A Walk with Lu-177 PSMA: How Close we Have Reached from Bench to Bedside?

Metastatic castration-resistant prostate cancer (mCRPC) is a natural sequela in advanced prostate cancer following resistance to standard treatment regimes, where patients develop with rising PSA, bone pains, and high disease volume. Further palliative treatment is the need of the hour for ensuring disease control and quality of life. In recent times, many novel methods have been evolved for these patients. Endo-radioligand therapy with Lutetium 177 prostate-specific membrane antigen 617 (Lu-177 PSMA) based on the Theranostic concept has emerged as a promising tool among these. We present here the current status of Lu177-PSMA for mCRPC patient and future directions.

Scintimammography screening for recurrent breast cancer in women.

Scintimammography (SM) is a nuclear medicine technique in which a tumour seeking radionuclide is used to localize or trace an active or residual tumour in breast tissue. It involves the injection ofa radiopharmaceutical into circulation and obtaining a scan of the breast tissue l0-15 min later. This procedure has been shown to be an accurate diagnostic tool in patients with symptomatic breast lesion with a non-diagnostic mammogram and for whom characterizing the lesion becomes important. This retrospective study was done using the case records of all 72 patients who had presented for scintimammography on follow -up for breast conservation surgery from January to August 2005. The result of scintimammography done using 99mTc tetrofosmin method was compared with mammograms and cytology reports when available. A total number of 52 patients, mean age 49.4 +/- 8.71 years (range 35-67) were analyzed. The commonest presentation was induration at site of surgery. In 43 patients without recurrent disease, scintimammography correctly characterized 42 while 8 out of the 10 patients with recurrent disease confirmed by histology reports were correctly identified The sensitivity of this study was 88.8%, while specificity was 95.4%. The positive predictive value was 80%, while the negative predictive value was 95.3%. Given the non-invasiveness of scintimammography and the high diagnostic index, it is a very useful tool in breast cancer diagnosis and followup. Furthermore, the radiation dose to the patient is lower than a chest radiograph and as such the fear of radiation comparatively is milder.

Can dose reduction to one parotid gland prevent xerostomia?--A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy.

AIMS: Dryness of the mouth is one of the most distressing chronic toxicities of radiation therapy in head and neck cancers. In this study, parotid function was assessed in patients with locally advanced head and neck cancers undergoing intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Parotid function was assessed with the help of a questionnaire and parotid scintigraphy, especially with regards to unilateral sparing of the parotid gland. MATERIALS AND METHODS: In total, 19 patients were treated with compensator-based IMRT between February 2003 and March 2004. The dose to the clinical target volume ranged between 66 and 70 Gy in 30-35 fractions to 95% of the isodose volume. Ipsilateral high-risk neck nodes received an average dose of 60 Gy and the contralateral low-risk neck received a dose of 54-56 Gy. Eight of 19 patients also received concomitant chemotherapy. RESULTS: Subjective toxicity to the parotid glands was assessed with the help of a questionnaire at 0, 3 and 6 months and objective toxicity was assessed with parotid scintigraphy at 0 and 3 months. The mean dose to the ipsilateral parotid gland ranged from 19.5 to 52.8 Gy (mean 33.14 Gy) and the mean dose to the contralateral gland was 11.1-46.6 Gy (mean 26.85 Gy). At a median follow-up of 13 months, 9/19 patients had no symptoms of dryness of the mouth (grade I), 8/19 had mild dryness of the mouth (grade II) and only 2/19 had grade III xerostomia, although the parotid gland could only be spared on one side in most of the patients. CONCLUSIONS: Minimising the radiation dose to one of the parotid glands with the help of IMRT in patients with advanced head and neck cancers can prevent xerostomia in most patients and parotid scintigraphy is a useful method of documenting xerostomia.

SURGERY FOR COMPLETE RECTAL PROLAPSE: A SIMPLIFIED APPROACH.

Complete prolapse of rectum (procedentia) is said to occur when the full circumference of the rectal wall is everted through the anus. Numerous techniques have been developed in order to treat procedentia, an uncommon pathology that is managed occasionally by the general surgeon. A simple, safe and effective procedure is recommended for surgeons who treat procedentia recti once in a while. We describe a simple rectopexy procedure which has been used effectively in 38 patients in the last 10 years. In this prospective study we evaluated the results which are comparable to other standard operative techniques in terms of morbidity, anatomic correction and bowel function. This technique is based on sound scientific principles in the aetiopathogenesis of rectal prolapse. This procedure obliterates the abnormally deep cul de sac of rectovesical pouch and supports the anterior rectal wall by suturing it to the bladder base to prevent initiation of sliding herniation of anterior rectal wall, which causes procedentia recti. Posterior dissection fibrosis fixes the posterior rectal wall to the sacrum after healing and restores the normal posterior curve of rectal canal and corrects the pathogenic straightening of rectum which promotes prolapse. Minimal mobilization of rectum is done and lateral ligaments are not dissected hence all attendant complications e.g. impotence, urinary incontinence, constipation etc are avoided. Simplicity, effectiveness, safety and non requirement of prosthetic material makes it an ideal operation suitable for a general surgeon working in the periphery.

Incidentally detected arterial thrombosis in (99m)Tc-methylene diphosphonate skeletal scintigraphy: an atypical observation.

The association between cancer and venous thrombosis is well established. However, that between malignancy and arterial thrombosis is less well described. We herein report a 48-year-old male patient diagnosed with base of tongue carcinoma, referred for Tc-methylene diphosphonate (MDP) bone scan study to evaluate recently developed pain and numbness in his right leg while undergoing chemoradiation. Tc-MDP bone scan study revealed complete absence of radiotracer distribution in the right lower limb below the knee region. This finding was inferred to be due to avascularity in this region secondary to thrombo-embolism that was substantiated by color Doppler sonography.