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Radiation osteitis following irradiation for breast cancer
Clin. Radiol. (1977) 28, 93 96 RADIATION OSTEITIS FOLLOWING IRRADIATION F O R BREAST C A N C E R A. O. LANGLANDS, W. A. SOUTER, E. SAMUEL and A. T. REDPATH
From the University of Edinburgh, Royal Infirmary, Western General Hospital, and Princess Margaret Rose Hospital, Edinburgh Radiographs of the shoulder girdle were examined in 180 women who attended the breast follow-up clinic at the Department of Radiotherapy, Edinburgh. These comprised 52 controls who had been treated by radical mastectomy alone and 128 patients who had received post-operative X-ray therapy. The significance of osteoporosis as a sequel to irradiation is doubtful as it occurred in a substantial proportion of the control cases. Osteitis of severe degree occurred in 13.3% of patients who had been irradiated and was present in a mild form in a further 8.6%. The development of severe osteitis requires an NSD of 1650 rets or more. Estimates of the frequency of radiation osteitis are of no value unless detailed information is also provided about the techniques and quality of radiation. INTRODUCTION
MATERIAL AND METHODS
The development of late structural and functional damage in irradiated bone has been most extensively studied in relation to the mandible. The clinical significance of radiation damage at this site is undoubtedly complicated by the ,part played by infection and trauma (Watson and Scarborough, 1938; Jacobsson, 1948; Niebel and Neenan, 1957). Siinilarly, the stress of weight bearing has drawn attention to damage to the femoral neck by pelvic irradiation, usually for cancer of the uterus or cervix (Stampfli and Kerr, 1947; Bonfiglio, 1953; Stephenson and Cohen, 1956). In contrast, and in spite of the extensive use of radiotherapy in the management of breast cancer, considerably less information exists regarding damage to the bones of the shoulder girdle. Ackerman (1955), in a study of 786 cases treated in the Department of Radiotherapy, Edinburgh, prior to 1947, reported radiation osteitis in the shoulder girdle or ribs in 6%. Much lower incidence figures have been reported by Parker (1972) who had only one case among 220 patients and Serna (1967) who gave no data for the shoulder joint in a series in which there was a 2% incidence of fractures of the ribs or clavicle. Slaughter (1942)has reported five cases of fractures of the clavicle following irradiation for breast cancer. Souter et al. (1976) have recorded 10 cases of humeral fracture as a result of radiation osteitis in patients treated by the Edinburgh technique. The histology of radiation osteitis of the humerus in three patients has been described by Sengupta and Prathap (1973). The present study was undertaken to try to assess the frequency of the development of osteitis in the bones of the shoulder girdle and to relate the frequency of its occurrence to the dose of radiation.
The patients studied were those attending for routine review examination having been treated for breast cancer between 1949 and 1963. Treatment in each case was by the departmental policy of simple mastectomy of the breast followed by post-operative radiotherapy (McWhirter, 1955), or, in the case of controls, by radical mastectomy. During the irradiation of the axilla and supraclavicular fossa the shoulder joint was inevitably included in the treatment field (parallel semi-opposed fields, approximately 25 x 10 cm, 250 or 300 kV, 15 mA, H.V.L. 3 mm Cu, Thoraeus III filter). Up to 1956 the maximum dose given was 4000-4500 rads in 3 weeks (15 fractions). Between 1956 and 1964 the dose was 4000-4250 rads but this was delivered in 20 fractions over 4 weeks. All case records were re-examined and for each patient a mean NSD was calculated according to the formula, NSD = RBE x D x N -0"24 × T -°'11 D is the total dose in rads N is the number of fractions T is the total treatment time in days RBE is the relative biological effect taken as 1.0 for 6°Co gamma-rays and 1.1 for 250-350 kV X-rays (Ellis, 1969). In 1964 a trial in breast cancer management was started and patients treated by radical mastectomy in this trial provided control cases. Standard antero-posterior radiographs of both shoulder joints were obtained in 1973. These were classified into four categories without knowledge of whether radiation had been given or which side had been treated. The classification categories were: 1. Normal. This included patients showing mild osteoporosis of both shoulders, since in the age
94
CLINICAL RADIOLOGY RESULTS
Fig. 1 - An example of the changes of severe radiation osteitis 19 years after X-ray therapy. group under study this was a fairly constant finding. 2. Osteoporosis, This was defined as a uniform reduction in bone density with no sclerosis. This was assessed subjectively, account also being taken of any asymmetrical reduction in cortical thickness relative to the width Of the shaft as a whole or loss o f t r a b e c u l a r definition. 3. Radiation osteitis (mild). The bone showed mottled radiotranslucencies with slight sclerosis and trabecular thickening. 4. Radiation osteitis (severe). These changes were very pronounced. Mottling was usually universal but the background picture would tend either towards gross osteoporosis or towards dense sclerosis and coarsening o f the trabecular pattern ('Pagetoid' appearance) (Fig. 1).
Table 1 - Mean age and mean time from exposure for the cases studied
Classification
Normal Osteoporosis Osteitis (mild) Osteitis (severe) All osteitis Controls
No.
57 43 11 17 28 52
Mean age
62.8 62.6 64.2 65.4 64.9 62.0
+ 8.0 + 9.0 + 5~2 +-8.1 + 7.0 + 8.6
Mean time .from exposure (years)
13.0 13.0 14.5 18.5 16.9 5.8
+ 2.9 + 3.0 + 3.0 + 2.6 +- 3.4 + 2.8
C o n t r o l Cases. - These numbered 52. Over 80% were correctly classified as normal but in 10 cases (19.2%) osteoporosis was described which was similar to that occurring in irradiated patients. Following classification in this way the case records were again reviewed. None of the cases showing osteoporosis had a complication of treatment such as lymphoedema or restriction of shoulder movement which might have explained the radiographic change. However cases which showed osteoporosis, contrary to expectation, proved to be younger (59.6 + 7.2 years) than the remainder o f the controls (62.6 + 8.9 years). No radical mastectomy had been carried out prior to 1964 and as a result control cases were examined on average 6 years post-mastectomy whereas irradiated cases date b a c k to 1949 (Table 1). Irradiated Patients. - The distribution of the 128 cases in the irradiated group according to the radiological classification is shown in Table 1. Patients treated prior to 1956 received a higher dose o f X-rays. This may explain the fact that patients showing changes of osteitis were seen on average 4 years later than patients showing osteoporosis only or negative X-rays. The mean ages in these radiological groups however show no significant difference and, unlike the control cases, patients with osteoporosis were not younger than those with normal X-rays. In the series as a whole there was radiological evidence o f osteitis in 28 out o f 128 cases (21.9%) and this was severe in 17/128 (13.3%). The variation in the radiological classification with the calculated NSD is shown in Table 2 and Fig. 2. The radiological changes o f osteitis are associated more frequently with a high NSD, though each group showed a wide variation in dose. Of the 17 cases with marked osteitis four (23.5%) had an NSD o f less than 1650. Among 114 cases classed as normal or showing osteoporosis 107 (94%) had an NSD o f less than 1650. X-rays o f the energies ( 2 5 0 - 3 0 0 kV) used in the treatment o f this series o f patients produce a higher
Table 2 - Calculated NSD for the cases according to their radiographic classification
Radiological classification
NSD
Normal Osteoporosis Osteitis (mild) Osteitis (severe) All osteitis
1510 1526 1526 1730 1650
+ 68 + 82 + 78 + 145 + 158
RADIATION OSTEITIS FOLLOWING IRRADIATION FOR BREAST CANCER
OSTEITIS
NSD 1800
( SEVERE) OSTEITIS (ALL CASES)
1700
OSTEITIS OSTEO(MILD) POROSIS 1600,NORMAL 1500t t 1/,00~Fig. 2 - Dose-response relationship for cases according to radiographic classification. absorbed dose in bone relative to soft tissue. We have tried to estimate this dose in a standard set-up assuming a shoulder thickness of 17 cm. The dose in the bones of the shoulder girdle ranged from 96 to 104% (mean 100%) with 4000 fads (the m a x i m u m skin dose) being equal to 117%. The calculated dose in bone is therefore 3420 rads. However, when allowance is made for the increased absorption which occurs in bone (x 1.3) the NSD in the bones o f the shoulder girdle in a standard set-up is 1650. After analysis o f the radiographs the case records of the 28 cases showing signs of osteitis were re-examined. Of the 11 cases classed as showing mild osteitis, restriction o f shoulder movement was recorded in one case only. This woman had had limitation of abduction to 90 ° since 1956, 3 years after treatment. It is interesting to note that the calculated NSD for this patient was 1746 which is considerably higher than the mean value for this group and comparable to the mean value for those with marked osteitis (Table 2). In contrast, among the 17 cases showing severe osteitis only six had no abnormal findings or symptoms. Lymphoedema occurred in five patients, soft tissue atrophy was marked in three cases, in one o f whom intractable ulceration occurred. There was restriction of arm abduction to about 90 ° in two patients. Pain was a presenting complaint in two cases. One patient had suffered a traumatic fracture of the surgical neck o f the humerus. This had united well with no disability. DISCUSSI ON Osteoporosis has been described as the main pathological change associated with fractures o f the
95
femoral neck following pelvic irradiation (Bonfiglio, 1953), though others have suggested that interference with blood supply may be responsible (Truelson, 1942; Serna, 1967). Infarction o f the femoral head has been recorded following irradiation (Samuel, 1957). Fractures o f the femoral neck tend to occur not long after X-ray treatment. Stephenson and Cohen (1956) summarised the available data on this point and quote a range from 3 months to 9 years with an average o f 18 months. In our study it is difficult to allocate significance to the finding o f osteoporosis. A substantial proportion of controls (19.2%) showed this feature compared to 33.6% o f irradiated patients. Furthermore there was no apparent relationship between this finding and the calculated NSD. It is important to remember however that our cases were studied at a much longer average interval than that for postradiation fractures o f the femoral neck. Sourer et al. (1976) have recorded 10 cases of fracture o f the humerus based on osteitis. In these cases failure o f union is almost inevitable in marked contrast to the femoral fractures where union is the rule (Bonfiglio, 1953; Stephenson and Cohen, 1956). These observations suggest that the damage in the shoulder girdle is more severe and it may be that avascular necrosis is the main sequel to irradiation o f the shoulder girdle at tfigher doses and t h a t this develops at a longer interval from irradiation. As far as we are aware no figures, comparable to these which we report, exist for the frequency o f osteitis in the bones o f the shoulder girdle. Many of" the earlier reports have been restricted to descriptions of damage to the ribs or clavicle (Slaughter, 1942; Lester and Pohle, 1943; Wammock and Arbuclde, 1943; Elberhard, 1960; Serna, 1967) where fractures are commoner and recognition o f radiation effects consequently easier. There is correspondingly even less information on the possible dose relationship. Our data for the shoulder girdle is shown in Fig. 2
Table 3 - Summary of calculated NSDs for cases of osteitis Author
Serna (1976) Kolaretal. (1967)
Sengupta and Prathap (1973) Present series (A) (B) (A) Mild osteitis
(B) Severe osteitis
No. o f cases
Calculated NSD
3 1
1573 2000- 2270
3
1705- 1770
11 17
1526 + 145 1650-+ 158
96
CLINICAL RADIOLOGY
and rib involvement is not included when this is the sole manifestation. Damage to ribs is most easily detected in a standard chest radiograph which was not done in the cases we are reporting. We attempted to calculate an NSD for the cases reported by Kolar et al, (1967), Serna (1967), and Sengupta and Prathap (1973) and these are summarised in Table 3. It is clear from this table that the development o f osteitis is dose-dependent requiring an N S D o f about 1650 if it is marked. For this reason estimates o f its frequency are of little value unless detailed descriptions are given of the treatment techniques involved. It is also interesting to compare these dose estimates with those given for femoral neck fractures. Both Woodard and Coley (1947) and Bonfiglio (1953) give an estimated dose in the femur o f 3000 rads. Neither provided enough detail for us to calculate the NSD. However, in our calculations o f the dose in the bones o f the shoulder girdle, we arrived at a dose o f 3420 rads in 4 weeks, which is not dissimilar.
REFERENCES Ackerman, k. V. (1955). An evaluation of the treatment of cancer of the breast at the University of Edinburgh (Scotland) under the direction of Dr R. McWhirter. Cancer, 8, 883-887. Bonfiglio, M. (1953). Pathology of fractures of the femoral neck following irradiation. Americal Journal of Roentgenology, 70, 449-459. Elberhard, B. (1960). Radiation damage to the ribs and clavicle in breast cancer. Strahlentherapie, 113, 312-318. Ellis, F. (1969). Dose, time and fractionation. A clinical hypothesis. Clinical Radiology, 20, 1-7. Jacobsson, F. (1948). Carcinoma of the tongue. A clinical study of 277 cases treated at Radiumhemmet. Acta Radiologica, Stockholm, Suppl. 68, 167-169. Kolar, J., Vrabec, E. & Chyba, J. (1967). Arthropatbies after
irradiation. Journal of Bone and Joint Surgery, 49A, Part 2, 1157-1166. Lester, W. P. & Pohle, E. A. (1943). Radiation osteitis of the ribs. Radiology, 38, 543- 551. McWhirter, R. (1955). Simple mastectomy and radiotherapy in the treatment of breast cancer. British Journal of Radiology, 28, 128-139. Niebel, H. H. & Neenan, E. W. (1957). Dental aspects of osteoradionecrosis. Oral Surgery, 10, 1011-1024. Parker, R. G. (1972). Tolerance of mature bone and cartilage in clinical radiation therapy. In Frontiers o f Radiation Therapy and Oncology, ed. Vaeth, J. M., Vol. 6, pp. 312-331. S. Karger, Basel, Switzerland. Samuel, E. S. (1957). Post-irradiation infarction of the femoral head. South African Medical Journal, 31/34, 841-842. Sengupta, S. & Prathap, K. (1973). Radiation necrosis of the humerus. Acta radiologica (Therapy), NS 12, 313-320. Serna, G. M. (1967). Osteoradionecrosis. Missouri Medicine, 64, 997-1000. Slaughter, D. P. (1942). Radiation osteitis and fractures following irradiation with report of 5 cases of fractured clavicle. American Journal o f Roentgenology and Radiation Therapy, 48, 201-212. Souter, W. A., Stableforth, P. G. & Wilkes, L. L. (1976). Pathological fractures of the humerus due to radiation necrosis. (In preparation). Stampfli, W. P. & Kerr, H. D. (1947). Fractures of the femoral neck following pelvic irradiation. American Jouv nal of Roentgenology and Radiation Therapy, 57, 71- 83. Stephenson, W. H. & Cohen, B. (1956). Postqrradiation fractures of the neck of the femur. Journal of Bone and Joint Surgery, 38B, 830-845. Wammock, H. & Arbuckle, R. IC (1943). Fractures of the rib cage following interstitial radium therapy for cancer of the breast. American Journal of Roentgenology and Radiation Therapy, 50, 609-613. Watson, W. L. & Scarborough, J. E. (1938). Osteoradionecrosis in intra-oral cancer. American Journal of Roentgenology and Radiation Therapy, 40, 524-534. Woodward, H. Q. & Coley, B. L. (1947). Correlation of tissue dose and clinical response in irradiation of bone turnouts and of normal bone. American Journal of Roentgenology and Radiation Therapy, 57, 464-471.
From the University of Edinburgh, Royal Infirmary, Western General Hospital, and Princess Margaret Rose Hospital, Edinburgh Radiographs of the shoulder girdle were examined in 180 women who attended the breast follow-up clinic at the Department of Radiotherapy, Edinburgh. These comprised 52 controls who had been treated by radical mastectomy alone and 128 patients who had received post-operative X-ray therapy. The significance of osteoporosis as a sequel to irradiation is doubtful as it occurred in a substantial proportion of the control cases. Osteitis of severe degree occurred in 13.3% of patients who had been irradiated and was present in a mild form in a further 8.6%. The development of severe osteitis requires an NSD of 1650 rets or more. Estimates of the frequency of radiation osteitis are of no value unless detailed information is also provided about the techniques and quality of radiation. INTRODUCTION
MATERIAL AND METHODS
The development of late structural and functional damage in irradiated bone has been most extensively studied in relation to the mandible. The clinical significance of radiation damage at this site is undoubtedly complicated by the ,part played by infection and trauma (Watson and Scarborough, 1938; Jacobsson, 1948; Niebel and Neenan, 1957). Siinilarly, the stress of weight bearing has drawn attention to damage to the femoral neck by pelvic irradiation, usually for cancer of the uterus or cervix (Stampfli and Kerr, 1947; Bonfiglio, 1953; Stephenson and Cohen, 1956). In contrast, and in spite of the extensive use of radiotherapy in the management of breast cancer, considerably less information exists regarding damage to the bones of the shoulder girdle. Ackerman (1955), in a study of 786 cases treated in the Department of Radiotherapy, Edinburgh, prior to 1947, reported radiation osteitis in the shoulder girdle or ribs in 6%. Much lower incidence figures have been reported by Parker (1972) who had only one case among 220 patients and Serna (1967) who gave no data for the shoulder joint in a series in which there was a 2% incidence of fractures of the ribs or clavicle. Slaughter (1942)has reported five cases of fractures of the clavicle following irradiation for breast cancer. Souter et al. (1976) have recorded 10 cases of humeral fracture as a result of radiation osteitis in patients treated by the Edinburgh technique. The histology of radiation osteitis of the humerus in three patients has been described by Sengupta and Prathap (1973). The present study was undertaken to try to assess the frequency of the development of osteitis in the bones of the shoulder girdle and to relate the frequency of its occurrence to the dose of radiation.
The patients studied were those attending for routine review examination having been treated for breast cancer between 1949 and 1963. Treatment in each case was by the departmental policy of simple mastectomy of the breast followed by post-operative radiotherapy (McWhirter, 1955), or, in the case of controls, by radical mastectomy. During the irradiation of the axilla and supraclavicular fossa the shoulder joint was inevitably included in the treatment field (parallel semi-opposed fields, approximately 25 x 10 cm, 250 or 300 kV, 15 mA, H.V.L. 3 mm Cu, Thoraeus III filter). Up to 1956 the maximum dose given was 4000-4500 rads in 3 weeks (15 fractions). Between 1956 and 1964 the dose was 4000-4250 rads but this was delivered in 20 fractions over 4 weeks. All case records were re-examined and for each patient a mean NSD was calculated according to the formula, NSD = RBE x D x N -0"24 × T -°'11 D is the total dose in rads N is the number of fractions T is the total treatment time in days RBE is the relative biological effect taken as 1.0 for 6°Co gamma-rays and 1.1 for 250-350 kV X-rays (Ellis, 1969). In 1964 a trial in breast cancer management was started and patients treated by radical mastectomy in this trial provided control cases. Standard antero-posterior radiographs of both shoulder joints were obtained in 1973. These were classified into four categories without knowledge of whether radiation had been given or which side had been treated. The classification categories were: 1. Normal. This included patients showing mild osteoporosis of both shoulders, since in the age
94
CLINICAL RADIOLOGY RESULTS
Fig. 1 - An example of the changes of severe radiation osteitis 19 years after X-ray therapy. group under study this was a fairly constant finding. 2. Osteoporosis, This was defined as a uniform reduction in bone density with no sclerosis. This was assessed subjectively, account also being taken of any asymmetrical reduction in cortical thickness relative to the width Of the shaft as a whole or loss o f t r a b e c u l a r definition. 3. Radiation osteitis (mild). The bone showed mottled radiotranslucencies with slight sclerosis and trabecular thickening. 4. Radiation osteitis (severe). These changes were very pronounced. Mottling was usually universal but the background picture would tend either towards gross osteoporosis or towards dense sclerosis and coarsening o f the trabecular pattern ('Pagetoid' appearance) (Fig. 1).
Table 1 - Mean age and mean time from exposure for the cases studied
Classification
Normal Osteoporosis Osteitis (mild) Osteitis (severe) All osteitis Controls
No.
57 43 11 17 28 52
Mean age
62.8 62.6 64.2 65.4 64.9 62.0
+ 8.0 + 9.0 + 5~2 +-8.1 + 7.0 + 8.6
Mean time .from exposure (years)
13.0 13.0 14.5 18.5 16.9 5.8
+ 2.9 + 3.0 + 3.0 + 2.6 +- 3.4 + 2.8
C o n t r o l Cases. - These numbered 52. Over 80% were correctly classified as normal but in 10 cases (19.2%) osteoporosis was described which was similar to that occurring in irradiated patients. Following classification in this way the case records were again reviewed. None of the cases showing osteoporosis had a complication of treatment such as lymphoedema or restriction of shoulder movement which might have explained the radiographic change. However cases which showed osteoporosis, contrary to expectation, proved to be younger (59.6 + 7.2 years) than the remainder o f the controls (62.6 + 8.9 years). No radical mastectomy had been carried out prior to 1964 and as a result control cases were examined on average 6 years post-mastectomy whereas irradiated cases date b a c k to 1949 (Table 1). Irradiated Patients. - The distribution of the 128 cases in the irradiated group according to the radiological classification is shown in Table 1. Patients treated prior to 1956 received a higher dose o f X-rays. This may explain the fact that patients showing changes of osteitis were seen on average 4 years later than patients showing osteoporosis only or negative X-rays. The mean ages in these radiological groups however show no significant difference and, unlike the control cases, patients with osteoporosis were not younger than those with normal X-rays. In the series as a whole there was radiological evidence o f osteitis in 28 out o f 128 cases (21.9%) and this was severe in 17/128 (13.3%). The variation in the radiological classification with the calculated NSD is shown in Table 2 and Fig. 2. The radiological changes o f osteitis are associated more frequently with a high NSD, though each group showed a wide variation in dose. Of the 17 cases with marked osteitis four (23.5%) had an NSD o f less than 1650. Among 114 cases classed as normal or showing osteoporosis 107 (94%) had an NSD o f less than 1650. X-rays o f the energies ( 2 5 0 - 3 0 0 kV) used in the treatment o f this series o f patients produce a higher
Table 2 - Calculated NSD for the cases according to their radiographic classification
Radiological classification
NSD
Normal Osteoporosis Osteitis (mild) Osteitis (severe) All osteitis
1510 1526 1526 1730 1650
+ 68 + 82 + 78 + 145 + 158
RADIATION OSTEITIS FOLLOWING IRRADIATION FOR BREAST CANCER
OSTEITIS
NSD 1800
( SEVERE) OSTEITIS (ALL CASES)
1700
OSTEITIS OSTEO(MILD) POROSIS 1600,NORMAL 1500t t 1/,00~Fig. 2 - Dose-response relationship for cases according to radiographic classification. absorbed dose in bone relative to soft tissue. We have tried to estimate this dose in a standard set-up assuming a shoulder thickness of 17 cm. The dose in the bones of the shoulder girdle ranged from 96 to 104% (mean 100%) with 4000 fads (the m a x i m u m skin dose) being equal to 117%. The calculated dose in bone is therefore 3420 rads. However, when allowance is made for the increased absorption which occurs in bone (x 1.3) the NSD in the bones o f the shoulder girdle in a standard set-up is 1650. After analysis o f the radiographs the case records of the 28 cases showing signs of osteitis were re-examined. Of the 11 cases classed as showing mild osteitis, restriction o f shoulder movement was recorded in one case only. This woman had had limitation of abduction to 90 ° since 1956, 3 years after treatment. It is interesting to note that the calculated NSD for this patient was 1746 which is considerably higher than the mean value for this group and comparable to the mean value for those with marked osteitis (Table 2). In contrast, among the 17 cases showing severe osteitis only six had no abnormal findings or symptoms. Lymphoedema occurred in five patients, soft tissue atrophy was marked in three cases, in one o f whom intractable ulceration occurred. There was restriction of arm abduction to about 90 ° in two patients. Pain was a presenting complaint in two cases. One patient had suffered a traumatic fracture of the surgical neck o f the humerus. This had united well with no disability. DISCUSSI ON Osteoporosis has been described as the main pathological change associated with fractures o f the
95
femoral neck following pelvic irradiation (Bonfiglio, 1953), though others have suggested that interference with blood supply may be responsible (Truelson, 1942; Serna, 1967). Infarction o f the femoral head has been recorded following irradiation (Samuel, 1957). Fractures o f the femoral neck tend to occur not long after X-ray treatment. Stephenson and Cohen (1956) summarised the available data on this point and quote a range from 3 months to 9 years with an average o f 18 months. In our study it is difficult to allocate significance to the finding o f osteoporosis. A substantial proportion of controls (19.2%) showed this feature compared to 33.6% o f irradiated patients. Furthermore there was no apparent relationship between this finding and the calculated NSD. It is important to remember however that our cases were studied at a much longer average interval than that for postradiation fractures o f the femoral neck. Sourer et al. (1976) have recorded 10 cases of fracture o f the humerus based on osteitis. In these cases failure o f union is almost inevitable in marked contrast to the femoral fractures where union is the rule (Bonfiglio, 1953; Stephenson and Cohen, 1956). These observations suggest that the damage in the shoulder girdle is more severe and it may be that avascular necrosis is the main sequel to irradiation o f the shoulder girdle at tfigher doses and t h a t this develops at a longer interval from irradiation. As far as we are aware no figures, comparable to these which we report, exist for the frequency o f osteitis in the bones o f the shoulder girdle. Many of" the earlier reports have been restricted to descriptions of damage to the ribs or clavicle (Slaughter, 1942; Lester and Pohle, 1943; Wammock and Arbuclde, 1943; Elberhard, 1960; Serna, 1967) where fractures are commoner and recognition o f radiation effects consequently easier. There is correspondingly even less information on the possible dose relationship. Our data for the shoulder girdle is shown in Fig. 2
Table 3 - Summary of calculated NSDs for cases of osteitis Author
Serna (1976) Kolaretal. (1967)
Sengupta and Prathap (1973) Present series (A) (B) (A) Mild osteitis
(B) Severe osteitis
No. o f cases
Calculated NSD
3 1
1573 2000- 2270
3
1705- 1770
11 17
1526 + 145 1650-+ 158
96
CLINICAL RADIOLOGY
and rib involvement is not included when this is the sole manifestation. Damage to ribs is most easily detected in a standard chest radiograph which was not done in the cases we are reporting. We attempted to calculate an NSD for the cases reported by Kolar et al, (1967), Serna (1967), and Sengupta and Prathap (1973) and these are summarised in Table 3. It is clear from this table that the development o f osteitis is dose-dependent requiring an N S D o f about 1650 if it is marked. For this reason estimates o f its frequency are of little value unless detailed descriptions are given of the treatment techniques involved. It is also interesting to compare these dose estimates with those given for femoral neck fractures. Both Woodard and Coley (1947) and Bonfiglio (1953) give an estimated dose in the femur o f 3000 rads. Neither provided enough detail for us to calculate the NSD. However, in our calculations o f the dose in the bones o f the shoulder girdle, we arrived at a dose o f 3420 rads in 4 weeks, which is not dissimilar.
REFERENCES Ackerman, k. V. (1955). An evaluation of the treatment of cancer of the breast at the University of Edinburgh (Scotland) under the direction of Dr R. McWhirter. Cancer, 8, 883-887. Bonfiglio, M. (1953). Pathology of fractures of the femoral neck following irradiation. Americal Journal of Roentgenology, 70, 449-459. Elberhard, B. (1960). Radiation damage to the ribs and clavicle in breast cancer. Strahlentherapie, 113, 312-318. Ellis, F. (1969). Dose, time and fractionation. A clinical hypothesis. Clinical Radiology, 20, 1-7. Jacobsson, F. (1948). Carcinoma of the tongue. A clinical study of 277 cases treated at Radiumhemmet. Acta Radiologica, Stockholm, Suppl. 68, 167-169. Kolar, J., Vrabec, E. & Chyba, J. (1967). Arthropatbies after
irradiation. Journal of Bone and Joint Surgery, 49A, Part 2, 1157-1166. Lester, W. P. & Pohle, E. A. (1943). Radiation osteitis of the ribs. Radiology, 38, 543- 551. McWhirter, R. (1955). Simple mastectomy and radiotherapy in the treatment of breast cancer. British Journal of Radiology, 28, 128-139. Niebel, H. H. & Neenan, E. W. (1957). Dental aspects of osteoradionecrosis. Oral Surgery, 10, 1011-1024. Parker, R. G. (1972). Tolerance of mature bone and cartilage in clinical radiation therapy. In Frontiers o f Radiation Therapy and Oncology, ed. Vaeth, J. M., Vol. 6, pp. 312-331. S. Karger, Basel, Switzerland. Samuel, E. S. (1957). Post-irradiation infarction of the femoral head. South African Medical Journal, 31/34, 841-842. Sengupta, S. & Prathap, K. (1973). Radiation necrosis of the humerus. Acta radiologica (Therapy), NS 12, 313-320. Serna, G. M. (1967). Osteoradionecrosis. Missouri Medicine, 64, 997-1000. Slaughter, D. P. (1942). Radiation osteitis and fractures following irradiation with report of 5 cases of fractured clavicle. American Journal o f Roentgenology and Radiation Therapy, 48, 201-212. Souter, W. A., Stableforth, P. G. & Wilkes, L. L. (1976). Pathological fractures of the humerus due to radiation necrosis. (In preparation). Stampfli, W. P. & Kerr, H. D. (1947). Fractures of the femoral neck following pelvic irradiation. American Jouv nal of Roentgenology and Radiation Therapy, 57, 71- 83. Stephenson, W. H. & Cohen, B. (1956). Postqrradiation fractures of the neck of the femur. Journal of Bone and Joint Surgery, 38B, 830-845. Wammock, H. & Arbuckle, R. IC (1943). Fractures of the rib cage following interstitial radium therapy for cancer of the breast. American Journal of Roentgenology and Radiation Therapy, 50, 609-613. Watson, W. L. & Scarborough, J. E. (1938). Osteoradionecrosis in intra-oral cancer. American Journal of Roentgenology and Radiation Therapy, 40, 524-534. Woodward, H. Q. & Coley, B. L. (1947). Correlation of tissue dose and clinical response in irradiation of bone turnouts and of normal bone. American Journal of Roentgenology and Radiation Therapy, 57, 464-471.