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R J Amdur

Publications and source records attributed to R J Amdur.

At least 19 recordsLinked to original sources

An algorithm for evaluating the ethics of a placebo-controlled trial.

The purpose of this article is to clarify the decision points that are important to consider when evaluating the ethics of a placebo-controlled trial. The ethical requirements for research involving human subjects are reviewed, and the rationale for and potential problems with concomitant placebo control are explained. A series of case discussions are used to illustrate each decision point. The critical decision points in the evaluation of the ethics of a placebo-controlled trial are as follows: (i) Is placebo being used in place of standard therapy? (ii) Is standard therapy likely to be effective? (iii) Is the toxicity of standard therapy such that patients routinely refuse this treatment? (iv) Could the use of placebo result in severe suffering or irreversible harm? (v) Is the variability in the placebo response such that it is reasonable to consider other options for the control group? (vi) Would a reasonable person with an average degree of altruism and risk aversiveness agree to participate in this study? The algorithm presented in this article gives researchers and research monitors (such as Institutional Review Board members) the tools they need to evaluate the ethics of a study that uses concomitant placebo control.

Algorithms↗

T1-T2N0 squamous cell carcinoma of the glottic larynx treated with radiation therapy.

PURPOSE: The end results after radiation therapy for T1-T2N0 glottic carcinoma vary considerably. We analyze patient-related and treatment-related parameters that may influence the likelihood of cure. PATIENTS AND METHODS: Five hundred nineteen patients were treated with radiation therapy and had follow-up for >or= 2 years. Three patients who were disease-free were lost to follow-up at 7 months, 21 months, and 10.5 years. No other patients were lost to follow-up. RESULTS: Local control rates at 5 years after radiation therapy were as follows: T1A, 94%; T1B, 93%; T2A, 80%; and T2B, 72%. Multivariate analysis of local control revealed that the following parameters significantly influenced this end point: overall treatment time (P < .0001), T stage (P = .0003), and histologic differentiation (P = .013). Patients with poorly differentiated cancers fared less well than those with better differentiated lesions. Rates of local control with laryngeal preservation at 5 years were as follows: T1A and T1B, 95%; T2A, 82%; and T2B, 76%. Cause-specific survival rates at 5 years were as follows: T1A and T1B, 98%; T2A, 95%; and T2B, 90%. One patient with a T1N0 cancer and three patients with T2N0 lesions experienced severe late radiation complications. CONCLUSION: Radiation therapy cures a high percentage of patients with T1-T2N0 glottic carcinomas and has a low rate of severe complications. The major treatment-related parameter that influences the likelihood of cure is overall treatment time.

Adult↗

Squamous cell carcinomas of the soft palate treated with radiation therapy alone or followed by planned neck dissection.

PURPOSE: The present study presents the experience at the University of Florida with treatment of unselected patients with carcinomas of the soft palate with radiation therapy (RT) alone or followed by planned neck dissection. METHODS AND MATERIALS: One hundred seven patients treated with curative intent with RT alone or followed by neck dissection from 1965 to 1996 were included in the study. All patients had follow-up for at least 2 years. No patients were lost to follow-up. RESULTS: Local control rates at 5 years were 86% for T1, 91% for T2, 67% for T3, and 36% for T4 carcinomas. T-stage and overall treatment time significantly affected local control in multivariate analysis. Nodal control rates at 5 years were 86% for NO, 76% for N1, 61% for N2, and 67% for N3 carcinomas. Overall treatment time and planned neck dissection significantly affected nodal control in multivariate analysis. Ultimate local-regional control rates at 5 years were 90% for Stage I, 92% for Stage II, 84% for Stage III, and 60% for Stage IV disease. Overall treatment time and planned neck dissection significantly affected ultimate local-regional control in multivariate analysis. The overall survival rate at 5 years was 42% for all patients. Overall stage, overall treatment time, and planned neck dissection significantly affected overall survival in multivariate analysis. The cause-specific survival rate at 5 years was 70% for all patients. Overall treatment time and planned neck dissection significantly affected cause-specific survival in multivariate analysis. Three patients sustained severe postoperative complications and 3 patients sustained severe late complications. Sixteen patients had synchronous and 14 patients had metachronous carcinomas of the head and neck mucosal sites. CONCLUSION: For limited carcinomas of the soft palate, RT (alone or followed by planned neck dissection) results in relatively high local-regional control and survival rates. For advanced carcinomas of the soft palate, local-regional control and survival rates are relatively low and local-regional recurrence rates are substantial. Advanced carcinomas of the soft palate may be better treated with RT and concomitant chemotherapy.

Adult↗

Squamous cell carcinomas metastatic to cervical lymph nodes from an unknown head-and-neck mucosal site treated with radiation therapy alone or in combination with neck dissection.

PURPOSE: The present study presents the experience at the University of Florida with treatment of patients with squamous cell carcinomas (SCC) metastatic to cervical lymph nodes from an unknown head-and-neck mucosal (H&NM) site with radiotherapy (RT) alone or in combination with neck dissection (ND). METHODS AND MATERIALS: The study included 126 patients treated with curative intent from 1964 to 1997. All patients had follow-up for at least 2 years. No patients were lost to follow-up. RESULTS: Twelve patients (10%) developed SCC in H&NM sites at 0.5 to 10.9 years (median, 1.8 years). The rate of developing carcinomas in H&NM sites at 5 years was 13%. Histologic differentiation significantly affected the rate of developing carcinomas in H&NM sites in multivariate analysis. Sixteen patients (13%) had persistent nodal disease and 12 patients (10%) developed recurrent nodal disease at 0.5 to 10.9 years (median, 1.1 years). The nodal control rate at 5 years was 78%. Nodal size, N stage, and planned ND significantly affected the rate of nodal control in multivariate analysis. Nineteen patients (15%) developed distant metastasis at 0.2-5.1 years (median, 0.9 years). The distant metastases rate at 5 years was 14%. Extracapsular extension and RT dose significantly affected the risk of distant metastases in multivariate analysis. The overall absolute survival rate at 5 years was 47%. Extracapsular extension, N stage, RT dose for H&NM sites, and planned ND significantly affected absolute survival in multivariate analysis. The rate of cause-specific survival at 5 years was 67%. Extracapsular extension, nodal size, N stage, overall treatment time, and planned ND significantly affected cause-specific survival in multivariate analysis. Eight patients (6%) had severe postoperative complications and 6 patients (5%) had severe late complications. CONCLUSION: The present study supports the effectiveness of RT in lowering the rate of developing carcinomas in the H&NM sites.

Adult↗

Synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites.

PURPOSE: The present study presents the experience at the University of Florida with synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites. PATIENTS AND METHODS: This study included 1,112 patients with squamous cell carcinomas of the oropharynx, hypopharynx, and supraglottic larynx treated with radiation therapy with curative intent from 1964 to 1997. All patients had follow-up for at least 2 years. No patients were lost to follow-up. RESULTS: The overall survival rate was 45% and the disease-specific survival rate was 67% at 5 years after initial diagnosis of carcinoma of the head and neck mucosal sites. Seventy-seven patients (7%) presented with synchronous carcinomas of the head and neck mucosal sites and 103 patients (9%) developed metachronous carcinomas of the head and neck mucosal sites at 0.6 to 21.7 years (median, 3.6 years). The overall survival rate was 31%, and the disease-specific survival rate was 50% at 5 years after metachronous carcinomas of the head and neck mucosal sites. Seven patients (1%) developed metachronous carcinomas of the thoracic esophagus at 1 to 11.1 years (median, 2.8 years), 15 patients (1%) presented with synchronous carcinomas of the lung, and 83 patients (7%) developed metachronous carcinomas of the lung at 0.6 to 17.6 years (median, 3.5 years). CONCLUSION: Development of synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites are in part responsible for failure to improve overall survival rates for patients with squamous cell carcinomas of the head and neck mucosal sites, justifying rigorous follow-up and studies on chemoprevention.

Adult↗

Organ preservation with radiotherapy for T1-T2 carcinoma of the pyriform sinus.

PURPOSE: To report long-term results using radiotherapy with or without a planned neck dissection for T1-T2 carcinoma of the pyriform sinus. METHODS: An analysis of 101 patients treated at the University of Florida with RT with or without a planned neck dissection for organ preservation. RESULTS: The 5-year local control rates after RT were 90% for T1 cancers and 80% for T2 lesions. The only parameter that significantly influenced local control in univariate analyses was apex involvement for T1 tumors. Multivariate analysis revealed no parameter that significantly affected local control. Cause-specific survival rates at 5 years were as follows: stage I-II, 96%; stage III, 62%; stage IVA, 49%; and stage IVB, 33%. The absolute survival rates were as follows: stage I, 57%; stage II, 61%; stage III, 41%; stage IVA, 29%; and stage IVB, 25%. Moderate to severe long-term complications developed in 12% of patients. CONCLUSIONS: RT alone or combined with a planned neck dissection resulted in local control with larynx preservation in a high proportion of patients. The chance of cure is comparable to that observed after conservation surgery, and the risk of major complications is lower. The addition of adjuvant chemotherapy is unlikely to improve the probability of organ preservation, but might improve locoregional control for patients with advanced nodal disease.

Adult↗

Definitive radiotherapy in the management of chemodectomas arising in the temporal bone, carotid body, and glomus vagale.

PURPOSE: To evaluate the results of treatment for 71 patients with 80 chemodectomas of the temporal bone, carotid body, or glomus vagale who were treated with radiation therapy (RT) alone (72 tumors in 71 patients) or subtotal resection and RT (8 tumors) at the University of Florida between 1968 and 1998. METHODS AND MATERIALS: Sixty-six lesions were previously untreated, whereas 14 had undergone prior treatment (surgery, 11 lesions; RT, 1 lesion; or both, 2 lesions) and were treated for locally recurrent disease. All three patients who received prior RT had been treated at other institutions. Patients had minimum follow-up times as follows: 2 years, 66 patients (93%); 5 years, 53 patients (75%); 10 years, 37 patients (52%); 15 years, 29 patients (41%); 20 years, 18 patients (25%); 25 years, 12 patients (17%); and 30 years, 4 patients (6%). RESULTS: There were five local recurrences at 2.6 years, 4.6 years, 5.3 years, 8.3 years, and 18.8 years, respectively. Four were in glomus jugulare tumors and one was a carotid body tumor. Two of the four patients with glomus jugulare failures were salvaged, one with stereotactic radiosurgery and one with surgery and postoperative RT at another institution. Two of the five recurrences had been treated previously at other institutions with RT and/or surgery. Treatment for a third recurrence was discontinued, against medical advice, before receiving the prescribed dose. There were, therefore, only 2 failures in 65 previously untreated lesions receiving the prescribed course of RT. The overall crude local control rate for all 80 lesions was 94%, with an ultimate local control rate of 96% after salvage treatment. The incidence of treatment-related complications was low. CONCLUSIONS: Irradiation offers a high probability of tumor control with relatively minimal risks for patients with chemodectomas of the temporal bone and neck. There were no severe treatment complications.

Adult↗

Patterns of failure in squamous cell carcinoma of the vagina treated with definitive radiotherapy alone: what is the appropriate treatment volume?

The purpose of this study was to review treatment results, sites of failure, and complications in relation to the irradiation volume for carcinoma of the vagina treated with radiotherapy alone. A retrospective review of 65 patients with histologically confirmed squamous cell carcinoma of the vagina who received definitive radiotherapy was undertaken. The 5-year cause-specific survival rates were as follows: Stage I, 91%; Stage IIA (paravaginal extension), 90%; Stage IIB, 55%; Stage III, 89%; and Stage IVA, 62%. The pelvic disease control rates at 5 years were as follows: Stage I, 74%; Stage IIA, 90%; Stage IIB, 79%; Stage III, 89%; and Stage IVA, 67%. Recurrence in the pelvis occurred in 22% of patients. Eighty-five percent of pelvis recurrences were in the primary treatment field. Although pelvic control rates were not increased by use of larger treatment fields (>2,700 cm(3)), moderate acute and late effects were increased with these fields. Carcinoma of the vagina appears to have a different failure pattern than carcinoma of the cervix. The primary failure sites are the vagina and the paracolpal tissues and the inguinal nodes. Because of this, the superior edge of the pelvic fields does not have to extend above the bottom of the sacroiliac joints except with advanced lesions.

Carcinoma, Squamous Cell↗

Treatment of paragangliomas with radiation therapy.

Paragangliomas of the head and neck may be treated successfully with surgery, radiation therapy, or stereotactic radiosurgery. The choice of treatment depends on the location and extent of the tumor, the presence of multiple tumors, the age and health of the patient, and the preference of the patient and attending physician. This article reviews the role of radiation therapy in the treatment of patients with paragangliomas of the head and neck.

Female↗

Radiotherapy and radiosurgery for skull base tumors.

Tumors arising in the vicinity of the skull base are relatively uncommon; however, lesions that may be successfully treated by radiotherapy and radiosurgery include temporal bone chemodectomas, schwannomas, juvenile angiofibromas, pituitary adenomas, and meningiomas. This article reviews treatment techniques and results and discusses the pertinent literature.

Angiofibroma↗

Squamous cell carcinomas metastatic to cervical lymph nodes from an unknown head and neck mucosal site treated with radiation therapy with palliative intent.

Minimal information has been published about the results of palliative irradiation for squamous cell carcinoma metastatic to cervical lymph nodes from an unknown head and neck primary site. Forty patients with this diagnosis were treated at the University of Florida with radiation therapy with palliative intent. The nodal response rate was 65% and the symptomatic response rate was 57% at 1 year. The absolute survival rate was 25% at 1 year, as was the cause-specific survival rate. Radiotherapy successfully palliates more than half of those treated. Approximately one fourth are alive 1 year after irradiation.

Adult↗

Skin cancer of the head and neck with clinical perineural invasion.

PURPOSE: To review treatment and outcomes in 62 patients with clinical and/or gross evidence of perineural invasion from skin cancer of the head and neck. METHODS AND MATERIALS: Sixty-two patients received radiotherapy at the University of Florida as part or all of their treatment between January 1965 and April 1995. All patients had clinical signs and symptoms of perineural involvement and/or documentation of tumor extending to grossly involve nerve(s). Twenty-one patients underwent therapy for previously untreated lesions, including 12 who received radiotherapy alone and nine who had surgery with postoperative radiotherapy. Forty-one patients underwent therapy for recurrent lesions, including 18 treated with radiotherapy alone and 23 who received preoperative or postoperative radiotherapy. RESULTS: Factors on multivariate analysis that predicted local control included patient age, previously untreated vs. recurrent lesions, presence of clinical symptoms, and extent of radiotherapy fields. Recurrence patterns were predominantly local; 26 of 31 patients (84%) who developed local recurrence after treatment had recurrent cancer limited to the primary site. CONCLUSIONS: Many patients with skin cancer and symptomatic perineural invasion have disease that is incompletely resectable. Approximately half these patients will be cured with aggressive irradiation alone or combined with surgery. Age, prior treatment, and clinical symptoms influence the likelihood of cure.

Adult↗

Altered fractionation in definitive irradiation of squamous cell carcinoma of the head and neck.

The likelihood of local control after radiation therapy may be improved by increasing total dose or decreasing overall time. The probability of late complications increases with dose per fraction. Altered fractionation techniques usually employ two or more fractions per day using a dose per fraction that is similar or less than that employed in conventional fractionation. Altered fractionation may be broadly classified as hyperfractionation or accelerated fractionation. Data suggest that altered fractionation schedules may improve local control (and to a lesser extent, survival) compared with conventional irradiation.

Carcinoma, Squamous Cell↗

Is radiation therapy a preferred alternative to surgery for squamous cell carcinoma of the base of tongue?

PURPOSE: To evaluate irradiation alone for treatment of base-of-tongue cancer. PATIENTS AND METHODS: Two hundred seventeen patients with squamous cell carcinoma of the base of tongue were treated with radiation alone and had follow-up for >/= 2 years. RESULTS: Local control rates at 5 years were as follows: T1, 96%; T2, 91%; T3, 81%; and T4, 38%. Multivariate analysis revealed that T stage (P =.0001) and overall treatment time (P =.0006) significantly influenced local control. The 5-year rates of local-regional control were as follows: I, 100%; II, 100%; III, 83%; IVA, 64%; and IVB, 65%. Multivariate analysis revealed that the following parameters significantly affect the probability of this end point: T stage (P =.0001), overall treatment time (P =.0001), overall stage (P =.0131), and addition of a neck dissection (P =.0021). The rates of absolute and cause-specific survival at 5 years were as follows: I, 50% and 100%; II, 81% and 100%; III, 65% and 76%; IVA, 42% and 56%; and IVB, 44% and 52%. Severe radiation complications developed in eight patients (4%). CONCLUSION: The likelihood of cure after external-beam irradiation was related to stage, overall treatment time, and addition of a planned neck dissection. The local-regional control rates and survival rates after radiation therapy were comparable to those after surgery, and the morbidity associated with irradiation was less.

Adult↗

Radiation therapy for squamous cell carcinoma of the tonsillar region: a preferred alternative to surgery?

PURPOSE: There are no definitive randomized studies that compare radiotherapy (RT) with surgery for tonsillar cancer. The purpose of this study was to evaluate the results of RT alone and RT combined with a planned neck dissection for carcinoma of the tonsillar area and to compare these data with the results of treatment with primary surgery. PATIENTS AND METHODS: Four hundred patients were treated between October 1964 and December 1997 and observed for at least 2 years. One hundred forty-one patients underwent planned neck dissection, and 18 patients received induction (17 patients) or concomitant (one patient) chemotherapy. RESULTS: Five-year local control rates, by tumor stage, were as follows: T1, 83%; T2, 81%; T3, 74%; and T4, 60%. Multivariate analysis revealed that local control was significantly influenced by tumor stage (P =.0001), fractionation schedule (P =.0038), and external beam dose (P =.0227). Local control after RT for early-stage cancers was higher for tonsillar fossa/posterior pillar cancers than for those arising from the anterior tonsillar pillar. Five-year cause-specific survival rates, by disease stage, were as follows: I, 100%; II, 86%; III, 82%; IVa, 63%; and IVb, 22%. Multivariate analysis revealed that cause-specific survival was significantly influenced by overall stage (P =.0001), planned neck dissection (P =.0074), and histologic differentiation (P =.0307). The incidence of severe late complications after treatment was 5%. CONCLUSION: RT alone or combined with a planned neck dissection provides cure rates that are as good as those after surgery and is associated with a lower rate of severe complications.

Adult↗

Prostate seed implant quality assessment using MR and CT image fusion.

PURPOSE: After a seed implant of the prostate, computerized tomography (CT) is ideal for determining seed distribution but soft tissue anatomy is frequently not well visualized. Magnetic resonance (MR) images soft tissue anatomy well but seed visualization is problematic. We describe a method of fusing CT and MR images to exploit the advantages of both of these modalities when assessing the quality of a prostate seed implant. METHODS AND MATERIALS: Eleven consecutive prostate seed implant patients were imaged with axial MR and CT scans. MR and CT images were fused in three dimensions using the Pinnacle 3.0 version of the ADAC treatment planning system. The urethra and bladder base were used to "line up" MR and CT image sets during image fusion. Alignment was accomplished using translation and rotation in the three ortho-normal planes. Accuracy of image fusion was evaluated by calculating the maximum deviation in millimeters between the center of the urethra on axial MR versus CT images. Implant quality was determined by comparing dosimetric results to previously set parameters. RESULTS: Image fusion was performed with a high degree of accuracy. When lining up the urethra and base of bladder, the maximum difference in axial position of the urethra between MR and CT averaged 2.5 mm (range 1.3-4.0 mm, SD 0.9 mm). By projecting CT-derived dose distributions over MR images of soft tissue structures, qualitative and quantitative evaluation of implant quality is straightforward. CONCLUSIONS: The image-fusion process we describe provides a sophisticated way of assessing the quality of a prostate seed implant. Commercial software makes the process time-efficient and available to any clinical practice with a high-quality treatment planning system. While we use MR to image soft tissue structures, the process could be used with any imaging modality that is able to visualize the prostatic urethra (e.g., ultrasound).

Brachytherapy↗