Amit Bahl

Mucinous adenocarcinoma of the rectum: a poor candidate for neo-adjuvant chemoradiation?

BACKGROUNDnMucinous adenocarcinoma (MA) is a distinct pathological entity associated with poor outcome. Due to different biological behavior, the response to neoadjuvant chemo-radiation (NACRT) may be inferior compared to non-mucinous tumours. In this study we compare the pathological response of mucinous tumours after NACRT.nnnMETHODSnA total of 183 patients who underwent NACRT for rectal cancer were classified as mucinous and non-MAs. The dose of radiation was 45 Gy (at 1.8 Gy per fraction) delivered over five weeks with weekly 5-flourouracil (5-FU) (325 mg/m(2)) and leucovorin (20 mg/m(2)). After surgery, the pathological specimens were evaluated and staged. The data are reported as descriptive statistics and chi-square test used to determine difference in proportions.nnnRESULTSnThe two varieties were comparable on the basis of the computed tomography (CT) scan in terms of tumour size and lymph node metastasis. However in terms of pathological response, it was seen that there was a higher incidence of pT4 tumours (73.5% vs. 10.7%), margin positivity (11.7% vs. 2.3%) and advanced nodal disease pN2 (29.4% vs. 9.3%) in mucinous and non-mucinous tumours respectively.nnnCONCLUSIONSnMA of the rectum show a poor response to NACRT as seen in terms of larger residual tumours, higher incidence of margin positivity, and greater residual nodal disease. Also they showed higher incidence of peritoneal and distant dissemination during NACRT. The role of NACRT in mucinous carcinoma of the rectum is of questionable benefit and needs to be examined in prospective trials.

Pulsed-dose-rate intracavitary brachytherapy for cervical carcinoma: the AIIMS experience.

Objective:The aim of present study was to analyze the results of pulsed-dose-rate (PDR) brachytherapy in patients with cervical carcinoma treated at our center. Methods:From September 2003 to September 2005, 48 patients with histopathologically proved cervical carcinoma, stages IB to IVA, were treated with PDR intracavitary radiotherapy (ICRT) and pelvic irradiation at our center. Radiotherapy consisted of whole pelvis external beam radiation therapy (EBRT) with a dose of 40 Gy in 22 fractions over 4.5 weeks followed by 10 Gy in 5 fractions over 1 week with midline shielding. Weekly chemotherapy (Cisplatin, 40 mg/m2) was administered during the course of EBRT to suitable patients. After an interval of 1 to 2 weeks, a single session of standard ICRT application was done to deliver a dose of 27 Gy to point A by PDR (hourly pulse, 70 cGy). Results:Median age was 50 years (range: 30–65). FIGO stage distribution of the patients was as follows: stage IB, 6; stage IIA, 1; stage IIB, 15; stage IIIB, 25; and stage IVA, 1. Follow-up period ranged from 3 to 50 months (median: 15 months). Ten patients had disease recurrence (5 each in stage IIB and stage IIIB). Eight patients had pelvic failure, 1 had bone metastases, and 1 had supraclavicular node metastases. Overall grades III to IV late toxicity rate at 50 months was 6%. For the median follow-up period of 15 months, the actuarial recurrence-free survival in stages I to II was 82% and stages III to IV was 78%. Conclusion:Our results reveal that PDR ICRT in combination with pelvic EBRT provides excellent pelvic disease control, survival, and low radiation related morbidity rate in the patients with cervical carcinoma.

Reirradiation for progressive brain metastases

Brain metastases constitute one of the most common distant metastases of cancer and are increasingly being detected with better diagnostic tools. The standard of care for solitary brain metastases with the primary disease under control is surgery followed by radiotherapy. Radiotherapy is also the primary modality for the treatment of multiple brain metastases, and improves both the quality of life and survival of patient. Unfortunately, more than half of these treated patients eventually progress leading to a therapeutic dilemma. Another course of radiotherapy is a viable but underutilized option. Reirradiation resolves distressing symptoms and has shown to improve survival with minimal late neurotoxicity. Reirradiation has conventionally been done with whole brain radiotherapy, but now studies with stereotactic radiosurgery have also shown promising results. In this review, we focus on reirradiation as a treatment modality in such patients. We performed a literature search in MEDLINE (www.pubmed.org) with key words brain metastases, reirradiation, whole brain radiotherapy, stereotactic radiosurgery, interstial brachytherapy, and brain. The search was limited to the English literature and human subjects.

CT and MR image fusion of tandem and ring applicator using rigid registration in intracavitary brachytherapy planning

The purpose of this study is to find the uncertainties in the reconstruction of MR compatible ring‐tandem intracavitary applicators of high‐dose rate image‐based brachytherapy treatment planning using rigid registration of 3D MR and CT image fusion. Tandem and ring reconstruction in MR image based brachytherapy planning was done using rigid registration of CT and MR applicator geometries. Verifications of registration for applicator fusion were performed in six verification steps at three different sites of tandem ring applicator set. The first site consists of three errors at the level of ring plane in (1) cranio–caudal shift (Cranial Shift) of ring plane along tandem axis, (2) antero–posterior shift (AP Shift) perpendicular to tandem axis on the plane containing the tandem, and (3) lateral shift (Lat Shift) perpendicular to the plane containing the tandem at the level of ring plane. The other two sites are the verifications at the tip of tandem and neck of the ring. The verification at the tip of tandem consists of two errors in (1) antero–posterior shift (AP Shift) perpendicular to tandem axis on the plane containing the tandem, and (2) lateral shift (Lat Shift) perpendicular to the plane containing the tandem. The third site of verification at the neck of the ring is the error due to the rotation of ring about tandem axis. The impact of translational errors from −5 mm to 5 mm in the step of 1 mm along x‐, y‐, and z‐axis and three rotational errors about these axes from −19.1° to 19.1° in the step of 3.28° on dose‐volume histogram parameters (D2cc,D1cc,D0.1cc, and D5cc of bladder, rectum, and sigmoid, and D90 and D98 of HRCTV were also analyzed. Maximum registration errors along cranio–caudal direction was 2.2 mm (1 case), whereas the errors of 31 out of 34 cases of registration were found within 1.5 mm, and those of two cases were less than 2 mm but greater than 1.5 mm. Maximum rotational error of ring about tandem axis was 3.15° (1.1 mm). In other direction and different sites of the ring applicator set, the errors were within 1.5 mm. The impacts of registration errors on DVH parameters of bladder, rectum, and sigmoid were very sensitive to antero–posterior shift. Cranio‐caudal errors of registration also largely affected the rectum DVH parameters. Largest change of 17.95% per mm and 20.65% per mm in all the DVH parameters of all OARs and HRCTV were observed for ϕ and Ψ rotational errors as compare to other translational and rotational errors. Catheter reconstruction in MR image using rigid registration of applicator geometries of CT and MR images is a feasible technique for MR image‐based intracavitary brachytherapy planning. The applicator registration using the contours of tandem and neck of the ring of CT and MR images decreased the rotational error about tandem axis. Verification of CT MR image fusion using applicator registration which consists of six steps of verification at three different sites in ring applicator set can report all the errors due to translation and rotational shift along θ,ϕ, and Ψ. ϕ and Ψ rotational errors, which produced potential changes in DVH parameters, can be tackled using AP Shift and Lat Shift at the tip of tandem. The maximum shift was still found along the tandem axis in this technique. PACS number: 87.55.km

Carcinoma lung presenting with choroidal metastasis as initial presentation: a rarity.

Diminished vision due to choroidal metastasis as the primary symptom of lung cancer is very uncommon. Here, we report such a presentation in a 54-year-old male patient of small cell lung cancer. The outcome is usually dismal with this kind of presentation. The patient received systemic chemotherapy as well as intravitreal bevacizumab but with no improvement in vision. The patient had been given external beam radiotherapy and showed subjective improvement in his ocular symptoms.

Comparison of bone marrow sparing intensity modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT) in carcinoma of anal canal: a prospective study.

BACKGROUNDnChemoradiation (CRT) is the standard of care in anal canal carcinoma. CRT leads to suppression of iliac bone marrow (BM) leading to hematological toxicity. Intensity modulated radiation therapy (IMRT) technique can be used to decrease radiation dose to iliac BM and thus decrease haematological toxicity. This study aims to compare the haematological and gastrointestinal toxicity in BM sparing IMRT with three-dimensional conformal radiation therapy (3DCRT) in anal carcinoma patients.nnnMETHODSnTwenty untreated, biopsy proven anal canal carcinoma (stages I-III) patients were randomized into IMRT and 3DCRT arm. All patients received CRT with 45 Gy in 25 fractions at 1.8 Gy/fraction and weekly concurrent inj. cisplatin and 5-FU. Patients were evaluated for acute haematological and gastrointestinal toxicity during treatment. Additional dosimetric comparison was made between the two groups.nnnRESULTSnIncidence of worst hematological toxicity grade II (GII) and GIII was seen in 40% [4] vs. 30% [3] and 20% [2] vs. 0% [0] respectively, in 3DCRT and IMRT group. However these did not come as statistically significant (P=0.228). Incidence of worst gastrointestinal toxicity during treatment in terms of GII was 30% [3] vs. 50% [5] and GIII was 60% [6] vs. 0% [0] in 3DCRT and IMRT group respectively (P=0.010). Other parameters indicating better tolerance of treatment with IMRT arm than 3DCRT arm were lesser need for administration of parenteral fluid 10% [1] vs. 60% [6] (P=0.019); lesser need for blood transfusion 0% [0] vs. 20% [2] (P=0.060) in IMRT arm than in 3DCRT arm respectively. Patient requiring supportive care during treatment like need for anti-motility drugs and WHO. Step II analgesics also favored IMRT arm. Overall treatment time for Arm B (33.40 days) was less than what was seen in Arm A patients (36.8 days), although difference was not statistically significant (P=0.569). In terms of dosimetric analysis, arm B with the use of IMRT showed superiority over arm A with 3DCRT. The mean volume of bladder receiving ≥30 and 40 Gy respectively was 100% and 96% for group A (3DCRT) as compared to 68% and 31% for the group B (IMRT) (P<0.05). For bowel, although, the V30 and V40 for 3DCRT versus IMRT respectively were 51% and 27% vs. 27% and 13%, statistical significance was not reached (P>0.05). There was also less mean BM receiving ≥10 Gy (80.4%) and ≥20 Gy (65.6%) for group B using IMRT, than in 3DCRT (group A) were it was 91% and 73% respectively. Although for V10 it was significant (P=0.04), it did not reach statistical significance for the V20 (P=0.550).nnnCONCLUSIONSnPreliminary outcomes suggest that BM sparing IMRT for anal canal cancers can decrease both haematological and gastrointestinal toxicity as compared to 3DCRT and thus CRT course can be completed effectively without treatment breaks.

Impact of Integrating Pet-Ct in Radiotherapy Planning of Non-small CellCarcinoma Lung: Dosimetric and Radiobiological Comparison

The integration of PET and CT scans allows the simultaneous use of biologic and anatomic imaging data for better delineating tumor and sparing normal critical structures. The aim of this study is to assess the impact on target volume delineation using CT vs. PETCT based plans, and to determine radiobiological effect on tumor and normal tissue by comparing Tumor control probability (TCP) & normal tissue complication probability (NTCP) of CT & PET-CT based plans. 15 patients of inoperable NSCLC planned for radical radiotherapy, underwent a planning CT scan of the thorax. Target volumes were contoured. Later PETCT images with the auto contoured MTV (Metabolic target volume) images, were fused with the planning CT images. Margins were similarly given to PETMTV for the generation of PET CTV and PET PTV. 3 Dimensional conformal radiotherapy (3DCRT) plans were made on the planning CT images and the planning PETCT images, and were compared dosimetrically and radio biologically. The study shows that the use of PETCT resulted in significant decrease in PETCT generated MTV versus GTV delineated on CT. Also, there was statistical significant decrease in the volume of the normal lung irradiated in terms of V40 and the MLD. TCP for PETCT based plans was significantly higher than that with CT based plans. Also, PETCT based planning resulted in a statistically significant decrease in the NTCP for lung and spinal cord. Therefore, the study concludes that incorporation of PETCT into radiotherapy planning of NSCLC is technically feasible and dosimetrically appealing strategy for patient treatment.

Primary adenoid cystic carcinoma of lung: A case report and review of the literature

Primary adenoid cystic carcinoma of lung is an unusual thoracic neoplasm, which is considered as a slow-growing low-grade malignancy. The primary treatment for this tumor is surgery. The role of radiotherapy, chemotherapy, and targeted agents is less well defined. Here we report a case of inoperable adenoid cystic carcinoma of the lung in a 42-year-old male, presenting with an unusual aggressive behavior. The patient received radiotherapy and oral tyrosine kinase inhibitor imatinib with effective palliation.

In Regard to Kelly et al

To the Editor:We read with interest the study by Kelly et al (1) and compliment the authors for giving guidelines on an important dose constraint in pancreatic cancer management. However, we believe that their correlation of duodenal toxicity with radiation dose needs to be interpreted, keeping in mind the following: in their analysis, 70% of the patients underwent three-dimensional conformal radiation therapy. The radiation portals and beam energy used in these patients are not mentioned in the study. In the patients receiving intensity modulated radiation therapy, it is not clear whether pancreatic motion was taken into account. Additionally, it would have been interesting to know the SIB dose schedule used in their analysis, because all of the above can have bearing on treatmentrelated toxicity. Further, all patients in their study received concurrent chemotherapy, with the majority also getting both neoadjuvant and adjuvant chemotherapy. The duodenal toxicity profile can be different for protocols using only neoadjuvant chemotherapy or adjuvant chemotherapy comparedwith concurrent chemotherapy, and the duodenal dose constraint might be different with such regimens (2, 3). A prospective randomized analysis using image guided radiation therapy with adequate motion management and different chemotherapy schedules is called for to further answer this question.

Primary amyloidoma of lung treated with radiation: A rare case report

Amyloidosis is a collection of diseases in which different proteins are deposited as insoluble beta-pleated sheets, disrupting organ function. Distribution of these deposits may be diffuse or localized throughout the body, depending on the pathophysiology of the underlying amyloid type. Isolated deposition of amyloid proteins in lung is a very rare entity. They are frequently misdiagnosed as bronchogenic carcinoma, metastatic disease, or focal fungal infections. The treatment of solitary pulmonary amyloidosis is not well-defined. We have treated a 65-year-old female patient with external beam radiation and corticosteroids in palliative intent and she is leading a good quality of life after six months of follow up.