Dosimetric and dose-fractionation concerns in vaginal cuff irradiation using high dose rate brachytherapy: regarding Noyes et al. IJROBP 32(5):1439-1443; 1995.
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Brachytherapy↗
Biomedical subjects
B Vikram
Publications and source records attributed to B Vikram.
Prognostic value of tumor regression during radiotherapy or chemoradiotherapy for advanced head and neck cancers: regarding Jaulerry et al. IJROBP 33(2):271-279; 1995.
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Antineoplastic Combined Chemotherapy Protocols↗
Sphincter-sparing surgery.
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Anastomosis, Surgical↗
Radiation therapy of metastatic pheochromocytoma: case report and review of the literature.
Malignant pheochromocytomas are rare tumors, which are considered radioresistant on the basis of little information. We report a patient, with cranial nerve deficits from a pheochromocytoma metastatic to the parasellar region, who promptly responded to radiation therapy (2,500 cGy) with reversal of neurologic deficit. The disease recurred 2 years later and again promptly responded upon treatment to 2,000 cGy. Hepatic metastases were controlled for over 1 year with 3,240 cGy. The radiotherapy of pheochromocytoma and chemodectoma is reviewed, and the similarities between the two kinds of tumor are discussed. We speculate that a higher initial radiation dose might have resulted in a more sustained remission in our patient and recommend doses of 4,000-5,000 cGy if they can be safely administered, in 4-5 weeks for pheochromocytomas.
Adrenal Gland Neoplasms↗
Customization of a radiation management system to support in vivo patient dosimetry using diodes.
Considerable effort is generally made in the quality control of radiation therapy units and in patient chart checking to ensure accurate delivery of treatment to the patients. Record and verify (RV) systems have been implemented which will inhibit the beam from being turned ON if the parameters set on the medical linear accelerators do not match a preprogrammed file. It should be emphasized, however, that RV systems are designed only to ensure proper setup of parameters on the therapy units and bear no direct link with proper patient position. The only real link between treatment planning and delivery to the patient is in-vivo dosimetry. Diodes provide a convenient way of measuring the dose received by the patient in real time and, after the initial tedious calibrations, require very little additional effort. In order to facilitate diode use by the therapists in our institution, the radiation management system (RMS) database in use with our linear accelerators was interfaced with the output obtained from a commercially available diode dosimetry system. The chart printout format was altered to read this value from the RMS database allowing a near real-time recording of the actual dose received by the patient for up to three sites concurrently. This provides for an immediate additional check to the planned and received doses already recorded by the RMS RV software. This procedure, if carried out during the first treatment and subsequently on a weekly basis, would ensure that differences of the order of 5% or larger between planned and delivered dose would not go undetected.
Documentation↗
Chemoradiation in advanced nonsmall cell lung cancer.
PURPOSE: Resectability, local control, and survival were evaluated in advanced stage nonsmall cell lung cancer treated with simultaneous chemoradiation therapy delivered in an accelerated, interrupted twice-a-day schedule. METHODS AND MATERIALS: Forty-seven consecutive patients with Stage IIIA or IIIB nonsmall cell lung cancer, consenting to participation in the study, received cisplatin, 30 mg/m2 for 3 days, etoposid, 80 mg/m2 for 3 days, and 5-fluorouracil, 900 mg/m2 for 4 days. Radiation therapy consisted of 2 Gy given twice a day for 5 days. Two weeks rest was planned between cycles. Patients were evaluated for resectability after the second cycle. Any patient with unresectable tumor received a third cycle of treatment. RESULTS: Forty-seven patients were evaluable for acute toxicity: eighteen (38%) required an extended rest period for esophagitis or low blood count; 3 (6%) had sepsis, of whom 1 (2%) expired. Three patients (6%) had multiple blood transfusions for low hemoglobin. Median follow-up is 23.6 months, with a range of 10-49 months. Nine patients (19%) failed locally; 15 (32%) had local and distant failure; 7 (15%) failed only at distant sites. Twelve patients (25.5%) are alive with no evidence of disease; 4 patients were lost to follow-up with disease. The 2-year actuarial survival is 49%, and the 4-year is 28.2%. CONCLUSION: Simultaneous chemoradiation is well tolerated with acceptable toxicity. The overall 2- and 4-year actuarial survival is somewhat better than that reported in the literature. Resectability in Stage IIIB patients was not increased with this regimen nor was any surgical specimen free of cancer. The 47% distant failure rate is not different from those reported by others.
Adult↗
Five dosimetric considerations in perineal templates: regarding Kavanagh et al., IJROBP 30:508; 1994.
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Brachytherapy↗
Chemotherapy rapidly alternating with twice-a-day accelerated radiation therapy in carcinomas involving the hypopharynx or esophagus: an update.
Laboratory studies have suggested that rapidly alternating chemotherapy and radiation therapy might act synergistically. We undertook this study to evaluate the toxicity and effectiveness of this approach in patients with carcinoma involving the hypopharynx or esophagus. Between 1987 and 1991, we treated 47 patients (23 with carcinoma involving the hypopharynx and 24 with carcinoma involving the esophagus) by three cycles of chemotherapy (during weeks 1, 4, and 7) rapidly alternating with twice-a-day radiation therapy (during weeks 2, 5, and 8). Chemotherapy consisted of cisplatin 100 mg/m2 and 5-fluorouracil 3-4 g/m2 given over 4 days. Radiation therapy consisted of 180-200 cGy twice each day to 2000 cGy/cycle, total 6000 cGy over 7 weeks. The histology was squamous cell carcinoma in 44 patients and adenocarcinoma in 3 patients with esophagus cancer. Median follow-up is 2 years (range 1-5 years). The observed survival rate for all 47 patients was 54% at 1 year and 38% at 2 years. Acute toxicity was considerable. Twelve patients (25%) died during therapy from toxicity, without tumor progression, leaving 35 patients (18 hypopharynx, 17 esophagus) evaluable for response. Among the hypopharyngeal patients, 83% had a complete response, 11% had a partial response, and 6% had no response. Among the esophageal patients, 94% had a complete response, and 6% had a partial response. Local control was better for the esophageal patients than the hypopharyngeal patients (98% vs. 52% at 2 years, p = 0.038). The incidence of distant metastases was 25% at 2 years and not significantly different between the two groups. A high rate of local control was achieved, particularly in esophageal cancer, by delivering chemotherapy and radiation therapy in a rapidly alternating fashion. This was achieved at a considerable cost in terms of toxicity, however. Although our response rates and local control compare favorably with those of other recently published studies of combined modality therapy in esophagus or head and neck cancer, much additional work is required to reduce the toxicity and, in hypopharyngeal cancer, to further improve the local control.
Adenocarcinoma↗
New barriers to ventricular invasion in paraglottic laryngeal cancer.
BACKGROUND: Anatomic barriers to the spread of laryngeal cancer include the conus elasticus, the quadrangular membrane, and the thyroid cartilage. It has been speculated that an elastic barrier surrounds and protects the ventricle. METHODS: The authors studied the microanatomic patterns of spread of 17 cases of patients who had laryngeal cancer with paraglottic disease and confirmed their findings by examining normal autopsy specimens. RESULTS: Five patients of the seventeen cases showed no ventricular mucosal involvement despite extensive paraglottic disease. Both an inner, central, subepithelial periventricular elastic membrane barrier were identified; the latter was in continuity with the conus elasticus and quadrangular membrane. CONCLUSIONS: Two weak fibroelastic barriers surround the ventricle. The outer, peripheral, fibroelastic membrane is contiguous with the conus elasticus and the quadrangular membrane. Therefore, ventricular involvement is not a sensitive indicator of paraglottic spread. Squamous cell cancer may grow around the periventricular barriers to involve both the true and false cords but may spare the ventricle. The prognostic significance of the violation or preservation of the periventricular elastic barriers is unknown.
Carcinoma, Squamous Cell↗
Permanent iodine-125 (I-125) boost implants after external radiation therapy in nasopharyngeal cancer.
PURPOSE: Higher doses of external irradiation in patients with nasopharyngeal cancer have resulted in improved control of the primary tumor, but can result in significant late toxicity. Tumor control in locally advanced nasopharyngeal cancer remains suboptimal due to the technical difficulties associated with delivering high doses of radiation to the tumor while shielding the brainstem, spinal cord, optic chiasm, etc. We report the use of I-125 boost implants following moderate dose external radiation therapy in nasopharyngeal cancer, in an attempt at improving the local tumor control without increasing toxicity. METHODS AND MATERIALS: Twenty consecutive patients with nasopharyngeal cancer were treated with external beam irradiation (median dose 60 Gy over 6 weeks) to the primary site and the neck followed by I-125 implant to the primary site. RESULTS: With a median follow-up of 2 years (range 1-5 years) there has been no instance of necrosis or other complications related to the implant. So far, in no patient has the tumor recurred at the primary site, although 6 of the 20 patients (30%) have developed metastases. CONCLUSIONS: These data indicate that elective I-125 implantation could be performed safely after external irradiation in nasopharyngeal cancer, and has yielded an encouraging level of primary tumor control, to date.
Adolescent↗
Predictors of axillary lymph node metastases in patients with T1 breast cancer. A multivariate analysis.
BACKGROUND: In T1 tumors, the reported incidence of lymph node metastases ranges from 21% to 35%. The authors analyzed the pathology parameters of T1 tumors for their association with the likelihood of axillary lymph node metastases. METHODS: Two hundred sixty-three patients with T1 unilateral invasive breast cancer were studied. All underwent axillary dissection, and the pathologic status of the nodes was known. The parameters of the primary tumor evaluated included size, histologic subtype, nuclear grade, DNA ploidy, S-phase fraction (SPF), hormone receptor status, lymphatic/vascular invasion (LVI), and host reaction. RESULTS: Seventy-two (27%) patients had nodes that were positive for metastasis. Univariate analysis showed that lymph node metastases were associated with tumors larger than 1 cm (P = 0.001), moderate or poorly differentiated nuclear grade (P = 0.005), high SPF (P = 0.041), presence of LVI (P < 0.001) and patients younger than 60 years (P = 0.01). However, independent predictors of lymph node metastasis in the multivariate logistic regression analyses were tumor size and LVI. Twenty-five patients had tumors larger than 1.0 cm and presence of LVI; of these, 17 (68%) had lymph node metastases. Of the 79 patients who had neither of these features, only 7 (9%) had lymph node metastases. CONCLUSIONS: The authors conclude that characteristics of the primary tumor can help assess the risk for axillary lymph node metastases. Selected patients who are assessed to be at minimal risk might be spared routine axillary dissection or radiation therapy to the axilla.
Adult↗
Patterns of failure in carcinoma of the upper esophagus after alternating chemoradiotherapy.
Alternating chemoradiotherapy has recently been reported to produce encouraging results in patients with advanced head and neck cancer. We have treated 17 patients with squamous cell carcinoma of the upper esophagus by alternating chemoradiotherapy and by following the patients for 2 to 5 years, or until their death. Chemotherapy (cisplatin and 5-fluorouracil) was delivered during weeks 1, 4, and 7, and radiotherapy (180 to 200 cGy twice each day to 2,000 cGy) during weeks 2, 5, and 8 (total 6,000 cGy). Three patients (18%) died of toxicity (nadir sepsis). All 14 patients who survived the treatment achieved a complete response as shown by endoscopy and biopsy specimens, with restoration of swallowing, and none experienced a local relapse. Three patients died of distant metastases (actuarial incidence 32% at 3 years). The 5-year survival rate was only 16%, however, because 8 other patients with no evidence of the cancer died of a variety of other causes: radiation pneumonitis (1), chronic neutropenia (1), esophageal actinomycosis (1), pneumonia (2), stroke (1), myocardial infarction (1), and small-cell lung cancer (1). Conceivably, some further improvement in the results might occur from cytokines, stem cells, and brachytherapy (by decreasing deaths due to toxicity), but with so many causes of comorbidity it seems unlikely, for the foreseeable future, that the 5-year survival rate could be much improved by better treatment of esophageal cancer.
Aged↗
A pilot study of chemotherapy alternating with twice-a-day accelerated radiation therapy as an alternative to cystectomy in muscle infiltrating (stages T2 and T3) cancer of the bladder: preliminary results.
Laboratory studies have suggested that rapidly alternating chemotherapy and accelerated radiation therapy might act synergistically. We evaluated the toxicity and effectiveness of this approach in muscle infiltrating transitional cell carcinoma of the bladder in patients who were poor risks for or who refused cystectomy. We treated 18 men and 3 women with stage T2 or T3 transitional cell carcinoma of the bladder by transurethral resection, followed by 3 cycles of chemotherapy (during weeks 1, 4 and 7) rapidly alternating with 3 cycles of twice-a-day radiation therapy (during weeks 2, 5 and 8). Chemotherapy consisted of methotrexate, vinblastine, doxorubicin and cisplatin. The total dose of radiation therapy was 5,400 to 6,000 cGy, during 6 1/2 weeks and the total duration of chemotherapy and radiation therapy was 7 1/2 weeks. One patient died of hematological toxicity during treatment. With a median followup of 2 years (range 0.5 to 5.5 years) the observed survival rate was 72% at 2 years and 60% at 3 years. To date, only 1 patient (5%) had recurrence of invasive cancer in the pelvis. Only 3 others (15%) had carcinoma in situ but to date none has required cystectomy. Bladder function was normal in 15 of 18 evaluable patients (83.5%). This pilot study suggests that chemotherapy alternating with radiation therapy produced an encouraging survival rate without cystectomy and deserves further study. These patients require continued surveillance for carcinoma in situ.
Actuarial Analysis↗
Palladium 103 plaque radiotherapy for uveal melanoma. Clinical experience.
PURPOSE: To evaluate the effect of palladium 103(103Pd) ophthalmic plaque brachytherapy on patients with uveal melanoma. BACKGROUND: Radioactive 103Pd seeds have become available for plaque brachytherapy, and computer-aided simulations have compared the intraocular dose distribution of 103Pd versus iodine 125 (125I) plaques in patients with uveal melanoma. The use of the lower-energy radionuclide 103Pd increased the radiation to the tumors and decreases irradiation of most normal ocular structures. METHODS: The authors have begun a phase 1 clinical trial evaluating the effect of 103Pd ophthalmic plaque radiotherapy on intraocular tumors. Uveal melanoma was diagnosed, and the patients were found to be negative for metastatic disease. All patients were given one 103Pd radioactive plaque treatment, and six patients also were given adjuvant microwave hyperthermia. RESULTS: Palladium 103 ophthalmic plaque radiotherapy was used to treat 23 patients with uveal melanoma. Patients were followed for up to 27 months (mean, 13.5 months). One eye was enucleated for progressive tumor enlargement (4 months after treatment). One patient died (of metastatic melanoma). Eight patients have lost greater than two lines of visual acuity, one has gained more than two lines. Fifteen patients (65%) were within two lines or had better than their preoperative visual acuity. Relating to the effect of treatment on visual acuity, 15 (65%) tumors were located equal to or less than 2 mm from the fovea. CONCLUSION: Palladium 103 ophthalmic plaque radiotherapy was noted to control the growth of uveal melanomas. Compared with other forms of plaque radiotherapy at this follow-up interval, the authors have noted no new complications, no difference in local control, and/or changes in tumor response to treatment. More long-term follow-up will be required to demonstrate differences between 125I and 103Pd ophthalmic plaque brachytherapy.
Brachytherapy↗
Predictors of response: new versus old?
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Antigen-Antibody Complex↗
Does hyperfractionation reduce late complications in head and neck cancers?
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Head and Neck Neoplasms↗
Tolerance of the carotid-sheath contents to brachytherapy: an experimental study.
Tumor invasion of the carotid artery is a potential indication for brachytherapy, which delivers a high dose of irradiation to residual tumor while limiting the dose to adjacent healthy tissues. The tolerance of carotid-sheath contents to varying doses of brachytherapy, however, has not been clearly established. In order to evaluate brachytherapy effects on carotid-sheath contents, after-loading catheters were implanted bilaterally in 3 groups of 6 rabbits each (18 rabbits). Iridium 192 brachytherapy doses of either 5000 cGy (rad), 9000 cGy, or 13,000 cGy were delivered unilaterally, with the contralateral neck serving as a nonirradiated control in each animal. There were no carotid ruptures and wound healing was normal. Two animals from each group were killed at 6, 20, and 48 weeks. Even at the highest dose (13,000 cGy), nerve conduction studies performed on the vagus nerve prior to sacrifice revealed no increased latency, histologic changes were minimal, and carotid arteries were patent. These observations suggest that the carotid-sheath contents in healthy rabbits could tolerate high doses (up to 13,000 cGy) of low-dose-rate interstitial brachytherapy without complications.
Animals↗
Impact of the time interval between surgery and postoperative radiation therapy on locoregional control in advanced head and neck cancer.
Between January 1975 and December 1980, 111 patients with AJCC stages III and IV squamous cell carcinoma of the head and neck were treated with surgery followed by planned postoperative radiation therapy. A previous analysis of a subgroup of these patients showed that, when radiation was delayed more than 6 weeks from surgery, a higher incidence of regional failure occurred compared with the incidence observed when therapy began within a 6 week period. We have looked back at this group of patients plus others in an attempt to determine whether other factors played a role in the results obtained. In the current study, 50 patients had a delay of 6 weeks or more and, of these, 11 (22%) suffered a locoregional recurrence. However, 8 of these 11 patients received suboptimal radiation doses (less than 56 Gy) for permanent control of the disease. In fact, of 17 patients who received at least 60 Gy and had more than a 6 week delay, only 2 (12%) had locoregional failure. This was similar to the incidence of failure in the patients who received at least 60 Gy and who started radiation within the first 6 weeks from surgery (3/20 [15%]). The effect of delay was apparent only in those who received less than 60 Gy (27% vs. 7%, P less than 0.05). Therefore, we cannot validate the previous conclusion that a greater than 6 week delay in the delivery of postoperative radiation therapy in advanced head and neck cancers produces poorer results. The current analysis suggests that a prolonged delay in postoperative radiation therapy in itself does not have a negative impact on locoregional control as long as appropriate tumorcidal doses of more than 60 Gy are employed.
Carcinoma, Squamous Cell↗