Monday, October 14, 2019
Radiation Doses vs Patientââ¬â¢s Life Styles
Radiation Doses vs Patientââ¬â¢s Life Styles Radiation doses from 131I treated hyperthyroidism patientsââ¬â¢ vs life style- Aà survey A.S. Shah*, Hameedullah, F. Saeed, K.A.Shah, A. Khan, M. Rauf Khattak ABSTRACT The Radioactive Iodine is widely used for the treatment of various thyroid disorders. The patientsà undergoing such treatments are advised to restrict their social and work related activities to limità radiation exposures to others. The present work describes the results of a structured surveyà conducted on patients visiting Institute of Radiotherapy and nuclear Medicine (IRNUM), Peshawar,à for the thyrotoxicosis treatment. The patients were asked about their housing conditions, family setà up, number of kids, travelling mode and time back home from the hospital. The radiation doses to theà other people with whom they might come in contact in their living environment were estimated. Theà radiation doses to others at one meter from the patients were calculated as 0.76, 1.53, 2.29, 3.06, 3.82à and 4.58mSv. The results of the survey indicate that the radiation protection advice and otherà regulatory requirements need to be reviewed keeping in view individual patientâ⠬â¢s circumstances. INTRODUCTION The radioactive iodine (RAI) is widely used for the treatment of various thyroid disordersà since long. The differentiated thyroid cancer (DTC) is treated by admitting the patients inà hospital where as hyperthyroidism patients are treated on out patient basis in most of theà countries (1-4). The safety issues for the patients, their families, comforters, hospital staff andà the general public arise with either treatment approach. The radiation hazards are more inà case of hyperthyroidism treatment than the DTC treatment due to shorter effective half lifeà of the 131I in the later application. Therefore at the time of release of the patient fromà medical confinement, the retained radioactivity in DTC patients is much lower causing lowà risk of radiation exposure to other people. In case of thyrotoxicosis treatment theà administered radioactivity is much lower as compared to DTC treatment but radiationà doses to others are more due to high uptake of RAI by these pa tients (5-8). The patientsà undergoing such treatments are advised to restrict their social and work related activitiesà to reduce radiation exposure to others when they return to their families in community (9-16). This radiation protection advice is usually based on residual activity or radiation exposure level and is not specific to an individual patient circumstances or socioeconomicà condition. These advices are usually formulated by the developed countries and areà adopted as such in most of the developing countries. In actual practice the compliance to theà protection advice depends on socioeconomic conditions and the life style of the patients. Therefore keeping in view this aspect of RAI treatments, an interview based structuredà survey was conducted on patients visiting our hospital for the treatment of thyrotoxicosis. The patients were asked about their housing conditions, family/home set up, number ofà kids, mode of travelling and travelling time to back home from the hospital. The radiationà doses to the other people with whom they might come in contact in their livingà environment MATERIAL AND METHODS The patients were asked about their housing conditions, family set up, number of kids andà travelling periods back home. The total number of patients inducted in the present surveyà was 419. The data collected was tabulated and reviewed for completeness. A calibratedà dose of 131I (185-1106MBq) was administered to the patients. The exposure rate from theà patient was measured at a distance of one meter from standing position with a hand-heldà pressurized battery operated à ² à ³ survey meter, Victoreen Model 450P, calibrated fromà secondary standard dosemetry laboratory, Islamabad. The dose rate was recorded in unitsà of à ¼Svhr-1. The patients were instructed to sleep alone, drink fluids liberally and avoid prolonged close personal contact with others for the first 2 days. The patients and familymembers were told that they could resume normal activities thereafter (9-12). The estimatedà radiation doses to the maximally exposed person were calculated using the form ula given inà equation 2 (14). RESULTS There were 385 (93%) patients residing in joint and 29 (07%) in separate family systemà Table 1. It was found that 15.27 % of the patients were male and 84.73% females with ageà wise distribution as shown in Table 2. The measured hospital leaving dose rate at one meter from the patients were 5.7, 11.0, 15.7,à 18.7, 23.0 and 28.0à ¼Svh-1 for administered RAI activity of 5, 10, 15, 20, 25 and 29.9mCià respectively. The corresponding radiation doses to others from exposure to the patient atà one meter using occupancy factor of 0.25 were calculated as 0.76, 1.53, 2029, 3.06, 3.82 andà 4.58mSv Table 3. They survey showed that 4.77, 17.66, 22.91, 24.10, 12.66 and 17.90% patients hadà accommodation consisting of one, two, three, four, five and more than five roomsà respectively Table 4. It was observed that 78.04% patients used public transport and 21.96% used privateà transport for back home after RAI administration. The radiation doses to others duringà travelling were estimated using occupancy factor of 0.1m and 1m distance plotted versusà travelling time of the patient from hospital to back home Figure 1 and Figure 2 respectively.à It was also observed that 1.67% of the patients had no sanitary arrangements at home andà they used open space in the fields as toilet. The patients residing in localities where there isà comparatively better sanitation arrangements had one (31.74%), two (36.04%), threeà (17.42%) and more than three (13.13%) toilets available Table 5. In addition 11.93% of the patients had no kids where 10.74% lived in joint family systemà and 1.19% as separate. The survey showed that 88.7% of the patients had kids and 82.33%à of these lived in joint family system where as 5.73% lived separate. The number of kids andà the family status showed that 17.18%, 31.50% and 33.65% patients had 1-3, 4-6 and moreà than 6 kids respectively lived in joint family system while 2.86%, 1.91% and 0.95% patientsà had 1-3, 4-6 and more than 6 kids respectively and they used to live in separate familyà system Table 6. DISCUSSION The patients treated for thyrotoxicosis with RAI (131I) are advised certain restrictions onà behavior in order to ensure the radiation safety of all other individuals with whom they mayà come into contact. Generally it is assumed that the patients are unlikely to create a hazardà to other persons. A dose limit of 5mSv and 1mSv had been recommended for these peoplesà depending upon the nature and type of their interaction with the patient (17). Theà compliance to the safety instructions depend upon patientââ¬â¢s literacy level, decision makingà capacity, health education, grasping and understanding disclosure of treatment in generalà and patientââ¬â¢s socioeconomic conditions and life styles in particular(18,19). The over all literacy level of the survey region is 37.26 % (20). Literacy level reflects theà ability of the patients to comprehend that they emit detectable levels of radiation forà specified period of time after their treatment which are hazardous for other peoples. It wasà observed that 93% of the patients inducted in the survey used to reside in joint familyà system and 07% lived in separate system Table 1. This aspect coupled with the low literacyà level puts emphasis on the patients receiving treatments to comply with the instructionsà strictly to limit radiation exposure to others. The restriction on mode of travelling back to home is important factor in RAI treatmentà especially when 78.96% of the patients used public transport to back home from hospital. Ità is practically difficult to measure radiation doses to other passengers traveling in the sameà vehicle. The measured hospital leaving dose rate at one meter from the patients suggestà that the time restrictions to travel by private transport (at 1m distance) are not required,à although they should not sit immediately adjacent to another passenger, accompanyingà person or driver Table 3. Similarly restrictions would not be required for public transport (0.1m distance) for oneà hour journey. It was observed that radiation doses to others at 1m and 0.1m withà administered 131I radioactivity of 185, 555 and 1106MBq increases linearly with the travelling time Figure 1 2. The patients needing greater travelling time back home shouldà use private transport after RAI administration. Therefore regulatory authorities need toà reassess the situation with respect to private or public mode of travelling whileà recommending discharge limits for RAI treatments. The radiation doses from the exposureà to the patient to total decay (t=âËž) at one meter using occupancy factor of 0.25 for RAIà administered were well within recommended dose limit of 5mSv for adult comforters Tableà 3. However for patients residing in single room accommodation, with kids and joint familyà system, the dose limit of 1mSv is unlikely to be adhered. This aspect becomes moreà important where a very large percentage of the patients (88.07%) had kids and 82.33% ofà those used to live in joint family system as observed in the present survey Table 6. Theà sanitary conditions of the patients at home are important to protect family members fromà radioactive contamination and associated external radiation exposure. It was observed thatà patients having better sanitation arrangements would not pose radiation related problems. However patients having no proper sanitation (1.67%) are source of concern for theà communities where they reside Table 5. The trends observed indicate that the patients with single room accommodation, havingà kids and joint family system need strict compliance to radiation protection advice to restrictà radiation doses to the immediate family members. Therefore RAI treatments need to beà carried out keeping in view patientââ¬â¢s living conditions and life styles. CONCLUSION The radiation protection advice and regulatory requirements need to be formulatedà keeping in view patientââ¬â¢s socioeconomic, life style and living conditions. It needs to beà reviewed depending upon individual patientââ¬â¢s circumstances. Table 1 Family Status (N=419) Status No of patients (%) Joint Family 390 (93) Separate Family 29(07) Table 2 Age and Sex Distribution of Patients Age No. of Patients (%) 17 to 28 36(8.59) 29 to 40 161 (38.42) 41 to 50 119 (28.4) 51 TO 60 67 (15.9) >60 33 (7.8) *15.27 % of patients are males ** 84.73 % of patients are females Table 3 131I administered Vs Average Radiation Doses S.No 131I activity (mCi) No. of patients (%) Average leaving dose rate at 1 meter (à ¼Sv/hr) Average Dose* to others at 1 meter (mSv) 1 05 12 (2.88) 5.7 0.76 2 10 18 (4.3) 11 1.53 3 15 99 (23.62) 15.7 2.29 4 20 233 (55.6) 18.7 3.06 5 25 47 (11.21) 23 3.82 6 29.9 10 (2.3) 28 4.58 * Average doses to total decay (t=âËž) to other individual exposed to the patient at one meter usingà occupancy factor of 0.25. Table 4 Status of Patients in Relation to No. of Rooms in Joint/ Separate System No. of rooms in home No. of Patients (%) Patients living in Joint Family System Patients living in Separately 1 20(4.77) 18 2 2 74(17.66) 69 7 3 96(22.91) 90 7 4 101(24.10) 96 4 5 53(12.66) 46 4 More than 5 75(17.90) 71 5 Table 5 Sanitary Status of Patients No. of Toilets in home of Patients No. of Patients (%) Open without flush 07(1.67) With one flush 133(31.74) With two flush 151(36.04) With three flush 73(17.42) More than three flush 55(13.13) Table 6 Kids Status Vs Family System Figure 1 Radiation Doses (mSv) at 0.1m Vs Travelling Time (Hrs) Kids Status Joint Families (%) Separate Families (%) Without Kids 50(11.93) 45(10.74) 05(1.19) With Kids 369(88.07) 345(82.33) 24(5.73) Up to 3 Kids 4 to 6 Kids 7 and above 72(17.18) 132(31.50) 141(33.65) 12(2.86) 08(1.91) 04(0.95) Figure 2 Radiation Doses (mSv) at 1m Vs Travelling Time (Hrs)
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment