A retrospective quality of life analysis using the Lung Cancer Symptom Scale in patients treated with palliative radiotherapy for advanced nonsmall cell lung cancer.

PURPOSE: To measure symptom palliation in patients treated with radiation therapy for advanced nonsmall cell lung cancer (NSCLC). METHODS AND MATERIALS: Five hundred thirty patients with NSCLC were treated at the Medical College of Virginia between 1988 and 1993. Sixty-three patients with the least favorable prognostic features received palliative radiation to 30 Gy in 10 or 12 fractions for symptoms related to the presence of intrathoracic tumor. The observer portion of the Lung Cancer Symptom Scale (LCSS) was employed in a retrospective chart review, scoring measures of appetite, fatigue, cough, dyspnea, hemoptysis, and pain. RESULTS: In 54 evaluable patients, median survival was 4 months and was independent of age, stage, performance status, or histology. Ninety-six percent of the patients had at least one LCSS symptom at presentation. Fatigue was unaffected by therapy. Improvements in appetite (p = 0.68) and pain (p = 0.61) were not statistically significant. There was, however, a statistically significant reduction in cough (p = 0.01), hemoptysis (p = 0.001), and dyspnea (p = 0.0003). Self-limiting acute side effects included transient esophagitis in 37% of patients, though no severe toxicities were noted. CONCLUSIONS: These results suggest symptomatic benefit from radiotherapy even in those NSCLC patients with advanced disease and a limited life expectancy. Treatment should be given to patients whose symptoms are most amenable to palliation. A site-specific quality of life instrument such as the LCSS should be included within any future clinical trial of NSCLC management so that symptom control may be scored as a treatment outcome in addition to disease-free survival.

Tissue compensation using dynamic collimation on a linear accelerator.

PURPOSE: The availability of computer-controlled collimators on some accelerators has led to techniques for dynamic beam modification, mainly to simulate beam wedge filters. This work addresses the practical aspects of dynamic tissue compensation in one dimension using available treatment-planning software. METHODS AND MATERIALS: Data derived from the treatment-planning program is used with an iterative calculational routine to determine the monitor unit settings needed for the collimator-controlling computer. The method was first tested by simulating a 60 degrees physical wedge. Further studies were carried out on a specially fabricated plastic phantom that modeled the sagittal contour of the upper torso, neck, and lower head regions. RESULTS: Dynamic wedge point doses generated by the planning program agreed within 1% with the values directly measured in a polystyrene phantom. In the patient phantom, dynamic collimation achieved calculated dose uniformity within 0.5% in a reference plane near the phantom midline. A comparison of computer-generated and measured point doses in this case showed agreement within 3%. CONCLUSIONS: Dynamic collimation can provide effective compensation for contours that vary primarily along one direction. A conventional treatment-planning program can be used to plan dynamic collimation and deliver a prescribed dose with reliable accuracy.

Reirradiation of head and neck neoplasms using twice-a-day scheduling.

Between 1985 and 1988, we have explored the value of twice-a-day (BID) irradiation for the retreatment of head and neck neoplasms. In this pilot study of ten patients we used a schedule of BID irradiation at fraction sizes between 1.4 and 1.6 Gy separated by at least 6 h. Of the four patients were treated with curative intent, three patients received 30 Gy in 20 fractions over twelve days followed within ten days by an interstitial/intracavitary Ir-192 implant boost to doses of 30 to 40 Gy and one patient was treated with a 32 Gy BID boost. Four patients were reirradiated with aggressive palliation and received 45 Gy in 30 fractions over 26 days including a break in the third week. The remaining two patients were treated with palliative intent to 30 Gy in 20 fractions over twelve days. Eight patients were treated for recurrent/persistent or second carcinomas, one for a recurrent glomus jugulare tumor. At a median follow-up of 36 months, ranging from six to 61 months, nine of ten patients experienced excellent symptomatic relief. Five patients are alive and free of tumor, one patient is alive with distant metastases, and two each are dead from local or systemic tumor progression. All four patients retreated for cure are alive with no evidence of local disease. The tolerance and tumor control rate of the BID reirradiation schedule were good with severe late sequelae in only one patient.

External beam radiotherapy for primary spinal cord tumors.

Of 34 evaluated patients with primary spinal cord tumors, 32 were irradiated at our institutions between 1969 and 1983. The results are reported of 32 patients, 16 with ependymoma and 16 with astrocytoma, who were treated with postoperative external beam radiotherapy following biopsy or subtotal resection. Twenty-nine patients received 45-55 Gy megavoltage beam irradiation in five to six weeks, and the remaining three patients received less than 40 Gy. The minimum follow-up was five years. Five- and ten-year actuarial survival rates for the entire group of patients were 73% (22/30) and 50% (8/16), respectively, including three patients who were salvaged by surgery after radiotherapy failures. Corresponding five- and ten-year relapse-free survival rates were 60% (18/30) and 32% (6/19), respectively. Of the 29 patients who received more than 45 Gy, relapse-free survival at five years was 63% (17/27). Treatment failed in 13 patients, and all of those failures were within the irradiated portals. Patients with ependymomas have significantly better relapse free survival than those with astrocytomas, 80% vs. 40% (p less than 0.05). There was a significant difference in survival between patients with tumors involving the cervical spine and those with tumors in the other locations, 45% vs. 89% (p less than 0.05). There was no significant difference in survival between patients with cauda equina tumors and those with tumors of the spinal cord, 100% vs. 68% (p less than 0.05). No radiotherapy-related neurological deficit was noted with a maximum 20 year follow-up. This study confirms that external beam radiotherapy is a safe and effective treatment modality for primary spinal cord tumors.

Uterine thickness determination using real-time ultrasonography: a guide for intracavitary brachytherapy in the treatment of endometrial carcinoma.

Two patients with medically inoperable stage I endometrial carcinoma were treated with intracavitary implants alone using Simon capsules, tandems, and ovoids. In both cases, uterine thickness was measured during the implant procedure by realtime ultrasonography. Tumor doses in both patients were then calculated to the midmyometrium and to the serosal surface of the uterus. These estimates, rather than the usual milligram-hours or points A and B, were used to make treatment decisions.

Modulation in the radiosensitivity of MCF-7 human breast carcinoma cells by 17B-estradiol and tamoxifen.

Colony-forming ability after exposure to ionizing irradiation was compared for proliferating hormone response MCF-7 breast carcinoma cells and cells whose growth was inhibited by tamoxifen or 17B-estradiol. As compared with controls (Do = 1.20 Gy, n = 3.1), cells in 1 microM or 5 microM tamoxifen were less radiosensitive (Do = 1.20 Gy, n = 7.0; Do = 1.22 Gy, n = 7.0, respectively) with the predominant effect being a widened shoulder on the survival curve. This protective effect could be abolished by co-incubation of 5 microM tamoxifen with 100 nM 17B-estradiol (Do = 1.30 Gy, n = 2.6; Do = 1.20 Gy, n = 2.6, respectively). The decrease in radiosensitivity induced by tamoxifen was similar to that seen when replating of irradiated plateau-phase cultures was delayed for 24 h (Do = 1.30 Gy, n = 6.0). In contrast, when proliferation of MCF-7 cultures was inhibited by 10 microM 17B-estradiol, radiosensitivity was increased with a markedly diminished survival curve shoulder (Do = 1.40 Gy, n = 1.0). Different hormonal manipulations of cycling human breast carcinoma cells may have profound but disparate effects on radiosensitivity such that tamoxifen and estrogens may serve as useful agents with which to study the biochemical mechanisms of repair.

Tumor margin assessment as a guide to optimal conservation surgery and irradiation in early stage breast carcinoma.

Between 1982 and 1985, 108 women with AJC Stage I and II invasive mammary carcinoma were treated to 115 breasts with conservative surgery and irradiation. The irradiation dose was adjusted to the histopathological normal tissue margin around the carcinoma in the tumor excision specimens. Margins were arbitrarily determined negative, close, and positive with normal tissue margins in the inked tumor excision specimens of greater than 5 mm, 2-5 mm, and less than 2 mm, respectively. Negative, close, and positive tumor margin patients were treated to radiation doses of 60, 65, and 70 Gy, respectively. The boost in excess of 50 Gy was directed to the tumor bearing quadrant of the breast using interstitial Ir-192 implants for doses greater than or equal to 70 Gy. The draining lymphatics were irradiated to 50 Gy except in patients with tumor in the lateral half of the breast and no axillary lymph node metastases. Histopathological evaluation of re-excision specimens revealed the difficulty of obtaining negative margins for tumors greater than 2 cm. By our criteria, 54% of the patients had a positive resection margin. None of the patients experienced a local recurrence at 60 months median follow-up. Three patients failed regionally, two in un-irradiated lymph node areas, one in the skin of the contralateral breast; five patients failed systemically. Overall and disease-free survival for Stages T1/N0, T1/N1, T2/N0 was 100 and 95%, respectively, and for T2/N1, 90 and 80%, respectively. The cosmesis was excellent in 66% of the patients with minimal treatment related complications. Carefully planned standardized irradiation with assessment of resection margins yields both excellent local control rates and cosmetic results.

Comparison of contralateral breast doses from 1/2 beam block and isocentric treatment techniques for patients treated with primary breast irradiation with 60CO.

The risk of carcinogenesis in breast tissue subject to low to moderate radiation doses may be of concern to the clinical radiotherapist. With earlier diagnosis, more women, and especially younger women, are electing breast preservation radiation therapy. During therapy, tissue outside the treatment field is exposed to leakage and scattered radiation. Such exposure could lead to significant doses of radiation resulting in carcinogenesis. Therefore, reduction of contralateral breast dose may be an important factor to consider when selecting a treatment technique. This study measured dose in the contralateral breast on 15 patients treated with 60Co gamma rays with the source to skin distance (SSD), 1/2 beam block, and the source to axis distance (SAD), no 1/2 beam block, techniques. Thermoluminescent dosimeters (TLD), with 0.5 cm of superflab used as build-up material, were placed on the contralateral breast to measure dose from the medial tangential beam and from the lateral tangential beam. Dose measurements were done on patients in the treatment position and do not represent phantom or formula calculation of dose to the opposite breast. Our results indicated that total opposite breast dose ranged from 325-650 cGy for SSD treatments as opposed to 200-450 cGy for SAD treatments, in patients receiving a total prescribed dose of 5,040 cGy in 28 fractions to the involved breast. This paper points out that a simple solution for reduction of opposite breast dose for patients treated with 60Co may be utilization of the modified SAD treatment technique.