Esophageal Ulceration Following High-Dose-Rate Intraluminal Brachytherapy for Esophageal Cancer

Medical Dosimetry, Vol. 19, No. 1, pp. 51-52, 1994

Copyright 0 1994American Association of Medical Dosimetrists

Pergamon

Printed in the USA. AU rights resexved 0958-3947/94 $6.00 + .OO

095%3947(93)EOOO3-M

?? Selected Abstracts

From the Journal Radìotherapy and Oncology RADIATION THERAPY FOR MALIGNANT ASTROCYTOMAS IN ADULTS

Jeffrey D. Forman, Colin Orton, Gary Ezzell and Arthur T. Porter

Française Momex:

Department of Radiation Oncology, Wayne State University, Detroit, Ml, USA

Hala NayeP and Luc Taillandierb

“Département de Radiothérapie, Centre Léon Bérard, Lyon and bService de Neurologie, Hopital St Julien, Centre Hospitalier Universitaire, Nancy, France

Vol. 27, 1993, pp. 203-208 Key words: Locally advanced prostate cancer;

Hyperfractionated Dose escalation

Vol 27, 1993, pp. 181-191 Key words: High grade astrocytoma; Radiation therapy; Brachytherapy; Chemotherapy; Prognostic factors

radiotherapy;

The objective of this study was to build on our experience with 3-D conformal radiotherapy (CRT) by using a hyperfractionated dose escalation scheme to maximize the therapeutic ratio between improved local control and reduced morbidity in patients with locally advanced prostate cancer. Twenty patients with locally advanced (T3, T4) adenocarcinoma of the prostate were treated with a hyperfractionated radiotherapy schedule. Al1 fields were designed with a conforma1 therapy based beam’s eye view, 3-D planning system. The pelvic lymph nodes received 1.8 Gy/day to a total dose of 45 Gy in 5 weeks. Using partial transmission blocks, the prostate and periprostatic tissues received 1.3 Gy twice daily (minimum interval of 6 h) to a total dose of 78 Gy in 6 weeks. The dose was chosen by calculating the biologically effective dose (BED) which would produce the same effect in late reacting tissue but an increase for the tumor as our standard dose of 69 Gy delivered in 1.8-2.0 Gy fractions. The (Y/@chosen for late damage was 3 Gy and 10 Gy was used for the tumor. Al1 20 patients completed the planned course of treatment. Although an increase in the tumor BED would be expected to result in increased acute effects, no significant worsening of acute side-effects was ObseNed compared with standard treatment. Al1 patients had only mild (Grade 1) recta1 or bladder toxicity during treatment. One patient had an exacerbation of diverticulitis during treatment requiring hospitalization for antibiotics but completed treatment on schedule. In patients with locally advanced prostate cancer, a hyperfractionated schedule has demonstrated that it is feasible to deliver higher doses of radiation (78 Gy) with minimal acute toxicity. Further follow-up wil1 demonstrate whether the incidence of late complications wil1 be acceptable and whether histologie sterilization of the prostate cancer wil1 be enhanced.

High grade (or malignant) astrocytomas remain a formidable therapeutic challenge. The main prognostic factors are patient age, patient performance status, tumor grade, the extent of surgical resection and the presence of fits. These factors could help to identify different groups of patients and should be an advantage in deciding on treatment strategies. Modem imaging techniques provide a more precise idea of tumor volume. The study of tumor recurrence shows that they occur in the immediate vicinity ofthe primary site. Surgery aside, radiotherapy remains the most important treatment modality. Currently, its standards conceming optimal dose and target volume appear to be accepted overall. There is no doubt that a dose-response relation exists; however, doses exceeding 60 Gy increase morbidity. Therefore 60 Gy is the dose most often cited in the literature. Furthermore, as whole brain irradiation does not decrease the risk of recurrence, a focal irradiation including a defined mean volume is generally used today. Radiosensitizers and heavy particles have not fulfilled their initial promise. Brachytherapy remains an interesting altemative for a limited number of patients. Nevertheless, it seems to increase recurrence at a distance from the primary site and to lead to severe focal lesions. lnterstitial thermoradiotherapy may minimize local doses and thus help avoid serieus local necrosis. Amongst the other therapeutic alternatives, intravenous chemotherapy using nitrosoureas provides a certain but modest benefit. Other administration modalities are currently undergoing evaluation. These include intra-arterial chemotherapy or high dose chemotherapy with autobone marrow transplantation. The interest of this latter is concemed mainly with anaplastic astrocytomas. Finally, among the future alternatives, gene therapy appears to hold the most promise. Intensive therapies, combined modality treatments, with the recent help of biological innovations, should be proposed to favorable groups of patients.

ESOPHAGEAL ULCERATION DOSE-RATE INTRALUMINAL FOR ESOPHAGEAL CANCER

FOLLOWING HIGHBRACHYTHERAPY

Yoshio Hishikawa, Masayuki lzumi, Koichi Kurisu, Midori Taniguchi, and Norihiko Kamikonya

PRELIMINARY RESULTS OF A HYPERFRACTIONATED DOSE ESCALATION STUDY FOR LOCALLY ADVANCED ADENOCARCINOMA OF THE PROSTATE

Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya-city, Hyogo 663, Japan Vol. 28, 1993, pp. 252-254

Selected Abstracts-designed to keep readers up to date by providing original abstracts of current literature from Radiotherapy and Oncology,an Elsevier Science Ltd joumal.

Key words: Esophageal cancer; Radiotherapy;

brachytherapy; 51

Esophageal ulcer

lntraluminal

52

Selected Abstracts

Prophylaxis of esophageal ulceration was studied in 18 esophageal carcinoma patients after high-dose-rate intraluminal brachytherapy. Before the standard treatment regimen of radiotherapy was established, 15117 patients developed ulcers. This decreased to 19/38 with the standard treatment regimen, and to 9/23 when antiulcer therapy was added (p < 0.01).

CELL-CYCLE PROGRESSION DURING CONTINUOUS LOW DOSE RATE IRRADIATION OF A HUMAN BLADDER CARCINOMA CELL LINE Krzysztof Skladowski”,b, Trevor J. McMillanb, John Peacockb, Jennifer Titley”, and G. Gordon Steelb rentre of Oncology, Maria Sklodowska-Curie Memorial Institute, 44- 10 1 Gliwice, Wybrzeze Armii Czerwonej 15, Poland bRadiotherapy Research Department, ‘Section of Cel1 Biology and Experimental Pathology, The Institute of Cancer Research, 15 Cotswold Road, Sutton, Surrey SM2 5NG, UK Vol. 28, 1993, pp. 219-227 Key words: Dose rate effect; Cel1 cycle, Human tumour cel1 lines At very low radiation dose rates, the proliferation of mammalian cells continues unaffected but as the dose rate is increased there comes a point at which it is interrupted. The dose rate at which this happens is often thought to be a significant factor in the effects of brachytherapy: it may determine the range from an implanted source at which cellcycle redistribution and repopulation effects wil1 occur. By means of mitotic counts and DNA flow cytometry, we have examined the dose rate effect in a human bladder carcinoma cel1 line (MGH-U 1). Irradiation at dose rate 0.1 cGy/ min had little or no effect on cell-cycle progression. Suppression of mitosis and arrest of cells in G2 was observed at 0.4 cGy/min and above. Surprisingly, the duration of mitotic arrest showed little dose rate dependence; it was followed by an overshoot of cells in mitosis after 24-39 h of irradiation. An even more pronounced overshoot of cells in G2 occurred and persisted throughout the irradiation period. The cel1 kinetic data indicate that after the temporary black in cell-cycle progression, cel1 proliferation continued at al1 dose rates up to 1.4 cGy/min. We have evaluated these results in the light of previous studies in this department of the dose rate effect for cel1 survival in the MGH-U 1 cel1 line. After 24 h irradiation at 1.4 cGy/min the surviving fraction was below lO-*, also after 30 h at 1.O cGy/min. When cellcycle blockade is considerable, so is the leve1 of cel1 killing. Flow-cytometric data therefore are dominated by the properties of cells that are doomed to die. The concept of cel1 proliferation during continuous irradiation is thus an intricate one and we conclude that, in the context of brachytherapy for cancer, the existente or otherwise of radiation-induced cell-cycle blockade is of little practica1 significante.

HDR VERSUS LDR GYNECOLOGICAL BRACHYTHERAPY REVISITED P. Scalliet”, A. Gerbauletb, and B. Dubray” aDepartment of Radiotherapy, AZ Middelheim, Lindendreef 1, B2020 Antwerp, Belgium bService de

Curiethérapie, Institut Gustave Roussy, F94805 Villejuif cedex, France ‘Department de Radiothérapie, Institut Curie, F7523 1 Paris cedex 05, France Vol. 28, 1993, pp. 118-126 Key words: High-dose rate; Low-dose rate; Intracavitary

brachytherapy Despite the obvious breakthrough of high dose-rate (HDR) afterloading systems on the gynecological brachytherapy marke& questions stil1 remain regarding the transfer ofavailable expertise gained throughout the last 80 years with low dose-rate (LDR) radium and cesium, especially regarding the conversion of LDR total dose into equivalent HDR dose per fraction and total dose. Calculation of biologically equivalent schedules requires a knowledge of repair capacity and repair kinetics of tumors and normal tissues, both of which influence the biological effect of any radiation dose. The clinical experience with HDR is, however, accumulating and it is acknowledged that the new technique entails an acceptable therapeutic index as compared to the classica1 LDR. There is thus a state of apparent ‘equivalente’ between the two treatment modalities. This state is influenced by many factors in which, in contrast to what is frequently claimed, radiobiological factors do not play the most important role. It is probably its high-tech environment which makes HDR an acceptable alternative. Treatment at LDR, indeed, has proven to be quite tolerant to a lack of absolute precision, something that would be disastrous with HDR techniques. Because HDR intracavitary brachytherapy has not been compared in controlled trials with the best existing LDR brachytherapy, but only retrospectively with heterogeneous LDR clinical data, it cannot be claimed to be equivalent, but simply feasible.

A MODEL FOR CALCULATING THE COSTS OF IN VIVO DOSIMETRY AND PORTAL IMAGING IN RADIOTHERAPY DEPARTMENTS K. Kesteloota, A. Dutreixb, and E. van der Schuerenb ‘Center for Health Services Research and Department of Applied Economics, K.U. Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium bDepartment of Radiotherapy, University Hospita1 St. Rafaël, Leuven, Belgium Vol. 28, 1993, 108-117 Key wordsr Costs; In vivo dosimetry;

Portal imaging

The costs of in vivo dosimetry and portal imaging in radiotherapy are estimated, on the basis of a detailed overview of the activities involved in both quality assurance techniques. These activities require the availability of equipment, the use of material and workload. The tost calculations allow to conclude that for most departments in vivo dosimetry with diodes wil1 be a cheaper alternative than in vivo dosimetry with TLD-meters. Whether TLD measurements can be performed cheaper with an automatie reader (with a higher equipment tost, but lower workload) or with a semi-automatic reader (lower equipment tost, but higher workload), depends on the number of checks in the department. LSPsystems (with a very high equipment tost) as wel1 as on-line imaging systems wil1 be cheaper portal imaging techniques than conventional port films (with high material costs) for large departments, or for smaller departments that perform frequent volume checks.