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Dive into the research topics where Kenneth A. Leopold is active.

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Featured researches published by Kenneth A. Leopold.


Journal of Clinical Oncology | 2002

Randomized Phase II Study of Cisplatin With Gemcitabine or Paclitaxel or Vinorelbine as Induction Chemotherapy Followed by Concomitant Chemoradiotherapy for Stage IIIB Non–Small-Cell Lung Cancer: Cancer and Leukemia Group B Study 9431

Everett E. Vokes; James E. Herndon; Jeffrey Crawford; Kenneth A. Leopold; Michael C. Perry; Antonius A. Miller; Mark R. Green

PURPOSE To evaluate new drugs in combination with cisplatin in unresectable stage III non-small-cell lung cancer, Cancer and Leukemia Group B (CALGB) conducted a randomized phase II study of two cycles of induction chemotherapy followed by two additional cycles of the same drugs with concomitant radiotherapy. PATIENTS AND METHODS Eligible patients received four cycles of cisplatin at 80 mg/m(2) on days 1, 22, 43, and 64 with arm 1: gemcitabine 1,250 mg/m(2) on days 1, 8, 22, and 29 and 600 mg/m(2) on days 43, 50, 64, and 71; arm 2: paclitaxel 225 mg/m(2) for 3 hours on days 1 and 22 and 135 mg/m(2) on days 43 and 64; and arm 3: vinorelbine 25 mg/m(2) on days 1, 8, 15, 22, and 29 and 15 mg/m(2) on days 43, 50, 64, and 71. Radiotherapy was initiated on day 43 at 2 Gy/d (total dose, 66 Gy). RESULTS One hundred seventy-five eligible patients were analyzed. Toxicities during induction chemotherapy consisted primarily of grade 3 or 4 granulocytopenia. Grade 3 or 4 toxicities during concomitant chemoradiotherapy consisted of thrombocytopenia, granulo-cytopenia, and esophagitis. Response rates after completion of radiotherapy were 74%, 67%, and 73% for arms 1, 2, and 3, respectively. Median survival for all patients was 17 months. One-, 2-, and 3-year survival rates for the patients on the three arms were 68%/37%/28%, 62%/29%/19%, and 65%/40%/23%. CONCLUSION Four cycles of gemcitabine, vinorelbine, or paclitaxel in combination with cisplatin can be administered at these doses and schedules. The observed survival rates exceed those of previous CALGB trials and may be attributable to the use of concomitant chemoradiotherapy. Induction chemotherapy added to concomitant chemoradiotherapy is being evaluated in a phase III randomized trial.


International Journal of Radiation Oncology Biology Physics | 1993

Sensitivity of hyperthermia trial outcomes to temperature and time: Implications for thermal goals of treatment

James R. Oleson; Thaddeus V. Samulski; Kenneth A. Leopold; Scott T. Clegg; Mark W. Dewhirst; Richard K. Dodge; Stephen L. George

PURPOSE In previous work we have found that the cumulative minutes of treatment for which 90% of measured intratumoral temperatures (T90) exceeded 39.5 degrees C was highly associated with complete response of superficial tumors. Similarly, the cumulative time for which 50% of intratumoral temperatures (T50) exceeded 41.5 degrees C was highly associated with the presence of > 80% necrosis in soft tissue sarcomas resected after radiotherapy and hyperthermia. In the present work we have calculated the time for isoeffective treatments with T90 = 43 degrees C and T50 = 43 degrees C, respectively, using published thermal isoeffective dose formulae. The purpose of these calculations was to determine the sensitivity of treatment outcome to variations in thermal isoeffective dose. METHODS AND MATERIALS The basis for the calculations were the thermal parameters and treatment outcomes in three patient populations: 44 patients with moderate or high grade soft tissue sarcoma treated preoperatively with hyperthermia and radiation; 105 patients with superficial tumors treated with hyperthermia and radiation, and 59 patients with deep tumors treated with hyperthermia and radiation. RESULTS The thermal dose values calculated are strongly associated with outcome in multivariate logistic regression analysis. Simple dose-response equations result from the analysis, and we use these equations to assess the sensitivity of outcome upon variations in thermal dose. This information, in turn, allows us to estimate the number of patients required in Phase II and III trials of hyperthermia and radiation therapy. CONCLUSIONS For regimens of 5 to 10 hyperthermia treatments, improvements in median T90 (superficial tumors) and T50 (deep tumors) parameters by 1.2-1.5 degrees C could result in response rates high enough (compared to radiotherapy alone) to justify Phase III trials. A similar improvement in response rates would require an increase in overall duration of treatment by a factor of 3 to 5. This would be difficult to achieve while also avoiding thermal tolerance induction. Achieving these temperature goals may be possible with improvements in hyperthermia technology. Alternatively, there may be ways to increase the sensitivity of cells to temperatures that can be achieved currently, such as pH reduction or chemosensitization.


International Journal of Radiation Oncology Biology Physics | 1992

Relationships among tumor temperature, treatment time, and histopathological outcome using preoperative hyperthermia with radiation in soft tissue sarcomas

Kenneth A. Leopold; Mark W. Dewhirst; Thaddeus V. Samulski; John M. Harrelson; J.Alan Tucker; Stephen L. George; Richard K. Dodge; Wendy Grant; Scott T. Clegg; Leonard R. Prosnitz; James R. Oleson

The lack of an unambiguous thermal dosimetry continues to impede progress in clinical hyperthermia. In an attempt to define better this dosimetry, a model based on the cumulative minutes during which arbitrary percentages of measured tumor temperature points exceeded an index temperature was tested in patients with soft tissue sarcomas treated with preoperative hyperthermia and conventional radiation therapy. Patients received 5000-5040 cGy at 180-200 cGy per fraction. Hyperthermia was delivered 30-60 minutes after radiation therapy and given for 60 minutes. Patients were randomized between one and two hyperthermia treatments per week for a total of five or 10 treatments, respectively. Lesions were excised 4-6 weeks after completion of hyperthermia/radiation therapy. Successful treatment outcome was considered to be the finding of greater than 80% necrosis of the sarcoma upon histopathologic examination of the resected specimen. Forty-five patients were eligible with thermometry data available in 44 patients. An average of 19 interstitial sites were monitored each treatment per tumor. Sixty percent of tumors had a successful histopathologic outcome. Univariate analysis demonstrated that several descriptors of the temperature distribution were strongly related to treatment outcome; more strongly than nonthermometric factors, such as the number of treatments per week, tumor volume and patient age and more strongly than the commonly used temperature descriptors Tmin and Tmax. Descriptors that incorporated both temperature and time were also superior to the more commonly used descriptors Tmin and Tmax. Multivariate stepwise logistic regression analysis revealed that a descriptor of both the hyperthermia treatment time and the frequency distribution of intratumoral temperatures was the strongest predictor of histopathologic outcome and that the best predictive model combined this time/temperature descriptor and one versus two treatment per week grouping. The more conventional temperature descriptor, minimum measured tumor temperature, did not significantly enhance the predictive power of treatment group. Based on these results, we recommend that descriptors based on both the frequency distribution of intratumoral temperatures and hyperthermia treatment time be tested for relationships with treatment outcome in other clinical data bases. Furthermore, we recommend that temperature descriptors that are less sensitive to catheter placement and tumor boundary identification than Tmin and Tmax (such as T90, T50, and T10) be tested prospectively along with other important thermal variables in Phase II trials in further efforts to define a thermal dosimetry for spatially nonuniform temperature distributions.


International Journal of Radiation Oncology Biology Physics | 1993

Cumulative minutes with T90 greater than tempindex is predictive of response of superficial malignancies to hyperthermia and radiation

Kenneth A. Leopold; Mark W. Dewhirst; Thaddeus V. Samulski; Richard K. Dodge; Stephen L. George; Janye L. Blivin; Leonard R. Prosnitz; James R. Oleson

PURPOSE To better define thermal parameters related to tumor response in superficial malignancies treated with combined hyperthermia and radiation therapy. METHODS AND MATERIALS Patients were randomized to receive one or two hyperthermia treatments per week with hyperthermia given during each week of irradiation. Hyperthermia was given for 60 min with treatments begun within 1 hr following irradiation. Power was increased to patient tolerance or normal tissue temperature of 43.0 degrees C. Irradiation was generally given 5 times per week with doses prescribed to normal tissue tolerance (generally 24-70 Gy at 1.8-2.5 Gy per fraction). Multipoint thermometry was used with temperatures obtained every 5 min. RESULTS One hundred eleven individual treatment fields containing 1 or more tumor nodules were completely evaluable. The complete and overall response rates were 46% and 80%, respectively. Forty-one percent of all treatment fields (51% of responding lesions) remained controlled at 2 years. Multivariate analysis revealed that the cumulative minutes that the temperature achieved by 90% of the measured tumor sites (T90) was > or = 40.0 degrees C, tumor histology, tumor volume, and radiation dose were significantly associated with complete tumor response. The complete response rate was not significantly affected by the number of hyperthermia treatments given per week. The incidence of clinically significant complications was low. CONCLUSIONS These results support the usefulness of the cumulative minute system in describing time-temperature relationships. The significance of thermal variables with regard to tumor response strongly supports the contention that hyperthermia can be a useful adjunct to irradiation for the local control of cancer.


International Journal of Radiation Oncology Biology Physics | 1992

PATTERNS OF FAILURE FOLLOWING COMBINED MODALITY THERAPY FOR ESOPHAGEAL CANCER, 1984-1990

Brian D. Kavanagh; Mitchell S. Anscher; Kenneth A. Leopold; Margaret Deutsch; Gaydica Ef; Richard K. Dodge; Kathy Allen; David Allen; E.Wilson Staub; Gustavo S. Montana; Jeffrey Crawford; Walter G. Wolfe

From 1984-1990, 143 patients with squamous cell or adenocarcinoma of the esophagus were enrolled in a Phase I/II study of neoadjuvant chemotherapy followed by concurrent chemotherapy plus radiotherapy with or without subsequent esophagectomy. Patients received one cycle of Cisplatin or Carboplatin plus Etoposide for squamous cell carcinoma, or Cisplatin or Carboplatin plus 5FU for adenocarcinoma, followed by two cycles of the same chemotherapy given concurrently with 44-46 Gy over 5 weeks. Operable patients then underwent esophagectomy. Inoperable patients and those with positive surgical margins received additional irradiation (16-18 Gy). Twelve percent of the surgical group received preoperative radiotherapy doses > or = 50 Gy. Seventy-two percent (103) had clinical Stage I-III tumors and 28% (40) were clinical Stage IV (1983 American Joint Committee on Cancer criteria). Only clinical Stage I-III patients were analyzed with respect to patterns of failure. Isolated local failure occurred in 19/103 (18%) of clinical Stage I-III patients. Both local and distant relapse occurred in 15/103 (15%), and distant metastases alone occurred in 25/103 (24%). The 3-year actuarial rates of local and distant failures were 45% and 60%, respectively. Among the clinical Stage I-III patients who underwent surgery (n = 58) versus those who did not (n = 45), the 3-year actuarial local and distant failure rates were 30% versus 60% and 45% versus 45%, respectively. Multivariate analysis was performed to identify significant predictors of local control. For all clinical Stage I-III patients, treatment with surgery (p = 0.001) and with three or more cycles of chemotherapy (p = 0.02) were significant predictors of improved local control. Patients who underwent surgery were significantly younger and had a better performance status than those who did not. The improvement in local control with surgery did not translate into better survival, likely on account of a high operative mortality rate in older patients and those receiving > or = 50 Gy preoperatively. We conclude that local control remains poor with concurrent chemotherapy + radiotherapy for esophageal cancer. The addition of surgery improved local control, but distant metastases remain a problem both in this group of patients as well as those treated without esophagectomy. Efforts to improve local control appear warranted, but it remains to be demonstrated that improved local control translates into improved survival in esophageal cancer because of a high rate of distant metastases in patients whose disease is controlled in the esophagus.


Journal of Clinical Oncology | 1987

Stage I to IIB Hodgkin's disease: the combined experience at Stanford University and the Joint Center for Radiation Therapy.

Mark J. Crnkovich; Kenneth A. Leopold; Richard T. Hoppe; Peter Mauch

The treatment records of 180 patients with pathological stage (PS) IB to IIB Hodgkins disease treated at Stanford University Medical Center (SUMC) or the Joint Center for Radiation Therapy (JCRT) were reviewed. Pretreatment characteristics were analyzed to assess their influence on survival and freedom from relapse (FFR). The two most important disease characteristics predictive of relapse were the number and type of B symptoms present and the mediastinal mass ratio (MMR). Patients with both fevers and weight loss had a 7-year survival and FFR of only 57% and 48%, respectively. The poor prognosis in this group was apparent for treatment with either radiation (XRT) alone or combined modality therapy (CMT). Patients with night sweats only had no adverse effect of B symptoms on outcome. Patients with a MMR greater than 1/3 had a 7-year FFR of only 58% after XRT, but 79% after CMT (P = .12). The 7-year survivals for these patients were 85% and 88%, respectively. CMT improved the FFR of the entire group of 180 patients when compared with XRT (7-year FFR 86% and 74%, respectively, P = .02); however, survival in the two treatment groups was similar (88% and 89%). Among patients treated with radiation alone, there was a similar survival and FFR irrespective of whether pelvic irradiation was included in the initial treatment fields.


Cancer | 1994

Phase II study of neoadjuvant chemotherapy and radiation therapy with thoracotomy in the treatment of clinically staged IIIA non-small cell lung cancer

Margaret Deutsch; Jeffrey Crawford; Kenneth A. Leopold; Walter G. Wolfe; William Foster; James E. Herndon; Susan Blackwell; Rebecca Yost

Background. The purpose of this study was to assess the ability of administering to patients induction chemotherapy with carboplatin and etoposide (VP‐16), followed by full‐course radiation therapy and weekly carboplatin with tolerable toxicity as preoperative therapy to downstage disease thus allowing the resection of clinically staged IIIA non‐small cell lung cancer.


International Journal of Radiation Oncology Biology Physics | 1989

Preoperative hyperthermia and radiation for soft tissue sarcomas: Advantage of two vs one hyperthermia treatments per week☆

Kenneth A. Leopold; John M. Harrelson; Leonard R. Prosnitz; Thaddeus V. Samulski; Mark W. Dewhirst; James R. Oleson

As part of an ongoing Phase II trial at Duke University Medical Center (DUMC), patients with Stage IIB-IVA soft tissue sarcomas (STS) potentially amenable to wide local excision were treated with preoperative hyperthermia (HT) plus radiation therapy (RT), with HT randomized to one versus two treatments per week, stratified with respect to tumor volume. 17 patients were treated and analyzed. HT was given 30-60 minutes after RT, with heating maintained for 1 hour after 42.0 degrees C was reached. In patients treated with 2 HT per week, treatments were separated by 48 hrs. Concurrent RT was given with 180-200 cGy fractions, five treatments per week, to a nominal tumor dose of 5000-5040 cGy. Surgical extirpation was performed 4 weeks after completion of HT/RT. Treatment effect was evaluated by histopathologic examination of the resected lesions, according to a previously reported system. The mean number of HT given in the 1 and 2/wk groups was 4.4 and 7.3, respectively (p less than 0.01). Tmax for the 1 and 2 HT/wk groups was 42.4 +/- 2.1 degrees C and 43.5 +/- 1.8 degrees C, and T min was 38.1 +/- 0.8 degrees C and 38.6 +/- 0.5 degrees C, respectively. The increase in T min from first to last treatment was 0.5 +/- 1.2 degrees C and 1.0 +/- 0.8 degrees C, respectively. The T min from the best treatment was 39.1 +/- 1.2 degrees C and 40.0 +/- 1.0 degrees C, and the Tmax from the best treatment was 44.5 +/- 3.4 degrees C and 45.4 +/- 2.5 degrees C for the 1 and 2 HT/wk groups, respectively. There were no statistically significant differences between the 2 treatment groups for any of the above temperature parameters. Severe histopathologic changes were found in 71% (12 of 17) of the lesions. T min and Tmax and highest T min and Tmax were between 0.4-1.1 degrees C higher in patients with severe changes (p = NS). All 9 patients in the 2 HT/wk group had extensive changes, versus only 3 of the 8 patients in the 1 HT/wk group. This difference was highly statistically significant (p = 0.009, two-tailed Fishers exact test). These findings suggest an advantage to twice weekly, as opposed to weekly, HT in the setting of this study. Whether there is a corresponding therapeutic gain, or whether these results can be extrapolated to other settings requires further investigational efforts. It is recommended that treatment parameters, particularly temperature parameters, continue to be examined in Phase II trials.


International Journal of Hyperthermia | 1990

Clinical experience with a multi-element ultrasonic hyperthermia system: Analysis of treatment temperatures

Thaddeus V. Samulski; W. Grant; James R. Oleson; Kenneth A. Leopold; Mark W. Dewhirst; P. Vallario; Janye L. Blivin

A summary of tumour temperature data obtained from 31 patients who underwent 147 hyperthermia treatments with the Sonotherm 1000 ultrasonic system is presented. The treatment goal was to achieve a minimum of 42.0 degrees C in tumour for 60 min duration with normal tissues remaining below 43.0 degrees C. In 83% of treatments at least one measured tumour temperature reached or exceeded 42.0 degrees C at some time during the treatment. Nineteen per cent of these treatments had a time- and spatial-averaged temperature (measured in tumour) greater than or equal to 42.0 degrees C. A variety of anatomical sites were treated and these were grouped into four categories: groin/trunk, axilla, breast/chest wall and head/neck. Measured temperatures in tumours located in the groin and trunk sites were significantly higher (22% greater than or equal to 42 degrees C) than other locations. The head and neck treatment temperatures were significantly lower (8% of measured points greater than or equal to 42 degrees C.


International Journal of Radiation Oncology Biology Physics | 1995

High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: Unusual toxicity and promising early results

Stephen C. King; Jeffrey C. Acker; Peter Kussin; Lawrence B. Marks; Kenneth J. Weeks; Kenneth A. Leopold

PURPOSE The treatment of nonsmall cell lung cancer (NSCLC) with conventional radiotherapy (RT) results in inadequate local tumor control and survival. We report results of a Phase II trial designed to treat patients with a significantly increased total dose administered in a reduced overall treatment time using a hyperfractionated, accelerated treatment schedule with a concurrent boost technique. METHODS AND MATERIALS A total of 49 patients with unresectable Stage IIIA/IIIB (38 patients) or medically inoperable Stage I/II (11 patients) NSCLC were prospectively enrolled in this protocol. Radiation therapy was administered twice daily, 5 days/week with > 6 h between each treatment. The primary tumor and adjacent enlarged lymph nodes were treated to a total dose of 73.6 Gy in 46 fractions of 1.6 Gy each. Using a concurrent boost technique, electively irradiated nodal regions were simultaneously treated with a dose of 1.25 Gy/fraction for the first 36 fractions to a total dose of 45 Gy. RESULTS Median survival for the entire group of 49 patients is 15.3 months. Actuarial survival at 2 years is 46%: 60% for 11 Stage I/II patients, 55% for 21 Stage IIIA patients, and 26% for 17 Stage IIIB patients. The actuarial rate of freedom from local progression at 2 years is 64% for the entire group of 49 patients: 62% for Stage I/II patients, 70% for Stage IIIA patients, and 55% for Stage IIIB patients. Patients who underwent serial bronchoscopic reevaluation (4 Stage I/II, 8 Stage IIIA, and 6 Stage IIIB) have an actuarial rate of local control of 71% at 2 years. The median total treatment time was 32 days. Nine of 49 patients (18%) experienced Grade III acute esophageal toxicity. The 2-year actuarial risk of Grade III or greater late toxicity is 30%. The 2-year actuarial rate of severe-late pulmonary and skin-subcutaneous toxicity is 20% and 15%, respectively. CONCLUSION This treatment regimen administers a substantially higher biologically effective dose compared with conventional and pure hyperfractionation treatment schedules. The overall rate of acute and late toxicity was acceptable. Preliminary rates of overall survival and local control and freedom from local progression compare favorably to results reported with pure hyperfractionated radiotherapy and chemoradiotherapy.

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