- Email: [email protected]
43 poster: Dynamics of Hypoxia in Head and Neck Cancer During Chemoradiotherapy Evaluated with [18]F-Fluoromisonidazole PET
B IOLOGICAL TREATMENT PLANNING GTV30% and GTVsuv2.5). There is instead important difference between CT- target volume delineation (GTVCT) and FDG-PET target volume delineation (GTVVIS, GTV30% and GTVsuv2.5). FDG-PET target volume delineation might have an impact in term of efficiency and toxicity for patient treatment. 43 poster DYNAMICS OF HYPOXIA IN HEAD AND NECK CANCER DURING CHEMORADIOTHERAPY EVALUATED WITH [18]FFLUOROMISONIDAZOLE PET N. Wiedenmann1 , M. Mix2 , S. Bucher1 , S. Adebahr1 , C. Offermann1 , U. Nestle1 , W. Weber2 , A. L. Grosu1 , M. Hentschel3 1 U NIVERSITÄTSKLINIK F REIBURG, Department of Radiation Oncology, Freiburg, Germany 2 U NIVERSITÄTSKLINIK F REIBURG, Department of Nuclear Medicine, Freiburg, Germany 3 U NIVERSITÄTSKLINIK F REIBURG, Departments of Radiation Oncology and Nuclear Medicine, Freiburg, Germany Purpose: To assess the dynamics of tumor hypoxia before and during primary chemoradiotherapy for head and neck cancer. Materials: A prospective study was conducted in patients (pts) undergoing definitive radiochemotherapy (RCTx) for locally advanced head and neck cancer. Tumor hypoxia was assessed by F-MISO-PET prior and during the course of radiation treatment (RT) in week 2 and 5. For imaging, pts were immobilized with a head and neck mask, identical to the radiation position. Static F-MISO scans were acquired 2.5h p.i. Additionally all pts received CT, MRI and 18F-FDG-PET imaging prior to RT. MRI was repeated in treatment week 5. Treatment was delivered as conformal 3D RT or IMRT (5X2Gy/d; total dose 70 Gy). Cisplatin was given in week 1, 4, 7 (100mg/m2 ). F-MISO uptake was assessed quantitatively based on SUV-values normalized against normal tissue (muscle) and also visually evaluated. The index of SUVmax in tumors/SUVmean in muscle was calculated for each patient. Mean and median indices for the entire group were quantified separately for the first (pretreatment), second (week 2) and third (week 5) F-MISO PET investigation. The visual evaluation was scored from 0 (no hypoxia) to 3 (significant hypoxia). For follow-up pts were evaluated clinically and by MRI every 3 months. Results: Eight pts were included, undergoing definitive RCTx for locally advanced cancer of the oropharynx (2), hypopharynx (3) and larynx (3). T3stage was present in 3 and T4 in 5 cases respectively. Nodal stage was N2b in 1 and N2c in 7 pts. 7 of 8 pts conducted the F-MISO PET examinations as scheduled, 1 patient declined second and third PET studies. The mean SUVmax indices decreased from 1,74 (pre-treatment) to 1,26 (week 2) and 1,18 (week 3). The median SUVmax indices declined from 1,64 (pre-treatment), to 1,22 (week 2) and 1,15 (week 3). Visual assessment showed significant pre-treatment hypoxia in 6 of 8 pts. In week 2, hypoxia was reduced in 5 of 6 pts, while 1 patient had persistent significant tracer uptake. At week 5, no hypoxia could be found in 5 of 6 pts, whereas in 1 patient significant F-MISO uptake was persistent. This patient was evaluated with local progression at first follow-up, while all other pts were evaluated with partial or complete tumor remission. Conclusions: Significant and stable reduction of tumor hypoxia was found in the majority of pts. This study is among the first to evaluate the dynamics of hypoxia before and consecutively during RCTx. 44 poster PET ASSESSMENT OF TUMOR PROLIFERATION, METABOLISM AND HYPOXIA BEFORE AND DURING RADIOTHERAPY IN PATIENTS WITH NON SMALL CELL LUNG CANCER (NSCLC) B. Dubray1 , P. VERA2 , A. Edet-Sanson2 , P. Bohn2 , A. Salles2 , S. Hapdey2 , I. Gardin2 , J. Menard3 , L. Thiberville4 C ENTRE H ENRI B ECQUEREL, Radiotherapy, Rouen, France 2 C ENTRE H ENRI B ECQUEREL, Nuclear Medicine, Rouen, France 3 CHU, Statistics, Caen, France 4 CHU, Clinique Pneumologique, Caen, France 1
Purpose: To investigate the changes in tumor proliferation (FLT), metabolism (FDG) and hypoxia (F-Miso) during curative-intent radiotherapy in patients with non small cell lung cancer (NSCLC). Materials: 5 patients (4 males, 1 female) with histological proof of NSCLCC and candidate to curative-intent radiotherapy were included. 3 PET (Biograph S16, Siemens) were performed before (t0) and during (around dose 42 Gy, t42) radiotherapy with 48h minimal intervals between each PET. The tracers were fluorodeoxyglucose (FDG) for metabolism, fluorothymidine (FLT) for proliferation, and F-misonidasole (F-Miso) for hypoxia. The 3 image sets obtained at each time point were co-registrated (rigid : n = 9, elastic : n = 1, Leonardo, TrueD, Siemens) using FDG PET as a reference. VOIs were delineated (40% SUVmax values as threshold) for tumors and lymphnodes on FDG TEP, and automatically pasted on FLT and F-Miso PET. ANOVA and paired Willcoxon test were used for comparison of SUVmax values. Results: 5 tumors and 10 nodes were identified on initial FDG PET. 2 nodes
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had disappeared at t42, so that the analysis was performed on 5 tumors and 8 nodes. FLT SUVmax values were significantly lower (p = 0.001) at t42 in both tumors and nodes. The decrease in FDG SUVmax values did not reach statistical significance (p = 0.09) when tumors and nodes were analyzed together, but was of a larger magnitude in tumors than in nodes (p = 0.02). F-Miso SUVmax values were significantly higher in tumors than in nodes (p = 0.007) and did not change during radiotherapy (p = 0.77). Conclusions: 3 different PET acquisitions can be performed quasi simultaneously (4 to 7 days) before and during radiotherapy in patients with NSCLC. Our results at 42 Gy suggest a fast decrease in proliferation in both tumors and nodes during radiotherapy, at difference with metabolism (non significant decrease) and hypoxia (stable). 45 poster PET-CT BASED TARGET DELINEATION FOR INTENSITY MODULATED RADIOTHERAPY PLANNING IN A CASE OF CARCINOMA ESOPHAGUS G. Saini1 , V. Goel2 , A. Anand1 , K. Gupta1 , A. MIshra1 1 M AX C ANCER C ENTRE, Radiation Oncology, New Delhi, India 2 M AX C ANCER C ENTRE, New Delhi, India Purpose: Locally advanced adenocarcinoma of lower third esophagus (LACE) carries grim prognosis with 5yr OS of upto 20%. The most common site of failure is distant sites followed by local recurrence. PET-CT with accuracy for lymph node staging of upto 80% holds great promise in pre-treatment staging as stage may change in upto 20% cases. Pre-surgery staging with PET-CT is fast becoming a routine for LACE. With this analysis we studied the difference PET-CT based target volume delineation would make in Radiotherapy planning volumes for a patient planned with IMRT. Materials: Our case is a sixty year old male who was diagnosed as LACE . Endoscopically the growth was starting at 34 cm extending upto GE Junction (Gross extent=4-5cm). Histopathologically it was poorly differentiated adenocarcinoma. Contrast enhanced CT scan (CECT) did not report any enlarged lymph nodes. PET-CT scan reported FDG avid segment of esophagus of 7cm length with tiny avid lymph nodes in bilateral hilar, paratracheal, subcarinal and aortopulmonary window. Almost all the findings reported on PET-CT were indicative of disease extent much more than what would be otherwise imagined for this case during contouring. Target volumes of GTV, GTVn (nodal), CTV and PTV were drawn on Eclipse planning system both with and without PET-CT guidance and are reported. Results: As per Table
Underdosing of volumes contoured without PET guidance: 20-80% Conclusions: Using PET-CT guidance during contouring treatment volumes for RTP increased them by 21.5-78%. These changes in volumes are quite high. Considering that in our patient these volumes would have been underdosed to 20-80% of prescribed doses when planned with IMRT the issue becomes considerably important. We recommend PET-CT to be routine as staging work-up for all LACE scheduled for radiotherapy especially with IMRT to avoid any geographic miss. This fact must be studied in randomised clinical trials to estimate its impact on local control and survival. 46 poster QUANTITATIVE SPECT FOR PRE-THERAPEUTIC ASSESSMENT OF SIRSPHERES DISTRIBUTION D. Bailey1 , K. Willowson1 , C. Baldock3 1 R OYAL N ORTH S HORE H OSPITAL, Department of Nuclear Medicine, Sydney NSW, Australia 2 U NIVERSITY OF S YDNEY, Sydney, Australia 3 U NIVERSITY OF S YDNEY, School of Physics, Sydney, Australia
Purpose: To accurately determine the pre-therapuetic [99m Tc]-MAA dose distribution in the planning of selective internal radionuclide therapy (SIRT) with [90 Y]-SirSpheres using quantitative SPECT/CT (qSPECT). This allows the desired SirSpheres dose to be calculated based on tumour target and pulmonary fractional dose distributions. Materials: We employed a quantitative SPECT/CT method (Philips SKYLight gamma camera with Picker PQ5000 CT) previously published (Willowson et al, Phys Med Biol 53:3099-3112, 2008) to determine the total radioactivity of [99m Tc]-MAA in liver and the amount that bypassed the liver and was trapped in the lungs after selective hepatic arterial catheterisation. The CT-based
Purpose: To investigate the changes in tumor proliferation (FLT), metabolism (FDG) and hypoxia (F-Miso) during curative-intent radiotherapy in patients with non small cell lung cancer (NSCLC). Materials: 5 patients (4 males, 1 female) with histological proof of NSCLCC and candidate to curative-intent radiotherapy were included. 3 PET (Biograph S16, Siemens) were performed before (t0) and during (around dose 42 Gy, t42) radiotherapy with 48h minimal intervals between each PET. The tracers were fluorodeoxyglucose (FDG) for metabolism, fluorothymidine (FLT) for proliferation, and F-misonidasole (F-Miso) for hypoxia. The 3 image sets obtained at each time point were co-registrated (rigid : n = 9, elastic : n = 1, Leonardo, TrueD, Siemens) using FDG PET as a reference. VOIs were delineated (40% SUVmax values as threshold) for tumors and lymphnodes on FDG TEP, and automatically pasted on FLT and F-Miso PET. ANOVA and paired Willcoxon test were used for comparison of SUVmax values. Results: 5 tumors and 10 nodes were identified on initial FDG PET. 2 nodes
S 19
had disappeared at t42, so that the analysis was performed on 5 tumors and 8 nodes. FLT SUVmax values were significantly lower (p = 0.001) at t42 in both tumors and nodes. The decrease in FDG SUVmax values did not reach statistical significance (p = 0.09) when tumors and nodes were analyzed together, but was of a larger magnitude in tumors than in nodes (p = 0.02). F-Miso SUVmax values were significantly higher in tumors than in nodes (p = 0.007) and did not change during radiotherapy (p = 0.77). Conclusions: 3 different PET acquisitions can be performed quasi simultaneously (4 to 7 days) before and during radiotherapy in patients with NSCLC. Our results at 42 Gy suggest a fast decrease in proliferation in both tumors and nodes during radiotherapy, at difference with metabolism (non significant decrease) and hypoxia (stable). 45 poster PET-CT BASED TARGET DELINEATION FOR INTENSITY MODULATED RADIOTHERAPY PLANNING IN A CASE OF CARCINOMA ESOPHAGUS G. Saini1 , V. Goel2 , A. Anand1 , K. Gupta1 , A. MIshra1 1 M AX C ANCER C ENTRE, Radiation Oncology, New Delhi, India 2 M AX C ANCER C ENTRE, New Delhi, India Purpose: Locally advanced adenocarcinoma of lower third esophagus (LACE) carries grim prognosis with 5yr OS of upto 20%. The most common site of failure is distant sites followed by local recurrence. PET-CT with accuracy for lymph node staging of upto 80% holds great promise in pre-treatment staging as stage may change in upto 20% cases. Pre-surgery staging with PET-CT is fast becoming a routine for LACE. With this analysis we studied the difference PET-CT based target volume delineation would make in Radiotherapy planning volumes for a patient planned with IMRT. Materials: Our case is a sixty year old male who was diagnosed as LACE . Endoscopically the growth was starting at 34 cm extending upto GE Junction (Gross extent=4-5cm). Histopathologically it was poorly differentiated adenocarcinoma. Contrast enhanced CT scan (CECT) did not report any enlarged lymph nodes. PET-CT scan reported FDG avid segment of esophagus of 7cm length with tiny avid lymph nodes in bilateral hilar, paratracheal, subcarinal and aortopulmonary window. Almost all the findings reported on PET-CT were indicative of disease extent much more than what would be otherwise imagined for this case during contouring. Target volumes of GTV, GTVn (nodal), CTV and PTV were drawn on Eclipse planning system both with and without PET-CT guidance and are reported. Results: As per Table
Underdosing of volumes contoured without PET guidance: 20-80% Conclusions: Using PET-CT guidance during contouring treatment volumes for RTP increased them by 21.5-78%. These changes in volumes are quite high. Considering that in our patient these volumes would have been underdosed to 20-80% of prescribed doses when planned with IMRT the issue becomes considerably important. We recommend PET-CT to be routine as staging work-up for all LACE scheduled for radiotherapy especially with IMRT to avoid any geographic miss. This fact must be studied in randomised clinical trials to estimate its impact on local control and survival. 46 poster QUANTITATIVE SPECT FOR PRE-THERAPEUTIC ASSESSMENT OF SIRSPHERES DISTRIBUTION D. Bailey1 , K. Willowson1 , C. Baldock3 1 R OYAL N ORTH S HORE H OSPITAL, Department of Nuclear Medicine, Sydney NSW, Australia 2 U NIVERSITY OF S YDNEY, Sydney, Australia 3 U NIVERSITY OF S YDNEY, School of Physics, Sydney, Australia
Purpose: To accurately determine the pre-therapuetic [99m Tc]-MAA dose distribution in the planning of selective internal radionuclide therapy (SIRT) with [90 Y]-SirSpheres using quantitative SPECT/CT (qSPECT). This allows the desired SirSpheres dose to be calculated based on tumour target and pulmonary fractional dose distributions. Materials: We employed a quantitative SPECT/CT method (Philips SKYLight gamma camera with Picker PQ5000 CT) previously published (Willowson et al, Phys Med Biol 53:3099-3112, 2008) to determine the total radioactivity of [99m Tc]-MAA in liver and the amount that bypassed the liver and was trapped in the lungs after selective hepatic arterial catheterisation. The CT-based