Effectiveness of image-guided radiotherapy for locally advanced rectal cancer.

BACKGROUND: Image-guided radiotherapy (IGRT) combines precise target visualization with optimal delivery of radiation dose to spare normal tissue from radiation and may potentially reduce side-effects and long-term treatment complications. We have assessed the effectiveness of IGRT for locally advanced rectal cancer. METHODS: A retrospective review of 22 patients with locally advanced rectal cancer who underwent preoperative chemoradiation was conducted. RESULTS: Nineteen patients (median age, 69 years) underwent surgical resection after chemoradiation. All 19 patients achieved complete resection with negative margins. Seven patients (32%) had no residual tumor in the surgical specimen. One patient had grade 4 gastrointestinal toxicity and hematological toxicity probably related to inadvertent overdosing of capecitabine. The median survival for the whole group-patients who had pCR and those who did not have pCR-was 14, 17, and 15 months, respectively. CONCLUSIONS: Image-guided radiotherapy provided effective treatment for locally advanced rectal cancer with minimal toxicity and should be investigated in future prospective trials.

Radiation safety protocol for high dose 131I therapy of thyroid carcinoma in patients on hemodialysis for chronic renal failure.

Iodine ablation therapy for thyroid cancer on patients receiving dialysis poses unique radiation safety challenges. Exposure to gamma and beta negative particles by the hemodialysis (HD) staff is a concern that has not been well studied. A 53-y-old male patient on HD for chronic renal failure was scheduled for 131I high dose therapy as treatment for thyroid papillary carcinoma. The patient was on HD every other day, prior to ablation. A high dose of 131I (3,607.5 MBq) was required. The patient was admitted for 131I therapy, and continued HD. Thyroid cancer ablation therapy was administered according to our institutional protocol. New radiation safety measures were developed and implemented in order to give the patient an optimal treatment dose, reduce radiation to the patient (critical organs and whole body), and to protect the HD personnel. This included placing two lead shields between the patient and the HD nurse, and HD monitoring by two alternating nurses to reduce their radiation exposure. Film badges were used to measure radiation exposure to the nursing staff. Dosimetry calculations were obtained to determine radiation absorbed doses by the optic lens, skin, and whole body. Quality control verification for this shielding arrangement proved to be effective in protecting the HD staff against gamma and beta negative radiation from recent 131I high dose therapy. Implementation of this model proved to be an effective and adequate radiation safety protocol for limiting radiation exposure to the HD staff. The patient was given 3607.5 MBq for optimal treatment after HD. Hemodialysis was repeated after approximately 48 and 96 h to remove excess 131I and reduce radiation to the patient.

Feasibility of Tomotherapy-based image-guided radiotherapy to reduce aspiration risk in patients with non-laryngeal and non-pharyngeal head and neck cancer.

PURPOSE: The study aims to assess the feasibility of Tomotherapy-based image-guided radiotherapy (IGRT) to reduce the aspiration risk in patients with non-laryngeal and non-hypopharyngeal cancer. A retrospective review of 48 patients undergoing radiation for non-laryngeal and non-hypopharyngeal head and neck cancers was conducted. All patients had a modified barium swallow (MBS) prior to treatment, which was repeated one month following radiotherapy. Mean middle and inferior pharyngeal dose was recorded and correlated with the MBS results to determine aspiration risk. RESULTS: Mean pharyngeal dose was 23.2 Gy for the whole group. Two patients (4.2%) developed trace aspiration following radiotherapy which resolved with swallowing therapy. At a median follow-up of 19 months (1-48 months), all patients were able to resume normal oral feeding without aspiration. CONCLUSION AND CLINICAL RELEVANCE: IGRT may reduce the aspiration risk by decreasing the mean pharyngeal dose in the presence of large cervical lymph nodes. Further prospective studies with IGRT should be performed in patients with non-laryngeal and non-hypopharyngeal head and neck cancers to verify this hypothesis.

Feasibility of tomotherapy to reduce normal lung and cardiac toxicity for distal esophageal cancer compared to three-dimensional radiotherapy.

PURPOSE: To compare the effectiveness of tomotherapy and three-dimensional (3D) conformal radiotherapy to spare normal critical structures (spinal cord, lungs, and ventricles) from excessive radiation in patients with distal esophageal cancers. MATERIALS AND METHODS: A retrospective dosimetric study of nine patients who had advanced gastro-esophageal (GE) junction cancer (7) or thoracic esophageal cancer (2) extending into the distal esophagus. Two plans were created for each of the patients. A three-dimensional plan was constructed with either three (anteroposterior, right posterior oblique, and left posterior oblique) or four (right anterior oblique, left anterior oblique, right posterior oblique, and left posterior oblique) fields. The second plan was for tomotherapy. Doses were 45 Gy to the PTV with an integrated boost of 5 Gy for tomotherapy. RESULTS: Mean lung dose was respectively 7.4 and 11.8 Gy (p=0.004) for tomotherapy and 3D plans. Corresponding values were 12.4 and 18.3 Gy (p=0.006) for cardiac ventricles. Maximum spinal cord dose was respectively 31.3 and 37.4 Gy (p < 0.007) for tomotherapy and 3D plans. Homogeneity index was two for both groups. CONCLUSIONS: Compared to 3D conformal radiotherapy, tomotherapy decreased significantly the amount of normal tissue irradiated and may reduce treatment toxicity for possible dose escalation in future prospective studies.

Brain heterotopia.

We present a case with intractable partial complex seizures in a 14-year-old girl who was found to have brain heterotopia on MRI and PET-CT. The patient presented with intractable partial complex seizures and a normal electroencephalogram. Her brain magnetic resonance imaging showed heterotopic gray matter lining the ventricular margin of the right occipital horn. Subsequent PET-CT demonstrated moderate tracer localization in the heterotopic gray matter surrounding the ventricular margin of the right occipital horn. Heterotopia may demonstrate normal or increased FDG uptake on PET, therefore its appearance may be deceiving when other pathologies are being considered.

Squamous cell carcinoma of the right kidney on FDG PET-CT.

We report the PET-CT appearance of a newly diagnosed, biopsy proven squamous cell carcinoma of the right kidney in a 61-year-old man who presented with hematuria. This is a rare tumor, with few cases reported in the literature. The patient subsequently underwent right nephrectomy shortly after the initial staging PET-CT study.