering on film the image of an alignment marker. An evaluation of film-screen combination showed therapy verification film in a rare earth intensifying screen cassette to be best suited for this technique. The relationship between off-axis dose and the penumbral region of the portal image has been evaluated and should be useful in the interpretation of portal verification film relative to the treatment volume.

Cobalt Radioisotopes↗

PubMed1986

Management of locoregional recurrent breast cancer.

The influence of radiation and/or chemotherapy on locoregional tumor control and survival in patients treated for recurrent breast cancer after radical or modified radical mastectomy is retrospectively evaluated in 164 patients treated between 1972 and 1983 at the University of Texas M. D. Anderson Hospital. Treatment consisted of radiation alone in 57 patients, chemotherapy alone in 50 patients, and a combination of radiation and chemotherapy in 57 patients. Important differences in the composition of these three groups include a preponderance of postmenopausal women (44% vs. 32%) and more patients with four or more positive axillary nodes at the time of initial mastectomy (32% vs. 18%) in the radiotherapy group. Locoregional control of recurrent cancer was achieved in 65% of patients with radiotherapy compared to 46% of patients with chemotherapy (P = 0.049) and 67% with chemotherapy and radiotherapy. The addition of chemotherapy produced a trend toward improved disease-free survival rates. The two prognostic factors affecting tumor control and survival in this study are the tumor burden of the recurrence and the histologic axillary node status at the time of the initial mastectomy.

Adult↗

PubMedDate not supplied

Predictors of recurrence after local excision and postoperative chemoradiation therapy of adenocarcinoma of the rectum.

BACKGROUND: Local excision of rectal cancer preserves anal continence, bladder function, and normal sexual function. However, local recurrence after excision remains a significant problem. To further define the indications for local excision, we analyzed possible factors predictive of recurrence after local excision of rectal cancer. METHODS: The charts of all patients undergoing local excision of adenocarcinoma of the rectum between 1985 and 1995 at a single institution were reviewed. Patients with metastatic disease at the time of excision and patients treated preoperatively with chemoradiation therapy were excluded. All available slides were reviewed by a single pathologist, who assessed the depth of invasion; the presence or absence of vascular invasion, lymphatic invasion, perineural invasion, and lymphocytic infiltrate; the mucinous status; and the degree of differentiation. Using the log-rank test and Cox proportional hazards model, univariate and multivariate analyses were performed to identify predictors of recurrence. RESULTS: Ninety patients underwent local excision, 46 transanally and 44 using a Kraske approach. The breakdown of patients by tumor stage was as follows: Tis, 13%; T1, 41%; T2, 30%; T3, 15%; and Tx, 1%. Sixty-eight percent of patients with T1 tumors were treated with postoperative radiotherapy; all patients with T2 or T3 tumors were treated postoperatively with or without 5-fluorouracil. The median duration of follow-up was 51 months. The median tumor diameter was 2.5 cm (range, 0.4 to 7 cm), and the median distance of the tumor from the anal verge was 4.5 cm (range, 1 to 10 cm). The 4-year actuarial local disease-free survival rate broken down by tumor stage was as follows: Tis, 100%; T1, 95%; T2, 80%; and T3, 73%. The median time to local recurrence was 23 months (range, 7 to 61 months). Multivariate analysis showed that only tumor stage and margin status were predictors of local recurrence. CONCLUSIONS: Local excision and postoperative radiotherapy result in adequate local control of early stage (Tis and T1) adenocarcinoma of the rectum. Higher rates of recurrence were seen in patients with T2 and T3 tumors, especially in those with positive margins.

Adenocarcinoma↗

PubMedDate not supplied

Re-resection with brachytherapy for locally recurrent soft tissue sarcoma arising in a previously radiated field.

PURPOSE: The use of further radiotherapy among patients with soft tissue sarcoma that recurs in a previously irradiated area is controversial. Presented is a review of our 7-year experience with brachytherapy for recurrent soft tissue sarcoma. METHODS: A retrospective review was performed of 26 patients who underwent perioperative brachytherapy between 1990 and 1997 for recurrent soft tissue sarcoma. In all cases, the sarcoma recurred within a previously irradiated field. After-loading brachytherapy catheters were placed at the time of surgical extirpation of the sarcoma within a single-plane implant by use of 1-cm intercatheter spacing. Insertion of the radioactive 192Ir wire was delayed until the fifth to seventh postoperative day to allow initial wound healing. The prescribed dose rate for the 192Ir wire ranged between 50 and 80 cGy an hour, and the dose was specified at 0.5 cm from the plane of the implant. The anatomic locations treated included lower extremity (N = 10), upper extremity (N = 7), trunk (N = 7), and head and neck (N = 2). RESULTS: Total tumor extirpation, confirmed by negative frozen section margins, was accomplished in all cases. The mean dose of external-beam irradiation received before brachytherapy was 55.6 Gy +/- 1.8 Gy (range, 30.0 to 70.3 Gy). The mean dose of radiation prescribed at the implant procedure was 47.2 Gy +/- 1.6 Gy (range, 11.0 to 50.0 Gy). A tissue transfer flap was placed over the bed of resection in 13 cases. Complications occurred in five patients including, three with wound breakdown, one with osteonecrosis, and with neuralgia. Operative intervention was required in four of the five patients with complications; each of the patients requiring operative intervention for wound-related complications had undergone primary wound closure without tissue transfer. Recurrence of disease occurred in 13 patients: nine local and four distant metastases. The median follow-up was 16 months (range, 2 to 73 months). The 5-year local recurrence-free, distant recurrence-free, disease-free, and overall survival rates after brachytherapy were 52%, 75%, 33%, and 52%, respectively. CONCLUSION: Re-irradiation of recurrent soft tissue sarcoma by brachytherapy in conjunction with resection can be performed with acceptable complication rates. Local control can be achieved for the majority of patients who would otherwise require more radical surgical procedures.

Adult↗

PubMedDate not supplied

Preoperative chemoradiation and pancreaticoduodenectomy for adenocarcinoma of the pancreas.

The goal of multimodality therapy for localized pancreatic cancer is to maximize local-regional disease control and patient survival. In contrast to surgery for other solid tumors, prolonged recovery following pancreaticoduodenectomy may prevent the timely delivery of postoperative adjuvant therapy. Therefore, efforts at The University of Texas, M.D. Anderson Cancer Center have focused on the delivery of chemotherapy and radiation therapy prior to surgery in patients with localized pancreatic cancer. Clinical trials have emphasized the use of altered-fractionation schedules of radiation therapy combined with novel radiation-sensitizing agents. All treatment schemes aim to decrease toxicity and treatment time while improving therapeutic efficacy.

Adenocarcinoma↗