Postoperative radiotherapy for prostate cancer: a comparison of four consensus guidelines and dosimetric evaluation of 3D-CRT versus tomotherapy IMRT.

PURPOSE: Despite the benefits of adjuvant radiotherapy after radical prostatectomy, approximately one-half of patients relapse. Four consensus guidelines have been published (European Organization for Research and Treatment of Cancer, Faculty of Radiation Oncology Genito-Urinary Group, Princess Margaret Hospital, Radiation Therapy Oncology Group) with the aim of standardizing the clinical target volume (CTV) delineation and improve outcomes. To date, no attempt has been made to compare these guidelines in terms of treatment volumes or organ at risk (OAR) irradiation. The extent to which the guideline-derived plans meet the dosimetric constraints of present trials or of the Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) trial is also unknown. Our study also explored the dosimetric benefits of intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: A total of 20 patients treated with postoperative RT were included. The three-dimensional conformal radiotherapy (3D-CRT) plans were applied to cover the guideline-generated planning target volumes (66 Gy in 33 fractions). Dose-volume histograms (DVHs) were analyzed for CTV/planning target volume coverage and to evaluate OAR irradiation. The OAR DVHs were compared with the constraints proposed in the QUANTEC and Radiotherapy and Androgen Deprivation In Combination After Local Surgery (RADICALS) trials. 3D-CRT plans were compared with the tomotherapy plans for the Radiation Therapy Oncology Group planning target volume to evaluate the advantages of IMRT. RESULTS: The CTV differed significantly between guidelines (p < 0.001). The European Organization for Research and Treatment of Cancer-CTVs were significantly smaller than the other CTVs (p < 0.001). Differences in prostate bed coverage superiorly accounted for the major volumetric differences between the guidelines. Using 3D-CRT, the DVHs rarely met the QUANTEC or RADICALS rectal constraints, independent of the guideline used. The RADICALS bladder constraints were met most often by the European Organization for Research and Treatment of Cancer consensus guideline (14 of 20). The tomotherapy IMRT plans resulted in significant OAR sparing compared with the 3D-CRT plans; however, the RADICALS and QUANTEC criteria were still missed in a large percentage of cases. CONCLUSION: Treatment volumes using the current consensus guidelines differ significantly. For the four CTV guidelines, the rectal and bladder DVH constraints proposed in the QUANTEC and RADICALS trials are rarely met with 3D-CRT. IMRT results in significant OAR sparing; however, the RADICALS dose constraints are still missed for a large percentage of cases. The rectal and bladder constraints of RADICALS should be modified to avoid a reduction in the CTVs.

Postoperative radiotherapy in prostate cancer: the case of the missing target.

PURPOSE: Postoperative radiotherapy (XRT) increases survival in high-risk prostate cancer patients. Approximately 50% of patients on long-term follow-up relapse despite adjuvant XRT and the predominant site of failure remains local. Four consensus guidelines define postoperative clinical target volume (CTV) in prostate cancer. We explore the possibility that inadequate CTV coverage is an important cause of local failure. This study evaluates the utility of preoperative magnetic resonance imaging (MRI) in defining prostate bed CTV. METHODS AND MATERIALS: Twenty prostate cancer patients treated with postoperative XRT who also had preoperative staging MRI were included. The four guidelines were applied and the CTVs were expanded to create planning target volumes (PTVs). Preoperative MRIs were fused with postoperative planning CT scans. MRI-based prostate and gross visible tumors were contoured. Three-dimensional (3D) conformal four- and six-field XRT plans were developed and dose-volume histograms analyzed. Subtraction analysis was conducted to assess the adequacy of prostate/gross tumor coverage. RESULTS: Gross tumor was visible in 18 cases. In all 20 cases, the consensus CTVs did not fully cover the MRI-defined prostate. On average, 35% of the prostate volume and 32% of the gross tumor volume were missed using six-field 3D treatment plans. The entire MRI-defined gross tumor volume was completely covered in only two cases (six-field plans). The expanded PTVs did not cover the entire prostate bed in 50% of cases. Prostate base and mid-zones were the predominant site of inadequate coverage. CONCLUSIONS: Current postoperative CTV guidelines do not adequately cover the prostate bed and/or gross tumor based on preoperative MRI imaging. Additionally, expanded PTVs do not fully cover the prostate bed in 50% of cases. Inadequate CTV definition is likely a major contributing factor for the high risk of relapse despite adjuvant XRT. Preoperative imaging may lead to more accurate CTV definition, which should result in further improvements in survival for patients with high-risk prostate cancer.

A unique case of a sarcoma arising in a testicular non-seminomatous mixed germ cell tumour with a predominant yolk sac component.

We present a unique case of a sarcoma arising in a testicular non-seminomatous mixed germ cell tumour with a predominant yolk sac tumour (YST) component. This is the first case reported in which a sarcoma is linked to YST of the testis in a patient not having undergone prior chemotherapy. This finding confirms the ability of YST to contain sarcoma; it underlies its importance for urologists, oncologists and pathologists to be aware of this phenomenon and to modify treatment strategies appropriately.

Cytologic features of benign solitary pulmonary nodules with radiologic correlation and diagnostic pitfalls: a report of six cases.

BACKGROUND: The solitary pulmonary nodule (SPN) is a common radiologic abnormality often detected incidentally. The majority of SPNs represent benign processes, including granulotmatous inflammation, bronchogenic cysts and hamartomata. However, a solitary nodule may also potentially represent an early stage of lung cancer or a metastasis. Diagnostic procedures such as percutaneous fine needle aspiration biopsy can exclude malignancy in a majority of cases and may eliminate the need for more invasive surgical procedure. Correlation of the findings on the FNAB with radiologic features is helpful in establishing the benignity. CASES: We report the cytologic features of 6 cases of benign SPN: exogenous lipid pneumonia, sclerosing hemangioma, hemartoma, bronchogenic cyst, fungal granuloma and solitary fibrous tumor. We provide radiologic correlation for each entity and discuss the diagnostic pitfalls. CONCLUSION: Cytologically, lack of nuclear atypia with bland chromatin is useful in separating benign from malignant SPN. Radiologically, smaller lesions with smooth, well-defined margins and calcifications are more likely to be benign. Our cases illustrate the cytologic and immunohistochemical features that can help to make a more precise diagnosis. The identification of these features, when correlated with imaging findings, allows the cytopathologist to better approach the SPN.

Secondary prostatic adenocarcinoma: a cytopathological study of 50 cases.

Positive diagnosis of metastatic prostate adenocarcinoma (PAC) can be made by microscopic examination of the cytologic specimens and immunostaining for prostate-specific antigen (PSA) and prostate acid phosphatase (PAP). Immunohistochemical markers have been known to display negative, weak, or focal staining in poorly differentiated PAC and in patients with prior hormonal and/or radiation therapy. The purpose of this study is to characterize the cytopathology of metastatic PAC as it has not been documented in large series. Fifty cases of metastatic PAC with cytological specimens consisting of 41 fine-needle aspiration biopsies (FNAB), 6 pleural fluid aspirates, and 3 catheterized urine samples were reviewed and correlated with the surgical specimens and the clinical charts. Immunostaining for PSA, PAP, cytokeratin AE1/3, cytokeratin 7 (CK7), cytokeratin 20 (CK20), vimentin, and carcinoembryonic antigen (CEA) was done. Mean patient age was 77 +/- 8 yr; serum PSA, 4.1 +/- 2.3; and primary PAC Gleason score, 8.1 +/- 1.5. Cytologically, the specimens consisted of cell clusters or cell sheets with overlapping uniform hyperchromatic nuclei with or without nucleoli. Twelve cases were not reactive to PSA and PAP and 44 cases displayed negative immunoreactivity to both CK7 and CK20. Carcinoid-like lesions and small cell carcinomas were seen in 4 cases and were misdiagnosed as nonprostatic origin based on the following features: negative immunoreactivity to PSA and PAP with or without positive reactivity to CEA, and different histopathological features when compared with the primary PAC. In addition to the frequency of high-grade PAC, awareness of the negative immunoreactivity to PSA and PAP, the discrepancy in the histopathological patterns between the primary and secondary tumors, especially the frequent neuroendocrine differentiation, are helpful features for the diagnosis of metastases of prostatic origin.

Cytohistopathologic hybrid renal cell carcinoma with papillary and clear cell features.

Clear cell (CRCC) and papillary (PRCC) renal cell carcinomas (RCC) are the two most frequent subtypes of RCC. In this study, we studied RCC which displayed a hybrid morphology with areas of PRCC and CRCC or which contained papillary structures with clear cell changes (CCC). Consecutive cases of RCC collected over a 12-year period were reviewed to identify RCC with papillary structures and a possible admixture between CRCC and non-oncocytic PRCC. Special stains for glycogen and immunostaining for cytokeratin 7 were applied to sections containing both areas of classical PRCC and PRCC with CCC. Of the total of 541 RCC retrieved, there were 68 non-oncocytic RCC having papillary structures that could be grouped into: (a) group 1 (15 cases), CRCC with areas of papillary formation; (b) group 2a (9 cases), PRCC with extensive CCC with areas of foamy epithelial cells or macrophages; (c) group 2b (18 cases), RCC with areas of classical PRCC with focal CCC; and (d) group 3 (26 cases), RCC with features of groups 2a and 2b and containing areas of classical CRCC. There was a high rate (12/68) of sarcomatous transformation in the study cases. Groups 2 and 3 were associated with a higher rate of vascular invasion, distant metastasis, and mortality than classical PRCC and a higher rate of lymph node metastasis than CRCC. Our study identifies two groups of RCC (referred to as groups 2 and 3) that exhibit characteristic cytohistopathologic hybrid features that set them apart from classical RCC. This type of hybrid tumor seems to be associated with a more aggressive biologic behavior, and its recognition may facilitate the classification of RCC with ambiguous morphology.

Predictive value of prostatic adenocarcinoma after a negative prostate biopsy.

OBJECTIVE: To investigate the predictive value (PV) for all prostate cancers and for clinically significant cancer undiagnosed after a 10-core biopsy protocol, as the 10-core transrectal ultrasonography-guided biopsy is considered the standard technique of prostatic biopsy due to its high rate of detection of prostatic adenocarcinoma. PATIENTS AND METHODS: In all, 132 consecutive radical prostatectomy (RP) specimens, with their corresponding 10-core biopsies, were reviewed. Cases with unilateral core involvement by prostate cancer were retained for study. Morphometric analysis was conducted on the biopsy-negative hemi-prostates to determine the PV of the biopsy protocol with respect to the size, position and clinical significance of the lesion. RESULTS: In all, 70 resected prostates (RP) had unilateral core involvement by prostate cancer. In 38 cases, there was cancer in the biopsy-negative hemi-prostates (group 1); in the remaining 32 the hemi-prostates were free of cancer (group 2). Group 1 was categorized by morphometric criteria. Specifically, 23 cases had one to eight foci of prostate cancer in the posterior nontransitional zone (NTZ) (group 1a), while 15 had two to six foci of prostate cancer in the transitional zone (TZ), or the anterior horn (AH) of the peripheral zone or the TZ and AH (group 1b). There were two cases with clinically significant prostate cancer in group 1a, and six in group 1b. CONCLUSIONS: The PV of a negative five-core biopsy protocol on a hemi-prostate is 54% for prostate cancer and 11% for clinically significant prostate cancer. Most clinically significant prostate cancers were in the AH/TZ of the prostate.