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Biomedical subjects

J E Tepper

Publications and source records attributed to J E Tepper.

At least 55 records · Page 3Linked to original sources
PubMed1991

A comparison of postoperative techniques for carcinomas of the larynx and hypopharynx using 3-D dose distributions.

If a head and neck cancer originates low in the neck with a primary site below the shoulders, a technical challenge to the radiation oncologist exists in that the entire neck needs treatment while avoiding overlap of multiple fields on the spinal cord. No standard solution to this problem exists. We have developed a 3-D treatment planning tool that can be used to develop and compare 3-D treatment plans and dose distributions. Using this tool, we have studied the following techniques for the postoperative treatment of carcinomas of the larynx and hypopharynx, tumors that often embody the problems discussed above: (a) the mini-mantle technique used at the Massachussetts General Hospital, (b) a 3-field technique used at the University of Florida at Gainesville (UF 3-field), (c) a 3-field technique used at our institution and at many others (standard 3-field), and (d) the kicked out lateral technique used at our institution and at others. The 3-D dose distributions from these plans are compared. With 100% delivered just anterior to the vertebral body at mid-neck, the mini-mantle technique results in large 120% hot spots laterally and anteriorly in the neck. Near the mastoid tips, however, the dose falls to 100%. The upper neck nodes may be underdosed since this is 20% cooler than the lateral-anterior neck dose (where a large 120% hot spot exists). The spinal cord is adequately blocked. The two 3-field techniques result in small hot spots at the junction of the lateral and anterior fields. Because different methods are used to prevent overlap at the spinal cord, these hot spots occur anteriorly in the standard 3-field technique and laterally in the UF 3-field technique. The spinal cord block results in untreated neck tissue which can be supplemented with electrons in the standard 3-field technique, but is left untreated in the UF 3-field technique. Both techniques result in a generous length of spinal cord which does not receive full dose. The kicked out lateral technique treats the entire neck and reconstructed pharynx without matching fields at midneck. The upper mid mediastinum is underdosed 10-20% despite being within the posterior inferior portion of the beam. This could be minimized by using a tissue compensator. Unless there is significant subglottic extension or significant risk of disease in the upper mediastinum, we favor treating these malignancies with the kicked out lateral technique, which avoids the problem of junctioning lateral and anterior fields and provides a fairly homogeneous dose distribution.

Combined Modality Therapy↗
PubMed1991

Intraoperative electron beam radiation therapy for primary locally advanced rectal and rectosigmoid carcinoma.

To improve local control and survival in patients with primary locally advanced rectal and rectosigmoid carcinoma, intraoperative electron beam radiation therapy (IORT) has been used with a combination of moderate- to high-dose preoperative radiation therapy and surgical resection. Sixty-five patients underwent resection with the intention of using IORT if areas at high risk for local recurrence were apparent at surgery. For 20 patients undergoing complete resection with IORT, the 5-year actuarial local control and disease-free survival (DFS) was 88% and 53%, respectively. The results for 22 patients with pathologically documented residual carcinoma were less satisfactory with a 5-year actuarial local control and DFS of 60% and 32%, respectively. In this latter group, local control and DFS correlated with the extent of residual disease: patients with only microscopic disease had a 5-year actuarial local control and DFS of 69% and 47%, respectively, whereas for patients with macroscopic disease, these figures were 50% and 17%, respectively. For 18 patients undergoing complete resection without IORT or additional postoperative radiation therapy, the 5-year actuarial local control and DFS was 67% and 53%, respectively. Because local failure will occur in at least 30% of patients undergoing partial resection with or without IORT as well as patients undergoing complete resection of advanced tumors without IORT, additional postoperative radiation therapy should be considered.

Adult↗
PubMed1991

Recent advances in radiotherapy treatment planning.

Radiation treatment planning is currently in a state of rapid change. Dissatisfaction with past planning technology stems from the growing realization that: (1) Increases in the local regional tumor control rate will increase the cure rate in many malignancies. (2) Even at the best treatment centers geometric tumor misses are commonplace. (3) Traditional constraints on treatment techniques, originally imposed for simplicity and reproducibility, are no longer necessary, and can result in suboptimal treatment. (4) Treatment plans judged "optimal" in two dimensions may be far from optimal when viewed over the entire treatment volume. (5) Lack of treatment reproducibility is also commonplace, and can be demonstrated to adversely affect treatment outcome. On the positive side, recent developments in computer graphics, image processing, radiation physics, and radiation biology are now making it possible to define, design, and deliver sophisticated 3D radiation treatments. However, because many of these technologies are being developed for other disciplines, their applicability to radiation therapy treatment planning is not widely appreciated. We outline the current status and new developments in radiation therapy treatment planning.

Artificial Intelligence↗
PubMed1990

Patterns of failure following curative resection of gastric carcinoma.

To identify patterns of failure following curative resection of gastric carcinoma, the records of 130 patients undergoing resection with curative intent at the Massachusetts General Hospital were reviewed. The total local-regional failure rate was 38% (49/130 patients), with 21 patients having local-regional failure alone and 28 patients having local-regional failure and distant metastases. The incidence of local failure rose with the more advanced stages of disease. Tumors staged B2, B3, C2, and C3 had local-regional failure rates in excess of 35%. This group of patients might benefit from adjuvant radiation therapy to the tumor bed and regional lymphatics. Local-regional failure rate was highest in the anastomosis or stump 33/130 (25%), followed by the stomach bed 27/130 (21%). The overall incidence of distant metastases was 52% (67/130 patients) and rose in the more advanced disease stages. Tumors staged B2, B3, C2, and C3 had rates of distant metastases greater than 50%. Sixty-one patients (77%) had failure in the abdomen (liver, peritoneal surface, adrenal, kidney, and spleen, but excluding tumor bed, anastomosis, or regional nodes). Patients with Stage B2, B3, C2, and C3 tumors had total abdominal failure rates greater than 40%. The highest failure rates in the liver were in Stages B3 and C3, in which the subsequent development of liver metastasis was 40% and 47%, respectively. Peritoneal seeding occurred in 30/130 (23%) of patients and was highest in Stages C2 and C3, with rates of 27% and 41%, respectively.

Abdomen↗
PubMed1989

Three-dimensional display techniques in radiation therapy treatment planning.

Good radiation treatment planning requires that the target volume be treated with a high and uniform dose of radiation while irradiating normal tissue as little as possible. Even if the merits of a given treatment plan are judged only on the appearance of isodose lines in one or a few planes it can sometimes be difficult for the experienced radiation oncologist to select the best of several alternative plans. If consideration is given to the entire spatial distribution of dose, however, the problem becomes far more difficult because of the enormous amount of data that must be evaluated. We believe that the lack of suitable methods to display these data has greatly contributed to the slow incorporation of 3D considerations into routine radiation treatment planning. In the past few years there have been great advances in both the theory of how to produce effective 3D displays and in the display hardware itself. In this paper we survey some of the methods used at the University of North Carolina, and show specific examples of how these displays can be used in radiation therapy treatment planning.

Computer Graphics↗
PubMed1989

Postoperative radiation therapy for incompletely resected colorectal carcinoma.

The efficacy of high-dose post-operative radiation therapy was evaluated in 56 patients with pathologically proven or suspected residual disease after surgical resection of colon or rectal carcinoma. Patients had either microscopic or gross residual. They were treated with pelvic or abdominal irradiation to a dose of 4500 cGy followed by boost therapy to as much as 6000 to 7000 cGy if small bowel could be moved from the radiation field. Patients with microscopic residual had a local failure rate of 30% compared to 57% in those with gross residual disease. Five-year disease-free survival was 45% in patients with microscopic versus 10.6% for those with gross residual tumor. There was a trend toward a dose response curve for those with microscopic disease, but none was noted with gross residual. In view of the limited results obtained with current external beam techniques, it is recommended that newer avenues, such as high-dose preoperative therapy combined with intraoperative radiation, be investigated in this poor prognosis group.

Adult↗
PubMed1989

Treatment of locally advanced rectal cancer with external beam radiation, surgical resection, and intraoperative radiation therapy.

To try to improve the local control and survival of patients with locally advanced rectal cancer we have used a combination of high-dose pre-operative radiation therapy to 5,040 cGy followed by surgical resection and intraoperative electron beam radiation therapy (IORT) when there was visible or palpable residual disease, microscopically positive surgical margins, or persisting tumor adherence. A total of 75 patients were taken to surgery for resection +/- IORT who did not have distant metastases. Of the 49 patients with primary tumors, 11 did not have IORT as the tumor was thought to be completely resected. Of these 11, there were two local recurrences and a 3-year survival of 71%. Thirty-six patients with primary tumors had resection (20 complete, 16 partial) plus IORT, with a 3-year survival of 58% and three local failures. Twenty-six additional patients were treated for locally advanced recurrence of whom four could not receive IORT because of pelvic size or the extent of tumor. Of the 22 who received IORT, 7/9 with complete resection, 2/8 with partial resection, and 1/5 with no resection had local control with an overall 3-year actuarial survival of 32%. The local control and survival results in the primary tumors appear favorable compared to other series in the literature and suggest benefit to the use of IORT. For patients treated for local recurrence, local control and long-term survival can be obtained, but the results are not as encouraging as for the primary tumors.

Combined Modality Therapy↗
PubMed1989

Patterns of failure following local excision and local excision and postoperative radiation therapy for invasive rectal adenocarcinoma.

The clinical course of 40 patients undergoing conservative surgical excision and 26 patients undergoing local excision and postoperative radiation therapy of rectal carcinoma was reviewed. Surgical procedures were transanal excision (55 patients), Kraske procedure (ten patients), and fulguration (one patient). The five-year actuarial survival, disease-free survival, and local control of all 66 patients were 70%, 77%, and 63%, respectively. For patients undergoing local excision alone, the prognostic features of lesion size greater than 3 cm, poorly differentiated histology, invasion into muscularis propria or deeper, moderate to marked stromal fibrosis, vascular or lymph vessel invasion, fragmented resection, and positive resection margins were associated with a local failure rate of 20% or greater. Of the 26 patients receiving postoperative radiation therapy, four patients have developed local failure. For subgroups of patients with small rectal carcinomas confined to the mucosa, local excision may be a reasonable alternative to abdominoperineal resection. For tumors with deeper invasion but limited to the bowel wall, local excision plus pelvic irradiation can be offered to preserve anorectal function.

Adenocarcinoma↗
PubMed1989

Indications for adjuvant radiotherapy in extrapelvic colonic carcinoma.

Although the value of postoperative radiotherapy has been demonstrated for subsets of patients with rectal carcinoma, the efficacy of postoperative radiation therapy for colonic carcinoma (above the peritoneal reflection) is much less clear. Recent studies examining the failure patterns of colonic carcinoma following resection indicate that local failure increases as a function of bowel mobility, disease extension through bowel wall, and lymph node involvement. Retrospective series reporting the results of postoperative irradiation suggest that postoperative radiation therapy to the tumor bed may be beneficial for patients with Stage B3, C2 and C3 disease with limited nodal involvement. Randomized prospective trials are required to further evaluate the efficacy of such adjuvant radiotherapy.

Colonic Neoplasms↗
PubMed1988

Treatment of the patient with stage M0 soft tissue sarcoma.

During the period 1971 to 1985, 220 patients with soft tissue sarcoma of the extremities, torso, and head-neck region were managed by radiation and resectional surgery at the Massachusetts General Hospital (MGH). Actuarial 5-year local control and disease-free survival rates were 86% and 70%, respectively. The success rate improved during this time period. Namely, the local control rates for 1971 to 1975, 1976 to 1980, and 1981 to 1985 were 81%, 81%, and 94%, respectively. For the same time periods, the 5-year disease-free survival rates were 64%, 70%, and 76%. One hundred thirty-one patients were treated with postoperative radiation, and 89 with preoperative radiation. In the most recent 5-year period, the local control rates were 91% and 97% for the two groups (number of patients being 50 and 57 in the post- and preoperative groups, respectively). Treatment by preoperative radiation appears to have a major advantage for patients with very large sarcomas, ie, greater than 15 cm in maximum dimension. None of our patients with local control of grade 1 sarcoma have developed distant metastasis (DM). In contrast, among patients with grade 2 or 3 sarcomas, there is a relentless and progressive increase in the frequency of DM with size of the primary lesion, namely, 6% at less than or equal to 2.5 cm, congruent to 60% at 15 to 20 cm, and congruent to 80% at greater than 20 cm.

Combined Modality Therapy↗
PubMed1987

Postoperative radiation therapy of rectal cancer.

Beginning in December 1975, at the Massachusetts General Hospital (MGH) patients with rectal carcinomas thought to be at high risk of local recurrence after potentially curative surgical resection, were entered on a treatment protocol of high dose postoperative radiation therapy. Treatment was given with X rays of 10 MeV, generally using a four-field box technique to a dose of 4500 cGy with a boost to 5040 cGy or higher when the small bowel could be excluded from the reduced field. One-hundred sixty-five patients who began their radiation therapy between December 1975 and December 1982 were entered into the study. The median age was 65 years. The median follow-up in the survivors was 56 months, with a minimum follow-up of 17 months. All but 10 patients were followed for more than 2 years. Of the entire group, the actuarial 5-year survival was 53%, with survival of 71% in patients with Stage B-2, 39% in Stage C-2, and 17% in Stage C-3. Local failure was seen in 5/53 patients with Stage B-2 disease and 0/7 of patients with Stage B-3 disease. In patients with positive lymph nodes, local failure occurred in 2/10 (20%) of patients with Stage C-1, 16/77 (21%) of Stage C-2, and 8/15 (53%) of patients with Stage C-3 disease. Compared to previous series of surgery alone, the local failure rate has been decreased by more than one-half in all patients, except those with Stage C-3. Efforts to maximize the radiation doses in all stages should be made to minimize local failure. For Stage C-3, newer strategies such as intraoperative radiation therapy should be employed to decrease the continuing high incidence of failures.

Aged↗
PubMed1987

Adjuvant postoperative radiation therapy for colonic carcinoma.

One hundred thirty-three patients with Stage B2, B3, and C colonic carcinoma had resection for curative intent followed by adjuvant postoperative radiotherapy to the tumor bed. The 5-year actuarial local control and disease-free survival rates for these 133 patients were 82% and 61%, respectively. Stage for stage, the development of local regional failure was reduced for patients receiving postoperative radiotherapy compared with a historic control series. Local recurrence occurred in 8%, 21%, and 31% of patients with Stage B3, C2, and C3 tumors who had radiation therapy, respectively, whereas the local failure rates were 31%, 36%, and 53% in patients treated with surgery alone. There was a 13% and 12% improvement in the 5-year disease-free survival rate in the patients with Stage B3 and C3 lesions who had radiotherapy compared with the historic controls. For patients with Stage C disease, local control and disease-free survival rates decreased progressively with increasing nodal involvement; however, local control and disease-free survival rates were higher in the patients who had radiotherapy than in those who had surgery alone. Failure patterns in the patients who had radiotherapy did not show any notable changes compared with those for patients who had surgery alone. Postoperative radiation therapy for Stage B3, C2, and C3 colonic carcinoma is a promising treatment approach that deserves further investigation.

Adult↗