Clifford K.S. Chao

Analysis of Treatment Results for Oral Tongue Cancer

Objective The study reports the results of treatment of oral tongue cancer with five different treatment modalities with long‐term follow‐up.

The american brachytherapy society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

PURPOSE This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. METHODS Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. RESULTS The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or loading minimizes excessive central dose rates. These recommendations are intended only as guidelines. The responsibility for medical decisions ultimately rests with the treating radiation oncologist. CONCLUSION Guidelines are suggested for LDR brachytherapy for cervical cancer. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose-reporting policies.

Analysis of treatment results for base of tongue cancer

Objective The study reported the results of treatment for base of tongue cancer with five different treatment modalities with long‐term follow‐up.

Analysis of treatment results for floor-of-mouth cancer

Objective This study reports the results of treating floor‐of‐mouth cancer with five different treatment modalities with long‐term follow‐up.

A multivariate analysis of prognostic factors in management of pineal tumor

PURPOSE A multivariate analysis of prognostic factors of treatment outcome of pineal tumor. METHODS AND MATERIALS From February 1979 to June 1987, 25 patients with primary pineal tumors were treated in our department. Patients were treated with either AECL Co-60 unit or 10 MV linear accelerator to the primary tumor with an adequate margin or to the whole brain (median dose of 36 Gy) with or without a cone-down boost of 10 to 20 Gy. Craniospinal irradiation was performed in two patients with positive CSF cytology. Minimum follow-up was 40 months. Patients were further stratified according to tumor type. Group I consisted of seven patients with pineal germinoma. Group II included nine patients with nongerminoma, and Group III represented nine patients treated without a histological verification but clinical diagnosis. RESULTS The relapse-free survival (RFS) of Group I patients was 100% and 86% at 2 and 5 years, respectively. Relapse-free survival was 55% and 21% at 2 and 5 years, respectively, for Group II patients. Six of 9 patients in Group II died of disease due to either local recurrence or tumor seeding. Eight of 9 patients in Group III remain no evidence of disease, and RFS was 89% at 2 and 5 years. Multivariate analysis revealed that tumor histology is the only significant prognosticator. Age, gender, type of surgical procedure, RT field, and tumor dose were not. Coxs regression model also failed to demonstrate a significant correlation of tumor seeding with the type of surgery. CONCLUSION The type of tumors in the pineal region dictates the treatment outcome. Definitive radiation therapy is effective in controlling germinoma, whereas a more aggressive approach is needed to improve local control for nongerminoma. For a localized pineal lesion, we advocate that treatment can be tailored to the primary tumor with adequate margins. However, for locally advanced tumors whole brain or craniospinal irradiation should be considered. No definitive correlation between type of surgery and the probability of tumor seeding was identified.

Secondary malignancy among seminoma patients treated with adjuvant radiation therapy

PURPOSE Early-stage testicular seminoma is among the most radiosensitive tumors, with an overall cure rate of over 90%. Among those cured of the disease by orchiectomy and postoperative irradiation, there is a risk of having a second malignancy. We conducted a study to determine the relative risk of the occurrence of secondary malignancy. METHODS AND MATERIALS From 1964 through 1988, 128 patients with histologically confirmed early-stage seminoma of the testis underwent orchiectomy and postoperative irradiation at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, and affiliate hospitals. The follow-up periods ranged from 5 to 29 years, with a median of 11.7 years. The expected rate of developing a second cancer was computed by the standardized incidence ratio using the Connecticut Tumor Registry Database. The rate is based on the number of person-years at risk, taking into account age, gender, and race. RESULTS Nine second nontesticular malignancies were found; the time of appearance in years is indicated in brackets: two squamous cell carcinomas of the lung [3, 11], one adenocarcinoma of the rectum [15], one chronic lymphocytic leukemia [2], one adenocarcinoma of the pancreas [14], one diffuse histiocytic lymphoma of the adrenal gland [7], one sarcoma of the pelvis [5], and two transitional cell carcinomas of the renal pelvis and ureter [14, 17]. One patient who developed a contralateral testicular tumor was excluded from risk assessment. The actuarial risk of second nontesticular cancer is 3%, 5%, and 20%, respectively, at 5, 10, and 15 years of follow-up. When compared with the general population, the overall risk of second nontesticular cancer in the study group did not reach the 0.05 significance level, with an observed/expected (O/E) ratio of 2.09 (95% confidence interval, 0.39-3.35). When analyzed by the latency period after radiation treatment, during the period of 11 to 15 years, the risk was higher (O/E ratio of 4.45, 95% confidence interval, 1.22-11.63) than expected. The median duration for developing a second cancer was 11 years for tumors arising from tissues outside the irradiated field and 14 years for those within or near the irradiated area. CONCLUSIONS The overall observed incidence of second nontesticular malignancy among patients with early-stage testicular seminoma treated with adjuvant radiation therapy was not significantly increased in comparison with the expected incidence. Clinical implications are discussed.

Brachytherapy-related complications for medically inoperable Stage I endometrial carcinoma

PURPOSE The current study was conducted to investigate the incidence and risk factors for medical complications associated with low dose rate brachytherapy in patients with medically inoperable Stage I endometrial cancer treated with irradiation alone. METHODS AND MATERIALS From 1965 through 1991 at Mallinckrodt Institute of Radiology, 150 implants were performed on 96 patients who were deemed medically unfit for hysterectomy because of advanced age, obesity, and various medical problems. The records of these patients were examined retrospectively to determine the incidence of medical complications that occurred in the first 30 days following the initiation of brachytherapy. The association of risk factors that precluded major surgery and the occurrence of brachytherapy-related complications was examined by logistic regression. RESULTS Of these 96 patients, 40 patients were older than 75 years, and 31 patients were deemed morbidly obese. Medical problems included hypertension in 45 patients, and diabetes in 37; there was a history of congestive heart failure in 23, stroke in 11, myocardial infarction in 10, and thromboembolism in 8. There were concurrent malignancies in five patients. Implants were performed using intrauterine Simon-Heyman capsules, tandems, and vaginal ovoids in all patients. General anesthesia was used for 98 implants, spinal anesthesia for 26, local anesthesia for 25, and epidural anesthesia for 1. The duration of anesthesia ranged from 30 to 120 min (median, 60 min). The duration of radioisotope application ranged from 11 to 96 h (median, 46 h). Preventive measures included low dose subcutaneous heparin in 55 patients (since 1978), and intermittent pneumatic compression boots in 29 (since 1985). Four patients developed life-threatening complications including myocardial infarction (two patients), congestive heart failure (one patient), and pulmonary embolism (one patient). Two of these four patients died; one with a myocardial infarction and the other with pulmonary embolism. The morbidity rate was thus 4.2% (4 out of 96), and the mortality was 2.1% (2 out of 96). Although the four serious complications occurred within 30 days of the procedure, only one complication and one death occurred during treatment. There was no correlation between occurrence of complications and medical risk factors, type and duration of anesthesia, or type and duration of implant. CONCLUSIONS There is a low incidence of complications associated with conventional low dose rate brachytherapy. The procedure is well tolerated in patients with medically inoperable Stage I endometrial cancer. In comparison to the predicted serious complication rate of surgery in these patients, the number of life-threatening complications from brachytherapy appears to be quite acceptable.

Medically inoperable stage I endometrial carcinoma: A few dilemmas in radiotherapeutic management

PURPOSE The aggressiveness of radiation therapy for patients with medically inoperable endometrial carcinoma is controversial. Patients may die of their underlining medical disease before succumbing to cancer. We try to identify certain subgroup of patients who might benefit most from an aggressive approach and also investigate the impact of residual tumor present in dilatation and curettage (D&C) specimen obtained in second intracavitary implant (ICI). METHODS AND MATERIALS From 1965 to 1990, 101 patients were treated for clinical clinical Stage I endometrial carcinoma with RT alone due to medical problems. Ages ranged from 39 to 94 years (median 71 years). There were 18 patients with clinical Stage IA and 83 with clinical Stage IB disease. Histology included 44 well-differentiated, 37 moderately differentiated, and 20 poorly differentiated tumors. Radiation therapy consisted of external beam only in 3 patients, ICI alone in 26, whole pelvis plus ICI in 10, and whole pelvis plus split field plus ICI in 62. A second D&C was performed on 26 patients at the time of the second ICI. Minimum follow-up was 2 years (median, 6.3 years). RESULTS The 5-year actuarial disease-free survival (DFS) for the studied cohort is comparable to the expected survival of an age-matched population. Pelvic control was 100% for Stage IA and 88% for Stage IB with 5-year disease-free survivals of 80 and 84%, respectively. We also observed a greater disassociation of DFS and overall survial among patients older than 75 years (84 and 55%, respectively) than in younger patients (84 and 78%, respectively). This is mainly because older patients succumbed to their medical illness. Well-differentiated disease demonstrated the trend toward a better outcome than moderately or poorly differentiated lesions in Stage IB patients (p = 0.05), but not in Stage IA patients. Aggressive radiation therapy approach showed the trend toward a better result in Stage IB patients 75 years of age or younger. There were two failures among 19 patients with no tumor found in the D&C specimen at the time of second implant. In contrast, seven patients with residual tumor seen in the endometrial sample at the time of second implant remain disease free. CONCLUSIONS Radiation therapy alone is an effective treatment modality for medically inoperable Stage I endometrial carcinoma. Disease-free survival can be translated into longer overall survival in the younger age group, but not in older patients. The latter tend to die of their underlining medical illness. Tumor differentiation influenced the prognosis of Stage IB disease. No tumor seen in the endometrial sampling at the time of second implant did not correlate with a better disease control, and the treatment plan should not be modified on such information.

Chemotherapy and irradiation in locally advanced squamous cell carcinoma of the uterine cervix: A review

This article describes the potential role of chemotherapy combined with irradiation in the management of patients with locally advanced carcinoma of the uterine cervix. A review of a Medline literature search and preliminary data from a nonrandomized study comparing irradiation alone with irradiation plus chemotherapy (5-fluorouracil and cisplatin) in the management of patients with locally advanced carcinoma of the uterine cervix treated at Washington University between 1984 and 1992 are presented. Except for one report, there is currently no conclusive evidence that chemotherapy plus irradiation significantly improves tumor control or survival in these patients. Nevertheless, chemotherapy may have a potential role in managing carcinoma of the uterine cervix as an adjuvant to irradiation in patients with pelvic or para-aortic lymph nodes or recurrent tumor after surgery or radiation therapy. Treatment morbidity has been acceptable. Based on available data, chemotherapy should not be advocated in the standardmanagement of carcinoma of the uterine cervix, and patients and physicians should be strongly encouraged to participate in properly designed prospective clinical trials.