Int. J. Radiation Oncology Biol. Phvs., Vol. 37. No. 5. DD. 1005-1010, 1997 -. Copyright 0 1997~Jksevier Science Inc.

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ELSEVIER PI1 SO360-3016( 97)00105-3

l Clinical Investigation

EFFICACY AND SAFETY OF GRANULOCYTE MACROPHAGE-COLONY STIMULATING FACTOR (GM-CSF) ON THE FREQUENCY AND

SEVERITY OF RADIATION MUCOSITIS IN PATIENTS WITH HEAD AND NECK CARCINOMA

V. KANNAN, M.D., * POONAMALLEE P. BAPSY, M.D., D.M., + NARANAPPA ANANTHA, M.D., D.M.R.E., * DINESH CHANDFU DOVAL, M.D., +

HEMA VAITHIANATHAN, B.Sc., D.R.P.,” G. BANUMATHY, M.D.,*

KRISHNAMURTHY B. REDDY, M.D., * SAKLASPUR VEERAPPAIAH KUMARASWAMY, M.D.S.$ AND ASHOK MOHAN SHENOY, M.S.#

Departments of *Radiotherapy, +Medical Oncology, *Radiation Physics, “Oral Oncology, and ‘Head and Neck Surgery, Kidwai Memorial Institute of Oncology, Bangalore, India

Purpose: Based on the clinical evidence of mucosal protection by GM-CSF during cytotoxic chemotherapy, a pilotstudy was undertaken to determine the safety and mucosal reaction of patients receiving GM-CSF while undergoing definitive conventional fractionated radiotherapy in head and neck carcinoma. Methods and Materials: Patients were considered eligible if buccal mucosa and oropharynx were included in the teleradiation field. Ten adult patients with squamous cell carcinoma of head and neck (buccal mucosa-8 and posterior l/3 tongue-2) were entered into the trial. Radiation therapy was delivered with telecobalt machine at conventional 2 Gy fraction and 5 fractions/week. The radiation portals consisted of two parallel opposing lateral fields. GM-CSF was given subcutaneously at a dose of 1 pg/kg body weight, dally, after 20 Gy until the completion of radiation therapy. Patients were evaluated dally for mucosal reaction, pain, and functional im- pairment. Results: The median radiation dose was 66 Gy. Eight patients received 260 Gy. The tolerance to GM-CSF was good. All 10 patients completed the planned daily dose of GM-CSF without interruption. Mucosal toxicity was Grade I in four patients till the completion of radiotherapy (dose range 50-66 Gy ) . Six patients developed Grade II reaction, fibrinous mucosal lesions of maximum size 1.0-1.5 cm, during radiotherapy. None developed Grade III mucositis. The maximum mucosal pain was Grade I during GM-CSF therapy. In two patients after starting GM-CSF the pain reduced in intensity. Functional impairment was mild to moderate. All patients were able to maintain adequate oral intake during the treatment period. Total regression of mucosal reaction occured within 8 days following completion of radiotherapy. Conclusions: GM-CSF administration concurrently with conventional fractionated radiotherapy was feasible without sign&ant toxicity. The acute side effects of radiotherapy namely mucositis, pain, and functional im- pairment were nll to minimal. The results are suggestive of mucosal protection by GM-CSF during radiotherapy and warrants further study in randomized double blind trial. 0 1997 Elsevier Science Inc.

Radiation mucositis, GM-CSF, Radiotherapy, Head and neck carcinoma, Oral carcinoma.

INTRODUCTION

Oral and pharyngeal mucositis is a frequent side effect of radiotherapy for head and neck cancer (2). During con- ventional radiotherapy (2 Gy/day and 10 Gy/week) mu- cosal reaction starts in the second week. A slight or pro- nounced enanthema can be observed followed by spotted mucositis during the third week, which rapidly progresses to confluent mucositis ( 1, 36). In human oral mucosa the threshold for development of confluent mucositis after

fractional irradiation appears to be around 20 Gy (36). Acute mucositis is the result of hypoplasia of squamous epithelium due to sterilization of mucosal stem cells and inhibition of proliferation of transit cells (26). With con- tinuation of radiotherapy, cell regeneration cannot keep pace with cell killing and partial or complete denudation develops, presenting as spotted or confluent pseudomem- branous mucositis (26).

Mucositis causes discomfort, pain, and interferes with adequate oral nutrition. Mucositis can be a potential

Reprint requests to: Dr. V. Kannan, Department of Radiother- apy, Kidwai Memorial Institute of Oncology, Hosur Road, Ban- galore, 560 029, India. Acknowledgmelzts-Growth factor (Leucomaxe, GMICSF) was

available due to the generousity Fulford India, a subsidiary of Schering Plough and Sandoz India, Bombay. The secretarial as- sistance of Mrs. Bala Kannan is gratefully acknowledged.

Accepted for publication 12 December 1996.

1005

1006 I. J. Radiation Oncology 0 Biology 0 Physics Volume 37, Number 5, 1997

source of infection (12). Severe mucositis may lead to interruption of planned course of radiotherapy. Prolon- gation of overall time of radiation has an adverse effect on the radiocurability of head and neck squamous cell carcinoma (3, 14, 38).

Various drugs like systemic analgesics, antiinflamma- tory agents, local anesthetics, oral rinse with acetyl sali- cylic acid, and steroids have been used to relieve the symptoms of mucositis (22). Clinical results with Su- cralfate ( 15, 27 ) , Chlorhexidine (32), and Benzydamine (12, 30) are yet to prove the undisputed efficacy of these agents in the prevention of acute radiation mucositis. These agents probably act as local anesthetics reducing pain temporarily and facilitate eating and drinking ( 15 ) .

Cytokines like GM-CSF have been investigated for mu- cosal protection during cytotoxic cancer chemotherapy ( 18,34). These cytokines already have an established role in hematopoietic reconstitution during standard or high- dose chemotherapy (7) and in bone marrow transplants (9). Oral mucositis, a common side effect of chemother- apy, parallels the neutropenia that occurs after such ther- apy ( 18, 24). Infusion of GM-CSF was effective in re- ducing and shortening the duration of neutropenia after chemotherapy ( 18). The incidence of mucositis was found to be reduced when cytokines were used in children with agranulocytosis (5) and in patients with bladder can- cer on conventional dose chemotherapy ( 17). GM-CSF was found to shorten the duration of oral mucositis in patients undergoing stomatotoxic hematopoietic stem cell transplantation with chemotherapy and total body irradi- ation ( 18). Also, clinical studies of GM-CSF have found no stimulation of tumor growth (20).

Because there is limited knowledge on the prevention of radiation mucositis during conventional fractionated ra- diotherapy of head and neck cancer and the observed ef- ficacy of GM-CSF in oral mucositis in cytotoxic chemo- therapy treatment, we decided to carry out a pilot study of concurrent GM-CSF and radiotherapy in head and neck cancer.

METHODS AND MATERIALS

Patient eligibility Adult patients with histologically proven squamous cell

carcinoma of head and neck region (Karnofsky’s Perfor- mance Status of 2 70) who were to receive definitive radiotherapy were eligible for the study. Patients were not included if they had previous history of autoimmune or chronic inflammatory disease or had received previous ra- diotherapy, or cytotoxic chemotherapy. All patients had a complete medical evaluation including hemogram, blood sugar, serum electrolytes, liver, and renal function tests prior to inclusion in the trial and were eligible if they were within normal limits.

Patient characteristics Ten patients were enrolled into the study between Oc-

tober 1993 and August 1994. Prior to study entry no pa-

tient had open mouth sore. All patients had dental and oral evaluation before radiotherapy. There were two males and eight females. The median age was 55 years (range 40- 65 years). Eight patients had carcinoma of buccal mucosa and two had carcinoma of posterior l/3 tongue. Stage distribution (UICC-1987) showed eight patients in Stage III and two in Stage IV.

Drug administration GM-CSF (Leucomax) was supplied as lyophilized

form in vials containing 150 pg to be reconstituted with 1 ml sterile water for injection. The reconstituted drug was given subcutaneously at a dose of 1 pug/kg body weight per day. The sites of injections were rotated. Because fi- brinous exudative mucositis appears during the third week of conventional fractionated radiotherapy, the drug was started after completion of 20 Gy and was given daily excluding weekends till completion of radiation.

Radiotherapy The patients were treated with telecobalt radiation at 80

cm SSD at conventional fractionation of 2 Gy/fraction and five fractions/week. The treatment portals consisted of two lateral parallel opposing fields. In carcinoma buccal mucosa the treatment volume included the entire buccal mucosa and bilateral cervical nodes, levels I, II, and III. The field size varied from a width of 7- 10 cm to a length of 9- 12 cm. The dose delivered to the above volume was 44-46 Gy. This was followed by supplement radiation to the primary site and involved nodes to achieve a total dose of 60-66 Gy. In the two patients with posterior l/3 tongue carcinoma, the treatment volume included entire oropharynx and posterior 2/3 of buccal mucosa, together with entire cervical chain of nodes, levels I-V for a dose of 44 Gy. The mean field size was 9.5 cm width and 15 cm length. Supplement radiotherapy, 26 Gy was delivered to primary and involved nodal sites with a 6 X 10 cm field portals.

Evaluation All patients were treated as inpatients during the study.

Daily evaluation was carried out for mucosal reaction and toxicity. The grading of mucosal reaction, pain, and func- tional impairment is shown in Table 1.

All patients have been followed up till June 1995 or until death.

RESULTS

The median radiation dose was 66 Gy. Eight patients received 60-70 Gy. Two patients with buccal carcinoma refused further radiotherapy after 50 and 54 Gy, respec- tively, inspite of Grade I mucositis only, as they achieved complete tumor response at that dose. The median overall time was 46 days (range 31-58 days).

Granulocyte macrophage-colony stimulating factor l V. KANNAN et al. 1007

Table 1. Grading system used to evaluate mucosal reaction, pain and functional impairment

Mucosal reaction O-No reaction I-Erythema II-Patchy fibrinous mucositis, less than half the field III-Patchy fibrinous mucositis, more than half the field IV-Confluent fibrinous mucositis

Pain O-No pain I-Mild II-Moderate III-Severe

Functional impairment O-None I-Able to eat all kinds of food with slight difficulty II-Able to take semi solids and liquids III-Able to drink liquids only IV-Needs tube feeding

Feasibility and toxicity Administration of daily GM-CSF during radiotherapy

was feasible. All the 10 patients received daily the planned dose of GM-CSF, from the third week of radiotherapy (after 20 Gy) till the completion of treatment. However, two patients refused further radiation after 50 and 54 Gy, respectively, and therefore, GM-CSF was also stopped along with radiation for them. The side effects of the drug were minimal. Two patients developed itching and pap- ules over the injection sites for 3 and 4 days, respectively, during first week of GM-CSF. They received oral antihis- tamines and administration of GM-CSF was not inter- rupted. Four patients complained of diffuse body ache during the first week of GM-CSF therapy, which was treated with paracetamol. Leukocyte counts estimated twice weekly, during the trial varied from 4200 to 13000 cells/dl.

Mucositis The grade of mucositis is shown in Fig. 1. All patients

developed Grade I mucositis before 20 Gy (when GM- CSF was started). In four patients it remained as Grade I until completion of therapy. In six patients it progressed to Grade II at or after 40 Gy. It is interesting to note that none of the patients developed Grade III mucositis. There were nine lesions of fibrinous exudative reaction (Grade II) in the six patients, occurring in soft palate in four, tongue in one, retromolar trigone in one, and buccal mu- cosa in three. Two of these lesions were of 1.5 X 1 cm size. All the others were less than 1 cm. The Grade II reaction developed at a median overall time of 34 days (range 27-49 days) and the median dose was 46 Gy. All the reactions completely regressed over 3-8 days after completion of radiotherapy. None of the 10 patients de- veloped any clinical signs of infection in the irradiated mucosal area.

MUCOSITIS

g60

2; v) 50 8 5 40

5 30

3 20

10

12 3 4 5 6 7 8 9 10

PATIENTS

Fig. 1. Mucositis. Vertical bars represent grade of mucosal re- action of each patient at various dose levels. Black bars, Grade 0; dotted bars, Grade I: stippled bars, Grade II.

Pain The maximum pain was Grade I when patients were on

GM-CSF (Fig. 2). Initiation of GM-CSF was followed by reduction in pain in patient No. 5 from Grade II to I and in patient No. 10 from Grade I to 0. For Grade II pain, paracetamol and/or acetyl salicylate was given. There was disturbance neither to the daily routine activities nor to sleep because of pain.

Functional impairment Two patients developed Grade I and eight developed

Grade II severity before 20 Gy (Fig. 3 ) . One patient (No.

PAIN

60,

560

z 50

g 40 0 5 30

2 20

10

0 12 3 4 5 6 7 6 9 10

PATIENTS

Fig. 2. Pain. Vertical bars represent grade of pain of each patient at various dose levels. Black bars, Grade 0; dotted bars, Grade I; stippled bars, Grade II.

1008 I. J. Radiation Oncology l Biology l Physics

FUNCTIONAL IMPAIRMENT

70

360

w' 8 50

n z 4o 0 5 30

% 20 a

10

0 1 2 3 4 5 6 7 ii! 9 10

PATIENTS

Fig. 3. Functional impairment. Vertical bars represent grade of functional impairment of each patient at various dose levels. Dotted bars, Grade I; stippled bars, Grade II; hatched bars, Grade III.

2) progressed to Grade III severity at 46 Gy. In others, the functional impairment remained at the same level until the completion of treatment. Because oral nutrition was adequate, none required intubation or parenteral alimen- tation. This is reflected in the body weight of the patients. Pretreatment and posttreatment body weights revealed a loss of 1 kg in four and 2 kg in one, a gain of 1 kg in three, and no change in two patients.

Salivation and taste perception worsened progressively during radiotherapy. All the patients at the end of treat- ment had xerostomia. This was one of the main factors for functional impairement of Grades II and III, as they needed plenty of fluids for mastication and swallowing.

Patient outcome Seven patients achieved complete response after radio-

therapy. Six patients were alive, without any evidence of disease at the last follow-up (median 19 months, range 13-25 months) and one patient died of an unrelated cause in disease free status 1 week after completion of therapy. All the three patients who had less than complete response died of progressive disease at 10, 16, and 18 months, re- spectively.

DISCUSSION

Currently, there is no clear-cut established agent to pre- vent acute radiation mucositis ( 13). Administration of cy- tokines reduced the severity and duration of mucositis due to cytotoxic chemotherapy ( 17, 18). Because radio/che- motherapy mucositis is due to antiproliferative effects of the cytotoxic regimen on the germinative epithelial cells ( 18 ) , our trial was designed to evaluate the cytokine, GM- CSF, in radiation mucositis.

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In a study on the clinical effects of irradiation of oral tissues, mucosal plaque formation and ulceration were seen in most of the patients at 3 to 4 weeks after initiation of radiotherapy ( 1) . The early responses of mucosa of the oral cavity and oropharynx in 498 patients consisted of confluent severe mucositis in 52% of patients occuring at about 3 weeks after beginning of radiotherapy (25). Van Der Scheuren (36) reported confluent mucositis before 4 weeks, at conventional fractionation radiotherapy in all patients. EORTC randomized trial of conventional and hy- perfractionated radiotherapy in oropharyngeal carcinoma observed 42% Grade II and 49% Grade III mucositis in 2 Gy fractionation arm (21). The findings of Makkonen et al. (27) showed severe oral mucositis with ulceration in all patients, occurring at the third or fourth week of radio- therapy. North Central Cancer Treatment Group and Mayo Clinic trial of Chlorhexidine showed severe or very severe radiation mucositis in greater than 50% of the total number of patients. This occurred in spite of the radiation portal encompassing 2/3 or less volume of oral mucosa in majority of the patients ( 13 ) . Although small in num- ber, our trial is suggestive of mucosal protection by GM- CSF during radiotherapy, as we observed only Grade I and II mucositis in spite of large mucosal areas treated to a median dose of 66 Gy.

The radiation mucositis could result because of abnor- mal gram negative bacillary carriage in the oral cavity (28) as bacterial burden in the wounds inhibits contraction process (31)) enhances fibrynolysis (29)) and reduces collagen deposition (3 1) . Selective decontamination of the infection may lead to prevention or amelioration of radiation mucositis (28). Escherichia coli-infected acute and chronic granulating wounds in rats with topical ap- plication of GM-CSF showed increased rate of wound clo- sure ( 3 1) . This mechanism could be due to enhanced cy- totoxic and microbicidal function of mature granulocytes ( 11) and phagocytic activity of soft tissue macrophages (20). Also, the cytokine primes the leukocytes, increasing 5-Lipoxygenase gene transcription favoring Leukotriene B-4 production, which is needed for rapid clearance of inflammatory site (35). In addition, GM-CSF protects neutrophil from apoptosis and prolongs its half-life (23).

Wound healing after clearance of inflammatory debris is followed by neoangiogenesis, migration of fibroblasts, and collagen formation. GM-CSF receptors have been found on endothelial cells (6). GM-CSF transgenic mice have shown high m-RNA level for basic Fibroblast Growth Factor (FGF) in macrophages ( 19). Basic FGF stimulates proliferation of keratinocytes (4) and capillary endothelial cells (33) and fibroblast accumulation at wound site (10) favoring its healing. It also protects en- dothelial cells from radiation induced apoptosis ( 16).

Recent works on radiation molecular biology suggests that the mammalian cells respond to oxidative stress of radiation by activating genes that encode GM-CSF (37) and Interleukin- 1 (IL- 1) (39 ) . Even the Colony Stimu- lating Factors at the inflammatory site can cause secretion

Granulocyte macrophage-colony stimulating factor 0 V. KANNAN et al. 1009

of IL-l ( 19). Administration of IL-l during fractionated radiotherapy in C3H/K mice showed protection of lip mu- cosa and tongue from acute radiation reaction (40, 41) .

Therefore, GM-CSF with its ability to act on multiple cells could initiate a cascade of reaction at the inflamma- tory site. This may hasten wound healing or prevent its progression inspite of continued radiation injury.

Radiotherapy can decrease the integrity of intercellular desmosomes of mucosal cells making it possible for even normal function to result in enough trauma to produce further atrophy and ulceration (8). A direct salutory epi- thelial effect by GM-CSF has also been proposed favoring wound healing ( 18, 34).

It was observed in this pilot study that GM-CSF ad- ministration during radiotherapy was feasible. Discrete fo- cal fibrinous mucositis of oral and oropharyngeal mucosa was the maximum radiation reaction seen at conventional radiation fractionation when GM-CSF was started after 20 Gy. Four patients never developed any fibrinous mucosi- tis. Pain as a symptom of mucosal radiation was nil or mild during GM-CSF therapy, and in fact, it regressed in severity in two. Adequate oral nutrition was maintained in all. The results are suggestive of the mucosal protective effect of the cytokine during radiotherapy and warrants further evaluation in a randomized study with a larger number of patients.

REFERENCES

1. Al-Tikriti, U.; Martin, M. V.; Bramley, P. A. A pilot study of the clinical effects of irradiation on the oral tissues. Br. J. Oral. Maxillofac. Surg. 22:77-86; 1984.

2. Baker, D. G. The radiobiological basis for tissue reactions in the oral cavity following therapeutic x-irradiation. Arch. Otolaryngol. 108:21-24; 1982.

3. Bataini, J. P.; Asselain, B.; Jaulerry, Ch.; Brunin, F.; Bernier, J.; Pontvert, D.; Lave, C. A multivariate primary tumour con- trol analysis in 465 patients treated by radical radiotherapy for cancer of the tonsillar region: Clinical and treatment pa- rameters as prognostic factors. Radiother. Oncol. 14:265- 277; 1989.

4. Bennet, N. T.; Schultz, G. S. Growth factors and wound healing: Biochemical properties of growth factors and their receptors. Am. J. Surg. 165:728-737; 1993.

5. Bonilla, M. A.; Gillio, A. P.; Ruggeiro, M.; Keman, N. A.; Brochstein, J. A.; Abboud, M.; Fumagalli, L.; Vincent, M.; Gabrilove, J. L.; Welte, K.; Souza, L. M.; O’Reilly, R. J. Effects of recombinant human granulocye colony-stimulat- ing factor on neutropenia in patients with congenital agran- ulocytosis. N. Engl. J. Med. 320: 1574- 1580; 1989.

6. Bussolino, F.; Wang, J. M.; DiFilippi, P.; Turrini, F.; Sana- vio, F.; Edgell, C.-J. S.; Aglietta, M.; Arese, P.; Mantovani, A. Granulocyte and granulocyte-macrophage colony stimu- lating factors induce human endothelial cells to migrate and proliferate. Nature 337:47 l-473; 1989.

7. Cebon, J. S.; Lieschke, G. J. Granulocyte-Macrophage col- ony-stimulating factor for cancer treatment. Oncology 51:177-188; 1994.

8. Chase, L. P.; Toto, P. D.; Magalotti, M. F. Radiation induced changes in the epithelium of the buccal mucosa. J. Dent. Res. 40:929-935; 1961.

9. Dale, D. C. Where now for colony stimulating factors? Lan- cet 346:135-136; 1995.

10. Davidson, J. M.; Broadley, K. N. Manipulation of the wound healing process with fibroblast growth factor. Ann. NY Acad. Sci. 638:307-315; 1991.

11. Engelhard, M.; Brittinger, G. Clinical relevance of Granu- locyte-Macrophage Colony-Stimulating Factor. Semin. On- col. 21(Suppl. 16):1-4; 1994.

12. Epstein, J. B.; Stevenson-Moore, P.; Jackson, S.; Mohamed, J. H.; Spinelli, J. J. Prevention of oral mucositis in radiation therapy: A controlled study with benzydamine hydrochloride rinse. Int. J. Radiat. Oncol. Biol. Phys. 16: 1571- 1575; 1989.

13. Foote, R. L.; Loprinzi, C. L.; Frank, A. R.; O’Fallon, J. R.; Gulavita, S.; Tewfik, H. H.; Ryan, M. A.; Earle, J. M.; No- votny, P. Randomized trial of a chlorhexidine mouthwash for alleviation of radiation-induced mucositis. J. Clin. Oncol. 12:2630-2633; 1994.

14. Fowler, J. F.; Lindstrom, M. J. Loss of local control with prolongation in radiotherapy. Int. J. Radiat. Oncol. Biol. Phys. 23:457-467; 1992.

15. Franzen, L.; Hemiksson, R.; Littbrand, B.; Zackrisson, B. Effects of sucralfate on mucositis during and following ra- diotherapy of malignancies in the head and neck region. Acta Oncol. 34:219-223; 1995.

16. Fuks, Z.; Haimovitz-Friedman, A.; Kolesnick, R. N. The role of sphingomyelin pathway and Protein Kinase C in radiation induced cell kill. In: DeVita, V. T.; Hellman, S.; Rosenberg, S. A., eds. Important advances in Oncology 1995. Philadel- phia, PA: Lippincott Co; 1995: 19-3 1.

17. Gabrilove, J.; Jakubowski, A.; Scher, H.; Stemberg, C.; Wong, G.; Grous, J.; Yagoda, A.; Fain, K.; Moore, M. A.; Clarkson, B. Effect of granulocyte colony stimulating factor on neutropenia and associated morbidity due to chemother- apy for transitional cell carcinoma of the urothelium. N. Engl. J. Med. 318: 1414- 1422; 1988.

18. Gordon, B.; Spadinger, A.; Hodges, E.; Ruby, E.; Stanley, R.; Coccia, P. Effect of granulocyte-macrophage colony stimulating factor on oral mucositis after hematopoietic stem-cell transplantation. J. Clin. Oncol. 12:1917- 1922; 1994.

19. Hamilton, J. A. Colony stimulating factors, cytokines and monocyte- macrophages-Some controversies. Immunol. Today 14:18-24; 1993.

20. Hansen, F. Hemopoietic growth and inhibitory factors in treatment of malignancies. Acta Oncol. 34:453-468; 1995.

21. Horiot, J. C.; LeFur, R.; N’Guyen, T.; Chenal, C.; Schraub, S.; Alfonsi, S.; Gardani, G.; Van Den Bogaert, W.; Danczak, S.; Bolla, M.; Van Glabbeke, M.; De Pauw, M. Hyperfrac- tionation vs. conventional fractionation in oropharyngeal carcinoma: Final analysis of a randomized trial of the EORTC cooperative group of radiotherapy. Radiother. On- col. 25:231-241; 1992.

22. Jansma, J.; Vissink, A.; Bouma, J.; Vermey, A.; Panders, A. K.; Johannes’s-Gravenmade, E. A survey of prevention and treatment regimens for oral sequelae resulting from head and neck radiotherapy used in dutch radiotherapy institutes. Int. J. Radiat. Oncol. Biol. Phys. 24:359-367; 1992.

23. Lieschke, G. J.; Burgess, A. W. Granulocyte colony stimu- lating factor and granulocyte-macrophage colony-stimulat- ing factor. N. Engl. J. Med. 327:28-35; 1992.

24. Lockhart, P. B.; Sonis, S. T. Relationship of oral complica- tions to peripheral blood leukocyte and platelet counts in patients receiving cancer chemotherapy. Oral Surg. 48:21- 28; 1979.

25. Maciejewski, B.; Withers, H. R.; Taylor, J. M. G.; Hliniak, A. Dose fractionation and regeneration in radiotherapy for

1010 I. J. Radiation Oncology l Biology l Physics Volume 37, Number 5. 1997

cancer of oral cavity and oropharynx. Part 2. Normal tissue responses: Acute and late effects. Int. J. Radiat. Oncol. Biol. Phys. 18:101-111; 1990.

26. Maciejewski, B.; Zajusz, A.; Pilecki, B.; Swiatnicka, J.; Skladowski, K.; Dorr, W.; Kummermehr, J.; Trott, K. R. Acute mucositis in the stimulated oral mucosa of patients during radiotherapy for head and neck cancer. Radiother. Oncol. 22:7-l 1; 1991.

27. Makkonen, T. A.; Bostrom, P.; Vilja, P.; Joensuu, H. Su- cralfate mouth washing in the prevention of radiation-in- duced mucositis: A placebo-controlled double-blind ran- domized study. Int. J. Radiat. Oncol. Biol. Phys. 30:177- 182; 1994.

28. Martin, M. V. Irradiation mucositis: A reappraisal. Oral On- col. Eur. J. Cancer. 29B:l-2; 1993.

29. Perry, A. W.; Sutkin, H. S.; Gottlieb, L. J.; Stadelmann, W. K.; Krizek, T. J. Skin graft survival: The bacterial an- swer. Ann. Plast. Surg. 22:479-483; 1989.

30. Prada, A.; Chiesa, F. Effects of benzydamine on the oral mu- cositis during antineoplastic radiotherapy and/or intra-arterial chemotherapy. Int. J. Tissue React. 9:115-119; 1987.

3 1. Robson, M.; Kucukcelebi, A.; Carp, S. S.; Hayward, P. S.; Hui, P. S.; Cowan, W. T.; Ko, F.; Cooper, D. M. Effects of granulocyte-macrophage colony-stimulating factor on wound contraction. Eur. J. Clin. Microbial. Infect. Dis. 13 (Suppl. 2) :41-46; 1994.

32. Samaranayake, L. P.; Robertson, A. G.; MacFarlane, T. W.; Hunter, I. P.; MacFarlane, G.; Ferguson, M. M. The effect of chlorhexidine and benzydamine mouthwashes on mucos- itis induced by therapeutic irradiation. Clin. Radiol. 39:291- 294; 1988.

33. Schliephake, H.; Neukam, F. W.; Lohr, A.; Hutmacher, D. The use of basic fibroblast growth factor (bFGF) for en-

hancement of bone ingrowth into pyrolized bovine bone. Int. J. Oral Maxillofac. Surg. 24: 18 1 - 186; 1995.

34. Schuchter, L. M.; Luginbuhl, W. E.; Meropol, N. J. The cur- rent status of toxicity protectants in cancer therapy. Semin. Oncol. 19:742-751; 1992.

35. Stankova, J.; Rola-Pleszczynski, M.; Dubois, C. M. Granu- locyte-macrophage colony-stimulating factor increases 5-li- poxygenase gene transcription and protein expression in hu- man neutrophils. Blood 85:3719-3726; 1995.

36. Van Der Schueren, E.; Van Den Bogaert, W.; Vanuytsel, L.; Van limbergen, E. Radiotherapy by multiple fractions per day (MFD) in head and neck cancer: Acute reactions of skin and mucosa. Int. J. Radiat. Oncol. Biol. Phys. 19:301-311; 1990.

37. Weichselbaum, R. R.; Hallahan, D.; Fuks, Z.; Kufe, D. Ra- diation induction of immediate early genes: Effecters of the radiation-stress response. Int. J. Radiat. Oncol. Biol. Phys. 301229-234; 1994.

38. Withers, H. R.; Taylor, J. M. G.; Maciejewski, B. The hazard of accelerated tumour clonogen repopulation during radio- therapy. Acta Oncol. 27: 13 1- 146; 1988.

39. Woloschak, G. E.; Chang-Liu, G. M.; Jones, P. S.; Jones, C. A. Modulation of gene expression in murine and hamster embryo cells following ionizing radiation. Cancer Res. 53:339-344; 1990.

40. Zaghloul, M. S.; Dorie, M. J.; Kallman, R. F. Interleukin-1 modulatory effect on the action of chemotherapeutic drugs and localized irradiation of the lip, duodenum and tumour. Int. J. Radiat. Oncol. Biol. Phys. 26:417-425; 1993.

41. Zaghloul, M. S.; Dorie, M. J.; Kallman, R. F. Interleukin 1 increases thymidine labeling index of normal tissues of mice but not the tumour. Int. J. Radiat. Oncol. Biol. Phys. 29:805- 811; 1994.