Usefulness of 18F-FDG PET/CT for evaluating response of ocular adnexal lymphoma to treatment.

The purpose of this study was to investigate the efficacy of F-fluoro-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for evaluating the ocular adnexal lymphoma treatment responses.We retrospectively reviewed data for 9 histologically confirmed cases of malignant lymphoma. All patients had at least one ocular adnexal tumor site and underwent FDG PET/CT before and after treatment. Patients' histological disease subtypes included diffuse large B-cell lymphoma (n = 3), mucosa-associated lymphoid tissue lymphoma (n = 2), follicular lymphoma (n = 1), NK/T-cell lymphoma (n = 1), lymphoplasmacytic lymphoma (n = 1), and Hodgkin lymphoma (n = 1). The highest FDG uptake by the ocular adnexal lesions was calculated as the maximum standardized uptake value (SUVmax). FDG uptake at ocular adnexal sites and sites of systemic disease after treatment were also assessed using the 5-point Deauville scale.In 1 of the 9 patients, a conjunctival lesion could not be detected by either pre- or posttreatment PET/CT. For 8 of the 9 patients, the SUVmax value at the ocular adnexal site significantly decreased after treatment (7.1 ±â€Š5.1 vs 1.6 ±â€Š0.58; P = .0196). For 7 of the 9 patients, the first posttreatment FDG uptake at the ocular adnexal site was considered a complete metabolic response, and these patients showed an improved clinical ophthalmic presentation with no relapse at ocular adnexal sites during follow-up.FDG PET/CT is useful for evaluation of the response of ocular adnexal lymphoma to treatment, although its usefulness may depend on the histological subtype and site of the lesion.

Residual FDG uptake of primary thyroid lymphoma after treatment may overestimate residual lymphoma.

OBJECTIVE: To assess 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images in primary thyroid lymphoma (PTL) patients before and after treatment. METHODS: We conducted a retrospective review of data for ten patients (four men, six women) of mean age 65 (range 48-88) years, with histopathologically confirmed malignant thyroid lymphoma who underwent pre-treatment and post-treatment 18F-FDG PET between January 2005 and December 2014. Thyroid uptake was assessed by the 5-point scale score based on maximum intensity projection images. RESULTS: Four of the ten patients were judged to have a complete metabolic response (scores 1-3) and four to have a partial metabolic response (PMR; scores 4-5). Three of the four PMR patients had a good outcome with a treatment-free interval and overall survival of at least 53.0 months, although two of these three patients showed residual FDG uptake in the thyroid for more than 2 years after completion of treatment. Two of the ten patients were considered to have progressive metabolic disease. CONCLUSIONS: In patients with PTL, residual FDG uptake in the thyroid after treatment that corresponds to a PMR may not always indicate a poor outcome.

(18)F-FDG uptake of the spinal cord was decreased after conventional dose radiotherapy in esophageal cancer patients.

OBJECTIVE: We retrospectively investigated changes of (18)F-fluorodeocyglucose ((18)F-FDG) uptake in the spinal cord, inside and outside the radiation fields, in patients with esophageal cancer before and after conventional dose radiotherapy. METHODS: A total of 17 consecutive patients with esophageal cancer (16 males, one female; age 50-83 years, mean 67.0 years), who underwent conventional dose radiotherapy and (18)F-FDG PET/CT before and 5.1 months (range 1.6-8.6 months) after the radiotherapy, were retrospectively evaluated. Sixteen patients had esophageal cancer and one patient had esophageal metastasis from thyroid cancer. Mean standardized uptake values (SUVmean) of the cervical, thoracic (inside and outside the radiation fields) and lumbar spinal cord were measured. RESULTS: SUVmean of the thoracic spinal cord inside the radiation field was decreased significantly after radiotherapy compared to those before radiotherapy (p < 0.001). SUVmean of the cervical spinal cord showed the same trend but it was not statistically significant (p = 0.051). SUVmean of the thoracic spinal cord outside the radiation field and the lumbar spinal cord did not differ significantly before and after the radiotherapy (p = 0.146 and p = 0.701, respectively). CONCLUSIONS: The results suggest that glucose metabolism of the spinal cord is decreased in esophageal cancer patients after conventional dose radiotherapy.

Outcome of patients with localized prostate cancer treated by radiotherapy after confirming the absence of lymph node invasion.

OBJECTIVE: Management of lymph nodes in radiotherapy for prostate cancer is an issue for curative intent. To find the influence of lymph nodes, patients with T1-T3 prostate cancer and surgically confirmed negative nodes were treated with radiotherapy. METHODS: After lymphadenectomy, 118 patients received photon beam radiotherapy with 66 Gy to the prostate. No adjuvant treatment was performed until biochemical failure. After failure, hormone therapy was administered. Follow-up period was 57 months (mean). RESULTS: Biochemical failure occurred in 47 patients. Few failures were observed in patients with low (24%) and intermediate risks (14%). In contrast, 64% of high-risk patients experienced failure, 97% of whom showed until 36 months. Most patients with failure responded well to hormone therapy. After 15 months (mean), a second biochemical failure occurred in 21% of patients who had the first failure, most of them were high risk. Factors involving failure were high initial and nadir prostate-specific antigen, advanced stage, short prostate-specific antigen-doubling time and duration between radiation and first failure. Failure showed an insufficient reduction in prostate-specific antigen after radiotherapy. Factor for second failure was prostate-specific antigen-doubling time at first failure. CONCLUSIONS: Half of high-risk patients experienced biochemical failure, indicating one of the causes involves factors other than lymph nodes. Low-, intermediate- and the other half of high-risk patients did not need to take immediate hormone therapy after radiotherapy. After failure, delayed hormone therapy was effective. Prostate-specific antigen parameters were predictive factors for further outcome.

Radiotherapy doses at special reference points correlate with the outcome of cervical cancer therapy.

PURPOSE: The authors analyzed the correlation between radiotherapy doses at reference points on the uterine edge and the rectal wall and both pelvic control and late rectal complications of cervical cancer therapy. METHODS AND MATERIALS: Between 1997 and 2005, 57 patients with Stages IB-IVA cancer of uterine cervix were treated with a combination of external beam radiotherapy and high-dose-rate intracavitary brachytherapy. Their high-dose-rate intracavitary brachytherapy was planned by dose-point optimization at six dose points located on the edge of uterus by computed tomography. A rectal reference point located on the anterior wall of the rectum by computed tomography was also used. The pelvic control rate and the rate of late rectal complications were calculated according to the biologically effective dose (BED) at each point and several clinical parameters. RESULTS: The overall 3-year pelvic control rate was 69.4%. The patients with a BED >80 Gy10 at the point on the edge of the uterine cervix had better pelvic control (78.4% at 3 years) than the patients with a BED < or =80 Gy10 (54.4% at 3 years), and the difference was significant. The difference in the BED (Gy3) at the rectal reference point between the patients with Grade 0-1 late rectal complications (median, 114 Gy) and the patients who developed Grade > or =2 late rectal complications (median, 178 Gy) was significant. Chemotherapy was a borderline significant parameter in regard to correlation with pelvic control and late rectal complications, but there were no correlations with other dosimetric or clinical parameters. CONCLUSIONS: The radiotherapy dose at the reference point on the edge of the cervix affected pelvic control more than the clinical parameters, and the dose at the rectal reference point was more strongly correlated with the occurrence of late rectal complications.

Brachytherapy of stage II mobile tongue carcinoma. Prediction of local control and QOL.

BACKGROUND: There is no consensus as to the prognostic model for brachytherapy of tongue carcinoma. This study was designed to evaluate the prognostic factors for local control based on a large population under a unified treatment policy. RESULTS: Between 1970 and 1998, 433 patients with stage II tongue squamous cell carcinoma were treated by low-dose-rate brachytherapy. This series included 277 patients treated with a linear source with a minimum follow-up of 3 years. A spacer was introduced in 1987. The primary local control rates were 85.6%. CONCLUSION: In the multivariate analysis, an invasive growth pattern was a significant factor for local recurrence. The disease-related survival was influenced by old age and an invasive growth pattern. A spacer lowered mandibular bone complications. The growth pattern was the most important factor for recurrence. Brachytherapy was associated with a high cure rate and the use of spacers brought about good quality of life (QOL).

Interstitial brachytherapy and neck dissection for Stage III squamous cell carcinoma of the mobile tongue.

The purpose of this study is to describe the cause-specific survival rate, local control rate, salvage rate of neck metastasis, and post-treatment eating and speaking conditions for stage III mobile tongue squamous cell carcinomas and its subgroups. Between 1968 and 1999, 117 previously untreated patients with stage III mobile tongue carcinomas underwent mainly brachytherapy with external beam irradiation (EBRT) and neck dissection. A multivariate analysis was performed for the cause-specific survival rate on the various factors. The 1-, 3- and 5-year cause-specific survival rates for all patients were 76%, 54% and 54%, respectively. The 1-, 3- and 5-year primary control rates for all patients were 67.6%, 63.4% and 59.2%, respectively. There were statistically significant differences in cause-specific survival rates among stage III subgroups of T3N0, T1-2N1 and T3N1 (p = 0.0002). Our treatment method for patients with stage III mobile tongue squamous cell carcinoma was effective and acceptable.

Determination of the depth of 50% of maximum ionization, I50, for electron beams by the divided difference method.

A new characterization of depth-ionization parameters for electron beams is empirically deduced from our data analysis based on the divided difference method (the DD method), which employs the numerical differential of an ionization curve. The important feature of the present method is that it does not necessarily require normalized percent depth-ionization (NPDI) data. The depth of 50% of maximum ionization, I50, which is an important parameter for electron beam dosimetry, can be deduced from the analysis of an unnormalized (or partial) depth-ionization (UDI) curve obtained over a short interval of depth. The values of I50 determined by the DD method are in agreement to within 0.1 mm for energies of 4, 6, and 9 MeV, compared with the ones determined by the TG-51 protocol method (or the conventional method), and the difference was 0.9 mm for 12 and 15 MeV. The dose at the reference depth, dref, calculated from I50 by the DD method, is found to be in agreement with TG-51 to within 0.1%. The field size dependence of the DD method using UDI data was studied for three field sizes: 6 x 6, 10 x 10, and 20 x 20 cm2. For all energies, the discrepancies of I50 as determined by both methods were 0.9 mm on average for the 6 x 6 cm2 fields and 0.6 mm for the other two field sizes. This dependence was remarkable for 6 x 6 cm2 fields for 12 and 15 MeV, and the discrepancies shown by the DD method were 1.2 mm for 12 MeV and 1.8 mm for 15 MeV, respectively. Since the reference field size in clinical dosimetry is usually 10 x 10 cm2, this dependence will not affect clinical dosimetry. The DD method could be an alternative option for checking beam quality in dose calibration.

Oral pseudotumor: benign polypoid masses following radiation therapy.

BACKGROUND: The current study evaluated postirradiation pseudotumor in the oral cavity to investigate clinical and pathologic characteristics and incidence rates. METHODS: Between 1960 and 1999, 2719 patients with squamous cell carcinoma of the oral cavity were treated with radiation therapy at Tokyo Medical and Dental University Hospital. Of these, six patients developed clinically polypoid tumors pathologically diagnosed as pseudotumors. Histopathology, immunohistology, and the clinical courses of these lesions were investigated. RESULTS: Spindled fibroblastic cells arranged in whorled patterns were common pathologic features. Immunohistochemical results showed reactivity for vimentin and smooth muscle actin and nonreactivity for cytokeratin. The latent period from the initial radiation therapy to the development of the pseudotumor ranged from 45 to 145 months (median, 79 months). The overall cumulative incidence of pseudotumor was 0.22% during the 40 year period. All six patients were cured with simple excisions. CONCLUSIONS: Oral carcinoma patients treated with radiation therapy may develop pseudotumor in a low frequency with a shorter period than that of radiation induced carcinoma/sarcoma. Pseudotumor was curable with surgery. Pseudotumor should be added to the list of differential diagnosis for postirradiation oral polypoid masses.