during the early years that followed the discovery of x - ray , radiographers were unintentionally , incautious when dealing with it because of its unknown biological harmful effects .
many cases of cancer , sterility and death due to x - ray / radiation toxicity were documented during the early years of the 20 century .
for example , in 1907 , 6 out of 11 cases with x - ray - induced caners died .
moreover , many early workers in the field of dentistry suffered from radiation - induced ulceration , dermatitis and malignant tumors in their fingers . with strict compliance to the radiation protection guidelines , issued by the international commission on radiological protection ( icrp ) , diagnostic radiography is considered a safe practice .
, no other reports addressing the disastrous effects of x - ray radiation have been documented in the literature since 1960s . the present report , however , documents a case of thumbs carcinoma of a dental radiographer due to his neglect of radiation protection guidelines .
in august 2010 , a 49-year - old male working as a dental radiographer , lost his distal phalanges of both thumbs as a result of development of squamous cell carcinoma , due to neglect of the guidelines of protection related to x - ray imaging .
he was appointed in 1994 by the radiology division , primarily as an in - charge clerk within the oral medicine department ( faculty of dentistry , damascus university ) . as a school graduate with an intermediate certificate ,
his main task was merely to monitor the radiographic equipment . given that there was only one radiographic technician at that time , it was decided in 1995 to train him on how to use the dental x - ray machines and how to radiograph patients .
he was warned about the radiation risks and thoroughly educated on the appropriate protection standards .
on the other hand , he was accustomed to handling the periapical films with his thumb fingers . in 2003
although it was asymptomatic , he considered it as a traumatic ulcer and hence willingly neglected it for a period , which under normal circumstances would be considerably enough for such an ulcer to heal .
subsequently he then experimented with various courses of local and systemic antibiotic , but the ulcer did not show any signs of healing . based on his judgment
, it was asymptomatic and unprogressive , and accordingly he perceived to be a normal exfoliation , the result of his long - term handling of chemical processing solutions . in august 2010
( after 15 years of handling dental x - ray ) , he noticed a discharge oozing from his right thumb . by that time , he also took notice of a similar ulcer in his left thumb .
he consulted the professors in the department who in turn referred him to a general surgeon . on plane hand radiographs ,
an erosion of the distal phalanges of both thumbs was clearly evident [ figures 1 and 2 ] .
consequently , the surgeon planned to excise the discharging ulcerative lesion of the right thumb and to submit it for histopathological diagnosis , which clearly revealed squamous cell carcinoma grade ii [ figure 3 ] . based on such a diagnosis ,
the surgeon decided to excise the distal phalanges of both thumbs with tumor free - margins [ figure 4 ] .
out of ethical consideration , the radiographer was well - informed about the intent to publish his case and hereby he signed an informed consent .
plane hand radiograph reveals bone erosion in the right thumbs distal phalanges plane hand radiograph reveals bone erosion in the left thumbs distal phalanges histopathologic microphotographs reveal squamous cell carcinoma ( [ a ] 40 and [ b ] 100 )
early x - ray machines needed to be set and repeatedly adjusted . to achieve this
, radiographers would place their hands between the actively radiating tube and the film plate to check if the apparatus was functioning and that it was well focused on the film . by practicing this for 12 years , dr . kells
was the first victim of dental x - ray radiation with numerous cancerous tumors on his fingers . by that time , the icrp published guidelines for radiation protection that have been updated from time to time . in syria ,
the atomic energy commission adopted these guidelines and has since strictly emphasized the importance of their application by public and private institutions .
one of the guidelines clearly states that the film should never be hand held by a member of the dental practice staff , even for patients with special needs . holding periapical films in the patient 's mouth is still practiced in modern dentistry , but , fortunately , is not common .
sixty per cent of australian dentists never do this , but 25% will do so less than once every month , and 1.5% might do so more than 10 times a month .
the radiation - risk is the function of the radiation dose which is expressed as an effective dose .
the national commission for radiation protection in the united states reports that the mean effective dose received by dental workers is 0.2 msv / year .
similarly , the national radiological protection board , in the uk estimates a mean level of < 0.1 msv / year . in dose limit terms for workers ,
the current effective dose limit is 100 msv in any consecutive 5 years with a maximum of 50 msv in any year .
these limits are based on guidance from the icrp , with the effective dose limit being set at a level at which the stochastic risk is considered to be at the limit of acceptability .
the probability of radiation - induced stochastic effects for the whole population is 7.3  10 /sv . the working load in the radiology division within the faculty ranges between 100 and 150 patients a day .
hence , the radiographer in the current report received a fraction of about 600900 sv / day ; 13.219.8 msv / month ; 158237 msv / year and 2.43.6 sv in 15 years .
overall , he was at a greater risk of getting a stochastic effect by 2.43.6 times compared to the whole population , as the probability of radiation - induced stochastic effect for this case ranges from 18  10   to 26  10 /sv .
some authorities claim that any dose of radiation has the potential to induce malignant changes , and there is no threshold dose below which radiation is predictably safe .
the risk of induction of fatal cancer or serious hereditary ill - health from dental intra - oral radiography was estimated to be 1 in 10 million ( 10 ) per exposure .
this increased the risk of inducing fatal cancer or serious hereditary ill - health to 46 in 100 ( 10 ) .
however , the risk - estimates depend on the shape and length of the collimator or position indicating devices ( pids ) .
the short and pointed cones with closed - end , such as that which had been used by the radiographer in this report for 13 years ( fiad , dr 554 , italy ) , have the greatest probability of a stochastic effect ( 1 in 26  10 ) in comparison to the rectangular or round ones .
the latter , which are open - ended and have been used for the last 2 years of the radiographer 's work ( ardet s.r.l buccinasco [ mi ] orix 70 , italy ) , have a probability of a stochastic effect ranging from 1 in 4.6  10   to 1 in 23  10   according to the length .
overall , the shielded open - end pids , both round and rectangular in shape , have become more widely used during the past 40 years because of the reported decrease in patient exposure that is achieved . in general ,
dental radiography has a little dose and risk for the individual patient and dental workers provided that the principles of protection are applied ; it is less dangerous in comparison to a few days of natural background radiation to which we are all constantly exposed .
dental radiography doses and risks are minimal unless dealt without being cautious , which is the case of the radiographer presented here .
 dealing with diagnostic x - ray radiation may result in serious health problems , unless protection guidelines are followed . 
 this became prevalent immediately a decade following the invention of x - ray radiation , where it had not been known that the accumulative exposure to x - ray radiation may carry huge health hazards . 
 the reoccurrence of various fatal cancer cases compelled the concerned health authorities to develop safety standards to be followed by all x - ray clinics and technicians worldwide . 
 this report documents the clinical case of a dental radiographer , who developed thumbs carcinoma after 15 years of practicing the profession , most likely due to his neglect of the x - ray radiation protection guidelines . 