comparison study of radiation dose received during cone beam computerized tomography and portal imaging techniques

Although widely varied in modality and method, all radiographic guidance techniques have one thing in common; they can give a significant radiation dose to the patient; which may have a late radiation stochastic effect on normal body tissues. To quantify and compare radiation doses to the tumour and the surrounding critical organs resulting from the orthogonal pair portal and megavoltage cone beam computarized tomography [MV CBCT] imaging techniques. The dose to the patient resulting from the orthogonal pair and the MV CBCT imaging techniques, has been calculated based on a 6 MV Oncor linear accelerator equipped with an amorphous silicon flat panel. All calculations were done on Eclipse 3D treatment planning system. 18 patients representing three different treatment sites [head and neck, thorax, and pelvis] were analysed. Data from 6 patients for each treatment site were used to calculate the mean doses. Calculations were done for: The integral dose, maximum dose to the patient, dose at the isocenter, and mean dose to the tumour and each critical organ. The absolute dose measured as integral dose, maximum dose to the patient, dose at the isocenter, and mean dose to the tumour and each critical organ was higher for MV CBCT as compared to orthogonal pair technique for all treatment sites. For both techniques, the absolute dose was higher for head and neck and thorax as compared to pelvis. The difference of maximum dose to the patient showed greater variation for head and neck, but not for thorax and pelvis. There are relatively high dose regions generated by MV CBCT that occur inside critical organs as well treatment area and tend to be larger than those generated by the orthogonal pair technique

Completion thyroidectomy: Relation of timing with complications

To assess the association of timing with complications following completion thyroidectomy. Prospective, quasi-experimental clinical trial from June 2002 to March 2007. Surgical Unit-2, Jinnah Postgraduate Medical Centre [JPMC], Karachi. A total of 114 patients who underwent completion thyroidectomy. The patients were divided into two groups viz. Group-I [n = 76] where completion thyroidectomy was performed between 10 days and three months and Group-II [n = 38] where completion thyroidectomy was carried out beyond this time. Transient hypocalcaemia was seen in two cases of Group-I and one case of Group-IL while transient recurrent laryngeal nerve paresis was seen in two patients, one in each group. However, there was no statistically significant difference in the outcome between Group-I and IL in terms of complications. Timing does not influence the complication rate after completion thyroidectomy

Rationale for near total thyroidectomy in patients with multinodular goitre

To prove that Near total Thyroidectomy [NTT] with minimal residual tissue is the procedure of choice in patients with Multi-Nodular Goitre [MNG]. Retrospective study from February 2002 to December 2006. Surgical Ward-II, Jinnah Postgraduate Medical Centre [JPMC], Karachi. A total of 521 consecutive patients, operated for simple or toxic MNG were included in this study. Apart from detailed clinical work-up, investigations including thyroid function tests and thyroid scans were carried out in all cases. All patients underwent near total thyroidectomy with preservation of recurrent laryngeal nerves and parathyroid glands. Out of 521 cases, 73 [14%] had carcinoma on histopathological examination of the removed glands; 47 [64%] underwent completion thyroidectomy which was uneventful, while 22 had radioiodine ablation with decreased dosage for provision of minimal residual tissue and four declined further treatment. Near total thyroidectomy is a versatile surgical procedure for patients with MNG, keeping in view the risk of associated occult malignancy. Furthermore, the risk of damage to recurrent laryngeal nerve [RLN] and parathyroids is low in patients undergoing completion thyroidectomy. Hence, a more radical procedure should be adopted for surgical treatment in MNG

Extracapsular cataract extraction with posterior chamber IOL implantation at Helpers eye hospital, Quetta

We have only recently started intraocular lens [IOL] implantation surgery in Quetta, Baluchistan at the Helpers Eye Hospital, and this is the first report of our results of the manual extracapsular cataract extraction with posterior chamber [IOL] implantation. The procedure was performed on 134 patients. An important socioeconomic aspect of cataract surgery in our region was brought home by the fact that 31 of these patients did not return for follow-up. Another three patients died of acute myocardial infarction. In the remaining 100 patients, postoperative visual acuity ranged from 3/60 to 6/6; 79 patients regained unaided visual acuity of 6/24 [20/80], which improved to 6/9 [20/30] or better with correction; 14 patients had vision below 6/36 [20/120], which improved to 6/12 [20/40] with glasses; five patients could improve only to 6/60 [20/200] with best correction; two patients' visual acuity did not improve beyond 3/60 [10/200] due to the advanced macular degeneration. The postoperative complications include posterior capsule thickening in eight patients [8%]; anterior uveitis in seven patient [7%]; vascular congestion at and around the wound persisting after one month in 20 patients [20%]; traumatic wound dehiscence in three patients [3%]; IOL decentration in two patients [2%]; elevated intraocular pressure in two patients [2%]; traumatic vitreous hemorrhage in one patient [1%]; distortion of pupil in one patient [1%]; and endophthalmitis in one patient [1%]. [Pakistan Journal of Ophthalmology, 10:49-50, April and July, 1994]