Plasmacytoma of bronchus treated by radical radiotherapy--a rare case with four and a half years follow up.

Plasmacytoma of the bronchus is a very rare plasma cell neoplasm affecting the bronchus. Here we report a case of plasmacytoma of the bronchus treated by radical radiotherapy in July 2002. The tumor responded very well to treatment and showed a slow but sustained regression in the size over two years. Presently, he has completed four and a half years of follow-up and is free of disease.

A study on contralateral breast surface dose for various tangential field techniques and the impact of set-up error on this dose.

The risk of inducing contralateral breast (CLB) cancer in patients undergoing tangential field irradiation for the treatment of breast cancer is a serious concern in radiation oncology. A bilateral breast phantom made of wax attached onto the Alderson Rando phantom was used for studying the CLB dose for techniques using physical wedges, EDWs, IMRT and open fields. The skin dose to the CLB was measured at four different points (3 cm from the medial border of the tangential field (P1), nipple (P3), axilla (P4), midpoint between P3 and P1 (P2)). The highest measured dose occurred at P1 with the 60 degrees physical wedges; it was 15.3% of the dose at isocentre. Similarly, the dose measured at P3 (nipple) with 60 degrees physical wedges was 1.90 times higher than the dose with 60 degrees EDWs. The dose at P1 for IMRT (7.8%) was almost the same as that for the open field (8.7%). The skin dose measured at the nipple was 2.1 - 10.9 % of the isocentre dose. The highest CLB doses were contributed by medial wedged fields. The dose to the CLB can be reduced by using IMRT or avoiding wedging the medial tangential fields. A set-up error in the longitudinal direction has little impact on the CLB dose. Set-up errors > 1 cm in the vertical and lateral directions have significant impact on the CLB dose.

Evaluation of Tc99m-glucoheptonate for SPECT functional imaging of medulloblastoma.

OBJECTIVES: Functional imaging of medulloblastoma using SPECT has been a difficult problem as this tumour does not concentrate conventional brain tumour imaging radiopharmaceuticals. This study aimed to evaluate Tc99m-glucoheptonate as a "brain tumour-seeking" radiopharmaceutical for functional imaging of medulloblastoma. METHODS: Tc99m-glucoheptonate brain SPECT was performed in 27 patients with medulloblastoma after radiation therapy and with clinical suspicion of tumour recurrence. Histological verification was obtained within 7 days in patients with a SPECT diagnosis of tumour recurrence. Patients with a SPECT diagnosis of post-radiation gliosis were clinically observed for a minimum period of one year after the SPECT study. RESULTS: Fourteen patients had increased radiotracer uptake in the primary tumour bed, suggesting tumour recurrence. Histopathology confirmed viable medulloblastoma in all cases. Thirteen patients had no increased tracer uptake in the primary tumour bed, suggesting post-radiation gliosis. They all had a clinical course consistent with post-radiation gliosis. CONCLUSION: Tc99m-glucoheptonate is an ideal SPECT tracer for functional evaluation of medulloblastoma. SPECT utilising Tc99m-glucoheptonate is a reliable diagnostic modality to differentiate tumour recurrence from post-radiation gliosis in patients with medulloblastoma.

Role of Tc-glucoheptonic acid brain single photon emission computed tomography in differentiation of recurrent brain tumour and post-radiation gliosis.

Blood-brain barrier imaging of brain tumours is fast attracting interest now that it has been demonstrated that disruption of the blood-brain barrier is essential for uptake of all tumour-seeking agents. The aim of the present study was to differentiate recurrent tumour from post-radiation gliosis using (99m)technetium-glucoheptonate ((99m)Tc-GHA) as a tumour-seeking agent. Brain single photon emission computed tomography (SPECT) with (99m)Tc-GHA was performed in 73 patients with primary malignant brain tumours after radiotherapy, and the results were correlated with the clinical behaviour of the disease on follow up. The SPECT was suggestive of recurrent tumour in 55 patients. The clinical course was consistent with recurrence in 51 of the 55 patients. The clinical course was consistent with radiation necrosis in the remaining 21 patients, which included 17 patients with a negative SPECT and four patients with a positive SPECT study. Mean GHA index in recurrent tumour and post-radiation gliosis was 7.04 +/- 4.35 and 1.88 +/- 1.70, respectively (P = 0.0001). Mean GHA index in high-grade and low-grade glioma was 7.78 +/- 4.73 and 3.15 +/- 2.44, respectively (P = 0.001). (99m)Technetium-glucoheptonate brain SPECT is a sensitive and reliable diagnostic modality to differentiate recurrent tumour from post-radiation gliosis.